diff options
| author | ph10 <ph10@2f5784b3-3f2a-0410-8824-cb99058d5e15> | 2010-05-18 15:47:01 +0000 |
|---|---|---|
| committer | ph10 <ph10@2f5784b3-3f2a-0410-8824-cb99058d5e15> | 2010-05-18 15:47:01 +0000 |
| commit | 8f8b41c565c70ab99dd21a81f71a512958f867b5 (patch) | |
| tree | bb68328d748e596f734ebd085e4b3f648452ab61 | |
| parent | 85b995f30cc9bf0bb04f5b3b3707a216a56b6bdf (diff) | |
| download | pcre-8f8b41c565c70ab99dd21a81f71a512958f867b5.tar.gz | |
Added PCRE_UCP and related stuff to make \w etc use Unicode properties.
git-svn-id: svn://vcs.exim.org/pcre/code/trunk@518 2f5784b3-3f2a-0410-8824-cb99058d5e15
36 files changed, 2955 insertions, 1874 deletions
@@ -29,8 +29,13 @@ Version 8.10 03 May-2010 7. Minor change to pcretest.c to avoid a compiler warning. 8. Added four artifical Unicode properties to help with an option to make - \s etc use properties. The new properties are: Xan (alphanumeric), Xsp - (Perl space), Xps (POSIX space), and Xwd (word). + \s etc use properties (see next item). The new properties are: Xan + (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word). + +9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes + use Unicode properties. (*UCP) at the start of a pattern can be used to set + this option. Modified pcretest to add /W to test this facility. Added + REG_UCP to make it available via the POSIX interface. Version 8.02 19-Mar-2010 diff --git a/doc/html/index.html b/doc/html/index.html index d9af7e1..58dfe45 100644 --- a/doc/html/index.html +++ b/doc/html/index.html @@ -1,10 +1,10 @@ <html> -<!-- This is a manually maintained file that is the root of the HTML version of - the PCRE documentation. When the HTML documents are built from the man - page versions, the entire doc/html directory is emptied, this file is then - copied into doc/html/index.html, and the remaining files therein are +<!-- This is a manually maintained file that is the root of the HTML version of + the PCRE documentation. When the HTML documents are built from the man + page versions, the entire doc/html directory is emptied, this file is then + copied into doc/html/index.html, and the remaining files therein are created by the 132html script. ---> +--> <head> <title>PCRE specification</title> </head> @@ -74,11 +74,11 @@ The HTML documentation for PCRE comprises the following pages: </table> <p> -There are also individual pages that summarize the interface for each function +There are also individual pages that summarize the interface for each function in the library: </p> -<table> +<table> <tr><td><a href="pcre_compile.html">pcre_compile</a></td> <td> Compile a regular expression</td></tr> @@ -129,7 +129,7 @@ in the library: <tr><td><a href="pcre_maketables.html">pcre_maketables</a></td> <td> Build character tables in current locale</td></tr> - + <tr><td><a href="pcre_refcount.html">pcre_refcount</a></td> <td> Maintain reference count in compiled pattern</td></tr> diff --git a/doc/html/pcre.html b/doc/html/pcre.html index c4512df..7ca221b 100644 --- a/doc/html/pcre.html +++ b/doc/html/pcre.html @@ -30,10 +30,11 @@ support for one or two .NET and Oniguruma syntax items, and there is an option for requesting some minor changes that give better JavaScript compatibility. </P> <P> -The current implementation of PCRE corresponds approximately with Perl 5.10, -including support for UTF-8 encoded strings and Unicode general category -properties. However, UTF-8 and Unicode support has to be explicitly enabled; it -is not the default. The Unicode tables correspond to Unicode release 5.2.0. +The current implementation of PCRE corresponds approximately with Perl +5.10/5.11, including support for UTF-8 encoded strings and Unicode general +category properties. However, UTF-8 and Unicode support has to be explicitly +enabled; it is not the default. The Unicode tables correspond to Unicode +release 5.2.0. </P> <P> In addition to the Perl-compatible matching function, PCRE contains an @@ -255,21 +256,29 @@ the alternative matching function, <b>pcre_dfa_exec()</b>. </P> <P> 6. The character escapes \b, \B, \d, \D, \s, \S, \w, and \W correctly -test characters of any code value, but the characters that PCRE recognizes as -digits, spaces, or word characters remain the same set as before, all with -values less than 256. This remains true even when PCRE includes Unicode -property support, because to do otherwise would slow down PCRE in many common -cases. If you really want to test for a wider sense of, say, "digit", you -must use Unicode property tests such as \p{Nd}. Note that this also applies to -\b, because it is defined in terms of \w and \W. +test characters of any code value, but, by default, the characters that PCRE +recognizes as digits, spaces, or word characters remain the same set as before, +all with values less than 256. This remains true even when PCRE is built to +include Unicode property support, because to do otherwise would slow down PCRE +in many common cases. Note that this also applies to \b, because it is defined +in terms of \w and \W. If you really want to test for a wider sense of, say, +"digit", you can use explicit Unicode property tests such as \p{Nd}. +Alternatively, if you set the PCRE_UCP option, the way that the character +escapes work is changed so that Unicode properties are used to determine which +characters match. There are more details in the section on +<a href="pcrepattern.html#genericchartypes">generic character types</a> +in the +<a href="pcrepattern.html"><b>pcrepattern</b></a> +documentation. </P> <P> 7. Similarly, characters that match the POSIX named character classes are all -low-valued characters. +low-valued characters, unless the PCRE_UCP option is set. </P> <P> 8. However, the Perl 5.10 horizontal and vertical whitespace matching escapes -(\h, \H, \v, and \V) do match all the appropriate Unicode characters. +(\h, \H, \v, and \V) do match all the appropriate Unicode characters, +whether or not PCRE_UCP is set. </P> <P> 9. Case-insensitive matching applies only to characters whose values are less @@ -298,7 +307,7 @@ two digits 10, at the domain cam.ac.uk. </P> <br><a name="SEC6" href="#TOC1">REVISION</a><br> <P> -Last updated: 01 March 2010 +Last updated: 12 May 2010 <br> Copyright © 1997-2010 University of Cambridge. <br> diff --git a/doc/html/pcreapi.html b/doc/html/pcreapi.html index 2fa9251..ef64e65 100644 --- a/doc/html/pcreapi.html +++ b/doc/html/pcreapi.html @@ -560,8 +560,9 @@ set, any backslash in a pattern that is followed by a letter that has no special meaning causes an error, thus reserving these combinations for future expansion. By default, as in Perl, a backslash followed by a letter with no special meaning is treated as a literal. (Perl can, however, be persuaded to -give a warning for this.) There are at present no other features controlled by -this option. It can also be set by a (?X) option setting within a pattern. +give an error for this, by running it with the -w option.) There are at present +no other features controlled by this option. It can also be set by a (?X) +option setting within a pattern. <pre> PCRE_FIRSTLINE </pre> @@ -2086,7 +2087,7 @@ Cambridge CB2 3QH, England. </P> <br><a name="SEC22" href="#TOC1">REVISION</a><br> <P> -Last updated: 26 March 2010 +Last updated: 03 May 2010 <br> Copyright © 1997-2010 University of Cambridge. <br> diff --git a/doc/html/pcrepattern.html b/doc/html/pcrepattern.html index 5588fa5..4bbc2b0 100644 --- a/doc/html/pcrepattern.html +++ b/doc/html/pcrepattern.html @@ -18,7 +18,7 @@ man page, in case the conversion went wrong. <li><a name="TOC3" href="#SEC3">CHARACTERS AND METACHARACTERS</a> <li><a name="TOC4" href="#SEC4">BACKSLASH</a> <li><a name="TOC5" href="#SEC5">CIRCUMFLEX AND DOLLAR</a> -<li><a name="TOC6" href="#SEC6">FULL STOP (PERIOD, DOT)</a> +<li><a name="TOC6" href="#SEC6">FULL STOP (PERIOD, DOT) AND \N</a> <li><a name="TOC7" href="#SEC7">MATCHING A SINGLE BYTE</a> <li><a name="TOC8" href="#SEC8">SQUARE BRACKETS AND CHARACTER CLASSES</a> <li><a name="TOC9" href="#SEC9">POSIX CHARACTER CLASSES</a> @@ -124,9 +124,11 @@ they must be in upper case. If more than one of them is present, the last one is used. </P> <P> -The newline convention does not affect what the \R escape sequence matches. By -default, this is any Unicode newline sequence, for Perl compatibility. However, -this can be changed; see the description of \R in the section entitled +The newline convention affects the interpretation of the dot metacharacter when +PCRE_DOTALL is not set, and also the behaviour of \N. However, it does not +affect what the \R escape sequence matches. By default, this is any Unicode +newline sequence, for Perl compatibility. However, this can be changed; see the +description of \R in the section entitled <a href="#newlineseq">"Newline sequences"</a> below. A change of \R setting can be combined with a change of newline convention. @@ -308,11 +310,11 @@ zero, because no more than three octal digits are ever read. <P> All the sequences that define a single character value can be used both inside and outside character classes. In addition, inside a character class, the -sequence \b is interpreted as the backspace character (hex 08), and the -sequences \R and \X are interpreted as the characters "R" and "X", -respectively. Outside a character class, these sequences have different -meanings -<a href="#uniextseq">(see below).</a> +sequence \b is interpreted as the backspace character (hex 08). The sequences +\B, \N, \R, and \X are not special inside a character class. Like any other +unrecognized escape sequences, they are treated as the literal characters "B", +"N", "R", and "X" by default, but cause an error if the PCRE_EXTRA option is +set. Outside a character class, these sequences have different meanings. </P> <br><b> Absolute and relative back references @@ -337,13 +339,12 @@ Note that \g{...} (Perl syntax) and \g<...> (Oniguruma syntax) are <i>no synonymous. The former is a back reference; the latter is a <a href="#subpatternsassubroutines">subroutine</a> call. -</P> +<a name="genericchartypes"></a></P> <br><b> Generic character types </b><br> <P> -Another use of backslash is for specifying generic character types. The -following are always recognized: +Another use of backslash is for specifying generic character types: <pre> \d any decimal digit \D any character that is not a decimal digit @@ -356,8 +357,15 @@ following are always recognized: \w any "word" character \W any "non-word" character </pre> -Each pair of escape sequences partitions the complete set of characters into -two disjoint sets. Any given character matches one, and only one, of each pair. +There is also the single sequence \N, which matches a non-newline character. +This is the same as +<a href="#fullstopdot">the "." metacharacter</a> +when PCRE_DOTALL is not set. +</P> +<P> +Each pair of lower and upper case escape sequences partitions the complete set +of characters into two disjoint sets. Any given character matches one, and only +one, of each pair. </P> <P> These character type sequences can appear both inside and outside character @@ -475,7 +483,9 @@ convention, for example, a pattern can start with: <pre> (*ANY)(*BSR_ANYCRLF) </pre> -Inside a character class, \R matches the letter "R". +Inside a character class, \R is treated as an unrecognized escape sequence, +and so matches the letter "R" by default, but causes an error if PCRE_EXTRA is +set. <a name="uniextseq"></a></P> <br><b> Unicode character properties @@ -492,10 +502,13 @@ The extra escape sequences are: \X an extended Unicode sequence </pre> The property names represented by <i>xx</i> above are limited to the Unicode -script names, the general category properties, and "Any", which matches any -character (including newline). Other properties such as "InMusicalSymbols" are -not currently supported by PCRE. Note that \P{Any} does not match any -characters, so always causes a match failure. +script names, the general category properties, "Any", which matches any +character (including newline), and some special PCRE properties (described +in the +<a href="#extraprops">next section).</a> +Other Perl properties such as "InMusicalSymbols" are not currently supported by +PCRE. Note that \P{Any} does not match any characters, so always causes a +match failure. </P> <P> Sets of Unicode characters are defined as belonging to certain scripts. A @@ -603,10 +616,10 @@ Vai, Yi. </P> <P> -Each character has exactly one general category property, specified by a -two-letter abbreviation. For compatibility with Perl, negation can be specified -by including a circumflex between the opening brace and the property name. For -example, \p{^Lu} is the same as \P{Lu}. +Each character has exactly one Unicode general category property, specified by +a two-letter abbreviation. For compatibility with Perl, negation can be +specified by including a circumflex between the opening brace and the property +name. For example, \p{^Lu} is the same as \P{Lu}. </P> <P> If only one letter is specified with \p or \P, it includes all the general @@ -708,6 +721,26 @@ Matching characters by Unicode property is not fast, because PCRE has to search a structure that contains data for over fifteen thousand characters. That is why the traditional escape sequences such as \d and \w do not use Unicode properties in PCRE. +<a name="extraprops"></a></P> +<br><b> +PCRE's additional properties +</b><br> +<P> +As well as the standard Unicode properties described in the previous +section, PCRE supports four more that make it possible to convert traditional +escape sequences such as \w and \s and POSIX character classes to use Unicode +properties. These are: +<pre> + Xan Any alphanumeric character + Xps Any POSIX space character + Xsp Any Perl space character + Xwd Any Perl "word" character +</pre> +Xan matches characters that have either the L (letter) or the N (number) +property. Xps matches the characters tab, linefeed, vertical tab, formfeed, or +carriage return, and any other character that has the Z (separator) property. +Xsp is the same as Xps, except that vertical tab is excluded. Xwd matches the +same characters as Xan, plus underscore. <a name="resetmatchstart"></a></P> <br><b> Resetting the match start @@ -756,8 +789,11 @@ The backslashed assertions are: \z matches only at the end of the subject \G matches at the first matching position in the subject </pre> -These assertions may not appear in character classes (but note that \b has a -different meaning, namely the backspace character, inside a character class). +Inside a character class, \b has a different meaning; it matches the backspace +character. If any other of these assertions appears in a character class, by +default it matches the corresponding literal character (for example, \B +matches the letter B). However, if the PCRE_EXTRA option is set, an "invalid +escape sequence" error is generated instead. </P> <P> A word boundary is a position in the subject string where the current character @@ -853,8 +889,8 @@ PCRE_DOLLAR_ENDONLY option is ignored if PCRE_MULTILINE is set. Note that the sequences \A, \Z, and \z can be used to match the start and end of the subject in both modes, and if all branches of a pattern start with \A it is always anchored, whether or not PCRE_MULTILINE is set. -</P> -<br><a name="SEC6" href="#TOC1">FULL STOP (PERIOD, DOT)</a><br> +<a name="fullstopdot"></a></P> +<br><a name="SEC6" href="#TOC1">FULL STOP (PERIOD, DOT) AND \N</a><br> <P> Outside a character class, a dot in the pattern matches any one character in the subject string except (by default) a character that signifies the end of a @@ -879,6 +915,11 @@ The handling of dot is entirely independent of the handling of circumflex and dollar, the only relationship being that they both involve newlines. Dot has no special meaning in a character class. </P> +<P> +The escape sequence \N always behaves as a dot does when PCRE_DOTALL is not +set. In other words, it matches any one character except one that signifies the +end of a line. +</P> <br><a name="SEC7" href="#TOC1">MATCHING A SINGLE BYTE</a><br> <P> Outside a character class, the escape sequence \C matches any one byte, both @@ -2548,7 +2589,7 @@ Cambridge CB2 3QH, England. </P> <br><a name="SEC28" href="#TOC1">REVISION</a><br> <P> -Last updated: 27 March 2010 +Last updated: 05 May 2010 <br> Copyright © 1997-2010 University of Cambridge. <br> diff --git a/doc/html/pcresyntax.html b/doc/html/pcresyntax.html index 1a2749f..ad4399d 100644 --- a/doc/html/pcresyntax.html +++ b/doc/html/pcresyntax.html @@ -17,28 +17,29 @@ man page, in case the conversion went wrong. <li><a name="TOC2" href="#SEC2">QUOTING</a> <li><a name="TOC3" href="#SEC3">CHARACTERS</a> <li><a name="TOC4" href="#SEC4">CHARACTER TYPES</a> -<li><a name="TOC5" href="#SEC5">GENERAL CATEGORY PROPERTY CODES FOR \p and \P</a> -<li><a name="TOC6" href="#SEC6">SCRIPT NAMES FOR \p AND \P</a> -<li><a name="TOC7" href="#SEC7">CHARACTER CLASSES</a> -<li><a name="TOC8" href="#SEC8">QUANTIFIERS</a> -<li><a name="TOC9" href="#SEC9">ANCHORS AND SIMPLE ASSERTIONS</a> -<li><a name="TOC10" href="#SEC10">MATCH POINT RESET</a> -<li><a name="TOC11" href="#SEC11">ALTERNATION</a> -<li><a name="TOC12" href="#SEC12">CAPTURING</a> -<li><a name="TOC13" href="#SEC13">ATOMIC GROUPS</a> -<li><a name="TOC14" href="#SEC14">COMMENT</a> -<li><a name="TOC15" href="#SEC15">OPTION SETTING</a> -<li><a name="TOC16" href="#SEC16">LOOKAHEAD AND LOOKBEHIND ASSERTIONS</a> -<li><a name="TOC17" href="#SEC17">BACKREFERENCES</a> -<li><a name="TOC18" href="#SEC18">SUBROUTINE REFERENCES (POSSIBLY RECURSIVE)</a> -<li><a name="TOC19" href="#SEC19">CONDITIONAL PATTERNS</a> -<li><a name="TOC20" href="#SEC20">BACKTRACKING CONTROL</a> -<li><a name="TOC21" href="#SEC21">NEWLINE CONVENTIONS</a> -<li><a name="TOC22" href="#SEC22">WHAT \R MATCHES</a> -<li><a name="TOC23" href="#SEC23">CALLOUTS</a> -<li><a name="TOC24" href="#SEC24">SEE ALSO</a> -<li><a name="TOC25" href="#SEC25">AUTHOR</a> -<li><a name="TOC26" href="#SEC26">REVISION</a> +<li><a name="TOC5" href="#SEC5">GENERAL CATEGORY PROPERTIES FOR \p and \P</a> +<li><a name="TOC6" href="#SEC6">PCRE SPECIAL CATEGORY PROPERTIES FOR \p and \P</a> +<li><a name="TOC7" href="#SEC7">SCRIPT NAMES FOR \p AND \P</a> +<li><a name="TOC8" href="#SEC8">CHARACTER CLASSES</a> +<li><a name="TOC9" href="#SEC9">QUANTIFIERS</a> +<li><a name="TOC10" href="#SEC10">ANCHORS AND SIMPLE ASSERTIONS</a> +<li><a name="TOC11" href="#SEC11">MATCH POINT RESET</a> +<li><a name="TOC12" href="#SEC12">ALTERNATION</a> +<li><a name="TOC13" href="#SEC13">CAPTURING</a> +<li><a name="TOC14" href="#SEC14">ATOMIC GROUPS</a> +<li><a name="TOC15" href="#SEC15">COMMENT</a> +<li><a name="TOC16" href="#SEC16">OPTION SETTING</a> +<li><a name="TOC17" href="#SEC17">LOOKAHEAD AND LOOKBEHIND ASSERTIONS</a> +<li><a name="TOC18" href="#SEC18">BACKREFERENCES</a> +<li><a name="TOC19" href="#SEC19">SUBROUTINE REFERENCES (POSSIBLY RECURSIVE)</a> +<li><a name="TOC20" href="#SEC20">CONDITIONAL PATTERNS</a> +<li><a name="TOC21" href="#SEC21">BACKTRACKING CONTROL</a> +<li><a name="TOC22" href="#SEC22">NEWLINE CONVENTIONS</a> +<li><a name="TOC23" href="#SEC23">WHAT \R MATCHES</a> +<li><a name="TOC24" href="#SEC24">CALLOUTS</a> +<li><a name="TOC25" href="#SEC25">SEE ALSO</a> +<li><a name="TOC26" href="#SEC26">AUTHOR</a> +<li><a name="TOC27" href="#SEC27">REVISION</a> </ul> <br><a name="SEC1" href="#TOC1">PCRE REGULAR EXPRESSION SYNTAX SUMMARY</a><br> <P> @@ -80,6 +81,7 @@ syntax. \D a character that is not a decimal digit \h a horizontal whitespace character \H a character that is not a horizontal whitespace character + \N a character that is not a newline \p{<i>xx</i>} a character with the <i>xx</i> property \P{<i>xx</i>} a character without the <i>xx</i> property \R a newline sequence @@ -93,7 +95,7 @@ syntax. </pre> In PCRE, \d, \D, \s, \S, \w, and \W recognize only ASCII characters. </P> -<br><a name="SEC5" href="#TOC1">GENERAL CATEGORY PROPERTY CODES FOR \p and \P</a><br> +<br><a name="SEC5" href="#TOC1">GENERAL CATEGORY PROPERTIES FOR \p and \P</a><br> <P> <pre> C Other @@ -142,7 +144,16 @@ In PCRE, \d, \D, \s, \S, \w, and \W recognize only ASCII characters. Zs Space separator </PRE> </P> -<br><a name="SEC6" href="#TOC1">SCRIPT NAMES FOR \p AND \P</a><br> +<br><a name="SEC6" href="#TOC1">PCRE SPECIAL CATEGORY PROPERTIES FOR \p and \P</a><br> +<P> +<pre> + Xan Alphanumeric: union of properties L and N + Xps POSIX space: property Z or tab, NL, VT, FF, CR + Xsp Perl space: property Z or tab, NL, FF, CR + Xwd Perl word: property Xan or underscore +</PRE> +</P> +<br><a name="SEC7" href="#TOC1">SCRIPT NAMES FOR \p AND \P</a><br> <P> Arabic, Armenian, @@ -237,7 +248,7 @@ Ugaritic, Vai, Yi. </P> -<br><a name="SEC7" href="#TOC1">CHARACTER CLASSES</a><br> +<br><a name="SEC8" href="#TOC1">CHARACTER CLASSES</a><br> <P> <pre> [...] positive character class @@ -264,7 +275,7 @@ Yi. In PCRE, POSIX character set names recognize only ASCII characters. You can use \Q...\E inside a character class. </P> -<br><a name="SEC8" href="#TOC1">QUANTIFIERS</a><br> +<br><a name="SEC9" href="#TOC1">QUANTIFIERS</a><br> <P> <pre> ? 0 or 1, greedy @@ -285,7 +296,7 @@ In PCRE, POSIX character set names recognize only ASCII characters. You can use {n,}? n or more, lazy </PRE> </P> -<br><a name="SEC9" href="#TOC1">ANCHORS AND SIMPLE ASSERTIONS</a><br> +<br><a name="SEC10" href="#TOC1">ANCHORS AND SIMPLE ASSERTIONS</a><br> <P> <pre> \b word boundary (only ASCII letters recognized) @@ -302,19 +313,19 @@ In PCRE, POSIX character set names recognize only ASCII characters. You can use \G first matching position in subject </PRE> </P> -<br><a name="SEC10" href="#TOC1">MATCH POINT RESET</a><br> +<br><a name="SEC11" href="#TOC1">MATCH POINT RESET</a><br> <P> <pre> \K reset start of match </PRE> </P> -<br><a name="SEC11" href="#TOC1">ALTERNATION</a><br> +<br><a name="SEC12" href="#TOC1">ALTERNATION</a><br> <P> <pre> expr|expr|expr... </PRE> </P> -<br><a name="SEC12" href="#TOC1">CAPTURING</a><br> +<br><a name="SEC13" href="#TOC1">CAPTURING</a><br> <P> <pre> (...) capturing group @@ -326,19 +337,19 @@ In PCRE, POSIX character set names recognize only ASCII characters. You can use capturing groups in each alternative </PRE> </P> -<br><a name="SEC13" href="#TOC1">ATOMIC GROUPS</a><br> +<br><a name="SEC14" href="#TOC1">ATOMIC GROUPS</a><br> <P> <pre> (?>...) atomic, non-capturing group </PRE> </P> -<br><a name="SEC14" href="#TOC1">COMMENT</a><br> +<br><a name="SEC15" href="#TOC1">COMMENT</a><br> <P> <pre> (?#....) comment (not nestable) </PRE> </P> -<br><a name="SEC15" href="#TOC1">OPTION SETTING</a><br> +<br><a name="SEC16" href="#TOC1">OPTION SETTING</a><br> <P> <pre> (?i) caseless @@ -355,7 +366,7 @@ newline-setting options with similar syntax: (*UTF8) set UTF-8 mode </PRE> </P> -<br><a name="SEC16" href="#TOC1">LOOKAHEAD AND LOOKBEHIND ASSERTIONS</a><br> +<br><a name="SEC17" href="#TOC1">LOOKAHEAD AND LOOKBEHIND ASSERTIONS</a><br> <P> <pre> (?=...) positive look ahead @@ -365,7 +376,7 @@ newline-setting options with similar syntax: </pre> Each top-level branch of a look behind must be of a fixed length. </P> -<br><a name="SEC17" href="#TOC1">BACKREFERENCES</a><br> +<br><a name="SEC18" href="#TOC1">BACKREFERENCES</a><br> <P> <pre> \n reference by number (can be ambiguous) @@ -379,7 +390,7 @@ Each top-level branch of a look behind must be of a fixed length. (?P=name) reference by name (Python) </PRE> </P> -<br><a name="SEC18" href="#TOC1">SUBROUTINE REFERENCES (POSSIBLY RECURSIVE)</a><br> +<br><a name="SEC19" href="#TOC1">SUBROUTINE REFERENCES (POSSIBLY RECURSIVE)</a><br> <P> <pre> (?R) recurse whole pattern @@ -398,7 +409,7 @@ Each top-level branch of a look behind must be of a fixed length. \g'-n' call subpattern by relative number (PCRE extension) </PRE> </P> -<br><a name="SEC19" href="#TOC1">CONDITIONAL PATTERNS</a><br> +<br><a name="SEC20" href="#TOC1">CONDITIONAL PATTERNS</a><br> <P> <pre> (?(condition)yes-pattern) @@ -417,7 +428,7 @@ Each top-level branch of a look behind must be of a fixed length. (?(assert)... assertion condition </PRE> </P> -<br><a name="SEC20" href="#TOC1">BACKTRACKING CONTROL</a><br> +<br><a name="SEC21" href="#TOC1">BACKTRACKING CONTROL</a><br> <P> The following act immediately they are reached: <pre> @@ -435,7 +446,7 @@ pattern is not anchored. (*THEN) local failure, backtrack to next alternation </PRE> </P> -<br><a name="SEC21" href="#TOC1">NEWLINE CONVENTIONS</a><br> +<br><a name="SEC22" href="#TOC1">NEWLINE CONVENTIONS</a><br> <P> These are recognized only at the very start of the pattern or after a (*BSR_...) or (*UTF8) option. @@ -447,7 +458,7 @@ These are recognized only at the very start of the pattern or after a (*ANY) any Unicode newline sequence </PRE> </P> -<br><a name="SEC22" href="#TOC1">WHAT \R MATCHES</a><br> +<br><a name="SEC23" href="#TOC1">WHAT \R MATCHES</a><br> <P> These are recognized only at the very start of the pattern or after a (*...) option that sets the newline convention or UTF-8 mode. @@ -456,19 +467,19 @@ These are recognized only at the very start of the pattern or after a (*BSR_UNICODE) any Unicode newline sequence </PRE> </P> -<br><a name="SEC23" href="#TOC1">CALLOUTS</a><br> +<br><a name="SEC24" href="#TOC1">CALLOUTS</a><br> <P> <pre> (?C) callout (?Cn) callout with data n </PRE> </P> -<br><a name="SEC24" href="#TOC1">SEE ALSO</a><br> +<br><a name="SEC25" href="#TOC1">SEE ALSO</a><br> <P> <b>pcrepattern</b>(3), <b>pcreapi</b>(3), <b>pcrecallout</b>(3), <b>pcrematching</b>(3), <b>pcre</b>(3). </P> -<br><a name="SEC25" href="#TOC1">AUTHOR</a><br> +<br><a name="SEC26" href="#TOC1">AUTHOR</a><br> <P> Philip Hazel <br> @@ -477,9 +488,9 @@ University Computing Service Cambridge CB2 3QH, England. <br> </P> -<br><a name="SEC26" href="#TOC1">REVISION</a><br> +<br><a name="SEC27" href="#TOC1">REVISION</a><br> <P> -Last updated: 01 March 2010 +Last updated: 05 May 2010 <br> Copyright © 1997-2010 University of Cambridge. <br> diff --git a/doc/html/pcretest.html b/doc/html/pcretest.html index bab89a0..7f62c3f 100644 --- a/doc/html/pcretest.html +++ b/doc/html/pcretest.html @@ -204,6 +204,8 @@ effect as they do in Perl. For example: The following table shows additional modifiers for setting PCRE options that do not correspond to anything in Perl: <pre> + <b>/8</b> PCRE_UTF8 + <b>/?</b> PCRE_NO_UTF8_CHECK <b>/A</b> PCRE_ANCHORED <b>/C</b> PCRE_AUTO_CALLOUT <b>/E</b> PCRE_DOLLAR_ENDONLY @@ -211,6 +213,7 @@ not correspond to anything in Perl: <b>/J</b> PCRE_DUPNAMES <b>/N</b> PCRE_NO_AUTO_CAPTURE <b>/U</b> PCRE_UNGREEDY + <b>/W</b> PCRE_UCP <b>/X</b> PCRE_EXTRA <b>/<JS></b> PCRE_JAVASCRIPT_COMPAT <b>/<cr></b> PCRE_NEWLINE_CR @@ -221,15 +224,18 @@ not correspond to anything in Perl: <b>/<bsr_anycrlf></b> PCRE_BSR_ANYCRLF <b>/<bsr_unicode></b> PCRE_BSR_UNICODE </pre> -Those specifying line ending sequences are literal strings as shown, but the -letters can be in either case. This example sets multiline matching with CRLF -as the line ending sequence: +The modifiers that are enclosed in angle brackets are literal strings as shown, +including the angle brackets, but the letters can be in either case. This +example sets multiline matching with CRLF as the line ending sequence: <pre> /^abc/m<crlf> </pre> -Details of the meanings of these PCRE options are given in the +As well as turning on the PCRE_UTF8 option, the <b>/8</b> modifier also causes +any non-printing characters in output strings to be printed using the +\x{hh...} notation if they are valid UTF-8 sequences. Full details of the PCRE +options are given in the <a href="pcreapi.html"><b>pcreapi</b></a> -documentation. +documentation. </P> <br><b> Finding all matches in a string @@ -260,18 +266,6 @@ There are yet more modifiers for controlling the way <b>pcretest</b> operates. </P> <P> -The <b>/8</b> modifier causes <b>pcretest</b> to call PCRE with the PCRE_UTF8 -option set. This turns on support for UTF-8 character handling in PCRE, -provided that it was compiled with this support enabled. This modifier also -causes any non-printing characters in output strings to be printed using the -\x{hh...} notation if they are valid UTF-8 sequences. -</P> -<P> -If the <b>/?</b> modifier is used with <b>/8</b>, it causes <b>pcretest</b> to -call <b>pcre_compile()</b> with the PCRE_NO_UTF8_CHECK option, to suppress the -checking of the string for UTF-8 validity. -</P> -<P> The <b>/+</b> modifier requests that as well as outputting the substring that matched the entire pattern, pcretest should in addition output the remainder of the subject string. This is useful for tests where the subject contains @@ -720,7 +714,7 @@ Cambridge CB2 3QH, England. </P> <br><a name="SEC15" href="#TOC1">REVISION</a><br> <P> -Last updated: 26 March 2010 +Last updated: 12 May 2010 <br> Copyright © 1997-2010 University of Cambridge. <br> @@ -11,10 +11,11 @@ appeared in Perl are also available using the Python syntax, there is some support for one or two .NET and Oniguruma syntax items, and there is an option for requesting some minor changes that give better JavaScript compatibility. .P -The current implementation of PCRE corresponds approximately with Perl 5.10, -including support for UTF-8 encoded strings and Unicode general category -properties. However, UTF-8 and Unicode support has to be explicitly enabled; it -is not the default. The Unicode tables correspond to Unicode release 5.2.0. +The current implementation of PCRE corresponds approximately with Perl +5.10/5.11, including support for UTF-8 encoded strings and Unicode general +category properties. However, UTF-8 and Unicode support has to be explicitly +enabled; it is not the default. The Unicode tables correspond to Unicode +release 5.2.0. .P In addition to the Perl-compatible matching function, PCRE contains an alternative function that matches the same compiled patterns in a different @@ -150,7 +151,6 @@ documentation. . . .\" HTML <a name="utf8support"></a> -. .SH "UTF-8 AND UNICODE PROPERTY SUPPORT" .rs .sp @@ -189,7 +189,6 @@ compatibility with Perl 5.6. PCRE does not support this. . . .\" HTML <a name="utf8strings"></a> -. .SS "Validity of UTF-8 strings" .rs .sp @@ -231,6 +230,7 @@ encoded in a UTF-8-like manner as per the old RFC, you can set PCRE_NO_UTF8_CHECK to bypass the more restrictive test. However, in this situation, you will have to apply your own validity check. . +. .SS "General comments about UTF-8 mode" .rs .sp @@ -250,19 +250,32 @@ but its use can lead to some strange effects. This facility is not available in the alternative matching function, \fBpcre_dfa_exec()\fP. .P 6. The character escapes \eb, \eB, \ed, \eD, \es, \eS, \ew, and \eW correctly -test characters of any code value, but the characters that PCRE recognizes as -digits, spaces, or word characters remain the same set as before, all with -values less than 256. This remains true even when PCRE includes Unicode -property support, because to do otherwise would slow down PCRE in many common -cases. If you really want to test for a wider sense of, say, "digit", you -must use Unicode property tests such as \ep{Nd}. Note that this also applies to -\eb, because it is defined in terms of \ew and \eW. +test characters of any code value, but, by default, the characters that PCRE +recognizes as digits, spaces, or word characters remain the same set as before, +all with values less than 256. This remains true even when PCRE is built to +include Unicode property support, because to do otherwise would slow down PCRE +in many common cases. Note that this also applies to \eb, because it is defined +in terms of \ew and \eW. If you really want to test for a wider sense of, say, +"digit", you can use explicit Unicode property tests such as \ep{Nd}. +Alternatively, if you set the PCRE_UCP option, the way that the character +escapes work is changed so that Unicode properties are used to determine which +characters match. There are more details in the section on +.\" HTML <a href="pcrepattern.html#genericchartypes"> +.\" </a> +generic character types +.\" +in the +.\" HREF +\fBpcrepattern\fP +.\" +documentation. .P 7. Similarly, characters that match the POSIX named character classes are all -low-valued characters. +low-valued characters, unless the PCRE_UCP option is set. .P 8. However, the Perl 5.10 horizontal and vertical whitespace matching escapes -(\eh, \eH, \ev, and \eV) do match all the appropriate Unicode characters. +(\eh, \eH, \ev, and \eV) do match all the appropriate Unicode characters, +whether or not PCRE_UCP is set. .P 9. Case-insensitive matching applies only to characters whose values are less than 128, unless PCRE is built with Unicode property support. Even when Unicode @@ -293,6 +306,6 @@ two digits 10, at the domain cam.ac.uk. .rs .sp .nf -Last updated: 01 March 2010 +Last updated: 12 May 2010 Copyright (c) 1997-2010 University of Cambridge. .fi diff --git a/doc/pcre.txt b/doc/pcre.txt index 385ef56..51a526a 100644 --- a/doc/pcre.txt +++ b/doc/pcre.txt @@ -2,7 +2,7 @@ This file contains a concatenation of the PCRE man pages, converted to plain text format for ease of searching with a text editor, or for use on systems that do not have a man page processor. The small individual files that give -synopses of each function in the library have not been included. Neither has +synopses of each function in the library have not been included. Neither has the pcredemo program. There are separate text files for the pcregrep and pcretest commands. ----------------------------------------------------------------------------- @@ -26,8 +26,8 @@ INTRODUCTION give better JavaScript compatibility. The current implementation of PCRE corresponds approximately with Perl - 5.10, including support for UTF-8 encoded strings and Unicode general - category properties. However, UTF-8 and Unicode support has to be + 5.10/5.11, including support for UTF-8 encoded strings and Unicode gen- + eral category properties. However, UTF-8 and Unicode support has to be explicitly enabled; it is not the default. The Unicode tables corre- spond to Unicode release 5.2.0. @@ -222,21 +222,25 @@ UTF-8 AND UNICODE PROPERTY SUPPORT not available in the alternative matching function, pcre_dfa_exec(). 6. The character escapes \b, \B, \d, \D, \s, \S, \w, and \W correctly - test characters of any code value, but the characters that PCRE recog- - nizes as digits, spaces, or word characters remain the same set as - before, all with values less than 256. This remains true even when PCRE - includes Unicode property support, because to do otherwise would slow - down PCRE in many common cases. If you really want to test for a wider - sense of, say, "digit", you must use Unicode property tests such as - \p{Nd}. Note that this also applies to \b, because it is defined in - terms of \w and \W. + test characters of any code value, but, by default, the characters that + PCRE recognizes as digits, spaces, or word characters remain the same + set as before, all with values less than 256. This remains true even + when PCRE is built to include Unicode property support, because to do + otherwise would slow down PCRE in many common cases. Note that this + also applies to \b, because it is defined in terms of \w and \W. If you + really want to test for a wider sense of, say, "digit", you can use + explicit Unicode property tests such as \p{Nd}. Alternatively, if you + set the PCRE_UCP option, the way that the character escapes work is + changed so that Unicode properties are used to determine which charac- + ters match. There are more details in the section on generic character + types in the pcrepattern documentation. 7. Similarly, characters that match the POSIX named character classes - are all low-valued characters. + are all low-valued characters, unless the PCRE_UCP option is set. 8. However, the Perl 5.10 horizontal and vertical whitespace matching escapes (\h, \H, \v, and \V) do match all the appropriate Unicode char- - acters. + acters, whether or not PCRE_UCP is set. 9. Case-insensitive matching applies only to characters whose values are less than 128, unless PCRE is built with Unicode property support. @@ -263,11 +267,11 @@ AUTHOR REVISION - Last updated: 01 March 2010 + Last updated: 12 May 2010 Copyright (c) 1997-2010 University of Cambridge. ------------------------------------------------------------------------------ - - + + PCREBUILD(3) PCREBUILD(3) @@ -597,8 +601,8 @@ REVISION Last updated: 29 September 2009 Copyright (c) 1997-2009 University of Cambridge. ------------------------------------------------------------------------------ - - + + PCREMATCHING(3) PCREMATCHING(3) @@ -797,8 +801,8 @@ REVISION Last updated: 29 September 2009 Copyright (c) 1997-2009 University of Cambridge. ------------------------------------------------------------------------------ - - + + PCREAPI(3) PCREAPI(3) @@ -1281,48 +1285,49 @@ COMPILING A PATTERN letter that has no special meaning causes an error, thus reserving these combinations for future expansion. By default, as in Perl, a backslash followed by a letter with no special meaning is treated as a - literal. (Perl can, however, be persuaded to give a warning for this.) - There are at present no other features controlled by this option. It - can also be set by a (?X) option setting within a pattern. + literal. (Perl can, however, be persuaded to give an error for this, by + running it with the -w option.) There are at present no other features + controlled by this option. It can also be set by a (?X) option setting + within a pattern. PCRE_FIRSTLINE - If this option is set, an unanchored pattern is required to match - before or at the first newline in the subject string, though the + If this option is set, an unanchored pattern is required to match + before or at the first newline in the subject string, though the matched text may continue over the newline. PCRE_JAVASCRIPT_COMPAT If this option is set, PCRE's behaviour is changed in some ways so that - it is compatible with JavaScript rather than Perl. The changes are as + it is compatible with JavaScript rather than Perl. The changes are as follows: - (1) A lone closing square bracket in a pattern causes a compile-time - error, because this is illegal in JavaScript (by default it is treated + (1) A lone closing square bracket in a pattern causes a compile-time + error, because this is illegal in JavaScript (by default it is treated as a data character). Thus, the pattern AB]CD becomes illegal when this option is set. - (2) At run time, a back reference to an unset subpattern group matches - an empty string (by default this causes the current matching alterna- - tive to fail). A pattern such as (\1)(a) succeeds when this option is - set (assuming it can find an "a" in the subject), whereas it fails by + (2) At run time, a back reference to an unset subpattern group matches + an empty string (by default this causes the current matching alterna- + tive to fail). A pattern such as (\1)(a) succeeds when this option is + set (assuming it can find an "a" in the subject), whereas it fails by default, for Perl compatibility. PCRE_MULTILINE - By default, PCRE treats the subject string as consisting of a single - line of characters (even if it actually contains newlines). The "start - of line" metacharacter (^) matches only at the start of the string, - while the "end of line" metacharacter ($) matches only at the end of + By default, PCRE treats the subject string as consisting of a single + line of characters (even if it actually contains newlines). The "start + of line" metacharacter (^) matches only at the start of the string, + while the "end of line" metacharacter ($) matches only at the end of the string, or before a terminating newline (unless PCRE_DOLLAR_ENDONLY is set). This is the same as Perl. - When PCRE_MULTILINE it is set, the "start of line" and "end of line" - constructs match immediately following or immediately before internal - newlines in the subject string, respectively, as well as at the very - start and end. This is equivalent to Perl's /m option, and it can be + When PCRE_MULTILINE it is set, the "start of line" and "end of line" + constructs match immediately following or immediately before internal + newlines in the subject string, respectively, as well as at the very + start and end. This is equivalent to Perl's /m option, and it can be changed within a pattern by a (?m) option setting. If there are no new- - lines in a subject string, or no occurrences of ^ or $ in a pattern, + lines in a subject string, or no occurrences of ^ or $ in a pattern, setting PCRE_MULTILINE has no effect. PCRE_NEWLINE_CR @@ -1331,32 +1336,32 @@ COMPILING A PATTERN PCRE_NEWLINE_ANYCRLF PCRE_NEWLINE_ANY - These options override the default newline definition that was chosen - when PCRE was built. Setting the first or the second specifies that a - newline is indicated by a single character (CR or LF, respectively). - Setting PCRE_NEWLINE_CRLF specifies that a newline is indicated by the - two-character CRLF sequence. Setting PCRE_NEWLINE_ANYCRLF specifies + These options override the default newline definition that was chosen + when PCRE was built. Setting the first or the second specifies that a + newline is indicated by a single character (CR or LF, respectively). + Setting PCRE_NEWLINE_CRLF specifies that a newline is indicated by the + two-character CRLF sequence. Setting PCRE_NEWLINE_ANYCRLF specifies that any of the three preceding sequences should be recognized. Setting - PCRE_NEWLINE_ANY specifies that any Unicode newline sequence should be + PCRE_NEWLINE_ANY specifies that any Unicode newline sequence should be recognized. The Unicode newline sequences are the three just mentioned, - plus the single characters VT (vertical tab, U+000B), FF (formfeed, - U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and PS - (paragraph separator, U+2029). The last two are recognized only in + plus the single characters VT (vertical tab, U+000B), FF (formfeed, + U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and PS + (paragraph separator, U+2029). The last two are recognized only in UTF-8 mode. - The newline setting in the options word uses three bits that are + The newline setting in the options word uses three bits that are treated as a number, giving eight possibilities. Currently only six are - used (default plus the five values above). This means that if you set - more than one newline option, the combination may or may not be sensi- + used (default plus the five values above). This means that if you set + more than one newline option, the combination may or may not be sensi- ble. For example, PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is equivalent to - PCRE_NEWLINE_CRLF, but other combinations may yield unused numbers and + PCRE_NEWLINE_CRLF, but other combinations may yield unused numbers and cause an error. - The only time that a line break is specially recognized when compiling - a pattern is if PCRE_EXTENDED is set, and an unescaped # outside a - character class is encountered. This indicates a comment that lasts - until after the next line break sequence. In other circumstances, line - break sequences are treated as literal data, except that in + The only time that a line break is specially recognized when compiling + a pattern is if PCRE_EXTENDED is set, and an unescaped # outside a + character class is encountered. This indicates a comment that lasts + until after the next line break sequence. In other circumstances, line + break sequences are treated as literal data, except that in PCRE_EXTENDED mode, both CR and LF are treated as whitespace characters and are therefore ignored. @@ -1366,46 +1371,46 @@ COMPILING A PATTERN PCRE_NO_AUTO_CAPTURE If this option is set, it disables the use of numbered capturing paren- - theses in the pattern. Any opening parenthesis that is not followed by - ? behaves as if it were followed by ?: but named parentheses can still - be used for capturing (and they acquire numbers in the usual way). + theses in the pattern. Any opening parenthesis that is not followed by + ? behaves as if it were followed by ?: but named parentheses can still + be used for capturing (and they acquire numbers in the usual way). There is no equivalent of this option in Perl. PCRE_UNGREEDY - This option inverts the "greediness" of the quantifiers so that they - are not greedy by default, but become greedy if followed by "?". It is - not compatible with Perl. It can also be set by a (?U) option setting + This option inverts the "greediness" of the quantifiers so that they + are not greedy by default, but become greedy if followed by "?". It is + not compatible with Perl. It can also be set by a (?U) option setting within the pattern. PCRE_UTF8 - This option causes PCRE to regard both the pattern and the subject as - strings of UTF-8 characters instead of single-byte character strings. - However, it is available only when PCRE is built to include UTF-8 sup- - port. If not, the use of this option provokes an error. Details of how - this option changes the behaviour of PCRE are given in the section on + This option causes PCRE to regard both the pattern and the subject as + strings of UTF-8 characters instead of single-byte character strings. + However, it is available only when PCRE is built to include UTF-8 sup- + port. If not, the use of this option provokes an error. Details of how + this option changes the behaviour of PCRE are given in the section on UTF-8 support in the main pcre page. PCRE_NO_UTF8_CHECK When PCRE_UTF8 is set, the validity of the pattern as a UTF-8 string is - automatically checked. There is a discussion about the validity of - UTF-8 strings in the main pcre page. If an invalid UTF-8 sequence of - bytes is found, pcre_compile() returns an error. If you already know + automatically checked. There is a discussion about the validity of + UTF-8 strings in the main pcre page. If an invalid UTF-8 sequence of + bytes is found, pcre_compile() returns an error. If you already know that your pattern is valid, and you want to skip this check for perfor- - mance reasons, you can set the PCRE_NO_UTF8_CHECK option. When it is - set, the effect of passing an invalid UTF-8 string as a pattern is - undefined. It may cause your program to crash. Note that this option - can also be passed to pcre_exec() and pcre_dfa_exec(), to suppress the + mance reasons, you can set the PCRE_NO_UTF8_CHECK option. When it is + set, the effect of passing an invalid UTF-8 string as a pattern is + undefined. It may cause your program to crash. Note that this option + can also be passed to pcre_exec() and pcre_dfa_exec(), to suppress the UTF-8 validity checking of subject strings. COMPILATION ERROR CODES - The following table lists the error codes than may be returned by - pcre_compile2(), along with the error messages that may be returned by - both compiling functions. As PCRE has developed, some error codes have + The following table lists the error codes than may be returned by + pcre_compile2(), along with the error messages that may be returned by + both compiling functions. As PCRE has developed, some error codes have fallen out of use. To avoid confusion, they have not been re-used. 0 no error @@ -1461,7 +1466,7 @@ COMPILATION ERROR CODES 50 [this code is not in use] 51 octal value is greater than \377 (not in UTF-8 mode) 52 internal error: overran compiling workspace - 53 internal error: previously-checked referenced subpattern not + 53 internal error: previously-checked referenced subpattern not found 54 DEFINE group contains more than one branch 55 repeating a DEFINE group is not allowed @@ -1475,11 +1480,11 @@ COMPILATION ERROR CODES 62 subpattern name expected 63 digit expected after (?+ 64 ] is an invalid data character in JavaScript compatibility mode - 65 different names for subpatterns of the same number are not + 65 different names for subpatterns of the same number are not allowed 66 (*MARK) must have an argument - The numbers 32 and 10000 in errors 48 and 49 are defaults; different + The numbers 32 and 10000 in errors 48 and 49 are defaults; different values may be used if the limits were changed when PCRE was built. @@ -1488,32 +1493,32 @@ STUDYING A PATTERN pcre_extra *pcre_study(const pcre *code, int options const char **errptr); - If a compiled pattern is going to be used several times, it is worth + If a compiled pattern is going to be used several times, it is worth spending more time analyzing it in order to speed up the time taken for - matching. The function pcre_study() takes a pointer to a compiled pat- + matching. The function pcre_study() takes a pointer to a compiled pat- tern as its first argument. If studying the pattern produces additional - information that will help speed up matching, pcre_study() returns a - pointer to a pcre_extra block, in which the study_data field points to + information that will help speed up matching, pcre_study() returns a + pointer to a pcre_extra block, in which the study_data field points to the results of the study. The returned value from pcre_study() can be passed directly to - pcre_exec() or pcre_dfa_exec(). However, a pcre_extra block also con- - tains other fields that can be set by the caller before the block is + pcre_exec() or pcre_dfa_exec(). However, a pcre_extra block also con- + tains other fields that can be set by the caller before the block is passed; these are described below in the section on matching a pattern. - If studying the pattern does not produce any useful information, + If studying the pattern does not produce any useful information, pcre_study() returns NULL. In that circumstance, if the calling program - wants to pass any of the other fields to pcre_exec() or + wants to pass any of the other fields to pcre_exec() or pcre_dfa_exec(), it must set up its own pcre_extra block. - The second argument of pcre_study() contains option bits. At present, + The second argument of pcre_study() contains option bits. At present, no options are defined, and this argument should always be zero. - The third argument for pcre_study() is a pointer for an error message. - If studying succeeds (even if no data is returned), the variable it - points to is set to NULL. Otherwise it is set to point to a textual + The third argument for pcre_study() is a pointer for an error message. + If studying succeeds (even if no data is returned), the variable it + points to is set to NULL. Otherwise it is set to point to a textual error message. This is a static string that is part of the library. You - must not try to free it. You should test the error pointer for NULL + must not try to free it. You should test the error pointer for NULL after calling pcre_study(), to be sure that it has run successfully. This is a typical call to pcre_study(): @@ -1527,69 +1532,69 @@ STUDYING A PATTERN Studying a pattern does two things: first, a lower bound for the length of subject string that is needed to match the pattern is computed. This does not mean that there are any strings of that length that match, but - it does guarantee that no shorter strings match. The value is used by - pcre_exec() and pcre_dfa_exec() to avoid wasting time by trying to - match strings that are shorter than the lower bound. You can find out + it does guarantee that no shorter strings match. The value is used by + pcre_exec() and pcre_dfa_exec() to avoid wasting time by trying to + match strings that are shorter than the lower bound. You can find out the value in a calling program via the pcre_fullinfo() function. Studying a pattern is also useful for non-anchored patterns that do not - have a single fixed starting character. A bitmap of possible starting - bytes is created. This speeds up finding a position in the subject at + have a single fixed starting character. A bitmap of possible starting + bytes is created. This speeds up finding a position in the subject at which to start matching. LOCALE SUPPORT - PCRE handles caseless matching, and determines whether characters are - letters, digits, or whatever, by reference to a set of tables, indexed - by character value. When running in UTF-8 mode, this applies only to - characters with codes less than 128. Higher-valued codes never match - escapes such as \w or \d, but can be tested with \p if PCRE is built - with Unicode character property support. The use of locales with Uni- - code is discouraged. If you are handling characters with codes greater - than 128, you should either use UTF-8 and Unicode, or use locales, but + PCRE handles caseless matching, and determines whether characters are + letters, digits, or whatever, by reference to a set of tables, indexed + by character value. When running in UTF-8 mode, this applies only to + characters with codes less than 128. Higher-valued codes never match + escapes such as \w or \d, but can be tested with \p if PCRE is built + with Unicode character property support. The use of locales with Uni- + code is discouraged. If you are handling characters with codes greater + than 128, you should either use UTF-8 and Unicode, or use locales, but not try to mix the two. - PCRE contains an internal set of tables that are used when the final - argument of pcre_compile() is NULL. These are sufficient for many + PCRE contains an internal set of tables that are used when the final + argument of pcre_compile() is NULL. These are sufficient for many applications. Normally, the internal tables recognize only ASCII char- acters. However, when PCRE is built, it is possible to cause the inter- nal tables to be rebuilt in the default "C" locale of the local system, which may cause them to be different. - The internal tables can always be overridden by tables supplied by the + The internal tables can always be overridden by tables supplied by the application that calls PCRE. These may be created in a different locale - from the default. As more and more applications change to using Uni- + from the default. As more and more applications change to using Uni- code, the need for this locale support is expected to die away. - External tables are built by calling the pcre_maketables() function, - which has no arguments, in the relevant locale. The result can then be - passed to pcre_compile() or pcre_exec() as often as necessary. For - example, to build and use tables that are appropriate for the French - locale (where accented characters with values greater than 128 are + External tables are built by calling the pcre_maketables() function, + which has no arguments, in the relevant locale. The result can then be + passed to pcre_compile() or pcre_exec() as often as necessary. For + example, to build and use tables that are appropriate for the French + locale (where accented characters with values greater than 128 are treated as letters), the following code could be used: setlocale(LC_CTYPE, "fr_FR"); tables = pcre_maketables(); re = pcre_compile(..., tables); - The locale name "fr_FR" is used on Linux and other Unix-like systems; + The locale name "fr_FR" is used on Linux and other Unix-like systems; if you are using Windows, the name for the French locale is "french". - When pcre_maketables() runs, the tables are built in memory that is - obtained via pcre_malloc. It is the caller's responsibility to ensure - that the memory containing the tables remains available for as long as + When pcre_maketables() runs, the tables are built in memory that is + obtained via pcre_malloc. It is the caller's responsibility to ensure + that the memory containing the tables remains available for as long as it is needed. The pointer that is passed to pcre_compile() is saved with the compiled - pattern, and the same tables are used via this pointer by pcre_study() + pattern, and the same tables are used via this pointer by pcre_study() and normally also by pcre_exec(). Thus, by default, for any single pat- tern, compilation, studying and matching all happen in the same locale, but different patterns can be compiled in different locales. - It is possible to pass a table pointer or NULL (indicating the use of - the internal tables) to pcre_exec(). Although not intended for this - purpose, this facility could be used to match a pattern in a different + It is possible to pass a table pointer or NULL (indicating the use of + the internal tables) to pcre_exec(). Although not intended for this + purpose, this facility could be used to match a pattern in a different locale from the one in which it was compiled. Passing table pointers at run time is discussed below in the section on matching a pattern. @@ -1599,15 +1604,15 @@ INFORMATION ABOUT A PATTERN int pcre_fullinfo(const pcre *code, const pcre_extra *extra, int what, void *where); - The pcre_fullinfo() function returns information about a compiled pat- + The pcre_fullinfo() function returns information about a compiled pat- tern. It replaces the obsolete pcre_info() function, which is neverthe- less retained for backwards compability (and is documented below). - The first argument for pcre_fullinfo() is a pointer to the compiled - pattern. The second argument is the result of pcre_study(), or NULL if - the pattern was not studied. The third argument specifies which piece - of information is required, and the fourth argument is a pointer to a - variable to receive the data. The yield of the function is zero for + The first argument for pcre_fullinfo() is a pointer to the compiled + pattern. The second argument is the result of pcre_study(), or NULL if + the pattern was not studied. The third argument specifies which piece + of information is required, and the fourth argument is a pointer to a + variable to receive the data. The yield of the function is zero for success, or one of the following negative numbers: PCRE_ERROR_NULL the argument code was NULL @@ -1615,9 +1620,9 @@ INFORMATION ABOUT A PATTERN PCRE_ERROR_BADMAGIC the "magic number" was not found PCRE_ERROR_BADOPTION the value of what was invalid - The "magic number" is placed at the start of each compiled pattern as - an simple check against passing an arbitrary memory pointer. Here is a - typical call of pcre_fullinfo(), to obtain the length of the compiled + The "magic number" is placed at the start of each compiled pattern as + an simple check against passing an arbitrary memory pointer. Here is a + typical call of pcre_fullinfo(), to obtain the length of the compiled pattern: int rc; @@ -1628,131 +1633,131 @@ INFORMATION ABOUT A PATTERN PCRE_INFO_SIZE, /* what is required */ &length); /* where to put the data */ - The possible values for the third argument are defined in pcre.h, and + The possible values for the third argument are defined in pcre.h, and are as follows: PCRE_INFO_BACKREFMAX - Return the number of the highest back reference in the pattern. The - fourth argument should point to an int variable. Zero is returned if + Return the number of the highest back reference in the pattern. The + fourth argument should point to an int variable. Zero is returned if there are no back references. PCRE_INFO_CAPTURECOUNT - Return the number of capturing subpatterns in the pattern. The fourth + Return the number of capturing subpatterns in the pattern. The fourth argument should point to an int variable. PCRE_INFO_DEFAULT_TABLES - Return a pointer to the internal default character tables within PCRE. - The fourth argument should point to an unsigned char * variable. This + Return a pointer to the internal default character tables within PCRE. + The fourth argument should point to an unsigned char * variable. This information call is provided for internal use by the pcre_study() func- - tion. External callers can cause PCRE to use its internal tables by + tion. External callers can cause PCRE to use its internal tables by passing a NULL table pointer. PCRE_INFO_FIRSTBYTE - Return information about the first byte of any matched string, for a - non-anchored pattern. The fourth argument should point to an int vari- - able. (This option used to be called PCRE_INFO_FIRSTCHAR; the old name + Return information about the first byte of any matched string, for a + non-anchored pattern. The fourth argument should point to an int vari- + able. (This option used to be called PCRE_INFO_FIRSTCHAR; the old name is still recognized for backwards compatibility.) - If there is a fixed first byte, for example, from a pattern such as + If there is a fixed first byte, for example, from a pattern such as (cat|cow|coyote), its value is returned. Otherwise, if either - (a) the pattern was compiled with the PCRE_MULTILINE option, and every + (a) the pattern was compiled with the PCRE_MULTILINE option, and every branch starts with "^", or (b) every branch of the pattern starts with ".*" and PCRE_DOTALL is not set (if it were set, the pattern would be anchored), - -1 is returned, indicating that the pattern matches only at the start - of a subject string or after any newline within the string. Otherwise + -1 is returned, indicating that the pattern matches only at the start + of a subject string or after any newline within the string. Otherwise -2 is returned. For anchored patterns, -2 is returned. PCRE_INFO_FIRSTTABLE - If the pattern was studied, and this resulted in the construction of a + If the pattern was studied, and this resulted in the construction of a 256-bit table indicating a fixed set of bytes for the first byte in any - matching string, a pointer to the table is returned. Otherwise NULL is - returned. The fourth argument should point to an unsigned char * vari- + matching string, a pointer to the table is returned. Otherwise NULL is + returned. The fourth argument should point to an unsigned char * vari- able. PCRE_INFO_HASCRORLF - Return 1 if the pattern contains any explicit matches for CR or LF - characters, otherwise 0. The fourth argument should point to an int - variable. An explicit match is either a literal CR or LF character, or + Return 1 if the pattern contains any explicit matches for CR or LF + characters, otherwise 0. The fourth argument should point to an int + variable. An explicit match is either a literal CR or LF character, or \r or \n. PCRE_INFO_JCHANGED - Return 1 if the (?J) or (?-J) option setting is used in the pattern, - otherwise 0. The fourth argument should point to an int variable. (?J) + Return 1 if the (?J) or (?-J) option setting is used in the pattern, + otherwise 0. The fourth argument should point to an int variable. (?J) and (?-J) set and unset the local PCRE_DUPNAMES option, respectively. PCRE_INFO_LASTLITERAL - Return the value of the rightmost literal byte that must exist in any - matched string, other than at its start, if such a byte has been + Return the value of the rightmost literal byte that must exist in any + matched string, other than at its start, if such a byte has been recorded. The fourth argument should point to an int variable. If there - is no such byte, -1 is returned. For anchored patterns, a last literal - byte is recorded only if it follows something of variable length. For + is no such byte, -1 is returned. For anchored patterns, a last literal + byte is recorded only if it follows something of variable length. For example, for the pattern /^a\d+z\d+/ the returned value is "z", but for /^a\dz\d/ the returned value is -1. PCRE_INFO_MINLENGTH - If the pattern was studied and a minimum length for matching subject - strings was computed, its value is returned. Otherwise the returned - value is -1. The value is a number of characters, not bytes (this may - be relevant in UTF-8 mode). The fourth argument should point to an int - variable. A non-negative value is a lower bound to the length of any - matching string. There may not be any strings of that length that do + If the pattern was studied and a minimum length for matching subject + strings was computed, its value is returned. Otherwise the returned + value is -1. The value is a number of characters, not bytes (this may + be relevant in UTF-8 mode). The fourth argument should point to an int + variable. A non-negative value is a lower bound to the length of any + matching string. There may not be any strings of that length that do actually match, but every string that does match is at least that long. PCRE_INFO_NAMECOUNT PCRE_INFO_NAMEENTRYSIZE PCRE_INFO_NAMETABLE - PCRE supports the use of named as well as numbered capturing parenthe- - ses. The names are just an additional way of identifying the parenthe- + PCRE supports the use of named as well as numbered capturing parenthe- + ses. The names are just an additional way of identifying the parenthe- ses, which still acquire numbers. Several convenience functions such as - pcre_get_named_substring() are provided for extracting captured sub- - strings by name. It is also possible to extract the data directly, by - first converting the name to a number in order to access the correct + pcre_get_named_substring() are provided for extracting captured sub- + strings by name. It is also possible to extract the data directly, by + first converting the name to a number in order to access the correct pointers in the output vector (described with pcre_exec() below). To do - the conversion, you need to use the name-to-number map, which is + the conversion, you need to use the name-to-number map, which is described by these three values. The map consists of a number of fixed-size entries. PCRE_INFO_NAMECOUNT gives the number of entries, and PCRE_INFO_NAMEENTRYSIZE gives the size - of each entry; both of these return an int value. The entry size - depends on the length of the longest name. PCRE_INFO_NAMETABLE returns - a pointer to the first entry of the table (a pointer to char). The + of each entry; both of these return an int value. The entry size + depends on the length of the longest name. PCRE_INFO_NAMETABLE returns + a pointer to the first entry of the table (a pointer to char). The first two bytes of each entry are the number of the capturing parenthe- - sis, most significant byte first. The rest of the entry is the corre- + sis, most significant byte first. The rest of the entry is the corre- sponding name, zero terminated. - The names are in alphabetical order. Duplicate names may appear if (?| + The names are in alphabetical order. Duplicate names may appear if (?| is used to create multiple groups with the same number, as described in - the section on duplicate subpattern numbers in the pcrepattern page. - Duplicate names for subpatterns with different numbers are permitted - only if PCRE_DUPNAMES is set. In all cases of duplicate names, they - appear in the table in the order in which they were found in the pat- - tern. In the absence of (?| this is the order of increasing number; + the section on duplicate subpattern numbers in the pcrepattern page. + Duplicate names for subpatterns with different numbers are permitted + only if PCRE_DUPNAMES is set. In all cases of duplicate names, they + appear in the table in the order in which they were found in the pat- + tern. In the absence of (?| this is the order of increasing number; when (?| is used this is not necessarily the case because later subpat- terns may have lower numbers. - As a simple example of the name/number table, consider the following - pattern (assume PCRE_EXTENDED is set, so white space - including new- + As a simple example of the name/number table, consider the following + pattern (assume PCRE_EXTENDED is set, so white space - including new- lines - is ignored): (?<date> (?<year>(\d\d)?\d\d) - (?<month>\d\d) - (?<day>\d\d) ) - There are four named subpatterns, so the table has four entries, and - each entry in the table is eight bytes long. The table is as follows, + There are four named subpatterns, so the table has four entries, and + each entry in the table is eight bytes long. The table is as follows, with non-printing bytes shows in hexadecimal, and undefined bytes shown as ??: @@ -1761,31 +1766,31 @@ INFORMATION ABOUT A PATTERN 00 04 m o n t h 00 00 02 y e a r 00 ?? - When writing code to extract data from named subpatterns using the - name-to-number map, remember that the length of the entries is likely + When writing code to extract data from named subpatterns using the + name-to-number map, remember that the length of the entries is likely to be different for each compiled pattern. PCRE_INFO_OKPARTIAL - Return 1 if the pattern can be used for partial matching with - pcre_exec(), otherwise 0. The fourth argument should point to an int - variable. From release 8.00, this always returns 1, because the - restrictions that previously applied to partial matching have been - lifted. The pcrepartial documentation gives details of partial match- + Return 1 if the pattern can be used for partial matching with + pcre_exec(), otherwise 0. The fourth argument should point to an int + variable. From release 8.00, this always returns 1, because the + restrictions that previously applied to partial matching have been + lifted. The pcrepartial documentation gives details of partial match- ing. PCRE_INFO_OPTIONS - Return a copy of the options with which the pattern was compiled. The - fourth argument should point to an unsigned long int variable. These + Return a copy of the options with which the pattern was compiled. The + fourth argument should point to an unsigned long int variable. These option bits are those specified in the call to pcre_compile(), modified by any top-level option settings at the start of the pattern itself. In - other words, they are the options that will be in force when matching - starts. For example, if the pattern /(?im)abc(?-i)d/ is compiled with - the PCRE_EXTENDED option, the result is PCRE_CASELESS, PCRE_MULTILINE, + other words, they are the options that will be in force when matching + starts. For example, if the pattern /(?im)abc(?-i)d/ is compiled with + the PCRE_EXTENDED option, the result is PCRE_CASELESS, PCRE_MULTILINE, and PCRE_EXTENDED. - A pattern is automatically anchored by PCRE if all of its top-level + A pattern is automatically anchored by PCRE if all of its top-level alternatives begin with one of the following: ^ unless PCRE_MULTILINE is set @@ -1799,7 +1804,7 @@ INFORMATION ABOUT A PATTERN PCRE_INFO_SIZE - Return the size of the compiled pattern, that is, the value that was + Return the size of the compiled pattern, that is, the value that was passed as the argument to pcre_malloc() when PCRE was getting memory in which to place the compiled data. The fourth argument should point to a size_t variable. @@ -1807,10 +1812,10 @@ INFORMATION ABOUT A PATTERN PCRE_INFO_STUDYSIZE Return the size of the data block pointed to by the study_data field in - a pcre_extra block. That is, it is the value that was passed to + a pcre_extra block. That is, it is the value that was passed to pcre_malloc() when PCRE was getting memory into which to place the data - created by pcre_study(). If pcre_extra is NULL, or there is no study - data, zero is returned. The fourth argument should point to a size_t + created by pcre_study(). If pcre_extra is NULL, or there is no study + data, zero is returned. The fourth argument should point to a size_t variable. @@ -1818,21 +1823,21 @@ OBSOLETE INFO FUNCTION int pcre_info(const pcre *code, int *optptr, int *firstcharptr); - The pcre_info() function is now obsolete because its interface is too - restrictive to return all the available data about a compiled pattern. - New programs should use pcre_fullinfo() instead. The yield of - pcre_info() is the number of capturing subpatterns, or one of the fol- + The pcre_info() function is now obsolete because its interface is too + restrictive to return all the available data about a compiled pattern. + New programs should use pcre_fullinfo() instead. The yield of + pcre_info() is the number of capturing subpatterns, or one of the fol- lowing negative numbers: PCRE_ERROR_NULL the argument code was NULL PCRE_ERROR_BADMAGIC the "magic number" was not found - If the optptr argument is not NULL, a copy of the options with which - the pattern was compiled is placed in the integer it points to (see + If the optptr argument is not NULL, a copy of the options with which + the pattern was compiled is placed in the integer it points to (see PCRE_INFO_OPTIONS above). - If the pattern is not anchored and the firstcharptr argument is not - NULL, it is used to pass back information about the first character of + If the pattern is not anchored and the firstcharptr argument is not + NULL, it is used to pass back information about the first character of any matched string (see PCRE_INFO_FIRSTBYTE above). @@ -1840,21 +1845,21 @@ REFERENCE COUNTS int pcre_refcount(pcre *code, int adjust); - The pcre_refcount() function is used to maintain a reference count in + The pcre_refcount() function is used to maintain a reference count in the data block that contains a compiled pattern. It is provided for the - benefit of applications that operate in an object-oriented manner, + benefit of applications that operate in an object-oriented manner, where different parts of the application may be using the same compiled pattern, but you want to free the block when they are all done. When a pattern is compiled, the reference count field is initialized to - zero. It is changed only by calling this function, whose action is to - add the adjust value (which may be positive or negative) to it. The + zero. It is changed only by calling this function, whose action is to + add the adjust value (which may be positive or negative) to it. The yield of the function is the new value. However, the value of the count - is constrained to lie between 0 and 65535, inclusive. If the new value + is constrained to lie between 0 and 65535, inclusive. If the new value is outside these limits, it is forced to the appropriate limit value. - Except when it is zero, the reference count is not correctly preserved - if a pattern is compiled on one host and then transferred to a host + Except when it is zero, the reference count is not correctly preserved + if a pattern is compiled on one host and then transferred to a host whose byte-order is different. (This seems a highly unlikely scenario.) @@ -1864,18 +1869,18 @@ MATCHING A PATTERN: THE TRADITIONAL FUNCTION const char *subject, int length, int startoffset, int options, int *ovector, int ovecsize); - The function pcre_exec() is called to match a subject string against a - compiled pattern, which is passed in the code argument. If the pattern - was studied, the result of the study should be passed in the extra - argument. This function is the main matching facility of the library, + The function pcre_exec() is called to match a subject string against a + compiled pattern, which is passed in the code argument. If the pattern + was studied, the result of the study should be passed in the extra + argument. This function is the main matching facility of the library, and it operates in a Perl-like manner. For specialist use there is also - an alternative matching function, which is described below in the sec- + an alternative matching function, which is described below in the sec- tion about the pcre_dfa_exec() function. - In most applications, the pattern will have been compiled (and option- - ally studied) in the same process that calls pcre_exec(). However, it + In most applications, the pattern will have been compiled (and option- + ally studied) in the same process that calls pcre_exec(). However, it is possible to save compiled patterns and study data, and then use them - later in different processes, possibly even on different hosts. For a + later in different processes, possibly even on different hosts. For a discussion about this, see the pcreprecompile documentation. Here is an example of a simple call to pcre_exec(): @@ -1894,10 +1899,10 @@ MATCHING A PATTERN: THE TRADITIONAL FUNCTION Extra data for pcre_exec() - If the extra argument is not NULL, it must point to a pcre_extra data - block. The pcre_study() function returns such a block (when it doesn't - return NULL), but you can also create one for yourself, and pass addi- - tional information in it. The pcre_extra block contains the following + If the extra argument is not NULL, it must point to a pcre_extra data + block. The pcre_study() function returns such a block (when it doesn't + return NULL), but you can also create one for yourself, and pass addi- + tional information in it. The pcre_extra block contains the following fields (not necessarily in this order): unsigned long int flags; @@ -1908,7 +1913,7 @@ MATCHING A PATTERN: THE TRADITIONAL FUNCTION const unsigned char *tables; unsigned char **mark; - The flags field is a bitmap that specifies which of the other fields + The flags field is a bitmap that specifies which of the other fields are set. The flag bits are: PCRE_EXTRA_STUDY_DATA @@ -1918,96 +1923,96 @@ MATCHING A PATTERN: THE TRADITIONAL FUNCTION PCRE_EXTRA_TABLES PCRE_EXTRA_MARK - Other flag bits should be set to zero. The study_data field is set in - the pcre_extra block that is returned by pcre_study(), together with + Other flag bits should be set to zero. The study_data field is set in + the pcre_extra block that is returned by pcre_study(), together with the appropriate flag bit. You should not set this yourself, but you may - add to the block by setting the other fields and their corresponding + add to the block by setting the other fields and their corresponding flag bits. The match_limit field provides a means of preventing PCRE from using up - a vast amount of resources when running patterns that are not going to - match, but which have a very large number of possibilities in their - search trees. The classic example is a pattern that uses nested unlim- + a vast amount of resources when running patterns that are not going to + match, but which have a very large number of possibilities in their + search trees. The classic example is a pattern that uses nested unlim- ited repeats. - Internally, PCRE uses a function called match() which it calls repeat- - edly (sometimes recursively). The limit set by match_limit is imposed - on the number of times this function is called during a match, which - has the effect of limiting the amount of backtracking that can take + Internally, PCRE uses a function called match() which it calls repeat- + edly (sometimes recursively). The limit set by match_limit is imposed + on the number of times this function is called during a match, which + has the effect of limiting the amount of backtracking that can take place. For patterns that are not anchored, the count restarts from zero for each position in the subject string. - The default value for the limit can be set when PCRE is built; the - default default is 10 million, which handles all but the most extreme - cases. You can override the default by suppling pcre_exec() with a - pcre_extra block in which match_limit is set, and - PCRE_EXTRA_MATCH_LIMIT is set in the flags field. If the limit is + The default value for the limit can be set when PCRE is built; the + default default is 10 million, which handles all but the most extreme + cases. You can override the default by suppling pcre_exec() with a + pcre_extra block in which match_limit is set, and + PCRE_EXTRA_MATCH_LIMIT is set in the flags field. If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT. - The match_limit_recursion field is similar to match_limit, but instead + The match_limit_recursion field is similar to match_limit, but instead of limiting the total number of times that match() is called, it limits - the depth of recursion. The recursion depth is a smaller number than - the total number of calls, because not all calls to match() are recur- + the depth of recursion. The recursion depth is a smaller number than + the total number of calls, because not all calls to match() are recur- sive. This limit is of use only if it is set smaller than match_limit. - Limiting the recursion depth limits the amount of stack that can be + Limiting the recursion depth limits the amount of stack that can be used, or, when PCRE has been compiled to use memory on the heap instead of the stack, the amount of heap memory that can be used. - The default value for match_limit_recursion can be set when PCRE is - built; the default default is the same value as the default for - match_limit. You can override the default by suppling pcre_exec() with - a pcre_extra block in which match_limit_recursion is set, and - PCRE_EXTRA_MATCH_LIMIT_RECURSION is set in the flags field. If the + The default value for match_limit_recursion can be set when PCRE is + built; the default default is the same value as the default for + match_limit. You can override the default by suppling pcre_exec() with + a pcre_extra block in which match_limit_recursion is set, and + PCRE_EXTRA_MATCH_LIMIT_RECURSION is set in the flags field. If the limit is exceeded, pcre_exec() returns PCRE_ERROR_RECURSIONLIMIT. - The callout_data field is used in conjunction with the "callout" fea- + The callout_data field is used in conjunction with the "callout" fea- ture, and is described in the pcrecallout documentation. - The tables field is used to pass a character tables pointer to - pcre_exec(); this overrides the value that is stored with the compiled - pattern. A non-NULL value is stored with the compiled pattern only if - custom tables were supplied to pcre_compile() via its tableptr argu- + The tables field is used to pass a character tables pointer to + pcre_exec(); this overrides the value that is stored with the compiled + pattern. A non-NULL value is stored with the compiled pattern only if + custom tables were supplied to pcre_compile() via its tableptr argu- ment. If NULL is passed to pcre_exec() using this mechanism, it forces - PCRE's internal tables to be used. This facility is helpful when re- - using patterns that have been saved after compiling with an external - set of tables, because the external tables might be at a different - address when pcre_exec() is called. See the pcreprecompile documenta- + PCRE's internal tables to be used. This facility is helpful when re- + using patterns that have been saved after compiling with an external + set of tables, because the external tables might be at a different + address when pcre_exec() is called. See the pcreprecompile documenta- tion for a discussion of saving compiled patterns for later use. - If PCRE_EXTRA_MARK is set in the flags field, the mark field must be - set to point to a char * variable. If the pattern contains any back- - tracking control verbs such as (*MARK:NAME), and the execution ends up - with a name to pass back, a pointer to the name string (zero termi- - nated) is placed in the variable pointed to by the mark field. The - names are within the compiled pattern; if you wish to retain such a - name you must copy it before freeing the memory of a compiled pattern. - If there is no name to pass back, the variable pointed to by the mark - field set to NULL. For details of the backtracking control verbs, see + If PCRE_EXTRA_MARK is set in the flags field, the mark field must be + set to point to a char * variable. If the pattern contains any back- + tracking control verbs such as (*MARK:NAME), and the execution ends up + with a name to pass back, a pointer to the name string (zero termi- + nated) is placed in the variable pointed to by the mark field. The + names are within the compiled pattern; if you wish to retain such a + name you must copy it before freeing the memory of a compiled pattern. + If there is no name to pass back, the variable pointed to by the mark + field set to NULL. For details of the backtracking control verbs, see the section entitled "Backtracking control" in the pcrepattern documen- tation. Option bits for pcre_exec() - The unused bits of the options argument for pcre_exec() must be zero. - The only bits that may be set are PCRE_ANCHORED, PCRE_NEWLINE_xxx, - PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART, - PCRE_NO_START_OPTIMIZE, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL_SOFT, and + The unused bits of the options argument for pcre_exec() must be zero. + The only bits that may be set are PCRE_ANCHORED, PCRE_NEWLINE_xxx, + PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART, + PCRE_NO_START_OPTIMIZE, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL_SOFT, and PCRE_PARTIAL_HARD. PCRE_ANCHORED - The PCRE_ANCHORED option limits pcre_exec() to matching at the first - matching position. If a pattern was compiled with PCRE_ANCHORED, or - turned out to be anchored by virtue of its contents, it cannot be made + The PCRE_ANCHORED option limits pcre_exec() to matching at the first + matching position. If a pattern was compiled with PCRE_ANCHORED, or + turned out to be anchored by virtue of its contents, it cannot be made unachored at matching time. PCRE_BSR_ANYCRLF PCRE_BSR_UNICODE These options (which are mutually exclusive) control what the \R escape - sequence matches. The choice is either to match only CR, LF, or CRLF, - or to match any Unicode newline sequence. These options override the + sequence matches. The choice is either to match only CR, LF, or CRLF, + or to match any Unicode newline sequence. These options override the choice that was made or defaulted when the pattern was compiled. PCRE_NEWLINE_CR @@ -2016,243 +2021,243 @@ MATCHING A PATTERN: THE TRADITIONAL FUNCTION PCRE_NEWLINE_ANYCRLF PCRE_NEWLINE_ANY - These options override the newline definition that was chosen or - defaulted when the pattern was compiled. For details, see the descrip- - tion of pcre_compile() above. During matching, the newline choice - affects the behaviour of the dot, circumflex, and dollar metacharac- - ters. It may also alter the way the match position is advanced after a + These options override the newline definition that was chosen or + defaulted when the pattern was compiled. For details, see the descrip- + tion of pcre_compile() above. During matching, the newline choice + affects the behaviour of the dot, circumflex, and dollar metacharac- + ters. It may also alter the way the match position is advanced after a match failure for an unanchored pattern. - When PCRE_NEWLINE_CRLF, PCRE_NEWLINE_ANYCRLF, or PCRE_NEWLINE_ANY is - set, and a match attempt for an unanchored pattern fails when the cur- - rent position is at a CRLF sequence, and the pattern contains no - explicit matches for CR or LF characters, the match position is + When PCRE_NEWLINE_CRLF, PCRE_NEWLINE_ANYCRLF, or PCRE_NEWLINE_ANY is + set, and a match attempt for an unanchored pattern fails when the cur- + rent position is at a CRLF sequence, and the pattern contains no + explicit matches for CR or LF characters, the match position is advanced by two characters instead of one, in other words, to after the CRLF. The above rule is a compromise that makes the most common cases work as - expected. For example, if the pattern is .+A (and the PCRE_DOTALL + expected. For example, if the pattern is .+A (and the PCRE_DOTALL option is not set), it does not match the string "\r\nA" because, after - failing at the start, it skips both the CR and the LF before retrying. - However, the pattern [\r\n]A does match that string, because it con- + failing at the start, it skips both the CR and the LF before retrying. + However, the pattern [\r\n]A does match that string, because it con- tains an explicit CR or LF reference, and so advances only by one char- acter after the first failure. An explicit match for CR of LF is either a literal appearance of one of - those characters, or one of the \r or \n escape sequences. Implicit - matches such as [^X] do not count, nor does \s (which includes CR and + those characters, or one of the \r or \n escape sequences. Implicit + matches such as [^X] do not count, nor does \s (which includes CR and LF in the characters that it matches). - Notwithstanding the above, anomalous effects may still occur when CRLF + Notwithstanding the above, anomalous effects may still occur when CRLF is a valid newline sequence and explicit \r or \n escapes appear in the pattern. PCRE_NOTBOL This option specifies that first character of the subject string is not - the beginning of a line, so the circumflex metacharacter should not - match before it. Setting this without PCRE_MULTILINE (at compile time) - causes circumflex never to match. This option affects only the behav- + the beginning of a line, so the circumflex metacharacter should not + match before it. Setting this without PCRE_MULTILINE (at compile time) + causes circumflex never to match. This option affects only the behav- iour of the circumflex metacharacter. It does not affect \A. PCRE_NOTEOL This option specifies that the end of the subject string is not the end - of a line, so the dollar metacharacter should not match it nor (except - in multiline mode) a newline immediately before it. Setting this with- + of a line, so the dollar metacharacter should not match it nor (except + in multiline mode) a newline immediately before it. Setting this with- out PCRE_MULTILINE (at compile time) causes dollar never to match. This - option affects only the behaviour of the dollar metacharacter. It does + option affects only the behaviour of the dollar metacharacter. It does not affect \Z or \z. PCRE_NOTEMPTY An empty string is not considered to be a valid match if this option is - set. If there are alternatives in the pattern, they are tried. If all - the alternatives match the empty string, the entire match fails. For + set. If there are alternatives in the pattern, they are tried. If all + the alternatives match the empty string, the entire match fails. For example, if the pattern a?b? - is applied to a string not beginning with "a" or "b", it matches an - empty string at the start of the subject. With PCRE_NOTEMPTY set, this + is applied to a string not beginning with "a" or "b", it matches an + empty string at the start of the subject. With PCRE_NOTEMPTY set, this match is not valid, so PCRE searches further into the string for occur- rences of "a" or "b". PCRE_NOTEMPTY_ATSTART - This is like PCRE_NOTEMPTY, except that an empty string match that is - not at the start of the subject is permitted. If the pattern is + This is like PCRE_NOTEMPTY, except that an empty string match that is + not at the start of the subject is permitted. If the pattern is anchored, such a match can occur only if the pattern contains \K. - Perl has no direct equivalent of PCRE_NOTEMPTY or - PCRE_NOTEMPTY_ATSTART, but it does make a special case of a pattern - match of the empty string within its split() function, and when using - the /g modifier. It is possible to emulate Perl's behaviour after + Perl has no direct equivalent of PCRE_NOTEMPTY or + PCRE_NOTEMPTY_ATSTART, but it does make a special case of a pattern + match of the empty string within its split() function, and when using + the /g modifier. It is possible to emulate Perl's behaviour after matching a null string by first trying the match again at the same off- - set with PCRE_NOTEMPTY_ATSTART and PCRE_ANCHORED, and then if that + set with PCRE_NOTEMPTY_ATSTART and PCRE_ANCHORED, and then if that fails, by advancing the starting offset (see below) and trying an ordi- - nary match again. There is some code that demonstrates how to do this + nary match again. There is some code that demonstrates how to do this in the pcredemo sample program. PCRE_NO_START_OPTIMIZE - There are a number of optimizations that pcre_exec() uses at the start - of a match, in order to speed up the process. For example, if it is - known that a match must start with a specific character, it searches + There are a number of optimizations that pcre_exec() uses at the start + of a match, in order to speed up the process. For example, if it is + known that a match must start with a specific character, it searches the subject for that character, and fails immediately if it cannot find - it, without actually running the main matching function. When callouts - are in use, these optimizations can cause them to be skipped. This - option disables the "start-up" optimizations, causing performance to + it, without actually running the main matching function. When callouts + are in use, these optimizations can cause them to be skipped. This + option disables the "start-up" optimizations, causing performance to suffer, but ensuring that the callouts do occur. PCRE_NO_UTF8_CHECK When PCRE_UTF8 is set at compile time, the validity of the subject as a - UTF-8 string is automatically checked when pcre_exec() is subsequently - called. The value of startoffset is also checked to ensure that it - points to the start of a UTF-8 character. There is a discussion about - the validity of UTF-8 strings in the section on UTF-8 support in the - main pcre page. If an invalid UTF-8 sequence of bytes is found, - pcre_exec() returns the error PCRE_ERROR_BADUTF8. If startoffset con- + UTF-8 string is automatically checked when pcre_exec() is subsequently + called. The value of startoffset is also checked to ensure that it + points to the start of a UTF-8 character. There is a discussion about + the validity of UTF-8 strings in the section on UTF-8 support in the + main pcre page. If an invalid UTF-8 sequence of bytes is found, + pcre_exec() returns the error PCRE_ERROR_BADUTF8. If startoffset con- tains an invalid value, PCRE_ERROR_BADUTF8_OFFSET is returned. - If you already know that your subject is valid, and you want to skip - these checks for performance reasons, you can set the - PCRE_NO_UTF8_CHECK option when calling pcre_exec(). You might want to - do this for the second and subsequent calls to pcre_exec() if you are - making repeated calls to find all the matches in a single subject - string. However, you should be sure that the value of startoffset - points to the start of a UTF-8 character. When PCRE_NO_UTF8_CHECK is - set, the effect of passing an invalid UTF-8 string as a subject, or a - value of startoffset that does not point to the start of a UTF-8 char- + If you already know that your subject is valid, and you want to skip + these checks for performance reasons, you can set the + PCRE_NO_UTF8_CHECK option when calling pcre_exec(). You might want to + do this for the second and subsequent calls to pcre_exec() if you are + making repeated calls to find all the matches in a single subject + string. However, you should be sure that the value of startoffset + points to the start of a UTF-8 character. When PCRE_NO_UTF8_CHECK is + set, the effect of passing an invalid UTF-8 string as a subject, or a + value of startoffset that does not point to the start of a UTF-8 char- acter, is undefined. Your program may crash. PCRE_PARTIAL_HARD PCRE_PARTIAL_SOFT - These options turn on the partial matching feature. For backwards com- - patibility, PCRE_PARTIAL is a synonym for PCRE_PARTIAL_SOFT. A partial - match occurs if the end of the subject string is reached successfully, - but there are not enough subject characters to complete the match. If - this happens when PCRE_PARTIAL_HARD is set, pcre_exec() immediately - returns PCRE_ERROR_PARTIAL. Otherwise, if PCRE_PARTIAL_SOFT is set, - matching continues by testing any other alternatives. Only if they all - fail is PCRE_ERROR_PARTIAL returned (instead of PCRE_ERROR_NOMATCH). + These options turn on the partial matching feature. For backwards com- + patibility, PCRE_PARTIAL is a synonym for PCRE_PARTIAL_SOFT. A partial + match occurs if the end of the subject string is reached successfully, + but there are not enough subject characters to complete the match. If + this happens when PCRE_PARTIAL_HARD is set, pcre_exec() immediately + returns PCRE_ERROR_PARTIAL. Otherwise, if PCRE_PARTIAL_SOFT is set, + matching continues by testing any other alternatives. Only if they all + fail is PCRE_ERROR_PARTIAL returned (instead of PCRE_ERROR_NOMATCH). The portion of the string that was inspected when the partial match was - found is set as the first matching string. There is a more detailed + found is set as the first matching string. There is a more detailed discussion in the pcrepartial documentation. The string to be matched by pcre_exec() - The subject string is passed to pcre_exec() as a pointer in subject, a + The subject string is passed to pcre_exec() as a pointer in subject, a length (in bytes) in length, and a starting byte offset in startoffset. In UTF-8 mode, the byte offset must point to the start of a UTF-8 char- - acter. Unlike the pattern string, the subject may contain binary zero - bytes. When the starting offset is zero, the search for a match starts - at the beginning of the subject, and this is by far the most common + acter. Unlike the pattern string, the subject may contain binary zero + bytes. When the starting offset is zero, the search for a match starts + at the beginning of the subject, and this is by far the most common case. - A non-zero starting offset is useful when searching for another match - in the same subject by calling pcre_exec() again after a previous suc- - cess. Setting startoffset differs from just passing over a shortened - string and setting PCRE_NOTBOL in the case of a pattern that begins + A non-zero starting offset is useful when searching for another match + in the same subject by calling pcre_exec() again after a previous suc- + cess. Setting startoffset differs from just passing over a shortened + string and setting PCRE_NOTBOL in the case of a pattern that begins with any kind of lookbehind. For example, consider the pattern \Biss\B - which finds occurrences of "iss" in the middle of words. (\B matches - only if the current position in the subject is not a word boundary.) - When applied to the string "Mississipi" the first call to pcre_exec() - finds the first occurrence. If pcre_exec() is called again with just - the remainder of the subject, namely "issipi", it does not match, + which finds occurrences of "iss" in the middle of words. (\B matches + only if the current position in the subject is not a word boundary.) + When applied to the string "Mississipi" the first call to pcre_exec() + finds the first occurrence. If pcre_exec() is called again with just + the remainder of the subject, namely "issipi", it does not match, because \B is always false at the start of the subject, which is deemed - to be a word boundary. However, if pcre_exec() is passed the entire + to be a word boundary. However, if pcre_exec() is passed the entire string again, but with startoffset set to 4, it finds the second occur- - rence of "iss" because it is able to look behind the starting point to + rence of "iss" because it is able to look behind the starting point to discover that it is preceded by a letter. - If a non-zero starting offset is passed when the pattern is anchored, + If a non-zero starting offset is passed when the pattern is anchored, one attempt to match at the given offset is made. This can only succeed - if the pattern does not require the match to be at the start of the + if the pattern does not require the match to be at the start of the subject. How pcre_exec() returns captured substrings - In general, a pattern matches a certain portion of the subject, and in - addition, further substrings from the subject may be picked out by - parts of the pattern. Following the usage in Jeffrey Friedl's book, - this is called "capturing" in what follows, and the phrase "capturing - subpattern" is used for a fragment of a pattern that picks out a sub- - string. PCRE supports several other kinds of parenthesized subpattern + In general, a pattern matches a certain portion of the subject, and in + addition, further substrings from the subject may be picked out by + parts of the pattern. Following the usage in Jeffrey Friedl's book, + this is called "capturing" in what follows, and the phrase "capturing + subpattern" is used for a fragment of a pattern that picks out a sub- + string. PCRE supports several other kinds of parenthesized subpattern that do not cause substrings to be captured. Captured substrings are returned to the caller via a vector of integers - whose address is passed in ovector. The number of elements in the vec- - tor is passed in ovecsize, which must be a non-negative number. Note: + whose address is passed in ovector. The number of elements in the vec- + tor is passed in ovecsize, which must be a non-negative number. Note: this argument is NOT the size of ovector in bytes. - The first two-thirds of the vector is used to pass back captured sub- - strings, each substring using a pair of integers. The remaining third - of the vector is used as workspace by pcre_exec() while matching cap- - turing subpatterns, and is not available for passing back information. - The number passed in ovecsize should always be a multiple of three. If + The first two-thirds of the vector is used to pass back captured sub- + strings, each substring using a pair of integers. The remaining third + of the vector is used as workspace by pcre_exec() while matching cap- + turing subpatterns, and is not available for passing back information. + The number passed in ovecsize should always be a multiple of three. If it is not, it is rounded down. - When a match is successful, information about captured substrings is - returned in pairs of integers, starting at the beginning of ovector, - and continuing up to two-thirds of its length at the most. The first - element of each pair is set to the byte offset of the first character - in a substring, and the second is set to the byte offset of the first - character after the end of a substring. Note: these values are always + When a match is successful, information about captured substrings is + returned in pairs of integers, starting at the beginning of ovector, + and continuing up to two-thirds of its length at the most. The first + element of each pair is set to the byte offset of the first character + in a substring, and the second is set to the byte offset of the first + character after the end of a substring. Note: these values are always byte offsets, even in UTF-8 mode. They are not character counts. - The first pair of integers, ovector[0] and ovector[1], identify the - portion of the subject string matched by the entire pattern. The next - pair is used for the first capturing subpattern, and so on. The value + The first pair of integers, ovector[0] and ovector[1], identify the + portion of the subject string matched by the entire pattern. The next + pair is used for the first capturing subpattern, and so on. The value returned by pcre_exec() is one more than the highest numbered pair that - has been set. For example, if two substrings have been captured, the - returned value is 3. If there are no capturing subpatterns, the return + has been set. For example, if two substrings have been captured, the + returned value is 3. If there are no capturing subpatterns, the return value from a successful match is 1, indicating that just the first pair of offsets has been set. If a capturing subpattern is matched repeatedly, it is the last portion of the string that it matched that is returned. - If the vector is too small to hold all the captured substring offsets, + If the vector is too small to hold all the captured substring offsets, it is used as far as possible (up to two-thirds of its length), and the - function returns a value of zero. If the substring offsets are not of - interest, pcre_exec() may be called with ovector passed as NULL and - ovecsize as zero. However, if the pattern contains back references and - the ovector is not big enough to remember the related substrings, PCRE - has to get additional memory for use during matching. Thus it is usu- + function returns a value of zero. If the substring offsets are not of + interest, pcre_exec() may be called with ovector passed as NULL and + ovecsize as zero. However, if the pattern contains back references and + the ovector is not big enough to remember the related substrings, PCRE + has to get additional memory for use during matching. Thus it is usu- ally advisable to supply an ovector. The pcre_fullinfo() function can be used to find out how many capturing - subpatterns there are in a compiled pattern. The smallest size for - ovector that will allow for n captured substrings, in addition to the + subpatterns there are in a compiled pattern. The smallest size for + ovector that will allow for n captured substrings, in addition to the offsets of the substring matched by the whole pattern, is (n+1)*3. - It is possible for capturing subpattern number n+1 to match some part + It is possible for capturing subpattern number n+1 to match some part of the subject when subpattern n has not been used at all. For example, - if the string "abc" is matched against the pattern (a|(z))(bc) the + if the string "abc" is matched against the pattern (a|(z))(bc) the return from the function is 4, and subpatterns 1 and 3 are matched, but - 2 is not. When this happens, both values in the offset pairs corre- + 2 is not. When this happens, both values in the offset pairs corre- sponding to unused subpatterns are set to -1. - Offset values that correspond to unused subpatterns at the end of the - expression are also set to -1. For example, if the string "abc" is - matched against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are not - matched. The return from the function is 2, because the highest used + Offset values that correspond to unused subpatterns at the end of the + expression are also set to -1. For example, if the string "abc" is + matched against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are not + matched. The return from the function is 2, because the highest used capturing subpattern number is 1. However, you can refer to the offsets - for the second and third capturing subpatterns if you wish (assuming + for the second and third capturing subpatterns if you wish (assuming the vector is large enough, of course). - Some convenience functions are provided for extracting the captured + Some convenience functions are provided for extracting the captured substrings as separate strings. These are described below. Error return values from pcre_exec() - If pcre_exec() fails, it returns a negative number. The following are + If pcre_exec() fails, it returns a negative number. The following are defined in the header file: PCRE_ERROR_NOMATCH (-1) @@ -2261,7 +2266,7 @@ MATCHING A PATTERN: THE TRADITIONAL FUNCTION PCRE_ERROR_NULL (-2) - Either code or subject was passed as NULL, or ovector was NULL and + Either code or subject was passed as NULL, or ovector was NULL and ovecsize was not zero. PCRE_ERROR_BADOPTION (-3) @@ -2270,70 +2275,70 @@ MATCHING A PATTERN: THE TRADITIONAL FUNCTION PCRE_ERROR_BADMAGIC (-4) - PCRE stores a 4-byte "magic number" at the start of the compiled code, + PCRE stores a 4-byte "magic number" at the start of the compiled code, to catch the case when it is passed a junk pointer and to detect when a pattern that was compiled in an environment of one endianness is run in - an environment with the other endianness. This is the error that PCRE + an environment with the other endianness. This is the error that PCRE gives when the magic number is not present. PCRE_ERROR_UNKNOWN_OPCODE (-5) While running the pattern match, an unknown item was encountered in the - compiled pattern. This error could be caused by a bug in PCRE or by + compiled pattern. This error could be caused by a bug in PCRE or by overwriting of the compiled pattern. PCRE_ERROR_NOMEMORY (-6) - If a pattern contains back references, but the ovector that is passed + If a pattern contains back references, but the ovector that is passed to pcre_exec() is not big enough to remember the referenced substrings, - PCRE gets a block of memory at the start of matching to use for this - purpose. If the call via pcre_malloc() fails, this error is given. The + PCRE gets a block of memory at the start of matching to use for this + purpose. If the call via pcre_malloc() fails, this error is given. The memory is automatically freed at the end of matching. PCRE_ERROR_NOSUBSTRING (-7) - This error is used by the pcre_copy_substring(), pcre_get_substring(), + This error is used by the pcre_copy_substring(), pcre_get_substring(), and pcre_get_substring_list() functions (see below). It is never returned by pcre_exec(). PCRE_ERROR_MATCHLIMIT (-8) - The backtracking limit, as specified by the match_limit field in a - pcre_extra structure (or defaulted) was reached. See the description + The backtracking limit, as specified by the match_limit field in a + pcre_extra structure (or defaulted) was reached. See the description above. PCRE_ERROR_CALLOUT (-9) This error is never generated by pcre_exec() itself. It is provided for - use by callout functions that want to yield a distinctive error code. + use by callout functions that want to yield a distinctive error code. See the pcrecallout documentation for details. PCRE_ERROR_BADUTF8 (-10) - A string that contains an invalid UTF-8 byte sequence was passed as a + A string that contains an invalid UTF-8 byte sequence was passed as a subject. PCRE_ERROR_BADUTF8_OFFSET (-11) The UTF-8 byte sequence that was passed as a subject was valid, but the - value of startoffset did not point to the beginning of a UTF-8 charac- + value of startoffset did not point to the beginning of a UTF-8 charac- ter. PCRE_ERROR_PARTIAL (-12) - The subject string did not match, but it did match partially. See the + The subject string did not match, but it did match partially. See the pcrepartial documentation for details of partial matching. PCRE_ERROR_BADPARTIAL (-13) - This code is no longer in use. It was formerly returned when the - PCRE_PARTIAL option was used with a compiled pattern containing items - that were not supported for partial matching. From release 8.00 + This code is no longer in use. It was formerly returned when the + PCRE_PARTIAL option was used with a compiled pattern containing items + that were not supported for partial matching. From release 8.00 onwards, there are no restrictions on partial matching. PCRE_ERROR_INTERNAL (-14) - An unexpected internal error has occurred. This error could be caused + An unexpected internal error has occurred. This error could be caused by a bug in PCRE or by overwriting of the compiled pattern. PCRE_ERROR_BADCOUNT (-15) @@ -2343,7 +2348,7 @@ MATCHING A PATTERN: THE TRADITIONAL FUNCTION PCRE_ERROR_RECURSIONLIMIT (-21) The internal recursion limit, as specified by the match_limit_recursion - field in a pcre_extra structure (or defaulted) was reached. See the + field in a pcre_extra structure (or defaulted) was reached. See the description above. PCRE_ERROR_BADNEWLINE (-23) @@ -2366,78 +2371,78 @@ EXTRACTING CAPTURED SUBSTRINGS BY NUMBER int pcre_get_substring_list(const char *subject, int *ovector, int stringcount, const char ***listptr); - Captured substrings can be accessed directly by using the offsets - returned by pcre_exec() in ovector. For convenience, the functions + Captured substrings can be accessed directly by using the offsets + returned by pcre_exec() in ovector. For convenience, the functions pcre_copy_substring(), pcre_get_substring(), and pcre_get_sub- - string_list() are provided for extracting captured substrings as new, - separate, zero-terminated strings. These functions identify substrings - by number. The next section describes functions for extracting named + string_list() are provided for extracting captured substrings as new, + separate, zero-terminated strings. These functions identify substrings + by number. The next section describes functions for extracting named substrings. - A substring that contains a binary zero is correctly extracted and has - a further zero added on the end, but the result is not, of course, a C - string. However, you can process such a string by referring to the - length that is returned by pcre_copy_substring() and pcre_get_sub- + A substring that contains a binary zero is correctly extracted and has + a further zero added on the end, but the result is not, of course, a C + string. However, you can process such a string by referring to the + length that is returned by pcre_copy_substring() and pcre_get_sub- string(). Unfortunately, the interface to pcre_get_substring_list() is - not adequate for handling strings containing binary zeros, because the + not adequate for handling strings containing binary zeros, because the end of the final string is not independently indicated. - The first three arguments are the same for all three of these func- - tions: subject is the subject string that has just been successfully + The first three arguments are the same for all three of these func- + tions: subject is the subject string that has just been successfully matched, ovector is a pointer to the vector of integer offsets that was passed to pcre_exec(), and stringcount is the number of substrings that - were captured by the match, including the substring that matched the + were captured by the match, including the substring that matched the entire regular expression. This is the value returned by pcre_exec() if - it is greater than zero. If pcre_exec() returned zero, indicating that - it ran out of space in ovector, the value passed as stringcount should + it is greater than zero. If pcre_exec() returned zero, indicating that + it ran out of space in ovector, the value passed as stringcount should be the number of elements in the vector divided by three. - The functions pcre_copy_substring() and pcre_get_substring() extract a - single substring, whose number is given as stringnumber. A value of - zero extracts the substring that matched the entire pattern, whereas - higher values extract the captured substrings. For pcre_copy_sub- - string(), the string is placed in buffer, whose length is given by - buffersize, while for pcre_get_substring() a new block of memory is - obtained via pcre_malloc, and its address is returned via stringptr. - The yield of the function is the length of the string, not including + The functions pcre_copy_substring() and pcre_get_substring() extract a + single substring, whose number is given as stringnumber. A value of + zero extracts the substring that matched the entire pattern, whereas + higher values extract the captured substrings. For pcre_copy_sub- + string(), the string is placed in buffer, whose length is given by + buffersize, while for pcre_get_substring() a new block of memory is + obtained via pcre_malloc, and its address is returned via stringptr. + The yield of the function is the length of the string, not including the terminating zero, or one of these error codes: PCRE_ERROR_NOMEMORY (-6) - The buffer was too small for pcre_copy_substring(), or the attempt to + The buffer was too small for pcre_copy_substring(), or the attempt to get memory failed for pcre_get_substring(). PCRE_ERROR_NOSUBSTRING (-7) There is no substring whose number is stringnumber. - The pcre_get_substring_list() function extracts all available sub- - strings and builds a list of pointers to them. All this is done in a + The pcre_get_substring_list() function extracts all available sub- + strings and builds a list of pointers to them. All this is done in a single block of memory that is obtained via pcre_malloc. The address of - the memory block is returned via listptr, which is also the start of - the list of string pointers. The end of the list is marked by a NULL - pointer. The yield of the function is zero if all went well, or the + the memory block is returned via listptr, which is also the start of + the list of string pointers. The end of the list is marked by a NULL + pointer. The yield of the function is zero if all went well, or the error code PCRE_ERROR_NOMEMORY (-6) if the attempt to get the memory block failed. - When any of these functions encounter a substring that is unset, which - can happen when capturing subpattern number n+1 matches some part of - the subject, but subpattern n has not been used at all, they return an + When any of these functions encounter a substring that is unset, which + can happen when capturing subpattern number n+1 matches some part of + the subject, but subpattern n has not been used at all, they return an empty string. This can be distinguished from a genuine zero-length sub- - string by inspecting the appropriate offset in ovector, which is nega- + string by inspecting the appropriate offset in ovector, which is nega- tive for unset substrings. - The two convenience functions pcre_free_substring() and pcre_free_sub- - string_list() can be used to free the memory returned by a previous + The two convenience functions pcre_free_substring() and pcre_free_sub- + string_list() can be used to free the memory returned by a previous call of pcre_get_substring() or pcre_get_substring_list(), respec- - tively. They do nothing more than call the function pointed to by - pcre_free, which of course could be called directly from a C program. - However, PCRE is used in some situations where it is linked via a spe- - cial interface to another programming language that cannot use - pcre_free directly; it is for these cases that the functions are pro- + tively. They do nothing more than call the function pointed to by + pcre_free, which of course could be called directly from a C program. + However, PCRE is used in some situations where it is linked via a spe- + cial interface to another programming language that cannot use + pcre_free directly; it is for these cases that the functions are pro- vided. @@ -2456,7 +2461,7 @@ EXTRACTING CAPTURED SUBSTRINGS BY NAME int stringcount, const char *stringname, const char **stringptr); - To extract a substring by name, you first have to find associated num- + To extract a substring by name, you first have to find associated num- ber. For example, for this pattern (a+)b(?<xxx>\d+)... @@ -2465,35 +2470,35 @@ EXTRACTING CAPTURED SUBSTRINGS BY NAME be unique (PCRE_DUPNAMES was not set), you can find the number from the name by calling pcre_get_stringnumber(). The first argument is the com- piled pattern, and the second is the name. The yield of the function is - the subpattern number, or PCRE_ERROR_NOSUBSTRING (-7) if there is no + the subpattern number, or PCRE_ERROR_NOSUBSTRING (-7) if there is no subpattern of that name. Given the number, you can extract the substring directly, or use one of the functions described in the previous section. For convenience, there are also two functions that do the whole job. - Most of the arguments of pcre_copy_named_substring() and - pcre_get_named_substring() are the same as those for the similarly - named functions that extract by number. As these are described in the - previous section, they are not re-described here. There are just two + Most of the arguments of pcre_copy_named_substring() and + pcre_get_named_substring() are the same as those for the similarly + named functions that extract by number. As these are described in the + previous section, they are not re-described here. There are just two differences: - First, instead of a substring number, a substring name is given. Sec- + First, instead of a substring number, a substring name is given. Sec- ond, there is an extra argument, given at the start, which is a pointer - to the compiled pattern. This is needed in order to gain access to the + to the compiled pattern. This is needed in order to gain access to the name-to-number translation table. - These functions call pcre_get_stringnumber(), and if it succeeds, they - then call pcre_copy_substring() or pcre_get_substring(), as appropri- - ate. NOTE: If PCRE_DUPNAMES is set and there are duplicate names, the + These functions call pcre_get_stringnumber(), and if it succeeds, they + then call pcre_copy_substring() or pcre_get_substring(), as appropri- + ate. NOTE: If PCRE_DUPNAMES is set and there are duplicate names, the behaviour may not be what you want (see the next section). Warning: If the pattern uses the (?| feature to set up multiple subpat- - terns with the same number, as described in the section on duplicate - subpattern numbers in the pcrepattern page, you cannot use names to - distinguish the different subpatterns, because names are not included - in the compiled code. The matching process uses only numbers. For this - reason, the use of different names for subpatterns of the same number + terns with the same number, as described in the section on duplicate + subpattern numbers in the pcrepattern page, you cannot use names to + distinguish the different subpatterns, because names are not included + in the compiled code. The matching process uses only numbers. For this + reason, the use of different names for subpatterns of the same number causes an error at compile time. @@ -2502,51 +2507,51 @@ DUPLICATE SUBPATTERN NAMES int pcre_get_stringtable_entries(const pcre *code, const char *name, char **first, char **last); - When a pattern is compiled with the PCRE_DUPNAMES option, names for - subpatterns are not required to be unique. (Duplicate names are always - allowed for subpatterns with the same number, created by using the (?| - feature. Indeed, if such subpatterns are named, they are required to + When a pattern is compiled with the PCRE_DUPNAMES option, names for + subpatterns are not required to be unique. (Duplicate names are always + allowed for subpatterns with the same number, created by using the (?| + feature. Indeed, if such subpatterns are named, they are required to use the same names.) Normally, patterns with duplicate names are such that in any one match, - only one of the named subpatterns participates. An example is shown in + only one of the named subpatterns participates. An example is shown in the pcrepattern documentation. - When duplicates are present, pcre_copy_named_substring() and - pcre_get_named_substring() return the first substring corresponding to - the given name that is set. If none are set, PCRE_ERROR_NOSUBSTRING - (-7) is returned; no data is returned. The pcre_get_stringnumber() - function returns one of the numbers that are associated with the name, + When duplicates are present, pcre_copy_named_substring() and + pcre_get_named_substring() return the first substring corresponding to + the given name that is set. If none are set, PCRE_ERROR_NOSUBSTRING + (-7) is returned; no data is returned. The pcre_get_stringnumber() + function returns one of the numbers that are associated with the name, but it is not defined which it is. - If you want to get full details of all captured substrings for a given - name, you must use the pcre_get_stringtable_entries() function. The + If you want to get full details of all captured substrings for a given + name, you must use the pcre_get_stringtable_entries() function. The first argument is the compiled pattern, and the second is the name. The - third and fourth are pointers to variables which are updated by the + third and fourth are pointers to variables which are updated by the function. After it has run, they point to the first and last entries in - the name-to-number table for the given name. The function itself - returns the length of each entry, or PCRE_ERROR_NOSUBSTRING (-7) if - there are none. The format of the table is described above in the sec- - tion entitled Information about a pattern. Given all the relevant - entries for the name, you can extract each of their numbers, and hence + the name-to-number table for the given name. The function itself + returns the length of each entry, or PCRE_ERROR_NOSUBSTRING (-7) if + there are none. The format of the table is described above in the sec- + tion entitled Information about a pattern. Given all the relevant + entries for the name, you can extract each of their numbers, and hence the captured data, if any. FINDING ALL POSSIBLE MATCHES - The traditional matching function uses a similar algorithm to Perl, + The traditional matching function uses a similar algorithm to Perl, which stops when it finds the first match, starting at a given point in - the subject. If you want to find all possible matches, or the longest - possible match, consider using the alternative matching function (see - below) instead. If you cannot use the alternative function, but still - need to find all possible matches, you can kludge it up by making use + the subject. If you want to find all possible matches, or the longest + possible match, consider using the alternative matching function (see + below) instead. If you cannot use the alternative function, but still + need to find all possible matches, you can kludge it up by making use of the callout facility, which is described in the pcrecallout documen- tation. What you have to do is to insert a callout right at the end of the pat- - tern. When your callout function is called, extract and save the cur- - rent matched substring. Then return 1, which forces pcre_exec() to - backtrack and try other alternatives. Ultimately, when it runs out of + tern. When your callout function is called, extract and save the cur- + rent matched substring. Then return 1, which forces pcre_exec() to + backtrack and try other alternatives. Ultimately, when it runs out of matches, pcre_exec() will yield PCRE_ERROR_NOMATCH. @@ -2557,26 +2562,26 @@ MATCHING A PATTERN: THE ALTERNATIVE FUNCTION int options, int *ovector, int ovecsize, int *workspace, int wscount); - The function pcre_dfa_exec() is called to match a subject string - against a compiled pattern, using a matching algorithm that scans the - subject string just once, and does not backtrack. This has different - characteristics to the normal algorithm, and is not compatible with - Perl. Some of the features of PCRE patterns are not supported. Never- - theless, there are times when this kind of matching can be useful. For - a discussion of the two matching algorithms, and a list of features - that pcre_dfa_exec() does not support, see the pcrematching documenta- + The function pcre_dfa_exec() is called to match a subject string + against a compiled pattern, using a matching algorithm that scans the + subject string just once, and does not backtrack. This has different + characteristics to the normal algorithm, and is not compatible with + Perl. Some of the features of PCRE patterns are not supported. Never- + theless, there are times when this kind of matching can be useful. For + a discussion of the two matching algorithms, and a list of features + that pcre_dfa_exec() does not support, see the pcrematching documenta- tion. - The arguments for the pcre_dfa_exec() function are the same as for + The arguments for the pcre_dfa_exec() function are the same as for pcre_exec(), plus two extras. The ovector argument is used in a differ- - ent way, and this is described below. The other common arguments are - used in the same way as for pcre_exec(), so their description is not + ent way, and this is described below. The other common arguments are + used in the same way as for pcre_exec(), so their description is not repeated here. - The two additional arguments provide workspace for the function. The - workspace vector should contain at least 20 elements. It is used for + The two additional arguments provide workspace for the function. The + workspace vector should contain at least 20 elements. It is used for keeping track of multiple paths through the pattern tree. More - workspace will be needed for patterns and subjects where there are a + workspace will be needed for patterns and subjects where there are a lot of potential matches. Here is an example of a simple call to pcre_dfa_exec(): @@ -2598,52 +2603,52 @@ MATCHING A PATTERN: THE ALTERNATIVE FUNCTION Option bits for pcre_dfa_exec() - The unused bits of the options argument for pcre_dfa_exec() must be - zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NEW- + The unused bits of the options argument for pcre_dfa_exec() must be + zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NEW- LINE_xxx, PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL_HARD, PCRE_PAR- - TIAL_SOFT, PCRE_DFA_SHORTEST, and PCRE_DFA_RESTART. All but the last - four of these are exactly the same as for pcre_exec(), so their + TIAL_SOFT, PCRE_DFA_SHORTEST, and PCRE_DFA_RESTART. All but the last + four of these are exactly the same as for pcre_exec(), so their description is not repeated here. PCRE_PARTIAL_HARD PCRE_PARTIAL_SOFT - These have the same general effect as they do for pcre_exec(), but the - details are slightly different. When PCRE_PARTIAL_HARD is set for - pcre_dfa_exec(), it returns PCRE_ERROR_PARTIAL if the end of the sub- - ject is reached and there is still at least one matching possibility + These have the same general effect as they do for pcre_exec(), but the + details are slightly different. When PCRE_PARTIAL_HARD is set for + pcre_dfa_exec(), it returns PCRE_ERROR_PARTIAL if the end of the sub- + ject is reached and there is still at least one matching possibility that requires additional characters. This happens even if some complete matches have also been found. When PCRE_PARTIAL_SOFT is set, the return code PCRE_ERROR_NOMATCH is converted into PCRE_ERROR_PARTIAL if the end - of the subject is reached, there have been no complete matches, but - there is still at least one matching possibility. The portion of the - string that was inspected when the longest partial match was found is + of the subject is reached, there have been no complete matches, but + there is still at least one matching possibility. The portion of the + string that was inspected when the longest partial match was found is set as the first matching string in both cases. PCRE_DFA_SHORTEST - Setting the PCRE_DFA_SHORTEST option causes the matching algorithm to + Setting the PCRE_DFA_SHORTEST option causes the matching algorithm to stop as soon as it has found one match. Because of the way the alterna- - tive algorithm works, this is necessarily the shortest possible match + tive algorithm works, this is necessarily the shortest possible match at the first possible matching point in the subject string. PCRE_DFA_RESTART When pcre_dfa_exec() returns a partial match, it is possible to call it - again, with additional subject characters, and have it continue with - the same match. The PCRE_DFA_RESTART option requests this action; when - it is set, the workspace and wscount options must reference the same - vector as before because data about the match so far is left in them + again, with additional subject characters, and have it continue with + the same match. The PCRE_DFA_RESTART option requests this action; when + it is set, the workspace and wscount options must reference the same + vector as before because data about the match so far is left in them after a partial match. There is more discussion of this facility in the pcrepartial documentation. Successful returns from pcre_dfa_exec() - When pcre_dfa_exec() succeeds, it may have matched more than one sub- + When pcre_dfa_exec() succeeds, it may have matched more than one sub- string in the subject. Note, however, that all the matches from one run - of the function start at the same point in the subject. The shorter - matches are all initial substrings of the longer matches. For example, + of the function start at the same point in the subject. The shorter + matches are all initial substrings of the longer matches. For example, if the pattern <.*> @@ -2658,61 +2663,61 @@ MATCHING A PATTERN: THE ALTERNATIVE FUNCTION <something> <something else> <something> <something else> <something further> - On success, the yield of the function is a number greater than zero, - which is the number of matched substrings. The substrings themselves - are returned in ovector. Each string uses two elements; the first is - the offset to the start, and the second is the offset to the end. In - fact, all the strings have the same start offset. (Space could have - been saved by giving this only once, but it was decided to retain some - compatibility with the way pcre_exec() returns data, even though the + On success, the yield of the function is a number greater than zero, + which is the number of matched substrings. The substrings themselves + are returned in ovector. Each string uses two elements; the first is + the offset to the start, and the second is the offset to the end. In + fact, all the strings have the same start offset. (Space could have + been saved by giving this only once, but it was decided to retain some + compatibility with the way pcre_exec() returns data, even though the meaning of the strings is different.) The strings are returned in reverse order of length; that is, the long- - est matching string is given first. If there were too many matches to - fit into ovector, the yield of the function is zero, and the vector is + est matching string is given first. If there were too many matches to + fit into ovector, the yield of the function is zero, and the vector is filled with the longest matches. Error returns from pcre_dfa_exec() - The pcre_dfa_exec() function returns a negative number when it fails. - Many of the errors are the same as for pcre_exec(), and these are - described above. There are in addition the following errors that are + The pcre_dfa_exec() function returns a negative number when it fails. + Many of the errors are the same as for pcre_exec(), and these are + described above. There are in addition the following errors that are specific to pcre_dfa_exec(): PCRE_ERROR_DFA_UITEM (-16) - This return is given if pcre_dfa_exec() encounters an item in the pat- - tern that it does not support, for instance, the use of \C or a back + This return is given if pcre_dfa_exec() encounters an item in the pat- + tern that it does not support, for instance, the use of \C or a back reference. PCRE_ERROR_DFA_UCOND (-17) - This return is given if pcre_dfa_exec() encounters a condition item - that uses a back reference for the condition, or a test for recursion + This return is given if pcre_dfa_exec() encounters a condition item + that uses a back reference for the condition, or a test for recursion in a specific group. These are not supported. PCRE_ERROR_DFA_UMLIMIT (-18) - This return is given if pcre_dfa_exec() is called with an extra block + This return is given if pcre_dfa_exec() is called with an extra block that contains a setting of the match_limit field. This is not supported (it is meaningless). PCRE_ERROR_DFA_WSSIZE (-19) - This return is given if pcre_dfa_exec() runs out of space in the + This return is given if pcre_dfa_exec() runs out of space in the workspace vector. PCRE_ERROR_DFA_RECURSE (-20) - When a recursive subpattern is processed, the matching function calls - itself recursively, using private vectors for ovector and workspace. - This error is given if the output vector is not large enough. This + When a recursive subpattern is processed, the matching function calls + itself recursively, using private vectors for ovector and workspace. + This error is given if the output vector is not large enough. This should be extremely rare, as a vector of size 1000 is used. SEE ALSO - pcrebuild(3), pcrecallout(3), pcrecpp(3)(3), pcrematching(3), pcrepar- + pcrebuild(3), pcrecallout(3), pcrecpp(3)(3), pcrematching(3), pcrepar- tial(3), pcreposix(3), pcreprecompile(3), pcresample(3), pcrestack(3). @@ -2725,11 +2730,11 @@ AUTHOR REVISION - Last updated: 26 March 2010 + Last updated: 03 May 2010 Copyright (c) 1997-2010 University of Cambridge. ------------------------------------------------------------------------------ - - + + PCRECALLOUT(3) PCRECALLOUT(3) @@ -2909,8 +2914,8 @@ REVISION Last updated: 29 September 2009 Copyright (c) 1997-2009 University of Cambridge. ------------------------------------------------------------------------------ - - + + PCRECOMPAT(3) PCRECOMPAT(3) @@ -3066,8 +3071,8 @@ REVISION Last updated: 04 October 2009 Copyright (c) 1997-2009 University of Cambridge. ------------------------------------------------------------------------------ - - + + PCREPATTERN(3) PCREPATTERN(3) @@ -3146,11 +3151,13 @@ NEWLINE CONVENTIONS and that they must be in upper case. If more than one of them is present, the last one is used. - The newline convention does not affect what the \R escape sequence - matches. By default, this is any Unicode newline sequence, for Perl - compatibility. However, this can be changed; see the description of \R - in the section entitled "Newline sequences" below. A change of \R set- - ting can be combined with a change of newline convention. + The newline convention affects the interpretation of the dot metachar- + acter when PCRE_DOTALL is not set, and also the behaviour of \N. How- + ever, it does not affect what the \R escape sequence matches. By + default, this is any Unicode newline sequence, for Perl compatibility. + However, this can be changed; see the description of \R in the section + entitled "Newline sequences" below. A change of \R setting can be com- + bined with a change of newline convention. CHARACTERS AND METACHARACTERS @@ -3332,9 +3339,11 @@ BACKSLASH All the sequences that define a single character value can be used both inside and outside character classes. In addition, inside a character class, the sequence \b is interpreted as the backspace character (hex - 08), and the sequences \R and \X are interpreted as the characters "R" - and "X", respectively. Outside a character class, these sequences have - different meanings (see below). + 08). The sequences \B, \N, \R, and \X are not special inside a charac- + ter class. Like any other unrecognized escape sequences, they are + treated as the literal characters "B", "N", "R", and "X" by default, + but cause an error if the PCRE_EXTRA option is set. Outside a character + class, these sequences have different meanings. Absolute and relative back references @@ -3354,8 +3363,7 @@ BACKSLASH Generic character types - Another use of backslash is for specifying generic character types. The - following are always recognized: + Another use of backslash is for specifying generic character types: \d any decimal digit \D any character that is not a decimal digit @@ -3368,30 +3376,34 @@ BACKSLASH \w any "word" character \W any "non-word" character - Each pair of escape sequences partitions the complete set of characters - into two disjoint sets. Any given character matches one, and only one, - of each pair. + There is also the single sequence \N, which matches a non-newline char- + acter. This is the same as the "." metacharacter when PCRE_DOTALL is + not set. + + Each pair of lower and upper case escape sequences partitions the com- + plete set of characters into two disjoint sets. Any given character + matches one, and only one, of each pair. These character type sequences can appear both inside and outside char- - acter classes. They each match one character of the appropriate type. - If the current matching point is at the end of the subject string, all + acter classes. They each match one character of the appropriate type. + If the current matching point is at the end of the subject string, all of them fail, since there is no character to match. - For compatibility with Perl, \s does not match the VT character (code - 11). This makes it different from the the POSIX "space" class. The \s - characters are HT (9), LF (10), FF (12), CR (13), and space (32). If + For compatibility with Perl, \s does not match the VT character (code + 11). This makes it different from the the POSIX "space" class. The \s + characters are HT (9), LF (10), FF (12), CR (13), and space (32). If "use locale;" is included in a Perl script, \s may match the VT charac- ter. In PCRE, it never does. - In UTF-8 mode, characters with values greater than 128 never match \d, + In UTF-8 mode, characters with values greater than 128 never match \d, \s, or \w, and always match \D, \S, and \W. This is true even when Uni- - code character property support is available. These sequences retain + code character property support is available. These sequences retain their original meanings from before UTF-8 support was available, mainly - for efficiency reasons. Note that this also affects \b, because it is + for efficiency reasons. Note that this also affects \b, because it is defined in terms of \w and \W. The sequences \h, \H, \v, and \V are Perl 5.10 features. In contrast to - the other sequences, these do match certain high-valued codepoints in + the other sequences, these do match certain high-valued codepoints in UTF-8 mode. The horizontal space characters are: U+0009 Horizontal tab @@ -3425,75 +3437,78 @@ BACKSLASH U+2029 Paragraph separator A "word" character is an underscore or any character less than 256 that - is a letter or digit. The definition of letters and digits is con- - trolled by PCRE's low-valued character tables, and may vary if locale- - specific matching is taking place (see "Locale support" in the pcreapi - page). For example, in a French locale such as "fr_FR" in Unix-like - systems, or "french" in Windows, some character codes greater than 128 - are used for accented letters, and these are matched by \w. The use of + is a letter or digit. The definition of letters and digits is con- + trolled by PCRE's low-valued character tables, and may vary if locale- + specific matching is taking place (see "Locale support" in the pcreapi + page). For example, in a French locale such as "fr_FR" in Unix-like + systems, or "french" in Windows, some character codes greater than 128 + are used for accented letters, and these are matched by \w. The use of locales with Unicode is discouraged. Newline sequences - Outside a character class, by default, the escape sequence \R matches + Outside a character class, by default, the escape sequence \R matches any Unicode newline sequence. This is a Perl 5.10 feature. In non-UTF-8 mode \R is equivalent to the following: (?>\r\n|\n|\x0b|\f|\r|\x85) - This is an example of an "atomic group", details of which are given + This is an example of an "atomic group", details of which are given below. This particular group matches either the two-character sequence - CR followed by LF, or one of the single characters LF (linefeed, + CR followed by LF, or one of the single characters LF (linefeed, U+000A), VT (vertical tab, U+000B), FF (formfeed, U+000C), CR (carriage return, U+000D), or NEL (next line, U+0085). The two-character sequence is treated as a single unit that cannot be split. - In UTF-8 mode, two additional characters whose codepoints are greater + In UTF-8 mode, two additional characters whose codepoints are greater than 255 are added: LS (line separator, U+2028) and PS (paragraph sepa- - rator, U+2029). Unicode character property support is not needed for + rator, U+2029). Unicode character property support is not needed for these characters to be recognized. It is possible to restrict \R to match only CR, LF, or CRLF (instead of - the complete set of Unicode line endings) by setting the option + the complete set of Unicode line endings) by setting the option PCRE_BSR_ANYCRLF either at compile time or when the pattern is matched. (BSR is an abbrevation for "backslash R".) This can be made the default - when PCRE is built; if this is the case, the other behaviour can be - requested via the PCRE_BSR_UNICODE option. It is also possible to - specify these settings by starting a pattern string with one of the + when PCRE is built; if this is the case, the other behaviour can be + requested via the PCRE_BSR_UNICODE option. It is also possible to + specify these settings by starting a pattern string with one of the following sequences: (*BSR_ANYCRLF) CR, LF, or CRLF only (*BSR_UNICODE) any Unicode newline sequence - These override the default and the options given to pcre_compile() or - pcre_compile2(), but they can be overridden by options given to + These override the default and the options given to pcre_compile() or + pcre_compile2(), but they can be overridden by options given to pcre_exec() or pcre_dfa_exec(). Note that these special settings, which - are not Perl-compatible, are recognized only at the very start of a - pattern, and that they must be in upper case. If more than one of them + are not Perl-compatible, are recognized only at the very start of a + pattern, and that they must be in upper case. If more than one of them is present, the last one is used. They can be combined with a change of newline convention, for example, a pattern can start with: (*ANY)(*BSR_ANYCRLF) - Inside a character class, \R matches the letter "R". + Inside a character class, \R is treated as an unrecognized escape + sequence, and so matches the letter "R" by default, but causes an error + if PCRE_EXTRA is set. Unicode character properties When PCRE is built with Unicode character property support, three addi- - tional escape sequences that match characters with specific properties - are available. When not in UTF-8 mode, these sequences are of course - limited to testing characters whose codepoints are less than 256, but + tional escape sequences that match characters with specific properties + are available. When not in UTF-8 mode, these sequences are of course + limited to testing characters whose codepoints are less than 256, but they do work in this mode. The extra escape sequences are: \p{xx} a character with the xx property \P{xx} a character without the xx property \X an extended Unicode sequence - The property names represented by xx above are limited to the Unicode - script names, the general category properties, and "Any", which matches - any character (including newline). Other properties such as "InMusical- - Symbols" are not currently supported by PCRE. Note that \P{Any} does - not match any characters, so always causes a match failure. + The property names represented by xx above are limited to the Unicode + script names, the general category properties, "Any", which matches any + character (including newline), and some special PCRE properties + (described in the next section). Other Perl properties such as "InMu- + sicalSymbols" are not currently supported by PCRE. Note that \P{Any} + does not match any characters, so always causes a match failure. Sets of Unicode characters are defined as belonging to certain scripts. A character from one of these sets can be matched using a script name. @@ -3520,14 +3535,15 @@ BACKSLASH Tai_Tham, Tai_Viet, Tamil, Telugu, Thaana, Thai, Tibetan, Tifinagh, Ugaritic, Vai, Yi. - Each character has exactly one general category property, specified by - a two-letter abbreviation. For compatibility with Perl, negation can be - specified by including a circumflex between the opening brace and the - property name. For example, \p{^Lu} is the same as \P{Lu}. + Each character has exactly one Unicode general category property, spec- + ified by a two-letter abbreviation. For compatibility with Perl, nega- + tion can be specified by including a circumflex between the opening + brace and the property name. For example, \p{^Lu} is the same as + \P{Lu}. If only one letter is specified with \p or \P, it includes all the gen- - eral category properties that start with that letter. In this case, in - the absence of negation, the curly brackets in the escape sequence are + eral category properties that start with that letter. In this case, in + the absence of negation, the curly brackets in the escape sequence are optional; these two examples have the same effect: \p{L} @@ -3579,44 +3595,62 @@ BACKSLASH Zp Paragraph separator Zs Space separator - The special property L& is also supported: it matches a character that - has the Lu, Ll, or Lt property, in other words, a letter that is not + The special property L& is also supported: it matches a character that + has the Lu, Ll, or Lt property, in other words, a letter that is not classified as a modifier or "other". - The Cs (Surrogate) property applies only to characters in the range - U+D800 to U+DFFF. Such characters are not valid in UTF-8 strings (see + The Cs (Surrogate) property applies only to characters in the range + U+D800 to U+DFFF. Such characters are not valid in UTF-8 strings (see RFC 3629) and so cannot be tested by PCRE, unless UTF-8 validity check- - ing has been turned off (see the discussion of PCRE_NO_UTF8_CHECK in + ing has been turned off (see the discussion of PCRE_NO_UTF8_CHECK in the pcreapi page). Perl does not support the Cs property. - The long synonyms for property names that Perl supports (such as - \p{Letter}) are not supported by PCRE, nor is it permitted to prefix + The long synonyms for property names that Perl supports (such as + \p{Letter}) are not supported by PCRE, nor is it permitted to prefix any of these properties with "Is". No character that is in the Unicode table has the Cn (unassigned) prop- erty. Instead, this property is assumed for any code point that is not in the Unicode table. - Specifying caseless matching does not affect these escape sequences. + Specifying caseless matching does not affect these escape sequences. For example, \p{Lu} always matches only upper case letters. - The \X escape matches any number of Unicode characters that form an + The \X escape matches any number of Unicode characters that form an extended Unicode sequence. \X is equivalent to (?>\PM\pM*) - That is, it matches a character without the "mark" property, followed - by zero or more characters with the "mark" property, and treats the - sequence as an atomic group (see below). Characters with the "mark" - property are typically accents that affect the preceding character. - None of them have codepoints less than 256, so in non-UTF-8 mode \X + That is, it matches a character without the "mark" property, followed + by zero or more characters with the "mark" property, and treats the + sequence as an atomic group (see below). Characters with the "mark" + property are typically accents that affect the preceding character. + None of them have codepoints less than 256, so in non-UTF-8 mode \X matches any one character. - Matching characters by Unicode property is not fast, because PCRE has - to search a structure that contains data for over fifteen thousand + Matching characters by Unicode property is not fast, because PCRE has + to search a structure that contains data for over fifteen thousand characters. That is why the traditional escape sequences such as \d and \w do not use Unicode properties in PCRE. + PCRE's additional properties + + As well as the standard Unicode properties described in the previous + section, PCRE supports four more that make it possible to convert tra- + ditional escape sequences such as \w and \s and POSIX character classes + to use Unicode properties. These are: + + Xan Any alphanumeric character + Xps Any POSIX space character + Xsp Any Perl space character + Xwd Any Perl "word" character + + Xan matches characters that have either the L (letter) or the N (num- + ber) property. Xps matches the characters tab, linefeed, vertical tab, + formfeed, or carriage return, and any other character that has the Z + (separator) property. Xsp is the same as Xps, except that vertical tab + is excluded. Xwd matches the same characters as Xan, plus underscore. + Resetting the match start The escape sequence \K, which is a Perl 5.10 feature, causes any previ- @@ -3656,44 +3690,47 @@ BACKSLASH \z matches only at the end of the subject \G matches at the first matching position in the subject - These assertions may not appear in character classes (but note that \b - has a different meaning, namely the backspace character, inside a char- - acter class). + Inside a character class, \b has a different meaning; it matches the + backspace character. If any other of these assertions appears in a + character class, by default it matches the corresponding literal char- + acter (for example, \B matches the letter B). However, if the + PCRE_EXTRA option is set, an "invalid escape sequence" error is gener- + ated instead. - A word boundary is a position in the subject string where the current - character and the previous character do not both match \w or \W (i.e. - one matches \w and the other matches \W), or the start or end of the + A word boundary is a position in the subject string where the current + character and the previous character do not both match \w or \W (i.e. + one matches \w and the other matches \W), or the start or end of the string if the first or last character matches \w, respectively. Neither - PCRE nor Perl has a separte "start of word" or "end of word" metase- - quence. However, whatever follows \b normally determines which it is. + PCRE nor Perl has a separte "start of word" or "end of word" metase- + quence. However, whatever follows \b normally determines which it is. For example, the fragment \ba matches "a" at the start of a word. - The \A, \Z, and \z assertions differ from the traditional circumflex + The \A, \Z, and \z assertions differ from the traditional circumflex and dollar (described in the next section) in that they only ever match - at the very start and end of the subject string, whatever options are - set. Thus, they are independent of multiline mode. These three asser- + at the very start and end of the subject string, whatever options are + set. Thus, they are independent of multiline mode. These three asser- tions are not affected by the PCRE_NOTBOL or PCRE_NOTEOL options, which - affect only the behaviour of the circumflex and dollar metacharacters. - However, if the startoffset argument of pcre_exec() is non-zero, indi- + affect only the behaviour of the circumflex and dollar metacharacters. + However, if the startoffset argument of pcre_exec() is non-zero, indi- cating that matching is to start at a point other than the beginning of - the subject, \A can never match. The difference between \Z and \z is + the subject, \A can never match. The difference between \Z and \z is that \Z matches before a newline at the end of the string as well as at the very end, whereas \z matches only at the end. - The \G assertion is true only when the current matching position is at - the start point of the match, as specified by the startoffset argument - of pcre_exec(). It differs from \A when the value of startoffset is - non-zero. By calling pcre_exec() multiple times with appropriate argu- + The \G assertion is true only when the current matching position is at + the start point of the match, as specified by the startoffset argument + of pcre_exec(). It differs from \A when the value of startoffset is + non-zero. By calling pcre_exec() multiple times with appropriate argu- ments, you can mimic Perl's /g option, and it is in this kind of imple- mentation where \G can be useful. - Note, however, that PCRE's interpretation of \G, as the start of the + Note, however, that PCRE's interpretation of \G, as the start of the current match, is subtly different from Perl's, which defines it as the - end of the previous match. In Perl, these can be different when the - previously matched string was empty. Because PCRE does just one match + end of the previous match. In Perl, these can be different when the + previously matched string was empty. Because PCRE does just one match at a time, it cannot reproduce this behaviour. - If all the alternatives of a pattern begin with \G, the expression is + If all the alternatives of a pattern begin with \G, the expression is anchored to the starting match position, and the "anchored" flag is set in the compiled regular expression. @@ -3701,90 +3738,94 @@ BACKSLASH CIRCUMFLEX AND DOLLAR Outside a character class, in the default matching mode, the circumflex - character is an assertion that is true only if the current matching - point is at the start of the subject string. If the startoffset argu- - ment of pcre_exec() is non-zero, circumflex can never match if the - PCRE_MULTILINE option is unset. Inside a character class, circumflex + character is an assertion that is true only if the current matching + point is at the start of the subject string. If the startoffset argu- + ment of pcre_exec() is non-zero, circumflex can never match if the + PCRE_MULTILINE option is unset. Inside a character class, circumflex has an entirely different meaning (see below). - Circumflex need not be the first character of the pattern if a number - of alternatives are involved, but it should be the first thing in each - alternative in which it appears if the pattern is ever to match that - branch. If all possible alternatives start with a circumflex, that is, - if the pattern is constrained to match only at the start of the sub- - ject, it is said to be an "anchored" pattern. (There are also other + Circumflex need not be the first character of the pattern if a number + of alternatives are involved, but it should be the first thing in each + alternative in which it appears if the pattern is ever to match that + branch. If all possible alternatives start with a circumflex, that is, + if the pattern is constrained to match only at the start of the sub- + ject, it is said to be an "anchored" pattern. (There are also other constructs that can cause a pattern to be anchored.) - A dollar character is an assertion that is true only if the current - matching point is at the end of the subject string, or immediately + A dollar character is an assertion that is true only if the current + matching point is at the end of the subject string, or immediately before a newline at the end of the string (by default). Dollar need not - be the last character of the pattern if a number of alternatives are - involved, but it should be the last item in any branch in which it + be the last character of the pattern if a number of alternatives are + involved, but it should be the last item in any branch in which it appears. Dollar has no special meaning in a character class. - The meaning of dollar can be changed so that it matches only at the - very end of the string, by setting the PCRE_DOLLAR_ENDONLY option at + The meaning of dollar can be changed so that it matches only at the + very end of the string, by setting the PCRE_DOLLAR_ENDONLY option at compile time. This does not affect the \Z assertion. The meanings of the circumflex and dollar characters are changed if the - PCRE_MULTILINE option is set. When this is the case, a circumflex - matches immediately after internal newlines as well as at the start of - the subject string. It does not match after a newline that ends the - string. A dollar matches before any newlines in the string, as well as - at the very end, when PCRE_MULTILINE is set. When newline is specified - as the two-character sequence CRLF, isolated CR and LF characters do + PCRE_MULTILINE option is set. When this is the case, a circumflex + matches immediately after internal newlines as well as at the start of + the subject string. It does not match after a newline that ends the + string. A dollar matches before any newlines in the string, as well as + at the very end, when PCRE_MULTILINE is set. When newline is specified + as the two-character sequence CRLF, isolated CR and LF characters do not indicate newlines. - For example, the pattern /^abc$/ matches the subject string "def\nabc" - (where \n represents a newline) in multiline mode, but not otherwise. - Consequently, patterns that are anchored in single line mode because - all branches start with ^ are not anchored in multiline mode, and a - match for circumflex is possible when the startoffset argument of - pcre_exec() is non-zero. The PCRE_DOLLAR_ENDONLY option is ignored if + For example, the pattern /^abc$/ matches the subject string "def\nabc" + (where \n represents a newline) in multiline mode, but not otherwise. + Consequently, patterns that are anchored in single line mode because + all branches start with ^ are not anchored in multiline mode, and a + match for circumflex is possible when the startoffset argument of + pcre_exec() is non-zero. The PCRE_DOLLAR_ENDONLY option is ignored if PCRE_MULTILINE is set. - Note that the sequences \A, \Z, and \z can be used to match the start - and end of the subject in both modes, and if all branches of a pattern - start with \A it is always anchored, whether or not PCRE_MULTILINE is + Note that the sequences \A, \Z, and \z can be used to match the start + and end of the subject in both modes, and if all branches of a pattern + start with \A it is always anchored, whether or not PCRE_MULTILINE is set. -FULL STOP (PERIOD, DOT) +FULL STOP (PERIOD, DOT) AND \N Outside a character class, a dot in the pattern matches any one charac- - ter in the subject string except (by default) a character that signi- - fies the end of a line. In UTF-8 mode, the matched character may be + ter in the subject string except (by default) a character that signi- + fies the end of a line. In UTF-8 mode, the matched character may be more than one byte long. - When a line ending is defined as a single character, dot never matches - that character; when the two-character sequence CRLF is used, dot does - not match CR if it is immediately followed by LF, but otherwise it - matches all characters (including isolated CRs and LFs). When any Uni- - code line endings are being recognized, dot does not match CR or LF or + When a line ending is defined as a single character, dot never matches + that character; when the two-character sequence CRLF is used, dot does + not match CR if it is immediately followed by LF, but otherwise it + matches all characters (including isolated CRs and LFs). When any Uni- + code line endings are being recognized, dot does not match CR or LF or any of the other line ending characters. - The behaviour of dot with regard to newlines can be changed. If the - PCRE_DOTALL option is set, a dot matches any one character, without + The behaviour of dot with regard to newlines can be changed. If the + PCRE_DOTALL option is set, a dot matches any one character, without exception. If the two-character sequence CRLF is present in the subject string, it takes two dots to match it. - The handling of dot is entirely independent of the handling of circum- - flex and dollar, the only relationship being that they both involve + The handling of dot is entirely independent of the handling of circum- + flex and dollar, the only relationship being that they both involve newlines. Dot has no special meaning in a character class. + The escape sequence \N always behaves as a dot does when PCRE_DOTALL is + not set. In other words, it matches any one character except one that + signifies the end of a line. + MATCHING A SINGLE BYTE Outside a character class, the escape sequence \C matches any one byte, - both in and out of UTF-8 mode. Unlike a dot, it always matches any - line-ending characters. The feature is provided in Perl in order to - match individual bytes in UTF-8 mode. Because it breaks up UTF-8 char- - acters into individual bytes, what remains in the string may be a mal- - formed UTF-8 string. For this reason, the \C escape sequence is best + both in and out of UTF-8 mode. Unlike a dot, it always matches any + line-ending characters. The feature is provided in Perl in order to + match individual bytes in UTF-8 mode. Because it breaks up UTF-8 char- + acters into individual bytes, what remains in the string may be a mal- + formed UTF-8 string. For this reason, the \C escape sequence is best avoided. - PCRE does not allow \C to appear in lookbehind assertions (described - below), because in UTF-8 mode this would make it impossible to calcu- + PCRE does not allow \C to appear in lookbehind assertions (described + below), because in UTF-8 mode this would make it impossible to calcu- late the length of the lookbehind. @@ -3794,97 +3835,97 @@ SQUARE BRACKETS AND CHARACTER CLASSES closing square bracket. A closing square bracket on its own is not spe- cial by default. However, if the PCRE_JAVASCRIPT_COMPAT option is set, a lone closing square bracket causes a compile-time error. If a closing - square bracket is required as a member of the class, it should be the - first data character in the class (after an initial circumflex, if + square bracket is required as a member of the class, it should be the + first data character in the class (after an initial circumflex, if present) or escaped with a backslash. - A character class matches a single character in the subject. In UTF-8 + A character class matches a single character in the subject. In UTF-8 mode, the character may be more than one byte long. A matched character must be in the set of characters defined by the class, unless the first - character in the class definition is a circumflex, in which case the - subject character must not be in the set defined by the class. If a - circumflex is actually required as a member of the class, ensure it is + character in the class definition is a circumflex, in which case the + subject character must not be in the set defined by the class. If a + circumflex is actually required as a member of the class, ensure it is not the first character, or escape it with a backslash. - For example, the character class [aeiou] matches any lower case vowel, - while [^aeiou] matches any character that is not a lower case vowel. + For example, the character class [aeiou] matches any lower case vowel, + while [^aeiou] matches any character that is not a lower case vowel. Note that a circumflex is just a convenient notation for specifying the - characters that are in the class by enumerating those that are not. A - class that starts with a circumflex is not an assertion; it still con- - sumes a character from the subject string, and therefore it fails if + characters that are in the class by enumerating those that are not. A + class that starts with a circumflex is not an assertion; it still con- + sumes a character from the subject string, and therefore it fails if the current pointer is at the end of the string. - In UTF-8 mode, characters with values greater than 255 can be included - in a class as a literal string of bytes, or by using the \x{ escaping + In UTF-8 mode, characters with values greater than 255 can be included + in a class as a literal string of bytes, or by using the \x{ escaping mechanism. - When caseless matching is set, any letters in a class represent both - their upper case and lower case versions, so for example, a caseless - [aeiou] matches "A" as well as "a", and a caseless [^aeiou] does not - match "A", whereas a caseful version would. In UTF-8 mode, PCRE always - understands the concept of case for characters whose values are less - than 128, so caseless matching is always possible. For characters with - higher values, the concept of case is supported if PCRE is compiled - with Unicode property support, but not otherwise. If you want to use - caseless matching in UTF8-mode for characters 128 and above, you must - ensure that PCRE is compiled with Unicode property support as well as + When caseless matching is set, any letters in a class represent both + their upper case and lower case versions, so for example, a caseless + [aeiou] matches "A" as well as "a", and a caseless [^aeiou] does not + match "A", whereas a caseful version would. In UTF-8 mode, PCRE always + understands the concept of case for characters whose values are less + than 128, so caseless matching is always possible. For characters with + higher values, the concept of case is supported if PCRE is compiled + with Unicode property support, but not otherwise. If you want to use + caseless matching in UTF8-mode for characters 128 and above, you must + ensure that PCRE is compiled with Unicode property support as well as with UTF-8 support. - Characters that might indicate line breaks are never treated in any - special way when matching character classes, whatever line-ending - sequence is in use, and whatever setting of the PCRE_DOTALL and + Characters that might indicate line breaks are never treated in any + special way when matching character classes, whatever line-ending + sequence is in use, and whatever setting of the PCRE_DOTALL and PCRE_MULTILINE options is used. A class such as [^a] always matches one of these characters. - The minus (hyphen) character can be used to specify a range of charac- - ters in a character class. For example, [d-m] matches any letter - between d and m, inclusive. If a minus character is required in a - class, it must be escaped with a backslash or appear in a position - where it cannot be interpreted as indicating a range, typically as the + The minus (hyphen) character can be used to specify a range of charac- + ters in a character class. For example, [d-m] matches any letter + between d and m, inclusive. If a minus character is required in a + class, it must be escaped with a backslash or appear in a position + where it cannot be interpreted as indicating a range, typically as the first or last character in the class. It is not possible to have the literal character "]" as the end charac- - ter of a range. A pattern such as [W-]46] is interpreted as a class of - two characters ("W" and "-") followed by a literal string "46]", so it - would match "W46]" or "-46]". However, if the "]" is escaped with a - backslash it is interpreted as the end of range, so [W-\]46] is inter- - preted as a class containing a range followed by two other characters. - The octal or hexadecimal representation of "]" can also be used to end + ter of a range. A pattern such as [W-]46] is interpreted as a class of + two characters ("W" and "-") followed by a literal string "46]", so it + would match "W46]" or "-46]". However, if the "]" is escaped with a + backslash it is interpreted as the end of range, so [W-\]46] is inter- + preted as a class containing a range followed by two other characters. + The octal or hexadecimal representation of "]" can also be used to end a range. - Ranges operate in the collating sequence of character values. They can - also be used for characters specified numerically, for example - [\000-\037]. In UTF-8 mode, ranges can include characters whose values + Ranges operate in the collating sequence of character values. They can + also be used for characters specified numerically, for example + [\000-\037]. In UTF-8 mode, ranges can include characters whose values are greater than 255, for example [\x{100}-\x{2ff}]. If a range that includes letters is used when caseless matching is set, it matches the letters in either case. For example, [W-c] is equivalent - to [][\\^_`wxyzabc], matched caselessly, and in non-UTF-8 mode, if - character tables for a French locale are in use, [\xc8-\xcb] matches - accented E characters in both cases. In UTF-8 mode, PCRE supports the - concept of case for characters with values greater than 128 only when + to [][\\^_`wxyzabc], matched caselessly, and in non-UTF-8 mode, if + character tables for a French locale are in use, [\xc8-\xcb] matches + accented E characters in both cases. In UTF-8 mode, PCRE supports the + concept of case for characters with values greater than 128 only when it is compiled with Unicode property support. - The character types \d, \D, \p, \P, \s, \S, \w, and \W may also appear - in a character class, and add the characters that they match to the + The character types \d, \D, \p, \P, \s, \S, \w, and \W may also appear + in a character class, and add the characters that they match to the class. For example, [\dABCDEF] matches any hexadecimal digit. A circum- - flex can conveniently be used with the upper case character types to - specify a more restricted set of characters than the matching lower - case type. For example, the class [^\W_] matches any letter or digit, + flex can conveniently be used with the upper case character types to + specify a more restricted set of characters than the matching lower + case type. For example, the class [^\W_] matches any letter or digit, but not underscore. - The only metacharacters that are recognized in character classes are - backslash, hyphen (only where it can be interpreted as specifying a - range), circumflex (only at the start), opening square bracket (only - when it can be interpreted as introducing a POSIX class name - see the - next section), and the terminating closing square bracket. However, + The only metacharacters that are recognized in character classes are + backslash, hyphen (only where it can be interpreted as specifying a + range), circumflex (only at the start), opening square bracket (only + when it can be interpreted as introducing a POSIX class name - see the + next section), and the terminating closing square bracket. However, escaping other non-alphanumeric characters does no harm. POSIX CHARACTER CLASSES Perl supports the POSIX notation for character classes. This uses names - enclosed by [: and :] within the enclosing square brackets. PCRE also + enclosed by [: and :] within the enclosing square brackets. PCRE also supports this notation. For example, [01[:alpha:]%] @@ -3907,18 +3948,18 @@ POSIX CHARACTER CLASSES word "word" characters (same as \w) xdigit hexadecimal digits - The "space" characters are HT (9), LF (10), VT (11), FF (12), CR (13), - and space (32). Notice that this list includes the VT character (code + The "space" characters are HT (9), LF (10), VT (11), FF (12), CR (13), + and space (32). Notice that this list includes the VT character (code 11). This makes "space" different to \s, which does not include VT (for Perl compatibility). - The name "word" is a Perl extension, and "blank" is a GNU extension - from Perl 5.8. Another Perl extension is negation, which is indicated + The name "word" is a Perl extension, and "blank" is a GNU extension + from Perl 5.8. Another Perl extension is negation, which is indicated by a ^ character after the colon. For example, [12[:^digit:]] - matches "1", "2", or any non-digit. PCRE (and Perl) also recognize the + matches "1", "2", or any non-digit. PCRE (and Perl) also recognize the POSIX syntax [.ch.] and [=ch=] where "ch" is a "collating element", but these are not supported, and an error is given if they are encountered. @@ -3928,24 +3969,24 @@ POSIX CHARACTER CLASSES VERTICAL BAR - Vertical bar characters are used to separate alternative patterns. For + Vertical bar characters are used to separate alternative patterns. For example, the pattern gilbert|sullivan - matches either "gilbert" or "sullivan". Any number of alternatives may - appear, and an empty alternative is permitted (matching the empty + matches either "gilbert" or "sullivan". Any number of alternatives may + appear, and an empty alternative is permitted (matching the empty string). The matching process tries each alternative in turn, from left - to right, and the first one that succeeds is used. If the alternatives - are within a subpattern (defined below), "succeeds" means matching the + to right, and the first one that succeeds is used. If the alternatives + are within a subpattern (defined below), "succeeds" means matching the rest of the main pattern as well as the alternative in the subpattern. INTERNAL OPTION SETTING - The settings of the PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, and - PCRE_EXTENDED options (which are Perl-compatible) can be changed from - within the pattern by a sequence of Perl option letters enclosed + The settings of the PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, and + PCRE_EXTENDED options (which are Perl-compatible) can be changed from + within the pattern by a sequence of Perl option letters enclosed between "(?" and ")". The option letters are i for PCRE_CASELESS @@ -3955,46 +3996,46 @@ INTERNAL OPTION SETTING For example, (?im) sets caseless, multiline matching. It is also possi- ble to unset these options by preceding the letter with a hyphen, and a - combined setting and unsetting such as (?im-sx), which sets PCRE_CASE- - LESS and PCRE_MULTILINE while unsetting PCRE_DOTALL and PCRE_EXTENDED, - is also permitted. If a letter appears both before and after the + combined setting and unsetting such as (?im-sx), which sets PCRE_CASE- + LESS and PCRE_MULTILINE while unsetting PCRE_DOTALL and PCRE_EXTENDED, + is also permitted. If a letter appears both before and after the hyphen, the option is unset. - The PCRE-specific options PCRE_DUPNAMES, PCRE_UNGREEDY, and PCRE_EXTRA - can be changed in the same way as the Perl-compatible options by using + The PCRE-specific options PCRE_DUPNAMES, PCRE_UNGREEDY, and PCRE_EXTRA + can be changed in the same way as the Perl-compatible options by using the characters J, U and X respectively. - When one of these option changes occurs at top level (that is, not - inside subpattern parentheses), the change applies to the remainder of + When one of these option changes occurs at top level (that is, not + inside subpattern parentheses), the change applies to the remainder of the pattern that follows. If the change is placed right at the start of a pattern, PCRE extracts it into the global options (and it will there- fore show up in data extracted by the pcre_fullinfo() function). - An option change within a subpattern (see below for a description of + An option change within a subpattern (see below for a description of subpatterns) affects only that part of the current pattern that follows it, so (a(?i)b)c matches abc and aBc and no other strings (assuming PCRE_CASELESS is not - used). By this means, options can be made to have different settings - in different parts of the pattern. Any changes made in one alternative - do carry on into subsequent branches within the same subpattern. For + used). By this means, options can be made to have different settings + in different parts of the pattern. Any changes made in one alternative + do carry on into subsequent branches within the same subpattern. For example, (a(?i)b|c) - matches "ab", "aB", "c", and "C", even though when matching "C" the - first branch is abandoned before the option setting. This is because - the effects of option settings happen at compile time. There would be + matches "ab", "aB", "c", and "C", even though when matching "C" the + first branch is abandoned before the option setting. This is because + the effects of option settings happen at compile time. There would be some very weird behaviour otherwise. - Note: There are other PCRE-specific options that can be set by the - application when the compile or match functions are called. In some + Note: There are other PCRE-specific options that can be set by the + application when the compile or match functions are called. In some cases the pattern can contain special leading sequences such as (*CRLF) - to override what the application has set or what has been defaulted. - Details are given in the section entitled "Newline sequences" above. - There is also the (*UTF8) leading sequence that can be used to set + to override what the application has set or what has been defaulted. + Details are given in the section entitled "Newline sequences" above. + There is also the (*UTF8) leading sequence that can be used to set UTF-8 mode; this is equivalent to setting the PCRE_UTF8 option. @@ -4007,18 +4048,18 @@ SUBPATTERNS cat(aract|erpillar|) - matches one of the words "cat", "cataract", or "caterpillar". Without - the parentheses, it would match "cataract", "erpillar" or an empty + matches one of the words "cat", "cataract", or "caterpillar". Without + the parentheses, it would match "cataract", "erpillar" or an empty string. - 2. It sets up the subpattern as a capturing subpattern. This means - that, when the whole pattern matches, that portion of the subject + 2. It sets up the subpattern as a capturing subpattern. This means + that, when the whole pattern matches, that portion of the subject string that matched the subpattern is passed back to the caller via the - ovector argument of pcre_exec(). Opening parentheses are counted from - left to right (starting from 1) to obtain numbers for the capturing + ovector argument of pcre_exec(). Opening parentheses are counted from + left to right (starting from 1) to obtain numbers for the capturing subpatterns. - For example, if the string "the red king" is matched against the pat- + For example, if the string "the red king" is matched against the pat- tern the ((red|white) (king|queen)) @@ -4026,12 +4067,12 @@ SUBPATTERNS the captured substrings are "red king", "red", and "king", and are num- bered 1, 2, and 3, respectively. - The fact that plain parentheses fulfil two functions is not always - helpful. There are often times when a grouping subpattern is required - without a capturing requirement. If an opening parenthesis is followed - by a question mark and a colon, the subpattern does not do any captur- - ing, and is not counted when computing the number of any subsequent - capturing subpatterns. For example, if the string "the white queen" is + The fact that plain parentheses fulfil two functions is not always + helpful. There are often times when a grouping subpattern is required + without a capturing requirement. If an opening parenthesis is followed + by a question mark and a colon, the subpattern does not do any captur- + ing, and is not counted when computing the number of any subsequent + capturing subpatterns. For example, if the string "the white queen" is matched against the pattern the ((?:red|white) (king|queen)) @@ -4039,96 +4080,96 @@ SUBPATTERNS the captured substrings are "white queen" and "queen", and are numbered 1 and 2. The maximum number of capturing subpatterns is 65535. - As a convenient shorthand, if any option settings are required at the - start of a non-capturing subpattern, the option letters may appear + As a convenient shorthand, if any option settings are required at the + start of a non-capturing subpattern, the option letters may appear between the "?" and the ":". Thus the two patterns (?i:saturday|sunday) (?:(?i)saturday|sunday) match exactly the same set of strings. Because alternative branches are - tried from left to right, and options are not reset until the end of - the subpattern is reached, an option setting in one branch does affect - subsequent branches, so the above patterns match "SUNDAY" as well as + tried from left to right, and options are not reset until the end of + the subpattern is reached, an option setting in one branch does affect + subsequent branches, so the above patterns match "SUNDAY" as well as "Saturday". DUPLICATE SUBPATTERN NUMBERS Perl 5.10 introduced a feature whereby each alternative in a subpattern - uses the same numbers for its capturing parentheses. Such a subpattern - starts with (?| and is itself a non-capturing subpattern. For example, + uses the same numbers for its capturing parentheses. Such a subpattern + starts with (?| and is itself a non-capturing subpattern. For example, consider this pattern: (?|(Sat)ur|(Sun))day - Because the two alternatives are inside a (?| group, both sets of cap- - turing parentheses are numbered one. Thus, when the pattern matches, - you can look at captured substring number one, whichever alternative - matched. This construct is useful when you want to capture part, but + Because the two alternatives are inside a (?| group, both sets of cap- + turing parentheses are numbered one. Thus, when the pattern matches, + you can look at captured substring number one, whichever alternative + matched. This construct is useful when you want to capture part, but not all, of one of a number of alternatives. Inside a (?| group, paren- - theses are numbered as usual, but the number is reset at the start of - each branch. The numbers of any capturing buffers that follow the sub- - pattern start after the highest number used in any branch. The follow- - ing example is taken from the Perl documentation. The numbers under- + theses are numbered as usual, but the number is reset at the start of + each branch. The numbers of any capturing buffers that follow the sub- + pattern start after the highest number used in any branch. The follow- + ing example is taken from the Perl documentation. The numbers under- neath show in which buffer the captured content will be stored. # before ---------------branch-reset----------- after / ( a ) (?| x ( y ) z | (p (q) r) | (t) u (v) ) ( z ) /x # 1 2 2 3 2 3 4 - A back reference to a numbered subpattern uses the most recent value - that is set for that number by any subpattern. The following pattern + A back reference to a numbered subpattern uses the most recent value + that is set for that number by any subpattern. The following pattern matches "abcabc" or "defdef": /(?|(abc)|(def))\1/ - In contrast, a recursive or "subroutine" call to a numbered subpattern - always refers to the first one in the pattern with the given number. + In contrast, a recursive or "subroutine" call to a numbered subpattern + always refers to the first one in the pattern with the given number. The following pattern matches "abcabc" or "defabc": /(?|(abc)|(def))(?1)/ - If a condition test for a subpattern's having matched refers to a non- - unique number, the test is true if any of the subpatterns of that num- + If a condition test for a subpattern's having matched refers to a non- + unique number, the test is true if any of the subpatterns of that num- ber have matched. - An alternative approach to using this "branch reset" feature is to use + An alternative approach to using this "branch reset" feature is to use duplicate named subpatterns, as described in the next section. NAMED SUBPATTERNS - Identifying capturing parentheses by number is simple, but it can be - very hard to keep track of the numbers in complicated regular expres- - sions. Furthermore, if an expression is modified, the numbers may - change. To help with this difficulty, PCRE supports the naming of sub- + Identifying capturing parentheses by number is simple, but it can be + very hard to keep track of the numbers in complicated regular expres- + sions. Furthermore, if an expression is modified, the numbers may + change. To help with this difficulty, PCRE supports the naming of sub- patterns. This feature was not added to Perl until release 5.10. Python - had the feature earlier, and PCRE introduced it at release 4.0, using - the Python syntax. PCRE now supports both the Perl and the Python syn- - tax. Perl allows identically numbered subpatterns to have different + had the feature earlier, and PCRE introduced it at release 4.0, using + the Python syntax. PCRE now supports both the Perl and the Python syn- + tax. Perl allows identically numbered subpatterns to have different names, but PCRE does not. - In PCRE, a subpattern can be named in one of three ways: (?<name>...) - or (?'name'...) as in Perl, or (?P<name>...) as in Python. References - to capturing parentheses from other parts of the pattern, such as back - references, recursion, and conditions, can be made by name as well as + In PCRE, a subpattern can be named in one of three ways: (?<name>...) + or (?'name'...) as in Perl, or (?P<name>...) as in Python. References + to capturing parentheses from other parts of the pattern, such as back + references, recursion, and conditions, can be made by name as well as by number. - Names consist of up to 32 alphanumeric characters and underscores. - Named capturing parentheses are still allocated numbers as well as - names, exactly as if the names were not present. The PCRE API provides + Names consist of up to 32 alphanumeric characters and underscores. + Named capturing parentheses are still allocated numbers as well as + names, exactly as if the names were not present. The PCRE API provides function calls for extracting the name-to-number translation table from a compiled pattern. There is also a convenience function for extracting a captured substring by name. - By default, a name must be unique within a pattern, but it is possible + By default, a name must be unique within a pattern, but it is possible to relax this constraint by setting the PCRE_DUPNAMES option at compile - time. (Duplicate names are also always permitted for subpatterns with - the same number, set up as described in the previous section.) Dupli- - cate names can be useful for patterns where only one instance of the - named parentheses can match. Suppose you want to match the name of a - weekday, either as a 3-letter abbreviation or as the full name, and in + time. (Duplicate names are also always permitted for subpatterns with + the same number, set up as described in the previous section.) Dupli- + cate names can be useful for patterns where only one instance of the + named parentheses can match. Suppose you want to match the name of a + weekday, either as a 3-letter abbreviation or as the full name, and in both cases you want to extract the abbreviation. This pattern (ignoring the line breaks) does the job: @@ -4138,38 +4179,38 @@ NAMED SUBPATTERNS (?<DN>Thu)(?:rsday)?| (?<DN>Sat)(?:urday)? - There are five capturing substrings, but only one is ever set after a + There are five capturing substrings, but only one is ever set after a match. (An alternative way of solving this problem is to use a "branch reset" subpattern, as described in the previous section.) - The convenience function for extracting the data by name returns the - substring for the first (and in this example, the only) subpattern of - that name that matched. This saves searching to find which numbered + The convenience function for extracting the data by name returns the + substring for the first (and in this example, the only) subpattern of + that name that matched. This saves searching to find which numbered subpattern it was. - If you make a back reference to a non-unique named subpattern from - elsewhere in the pattern, the one that corresponds to the first occur- + If you make a back reference to a non-unique named subpattern from + elsewhere in the pattern, the one that corresponds to the first occur- rence of the name is used. In the absence of duplicate numbers (see the - previous section) this is the one with the lowest number. If you use a - named reference in a condition test (see the section about conditions - below), either to check whether a subpattern has matched, or to check - for recursion, all subpatterns with the same name are tested. If the - condition is true for any one of them, the overall condition is true. + previous section) this is the one with the lowest number. If you use a + named reference in a condition test (see the section about conditions + below), either to check whether a subpattern has matched, or to check + for recursion, all subpatterns with the same name are tested. If the + condition is true for any one of them, the overall condition is true. This is the same behaviour as testing by number. For further details of the interfaces for handling named subpatterns, see the pcreapi documen- tation. Warning: You cannot use different names to distinguish between two sub- - patterns with the same number because PCRE uses only the numbers when + patterns with the same number because PCRE uses only the numbers when matching. For this reason, an error is given at compile time if differ- - ent names are given to subpatterns with the same number. However, you - can give the same name to subpatterns with the same number, even when + ent names are given to subpatterns with the same number. However, you + can give the same name to subpatterns with the same number, even when PCRE_DUPNAMES is not set. REPETITION - Repetition is specified by quantifiers, which can follow any of the + Repetition is specified by quantifiers, which can follow any of the following items: a literal data character @@ -4183,17 +4224,17 @@ REPETITION a parenthesized subpattern (unless it is an assertion) a recursive or "subroutine" call to a subpattern - The general repetition quantifier specifies a minimum and maximum num- - ber of permitted matches, by giving the two numbers in curly brackets - (braces), separated by a comma. The numbers must be less than 65536, + The general repetition quantifier specifies a minimum and maximum num- + ber of permitted matches, by giving the two numbers in curly brackets + (braces), separated by a comma. The numbers must be less than 65536, and the first must be less than or equal to the second. For example: z{2,4} - matches "zz", "zzz", or "zzzz". A closing brace on its own is not a - special character. If the second number is omitted, but the comma is - present, there is no upper limit; if the second number and the comma - are both omitted, the quantifier specifies an exact number of required + matches "zz", "zzz", or "zzzz". A closing brace on its own is not a + special character. If the second number is omitted, but the comma is + present, there is no upper limit; if the second number and the comma + are both omitted, the quantifier specifies an exact number of required matches. Thus [aeiou]{3,} @@ -4202,49 +4243,49 @@ REPETITION \d{8} - matches exactly 8 digits. An opening curly bracket that appears in a - position where a quantifier is not allowed, or one that does not match - the syntax of a quantifier, is taken as a literal character. For exam- + matches exactly 8 digits. An opening curly bracket that appears in a + position where a quantifier is not allowed, or one that does not match + the syntax of a quantifier, is taken as a literal character. For exam- ple, {,6} is not a quantifier, but a literal string of four characters. - In UTF-8 mode, quantifiers apply to UTF-8 characters rather than to + In UTF-8 mode, quantifiers apply to UTF-8 characters rather than to individual bytes. Thus, for example, \x{100}{2} matches two UTF-8 char- acters, each of which is represented by a two-byte sequence. Similarly, when Unicode property support is available, \X{3} matches three Unicode - extended sequences, each of which may be several bytes long (and they + extended sequences, each of which may be several bytes long (and they may be of different lengths). The quantifier {0} is permitted, causing the expression to behave as if the previous item and the quantifier were not present. This may be use- - ful for subpatterns that are referenced as subroutines from elsewhere + ful for subpatterns that are referenced as subroutines from elsewhere in the pattern. Items other than subpatterns that have a {0} quantifier are omitted from the compiled pattern. - For convenience, the three most common quantifiers have single-charac- + For convenience, the three most common quantifiers have single-charac- ter abbreviations: * is equivalent to {0,} + is equivalent to {1,} ? is equivalent to {0,1} - It is possible to construct infinite loops by following a subpattern + It is possible to construct infinite loops by following a subpattern that can match no characters with a quantifier that has no upper limit, for example: (a?)* Earlier versions of Perl and PCRE used to give an error at compile time - for such patterns. However, because there are cases where this can be - useful, such patterns are now accepted, but if any repetition of the - subpattern does in fact match no characters, the loop is forcibly bro- + for such patterns. However, because there are cases where this can be + useful, such patterns are now accepted, but if any repetition of the + subpattern does in fact match no characters, the loop is forcibly bro- ken. - By default, the quantifiers are "greedy", that is, they match as much - as possible (up to the maximum number of permitted times), without - causing the rest of the pattern to fail. The classic example of where + By default, the quantifiers are "greedy", that is, they match as much + as possible (up to the maximum number of permitted times), without + causing the rest of the pattern to fail. The classic example of where this gives problems is in trying to match comments in C programs. These - appear between /* and */ and within the comment, individual * and / - characters may appear. An attempt to match C comments by applying the + appear between /* and */ and within the comment, individual * and / + characters may appear. An attempt to match C comments by applying the pattern /\*.*\*/ @@ -4253,19 +4294,19 @@ REPETITION /* first comment */ not comment /* second comment */ - fails, because it matches the entire string owing to the greediness of + fails, because it matches the entire string owing to the greediness of the .* item. - However, if a quantifier is followed by a question mark, it ceases to + However, if a quantifier is followed by a question mark, it ceases to be greedy, and instead matches the minimum number of times possible, so the pattern /\*.*?\*/ - does the right thing with the C comments. The meaning of the various - quantifiers is not otherwise changed, just the preferred number of - matches. Do not confuse this use of question mark with its use as a - quantifier in its own right. Because it has two uses, it can sometimes + does the right thing with the C comments. The meaning of the various + quantifiers is not otherwise changed, just the preferred number of + matches. Do not confuse this use of question mark with its use as a + quantifier in its own right. Because it has two uses, it can sometimes appear doubled, as in \d??\d @@ -4273,36 +4314,36 @@ REPETITION which matches one digit by preference, but can match two if that is the only way the rest of the pattern matches. - If the PCRE_UNGREEDY option is set (an option that is not available in - Perl), the quantifiers are not greedy by default, but individual ones - can be made greedy by following them with a question mark. In other + If the PCRE_UNGREEDY option is set (an option that is not available in + Perl), the quantifiers are not greedy by default, but individual ones + can be made greedy by following them with a question mark. In other words, it inverts the default behaviour. - When a parenthesized subpattern is quantified with a minimum repeat - count that is greater than 1 or with a limited maximum, more memory is - required for the compiled pattern, in proportion to the size of the + When a parenthesized subpattern is quantified with a minimum repeat + count that is greater than 1 or with a limited maximum, more memory is + required for the compiled pattern, in proportion to the size of the minimum or maximum. If a pattern starts with .* or .{0,} and the PCRE_DOTALL option (equiv- - alent to Perl's /s) is set, thus allowing the dot to match newlines, - the pattern is implicitly anchored, because whatever follows will be - tried against every character position in the subject string, so there - is no point in retrying the overall match at any position after the - first. PCRE normally treats such a pattern as though it were preceded + alent to Perl's /s) is set, thus allowing the dot to match newlines, + the pattern is implicitly anchored, because whatever follows will be + tried against every character position in the subject string, so there + is no point in retrying the overall match at any position after the + first. PCRE normally treats such a pattern as though it were preceded by \A. - In cases where it is known that the subject string contains no new- - lines, it is worth setting PCRE_DOTALL in order to obtain this opti- + In cases where it is known that the subject string contains no new- + lines, it is worth setting PCRE_DOTALL in order to obtain this opti- mization, or alternatively using ^ to indicate anchoring explicitly. - However, there is one situation where the optimization cannot be used. + However, there is one situation where the optimization cannot be used. When .* is inside capturing parentheses that are the subject of a back reference elsewhere in the pattern, a match at the start may fail where a later one succeeds. Consider, for example: (.*)abc\1 - If the subject is "xyz123abc123" the match point is the fourth charac- + If the subject is "xyz123abc123" the match point is the fourth charac- ter. For this reason, such a pattern is not implicitly anchored. When a capturing subpattern is repeated, the value captured is the sub- @@ -4311,8 +4352,8 @@ REPETITION (tweedle[dume]{3}\s*)+ has matched "tweedledum tweedledee" the value of the captured substring - is "tweedledee". However, if there are nested capturing subpatterns, - the corresponding captured values may have been set in previous itera- + is "tweedledee". However, if there are nested capturing subpatterns, + the corresponding captured values may have been set in previous itera- tions. For example, after /(a|(b))+/ @@ -4322,53 +4363,53 @@ REPETITION ATOMIC GROUPING AND POSSESSIVE QUANTIFIERS - With both maximizing ("greedy") and minimizing ("ungreedy" or "lazy") - repetition, failure of what follows normally causes the repeated item - to be re-evaluated to see if a different number of repeats allows the - rest of the pattern to match. Sometimes it is useful to prevent this, - either to change the nature of the match, or to cause it fail earlier - than it otherwise might, when the author of the pattern knows there is + With both maximizing ("greedy") and minimizing ("ungreedy" or "lazy") + repetition, failure of what follows normally causes the repeated item + to be re-evaluated to see if a different number of repeats allows the + rest of the pattern to match. Sometimes it is useful to prevent this, + either to change the nature of the match, or to cause it fail earlier + than it otherwise might, when the author of the pattern knows there is no point in carrying on. - Consider, for example, the pattern \d+foo when applied to the subject + Consider, for example, the pattern \d+foo when applied to the subject line 123456bar After matching all 6 digits and then failing to match "foo", the normal - action of the matcher is to try again with only 5 digits matching the - \d+ item, and then with 4, and so on, before ultimately failing. - "Atomic grouping" (a term taken from Jeffrey Friedl's book) provides - the means for specifying that once a subpattern has matched, it is not + action of the matcher is to try again with only 5 digits matching the + \d+ item, and then with 4, and so on, before ultimately failing. + "Atomic grouping" (a term taken from Jeffrey Friedl's book) provides + the means for specifying that once a subpattern has matched, it is not to be re-evaluated in this way. - If we use atomic grouping for the previous example, the matcher gives - up immediately on failing to match "foo" the first time. The notation + If we use atomic grouping for the previous example, the matcher gives + up immediately on failing to match "foo" the first time. The notation is a kind of special parenthesis, starting with (?> as in this example: (?>\d+)foo - This kind of parenthesis "locks up" the part of the pattern it con- - tains once it has matched, and a failure further into the pattern is - prevented from backtracking into it. Backtracking past it to previous + This kind of parenthesis "locks up" the part of the pattern it con- + tains once it has matched, and a failure further into the pattern is + prevented from backtracking into it. Backtracking past it to previous items, however, works as normal. - An alternative description is that a subpattern of this type matches - the string of characters that an identical standalone pattern would + An alternative description is that a subpattern of this type matches + the string of characters that an identical standalone pattern would match, if anchored at the current point in the subject string. Atomic grouping subpatterns are not capturing subpatterns. Simple cases such as the above example can be thought of as a maximizing repeat that - must swallow everything it can. So, while both \d+ and \d+? are pre- - pared to adjust the number of digits they match in order to make the + must swallow everything it can. So, while both \d+ and \d+? are pre- + pared to adjust the number of digits they match in order to make the rest of the pattern match, (?>\d+) can only match an entire sequence of digits. - Atomic groups in general can of course contain arbitrarily complicated - subpatterns, and can be nested. However, when the subpattern for an + Atomic groups in general can of course contain arbitrarily complicated + subpatterns, and can be nested. However, when the subpattern for an atomic group is just a single repeated item, as in the example above, a - simpler notation, called a "possessive quantifier" can be used. This - consists of an additional + character following a quantifier. Using + simpler notation, called a "possessive quantifier" can be used. This + consists of an additional + character following a quantifier. Using this notation, the previous example can be rewritten as \d++foo @@ -4378,45 +4419,45 @@ ATOMIC GROUPING AND POSSESSIVE QUANTIFIERS (abc|xyz){2,3}+ - Possessive quantifiers are always greedy; the setting of the + Possessive quantifiers are always greedy; the setting of the PCRE_UNGREEDY option is ignored. They are a convenient notation for the - simpler forms of atomic group. However, there is no difference in the - meaning of a possessive quantifier and the equivalent atomic group, - though there may be a performance difference; possessive quantifiers + simpler forms of atomic group. However, there is no difference in the + meaning of a possessive quantifier and the equivalent atomic group, + though there may be a performance difference; possessive quantifiers should be slightly faster. - The possessive quantifier syntax is an extension to the Perl 5.8 syn- - tax. Jeffrey Friedl originated the idea (and the name) in the first + The possessive quantifier syntax is an extension to the Perl 5.8 syn- + tax. Jeffrey Friedl originated the idea (and the name) in the first edition of his book. Mike McCloskey liked it, so implemented it when he - built Sun's Java package, and PCRE copied it from there. It ultimately + built Sun's Java package, and PCRE copied it from there. It ultimately found its way into Perl at release 5.10. PCRE has an optimization that automatically "possessifies" certain sim- - ple pattern constructs. For example, the sequence A+B is treated as - A++B because there is no point in backtracking into a sequence of A's + ple pattern constructs. For example, the sequence A+B is treated as + A++B because there is no point in backtracking into a sequence of A's when B must follow. - When a pattern contains an unlimited repeat inside a subpattern that - can itself be repeated an unlimited number of times, the use of an - atomic group is the only way to avoid some failing matches taking a + When a pattern contains an unlimited repeat inside a subpattern that + can itself be repeated an unlimited number of times, the use of an + atomic group is the only way to avoid some failing matches taking a very long time indeed. The pattern (\D+|<\d+>)*[!?] - matches an unlimited number of substrings that either consist of non- - digits, or digits enclosed in <>, followed by either ! or ?. When it + matches an unlimited number of substrings that either consist of non- + digits, or digits enclosed in <>, followed by either ! or ?. When it matches, it runs quickly. However, if it is applied to aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa - it takes a long time before reporting failure. This is because the - string can be divided between the internal \D+ repeat and the external - * repeat in a large number of ways, and all have to be tried. (The - example uses [!?] rather than a single character at the end, because - both PCRE and Perl have an optimization that allows for fast failure - when a single character is used. They remember the last single charac- - ter that is required for a match, and fail early if it is not present - in the string.) If the pattern is changed so that it uses an atomic + it takes a long time before reporting failure. This is because the + string can be divided between the internal \D+ repeat and the external + * repeat in a large number of ways, and all have to be tried. (The + example uses [!?] rather than a single character at the end, because + both PCRE and Perl have an optimization that allows for fast failure + when a single character is used. They remember the last single charac- + ter that is required for a match, and fail early if it is not present + in the string.) If the pattern is changed so that it uses an atomic group, like this: ((?>\D+)|<\d+>)*[!?] @@ -4428,37 +4469,37 @@ BACK REFERENCES Outside a character class, a backslash followed by a digit greater than 0 (and possibly further digits) is a back reference to a capturing sub- - pattern earlier (that is, to its left) in the pattern, provided there + pattern earlier (that is, to its left) in the pattern, provided there have been that many previous capturing left parentheses. However, if the decimal number following the backslash is less than 10, - it is always taken as a back reference, and causes an error only if - there are not that many capturing left parentheses in the entire pat- - tern. In other words, the parentheses that are referenced need not be - to the left of the reference for numbers less than 10. A "forward back - reference" of this type can make sense when a repetition is involved - and the subpattern to the right has participated in an earlier itera- + it is always taken as a back reference, and causes an error only if + there are not that many capturing left parentheses in the entire pat- + tern. In other words, the parentheses that are referenced need not be + to the left of the reference for numbers less than 10. A "forward back + reference" of this type can make sense when a repetition is involved + and the subpattern to the right has participated in an earlier itera- tion. - It is not possible to have a numerical "forward back reference" to a - subpattern whose number is 10 or more using this syntax because a - sequence such as \50 is interpreted as a character defined in octal. + It is not possible to have a numerical "forward back reference" to a + subpattern whose number is 10 or more using this syntax because a + sequence such as \50 is interpreted as a character defined in octal. See the subsection entitled "Non-printing characters" above for further - details of the handling of digits following a backslash. There is no - such problem when named parentheses are used. A back reference to any + details of the handling of digits following a backslash. There is no + such problem when named parentheses are used. A back reference to any subpattern is possible using named parentheses (see below). - Another way of avoiding the ambiguity inherent in the use of digits + Another way of avoiding the ambiguity inherent in the use of digits following a backslash is to use the \g escape sequence, which is a fea- - ture introduced in Perl 5.10. This escape must be followed by an - unsigned number or a negative number, optionally enclosed in braces. + ture introduced in Perl 5.10. This escape must be followed by an + unsigned number or a negative number, optionally enclosed in braces. These examples are all identical: (ring), \1 (ring), \g1 (ring), \g{1} - An unsigned number specifies an absolute reference without the ambigu- + An unsigned number specifies an absolute reference without the ambigu- ity that is present in the older syntax. It is also useful when literal digits follow the reference. A negative number is a relative reference. Consider this example: @@ -4466,33 +4507,33 @@ BACK REFERENCES (abc(def)ghi)\g{-1} The sequence \g{-1} is a reference to the most recently started captur- - ing subpattern before \g, that is, is it equivalent to \2. Similarly, + ing subpattern before \g, that is, is it equivalent to \2. Similarly, \g{-2} would be equivalent to \1. The use of relative references can be - helpful in long patterns, and also in patterns that are created by + helpful in long patterns, and also in patterns that are created by joining together fragments that contain references within themselves. - A back reference matches whatever actually matched the capturing sub- - pattern in the current subject string, rather than anything matching + A back reference matches whatever actually matched the capturing sub- + pattern in the current subject string, rather than anything matching the subpattern itself (see "Subpatterns as subroutines" below for a way of doing that). So the pattern (sens|respons)e and \1ibility - matches "sense and sensibility" and "response and responsibility", but - not "sense and responsibility". If caseful matching is in force at the - time of the back reference, the case of letters is relevant. For exam- + matches "sense and sensibility" and "response and responsibility", but + not "sense and responsibility". If caseful matching is in force at the + time of the back reference, the case of letters is relevant. For exam- ple, ((?i)rah)\s+\1 - matches "rah rah" and "RAH RAH", but not "RAH rah", even though the + matches "rah rah" and "RAH RAH", but not "RAH rah", even though the original capturing subpattern is matched caselessly. - There are several different ways of writing back references to named - subpatterns. The .NET syntax \k{name} and the Perl syntax \k<name> or - \k'name' are supported, as is the Python syntax (?P=name). Perl 5.10's + There are several different ways of writing back references to named + subpatterns. The .NET syntax \k{name} and the Perl syntax \k<name> or + \k'name' are supported, as is the Python syntax (?P=name). Perl 5.10's unified back reference syntax, in which \g can be used for both numeric - and named references, is also supported. We could rewrite the above + and named references, is also supported. We could rewrite the above example in any of the following ways: (?<p1>(?i)rah)\s+\k<p1> @@ -4500,67 +4541,67 @@ BACK REFERENCES (?P<p1>(?i)rah)\s+(?P=p1) (?<p1>(?i)rah)\s+\g{p1} - A subpattern that is referenced by name may appear in the pattern + A subpattern that is referenced by name may appear in the pattern before or after the reference. - There may be more than one back reference to the same subpattern. If a - subpattern has not actually been used in a particular match, any back + There may be more than one back reference to the same subpattern. If a + subpattern has not actually been used in a particular match, any back references to it always fail by default. For example, the pattern (a|(bc))\2 - always fails if it starts to match "a" rather than "bc". However, if + always fails if it starts to match "a" rather than "bc". However, if the PCRE_JAVASCRIPT_COMPAT option is set at compile time, a back refer- ence to an unset value matches an empty string. - Because there may be many capturing parentheses in a pattern, all dig- - its following a backslash are taken as part of a potential back refer- - ence number. If the pattern continues with a digit character, some - delimiter must be used to terminate the back reference. If the + Because there may be many capturing parentheses in a pattern, all dig- + its following a backslash are taken as part of a potential back refer- + ence number. If the pattern continues with a digit character, some + delimiter must be used to terminate the back reference. If the PCRE_EXTENDED option is set, this can be whitespace. Otherwise, the \g{ syntax or an empty comment (see "Comments" below) can be used. Recursive back references - A back reference that occurs inside the parentheses to which it refers - fails when the subpattern is first used, so, for example, (a\1) never - matches. However, such references can be useful inside repeated sub- + A back reference that occurs inside the parentheses to which it refers + fails when the subpattern is first used, so, for example, (a\1) never + matches. However, such references can be useful inside repeated sub- patterns. For example, the pattern (a|b\1)+ matches any number of "a"s and also "aba", "ababbaa" etc. At each iter- - ation of the subpattern, the back reference matches the character - string corresponding to the previous iteration. In order for this to - work, the pattern must be such that the first iteration does not need - to match the back reference. This can be done using alternation, as in + ation of the subpattern, the back reference matches the character + string corresponding to the previous iteration. In order for this to + work, the pattern must be such that the first iteration does not need + to match the back reference. This can be done using alternation, as in the example above, or by a quantifier with a minimum of zero. - Back references of this type cause the group that they reference to be - treated as an atomic group. Once the whole group has been matched, a - subsequent matching failure cannot cause backtracking into the middle + Back references of this type cause the group that they reference to be + treated as an atomic group. Once the whole group has been matched, a + subsequent matching failure cannot cause backtracking into the middle of the group. ASSERTIONS - An assertion is a test on the characters following or preceding the - current matching point that does not actually consume any characters. - The simple assertions coded as \b, \B, \A, \G, \Z, \z, ^ and $ are + An assertion is a test on the characters following or preceding the + current matching point that does not actually consume any characters. + The simple assertions coded as \b, \B, \A, \G, \Z, \z, ^ and $ are described above. - More complicated assertions are coded as subpatterns. There are two - kinds: those that look ahead of the current position in the subject - string, and those that look behind it. An assertion subpattern is - matched in the normal way, except that it does not cause the current + More complicated assertions are coded as subpatterns. There are two + kinds: those that look ahead of the current position in the subject + string, and those that look behind it. An assertion subpattern is + matched in the normal way, except that it does not cause the current matching position to be changed. - Assertion subpatterns are not capturing subpatterns, and may not be - repeated, because it makes no sense to assert the same thing several - times. If any kind of assertion contains capturing subpatterns within - it, these are counted for the purposes of numbering the capturing sub- + Assertion subpatterns are not capturing subpatterns, and may not be + repeated, because it makes no sense to assert the same thing several + times. If any kind of assertion contains capturing subpatterns within + it, these are counted for the purposes of numbering the capturing sub- patterns in the whole pattern. However, substring capturing is carried - out only for positive assertions, because it does not make sense for + out only for positive assertions, because it does not make sense for negative assertions. Lookahead assertions @@ -4570,38 +4611,38 @@ ASSERTIONS \w+(?=;) - matches a word followed by a semicolon, but does not include the semi- + matches a word followed by a semicolon, but does not include the semi- colon in the match, and foo(?!bar) - matches any occurrence of "foo" that is not followed by "bar". Note + matches any occurrence of "foo" that is not followed by "bar". Note that the apparently similar pattern (?!foo)bar - does not find an occurrence of "bar" that is preceded by something - other than "foo"; it finds any occurrence of "bar" whatsoever, because + does not find an occurrence of "bar" that is preceded by something + other than "foo"; it finds any occurrence of "bar" whatsoever, because the assertion (?!foo) is always true when the next three characters are "bar". A lookbehind assertion is needed to achieve the other effect. If you want to force a matching failure at some point in a pattern, the - most convenient way to do it is with (?!) because an empty string - always matches, so an assertion that requires there not to be an empty - string must always fail. The Perl 5.10 backtracking control verb + most convenient way to do it is with (?!) because an empty string + always matches, so an assertion that requires there not to be an empty + string must always fail. The Perl 5.10 backtracking control verb (*FAIL) or (*F) is essentially a synonym for (?!). Lookbehind assertions - Lookbehind assertions start with (?<= for positive assertions and (?<! + Lookbehind assertions start with (?<= for positive assertions and (?<! for negative assertions. For example, (?<!foo)bar - does find an occurrence of "bar" that is not preceded by "foo". The - contents of a lookbehind assertion are restricted such that all the + does find an occurrence of "bar" that is not preceded by "foo". The + contents of a lookbehind assertion are restricted such that all the strings it matches must have a fixed length. However, if there are sev- - eral top-level alternatives, they do not all have to have the same + eral top-level alternatives, they do not all have to have the same fixed length. Thus (?<=bullock|donkey) @@ -4610,62 +4651,62 @@ ASSERTIONS (?<!dogs?|cats?) - causes an error at compile time. Branches that match different length - strings are permitted only at the top level of a lookbehind assertion. - This is an extension compared with Perl (5.8 and 5.10), which requires + causes an error at compile time. Branches that match different length + strings are permitted only at the top level of a lookbehind assertion. + This is an extension compared with Perl (5.8 and 5.10), which requires all branches to match the same length of string. An assertion such as (?<=ab(c|de)) - is not permitted, because its single top-level branch can match two + is not permitted, because its single top-level branch can match two different lengths, but it is acceptable to PCRE if rewritten to use two top-level branches: (?<=abc|abde) In some cases, the Perl 5.10 escape sequence \K (see above) can be used - instead of a lookbehind assertion to get round the fixed-length + instead of a lookbehind assertion to get round the fixed-length restriction. - The implementation of lookbehind assertions is, for each alternative, - to temporarily move the current position back by the fixed length and + The implementation of lookbehind assertions is, for each alternative, + to temporarily move the current position back by the fixed length and then try to match. If there are insufficient characters before the cur- rent position, the assertion fails. PCRE does not allow the \C escape (which matches a single byte in UTF-8 - mode) to appear in lookbehind assertions, because it makes it impossi- - ble to calculate the length of the lookbehind. The \X and \R escapes, + mode) to appear in lookbehind assertions, because it makes it impossi- + ble to calculate the length of the lookbehind. The \X and \R escapes, which can match different numbers of bytes, are also not permitted. - "Subroutine" calls (see below) such as (?2) or (?&X) are permitted in - lookbehinds, as long as the subpattern matches a fixed-length string. + "Subroutine" calls (see below) such as (?2) or (?&X) are permitted in + lookbehinds, as long as the subpattern matches a fixed-length string. Recursion, however, is not supported. - Possessive quantifiers can be used in conjunction with lookbehind + Possessive quantifiers can be used in conjunction with lookbehind assertions to specify efficient matching of fixed-length strings at the end of subject strings. Consider a simple pattern such as abcd$ - when applied to a long string that does not match. Because matching + when applied to a long string that does not match. Because matching proceeds from left to right, PCRE will look for each "a" in the subject - and then see if what follows matches the rest of the pattern. If the + and then see if what follows matches the rest of the pattern. If the pattern is specified as ^.*abcd$ - the initial .* matches the entire string at first, but when this fails + the initial .* matches the entire string at first, but when this fails (because there is no following "a"), it backtracks to match all but the - last character, then all but the last two characters, and so on. Once - again the search for "a" covers the entire string, from right to left, + last character, then all but the last two characters, and so on. Once + again the search for "a" covers the entire string, from right to left, so we are no better off. However, if the pattern is written as ^.*+(?<=abcd) - there can be no backtracking for the .*+ item; it can match only the - entire string. The subsequent lookbehind assertion does a single test - on the last four characters. If it fails, the match fails immediately. - For long strings, this approach makes a significant difference to the + there can be no backtracking for the .*+ item; it can match only the + entire string. The subsequent lookbehind assertion does a single test + on the last four characters. If it fails, the match fails immediately. + For long strings, this approach makes a significant difference to the processing time. Using multiple assertions @@ -4674,18 +4715,18 @@ ASSERTIONS (?<=\d{3})(?<!999)foo - matches "foo" preceded by three digits that are not "999". Notice that - each of the assertions is applied independently at the same point in - the subject string. First there is a check that the previous three - characters are all digits, and then there is a check that the same + matches "foo" preceded by three digits that are not "999". Notice that + each of the assertions is applied independently at the same point in + the subject string. First there is a check that the previous three + characters are all digits, and then there is a check that the same three characters are not "999". This pattern does not match "foo" pre- - ceded by six characters, the first of which are digits and the last - three of which are not "999". For example, it doesn't match "123abc- + ceded by six characters, the first of which are digits and the last + three of which are not "999". For example, it doesn't match "123abc- foo". A pattern to do that is (?<=\d{3}...)(?<!999)foo - This time the first assertion looks at the preceding six characters, + This time the first assertion looks at the preceding six characters, checking that the first three are digits, and then the second assertion checks that the preceding three characters are not "999". @@ -4693,96 +4734,96 @@ ASSERTIONS (?<=(?<!foo)bar)baz - matches an occurrence of "baz" that is preceded by "bar" which in turn + matches an occurrence of "baz" that is preceded by "bar" which in turn is not preceded by "foo", while (?<=\d{3}(?!999)...)foo - is another pattern that matches "foo" preceded by three digits and any + is another pattern that matches "foo" preceded by three digits and any three characters that are not "999". CONDITIONAL SUBPATTERNS - It is possible to cause the matching process to obey a subpattern con- - ditionally or to choose between two alternative subpatterns, depending - on the result of an assertion, or whether a specific capturing subpat- - tern has already been matched. The two possible forms of conditional + It is possible to cause the matching process to obey a subpattern con- + ditionally or to choose between two alternative subpatterns, depending + on the result of an assertion, or whether a specific capturing subpat- + tern has already been matched. The two possible forms of conditional subpattern are: (?(condition)yes-pattern) (?(condition)yes-pattern|no-pattern) - If the condition is satisfied, the yes-pattern is used; otherwise the - no-pattern (if present) is used. If there are more than two alterna- + If the condition is satisfied, the yes-pattern is used; otherwise the + no-pattern (if present) is used. If there are more than two alterna- tives in the subpattern, a compile-time error occurs. - There are four kinds of condition: references to subpatterns, refer- + There are four kinds of condition: references to subpatterns, refer- ences to recursion, a pseudo-condition called DEFINE, and assertions. Checking for a used subpattern by number - If the text between the parentheses consists of a sequence of digits, + If the text between the parentheses consists of a sequence of digits, the condition is true if a capturing subpattern of that number has pre- - viously matched. If there is more than one capturing subpattern with - the same number (see the earlier section about duplicate subpattern + viously matched. If there is more than one capturing subpattern with + the same number (see the earlier section about duplicate subpattern numbers), the condition is true if any of them have been set. An alter- - native notation is to precede the digits with a plus or minus sign. In - this case, the subpattern number is relative rather than absolute. The - most recently opened parentheses can be referenced by (?(-1), the next - most recent by (?(-2), and so on. In looping constructs it can also - make sense to refer to subsequent groups with constructs such as + native notation is to precede the digits with a plus or minus sign. In + this case, the subpattern number is relative rather than absolute. The + most recently opened parentheses can be referenced by (?(-1), the next + most recent by (?(-2), and so on. In looping constructs it can also + make sense to refer to subsequent groups with constructs such as (?(+2). - Consider the following pattern, which contains non-significant white + Consider the following pattern, which contains non-significant white space to make it more readable (assume the PCRE_EXTENDED option) and to divide it into three parts for ease of discussion: ( \( )? [^()]+ (?(1) \) ) - The first part matches an optional opening parenthesis, and if that + The first part matches an optional opening parenthesis, and if that character is present, sets it as the first captured substring. The sec- - ond part matches one or more characters that are not parentheses. The + ond part matches one or more characters that are not parentheses. The third part is a conditional subpattern that tests whether the first set of parentheses matched or not. If they did, that is, if subject started with an opening parenthesis, the condition is true, and so the yes-pat- - tern is executed and a closing parenthesis is required. Otherwise, - since no-pattern is not present, the subpattern matches nothing. In - other words, this pattern matches a sequence of non-parentheses, + tern is executed and a closing parenthesis is required. Otherwise, + since no-pattern is not present, the subpattern matches nothing. In + other words, this pattern matches a sequence of non-parentheses, optionally enclosed in parentheses. - If you were embedding this pattern in a larger one, you could use a + If you were embedding this pattern in a larger one, you could use a relative reference: ...other stuff... ( \( )? [^()]+ (?(-1) \) ) ... - This makes the fragment independent of the parentheses in the larger + This makes the fragment independent of the parentheses in the larger pattern. Checking for a used subpattern by name - Perl uses the syntax (?(<name>)...) or (?('name')...) to test for a - used subpattern by name. For compatibility with earlier versions of - PCRE, which had this facility before Perl, the syntax (?(name)...) is - also recognized. However, there is a possible ambiguity with this syn- - tax, because subpattern names may consist entirely of digits. PCRE - looks first for a named subpattern; if it cannot find one and the name - consists entirely of digits, PCRE looks for a subpattern of that num- - ber, which must be greater than zero. Using subpattern names that con- + Perl uses the syntax (?(<name>)...) or (?('name')...) to test for a + used subpattern by name. For compatibility with earlier versions of + PCRE, which had this facility before Perl, the syntax (?(name)...) is + also recognized. However, there is a possible ambiguity with this syn- + tax, because subpattern names may consist entirely of digits. PCRE + looks first for a named subpattern; if it cannot find one and the name + consists entirely of digits, PCRE looks for a subpattern of that num- + ber, which must be greater than zero. Using subpattern names that con- sist entirely of digits is not recommended. Rewriting the above example to use a named subpattern gives this: (?<OPEN> \( )? [^()]+ (?(<OPEN>) \) ) - If the name used in a condition of this kind is a duplicate, the test - is applied to all subpatterns of the same name, and is true if any one + If the name used in a condition of this kind is a duplicate, the test + is applied to all subpatterns of the same name, and is true if any one of them has matched. Checking for pattern recursion If the condition is the string (R), and there is no subpattern with the - name R, the condition is true if a recursive call to the whole pattern + name R, the condition is true if a recursive call to the whole pattern or any subpattern has been made. If digits or a name preceded by amper- sand follow the letter R, for example: @@ -4790,77 +4831,77 @@ CONDITIONAL SUBPATTERNS the condition is true if the most recent recursion is into a subpattern whose number or name is given. This condition does not check the entire - recursion stack. If the name used in a condition of this kind is a + recursion stack. If the name used in a condition of this kind is a duplicate, the test is applied to all subpatterns of the same name, and is true if any one of them is the most recent recursion. - At "top level", all these recursion test conditions are false. The + At "top level", all these recursion test conditions are false. The syntax for recursive patterns is described below. Defining subpatterns for use by reference only - If the condition is the string (DEFINE), and there is no subpattern - with the name DEFINE, the condition is always false. In this case, - there may be only one alternative in the subpattern. It is always - skipped if control reaches this point in the pattern; the idea of - DEFINE is that it can be used to define "subroutines" that can be ref- - erenced from elsewhere. (The use of "subroutines" is described below.) - For example, a pattern to match an IPv4 address could be written like + If the condition is the string (DEFINE), and there is no subpattern + with the name DEFINE, the condition is always false. In this case, + there may be only one alternative in the subpattern. It is always + skipped if control reaches this point in the pattern; the idea of + DEFINE is that it can be used to define "subroutines" that can be ref- + erenced from elsewhere. (The use of "subroutines" is described below.) + For example, a pattern to match an IPv4 address could be written like this (ignore whitespace and line breaks): (?(DEFINE) (?<byte> 2[0-4]\d | 25[0-5] | 1\d\d | [1-9]?\d) ) \b (?&byte) (\.(?&byte)){3} \b - The first part of the pattern is a DEFINE group inside which a another - group named "byte" is defined. This matches an individual component of - an IPv4 address (a number less than 256). When matching takes place, - this part of the pattern is skipped because DEFINE acts like a false - condition. The rest of the pattern uses references to the named group - to match the four dot-separated components of an IPv4 address, insist- + The first part of the pattern is a DEFINE group inside which a another + group named "byte" is defined. This matches an individual component of + an IPv4 address (a number less than 256). When matching takes place, + this part of the pattern is skipped because DEFINE acts like a false + condition. The rest of the pattern uses references to the named group + to match the four dot-separated components of an IPv4 address, insist- ing on a word boundary at each end. Assertion conditions - If the condition is not in any of the above formats, it must be an - assertion. This may be a positive or negative lookahead or lookbehind - assertion. Consider this pattern, again containing non-significant + If the condition is not in any of the above formats, it must be an + assertion. This may be a positive or negative lookahead or lookbehind + assertion. Consider this pattern, again containing non-significant white space, and with the two alternatives on the second line: (?(?=[^a-z]*[a-z]) \d{2}-[a-z]{3}-\d{2} | \d{2}-\d{2}-\d{2} ) - The condition is a positive lookahead assertion that matches an - optional sequence of non-letters followed by a letter. In other words, - it tests for the presence of at least one letter in the subject. If a - letter is found, the subject is matched against the first alternative; - otherwise it is matched against the second. This pattern matches - strings in one of the two forms dd-aaa-dd or dd-dd-dd, where aaa are + The condition is a positive lookahead assertion that matches an + optional sequence of non-letters followed by a letter. In other words, + it tests for the presence of at least one letter in the subject. If a + letter is found, the subject is matched against the first alternative; + otherwise it is matched against the second. This pattern matches + strings in one of the two forms dd-aaa-dd or dd-dd-dd, where aaa are letters and dd are digits. COMMENTS - The sequence (?# marks the start of a comment that continues up to the - next closing parenthesis. Nested parentheses are not permitted. The - characters that make up a comment play no part in the pattern matching + The sequence (?# marks the start of a comment that continues up to the + next closing parenthesis. Nested parentheses are not permitted. The + characters that make up a comment play no part in the pattern matching at all. - If the PCRE_EXTENDED option is set, an unescaped # character outside a - character class introduces a comment that continues to immediately + If the PCRE_EXTENDED option is set, an unescaped # character outside a + character class introduces a comment that continues to immediately after the next newline in the pattern. RECURSIVE PATTERNS - Consider the problem of matching a string in parentheses, allowing for - unlimited nested parentheses. Without the use of recursion, the best - that can be done is to use a pattern that matches up to some fixed - depth of nesting. It is not possible to handle an arbitrary nesting + Consider the problem of matching a string in parentheses, allowing for + unlimited nested parentheses. Without the use of recursion, the best + that can be done is to use a pattern that matches up to some fixed + depth of nesting. It is not possible to handle an arbitrary nesting depth. For some time, Perl has provided a facility that allows regular expres- - sions to recurse (amongst other things). It does this by interpolating - Perl code in the expression at run time, and the code can refer to the + sions to recurse (amongst other things). It does this by interpolating + Perl code in the expression at run time, and the code can refer to the expression itself. A Perl pattern using code interpolation to solve the parentheses problem can be created like this: @@ -4870,182 +4911,182 @@ RECURSIVE PATTERNS refers recursively to the pattern in which it appears. Obviously, PCRE cannot support the interpolation of Perl code. Instead, - it supports special syntax for recursion of the entire pattern, and - also for individual subpattern recursion. After its introduction in - PCRE and Python, this kind of recursion was subsequently introduced + it supports special syntax for recursion of the entire pattern, and + also for individual subpattern recursion. After its introduction in + PCRE and Python, this kind of recursion was subsequently introduced into Perl at release 5.10. - A special item that consists of (? followed by a number greater than + A special item that consists of (? followed by a number greater than zero and a closing parenthesis is a recursive call of the subpattern of - the given number, provided that it occurs inside that subpattern. (If - not, it is a "subroutine" call, which is described in the next sec- - tion.) The special item (?R) or (?0) is a recursive call of the entire + the given number, provided that it occurs inside that subpattern. (If + not, it is a "subroutine" call, which is described in the next sec- + tion.) The special item (?R) or (?0) is a recursive call of the entire regular expression. - This PCRE pattern solves the nested parentheses problem (assume the + This PCRE pattern solves the nested parentheses problem (assume the PCRE_EXTENDED option is set so that white space is ignored): \( ( [^()]++ | (?R) )* \) - First it matches an opening parenthesis. Then it matches any number of - substrings which can either be a sequence of non-parentheses, or a - recursive match of the pattern itself (that is, a correctly parenthe- + First it matches an opening parenthesis. Then it matches any number of + substrings which can either be a sequence of non-parentheses, or a + recursive match of the pattern itself (that is, a correctly parenthe- sized substring). Finally there is a closing parenthesis. Note the use of a possessive quantifier to avoid backtracking into sequences of non- parentheses. - If this were part of a larger pattern, you would not want to recurse + If this were part of a larger pattern, you would not want to recurse the entire pattern, so instead you could use this: ( \( ( [^()]++ | (?1) )* \) ) - We have put the pattern into parentheses, and caused the recursion to + We have put the pattern into parentheses, and caused the recursion to refer to them instead of the whole pattern. - In a larger pattern, keeping track of parenthesis numbers can be - tricky. This is made easier by the use of relative references (a Perl - 5.10 feature). Instead of (?1) in the pattern above you can write + In a larger pattern, keeping track of parenthesis numbers can be + tricky. This is made easier by the use of relative references (a Perl + 5.10 feature). Instead of (?1) in the pattern above you can write (?-2) to refer to the second most recently opened parentheses preceding - the recursion. In other words, a negative number counts capturing + the recursion. In other words, a negative number counts capturing parentheses leftwards from the point at which it is encountered. - It is also possible to refer to subsequently opened parentheses, by - writing references such as (?+2). However, these cannot be recursive - because the reference is not inside the parentheses that are refer- - enced. They are always "subroutine" calls, as described in the next + It is also possible to refer to subsequently opened parentheses, by + writing references such as (?+2). However, these cannot be recursive + because the reference is not inside the parentheses that are refer- + enced. They are always "subroutine" calls, as described in the next section. - An alternative approach is to use named parentheses instead. The Perl - syntax for this is (?&name); PCRE's earlier syntax (?P>name) is also + An alternative approach is to use named parentheses instead. The Perl + syntax for this is (?&name); PCRE's earlier syntax (?P>name) is also supported. We could rewrite the above example as follows: (?<pn> \( ( [^()]++ | (?&pn) )* \) ) - If there is more than one subpattern with the same name, the earliest + If there is more than one subpattern with the same name, the earliest one is used. - This particular example pattern that we have been looking at contains + This particular example pattern that we have been looking at contains nested unlimited repeats, and so the use of a possessive quantifier for matching strings of non-parentheses is important when applying the pat- - tern to strings that do not match. For example, when this pattern is + tern to strings that do not match. For example, when this pattern is applied to (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa() - it yields "no match" quickly. However, if a possessive quantifier is - not used, the match runs for a very long time indeed because there are - so many different ways the + and * repeats can carve up the subject, + it yields "no match" quickly. However, if a possessive quantifier is + not used, the match runs for a very long time indeed because there are + so many different ways the + and * repeats can carve up the subject, and all have to be tested before failure can be reported. - At the end of a match, the values of capturing parentheses are those - from the outermost level. If you want to obtain intermediate values, a - callout function can be used (see below and the pcrecallout documenta- + At the end of a match, the values of capturing parentheses are those + from the outermost level. If you want to obtain intermediate values, a + callout function can be used (see below and the pcrecallout documenta- tion). If the pattern above is matched against (ab(cd)ef) - the value for the inner capturing parentheses (numbered 2) is "ef", - which is the last value taken on at the top level. If a capturing sub- + the value for the inner capturing parentheses (numbered 2) is "ef", + which is the last value taken on at the top level. If a capturing sub- pattern is not matched at the top level, its final value is unset, even if it is (temporarily) set at a deeper level. - If there are more than 15 capturing parentheses in a pattern, PCRE has - to obtain extra memory to store data during a recursion, which it does + If there are more than 15 capturing parentheses in a pattern, PCRE has + to obtain extra memory to store data during a recursion, which it does by using pcre_malloc, freeing it via pcre_free afterwards. If no memory can be obtained, the match fails with the PCRE_ERROR_NOMEMORY error. - Do not confuse the (?R) item with the condition (R), which tests for - recursion. Consider this pattern, which matches text in angle brack- - ets, allowing for arbitrary nesting. Only digits are allowed in nested - brackets (that is, when recursing), whereas any characters are permit- + Do not confuse the (?R) item with the condition (R), which tests for + recursion. Consider this pattern, which matches text in angle brack- + ets, allowing for arbitrary nesting. Only digits are allowed in nested + brackets (that is, when recursing), whereas any characters are permit- ted at the outer level. < (?: (?(R) \d++ | [^<>]*+) | (?R)) * > - In this pattern, (?(R) is the start of a conditional subpattern, with - two different alternatives for the recursive and non-recursive cases. + In this pattern, (?(R) is the start of a conditional subpattern, with + two different alternatives for the recursive and non-recursive cases. The (?R) item is the actual recursive call. Recursion difference from Perl - In PCRE (like Python, but unlike Perl), a recursive subpattern call is + In PCRE (like Python, but unlike Perl), a recursive subpattern call is always treated as an atomic group. That is, once it has matched some of the subject string, it is never re-entered, even if it contains untried - alternatives and there is a subsequent matching failure. This can be - illustrated by the following pattern, which purports to match a palin- - dromic string that contains an odd number of characters (for example, + alternatives and there is a subsequent matching failure. This can be + illustrated by the following pattern, which purports to match a palin- + dromic string that contains an odd number of characters (for example, "a", "aba", "abcba", "abcdcba"): ^(.|(.)(?1)\2)$ The idea is that it either matches a single character, or two identical - characters surrounding a sub-palindrome. In Perl, this pattern works; - in PCRE it does not if the pattern is longer than three characters. + characters surrounding a sub-palindrome. In Perl, this pattern works; + in PCRE it does not if the pattern is longer than three characters. Consider the subject string "abcba": - At the top level, the first character is matched, but as it is not at + At the top level, the first character is matched, but as it is not at the end of the string, the first alternative fails; the second alterna- tive is taken and the recursion kicks in. The recursive call to subpat- - tern 1 successfully matches the next character ("b"). (Note that the + tern 1 successfully matches the next character ("b"). (Note that the beginning and end of line tests are not part of the recursion). - Back at the top level, the next character ("c") is compared with what - subpattern 2 matched, which was "a". This fails. Because the recursion - is treated as an atomic group, there are now no backtracking points, - and so the entire match fails. (Perl is able, at this point, to re- - enter the recursion and try the second alternative.) However, if the + Back at the top level, the next character ("c") is compared with what + subpattern 2 matched, which was "a". This fails. Because the recursion + is treated as an atomic group, there are now no backtracking points, + and so the entire match fails. (Perl is able, at this point, to re- + enter the recursion and try the second alternative.) However, if the pattern is written with the alternatives in the other order, things are different: ^((.)(?1)\2|.)$ - This time, the recursing alternative is tried first, and continues to - recurse until it runs out of characters, at which point the recursion - fails. But this time we do have another alternative to try at the - higher level. That is the big difference: in the previous case the + This time, the recursing alternative is tried first, and continues to + recurse until it runs out of characters, at which point the recursion + fails. But this time we do have another alternative to try at the + higher level. That is the big difference: in the previous case the remaining alternative is at a deeper recursion level, which PCRE cannot use. To change the pattern so that matches all palindromic strings, not just - those with an odd number of characters, it is tempting to change the + those with an odd number of characters, it is tempting to change the pattern to this: ^((.)(?1)\2|.?)$ - Again, this works in Perl, but not in PCRE, and for the same reason. - When a deeper recursion has matched a single character, it cannot be - entered again in order to match an empty string. The solution is to - separate the two cases, and write out the odd and even cases as alter- + Again, this works in Perl, but not in PCRE, and for the same reason. + When a deeper recursion has matched a single character, it cannot be + entered again in order to match an empty string. The solution is to + separate the two cases, and write out the odd and even cases as alter- natives at the higher level: ^(?:((.)(?1)\2|)|((.)(?3)\4|.)) - If you want to match typical palindromic phrases, the pattern has to + If you want to match typical palindromic phrases, the pattern has to ignore all non-word characters, which can be done like this: ^\W*+(?:((.)\W*+(?1)\W*+\2|)|((.)\W*+(?3)\W*+\4|\W*+.\W*+))\W*+$ If run with the PCRE_CASELESS option, this pattern matches phrases such as "A man, a plan, a canal: Panama!" and it works well in both PCRE and - Perl. Note the use of the possessive quantifier *+ to avoid backtrack- - ing into sequences of non-word characters. Without this, PCRE takes a - great deal longer (ten times or more) to match typical phrases, and + Perl. Note the use of the possessive quantifier *+ to avoid backtrack- + ing into sequences of non-word characters. Without this, PCRE takes a + great deal longer (ten times or more) to match typical phrases, and Perl takes so long that you think it has gone into a loop. - WARNING: The palindrome-matching patterns above work only if the sub- - ject string does not start with a palindrome that is shorter than the - entire string. For example, although "abcba" is correctly matched, if - the subject is "ababa", PCRE finds the palindrome "aba" at the start, - then fails at top level because the end of the string does not follow. - Once again, it cannot jump back into the recursion to try other alter- + WARNING: The palindrome-matching patterns above work only if the sub- + ject string does not start with a palindrome that is shorter than the + entire string. For example, although "abcba" is correctly matched, if + the subject is "ababa", PCRE finds the palindrome "aba" at the start, + then fails at top level because the end of the string does not follow. + Once again, it cannot jump back into the recursion to try other alter- natives, so the entire match fails. SUBPATTERNS AS SUBROUTINES If the syntax for a recursive subpattern reference (either by number or - by name) is used outside the parentheses to which it refers, it oper- - ates like a subroutine in a programming language. The "called" subpat- + by name) is used outside the parentheses to which it refers, it oper- + ates like a subroutine in a programming language. The "called" subpat- tern may be defined before or after the reference. A numbered reference can be absolute or relative, as in these examples: @@ -5057,175 +5098,175 @@ SUBPATTERNS AS SUBROUTINES (sens|respons)e and \1ibility - matches "sense and sensibility" and "response and responsibility", but + matches "sense and sensibility" and "response and responsibility", but not "sense and responsibility". If instead the pattern (sens|respons)e and (?1)ibility - is used, it does match "sense and responsibility" as well as the other - two strings. Another example is given in the discussion of DEFINE + is used, it does match "sense and responsibility" as well as the other + two strings. Another example is given in the discussion of DEFINE above. - Like recursive subpatterns, a subroutine call is always treated as an - atomic group. That is, once it has matched some of the subject string, - it is never re-entered, even if it contains untried alternatives and - there is a subsequent matching failure. Any capturing parentheses that - are set during the subroutine call revert to their previous values + Like recursive subpatterns, a subroutine call is always treated as an + atomic group. That is, once it has matched some of the subject string, + it is never re-entered, even if it contains untried alternatives and + there is a subsequent matching failure. Any capturing parentheses that + are set during the subroutine call revert to their previous values afterwards. - When a subpattern is used as a subroutine, processing options such as + When a subpattern is used as a subroutine, processing options such as case-independence are fixed when the subpattern is defined. They cannot be changed for different calls. For example, consider this pattern: (abc)(?i:(?-1)) - It matches "abcabc". It does not match "abcABC" because the change of + It matches "abcabc". It does not match "abcABC" because the change of processing option does not affect the called subpattern. ONIGURUMA SUBROUTINE SYNTAX - For compatibility with Oniguruma, the non-Perl syntax \g followed by a + For compatibility with Oniguruma, the non-Perl syntax \g followed by a name or a number enclosed either in angle brackets or single quotes, is - an alternative syntax for referencing a subpattern as a subroutine, - possibly recursively. Here are two of the examples used above, rewrit- + an alternative syntax for referencing a subpattern as a subroutine, + possibly recursively. Here are two of the examples used above, rewrit- ten using this syntax: (?<pn> \( ( (?>[^()]+) | \g<pn> )* \) ) (sens|respons)e and \g'1'ibility - PCRE supports an extension to Oniguruma: if a number is preceded by a + PCRE supports an extension to Oniguruma: if a number is preceded by a plus or a minus sign it is taken as a relative reference. For example: (abc)(?i:\g<-1>) - Note that \g{...} (Perl syntax) and \g<...> (Oniguruma syntax) are not - synonymous. The former is a back reference; the latter is a subroutine + Note that \g{...} (Perl syntax) and \g<...> (Oniguruma syntax) are not + synonymous. The former is a back reference; the latter is a subroutine call. CALLOUTS Perl has a feature whereby using the sequence (?{...}) causes arbitrary - Perl code to be obeyed in the middle of matching a regular expression. + Perl code to be obeyed in the middle of matching a regular expression. This makes it possible, amongst other things, to extract different sub- strings that match the same pair of parentheses when there is a repeti- tion. PCRE provides a similar feature, but of course it cannot obey arbitrary Perl code. The feature is called "callout". The caller of PCRE provides - an external function by putting its entry point in the global variable - pcre_callout. By default, this variable contains NULL, which disables + an external function by putting its entry point in the global variable + pcre_callout. By default, this variable contains NULL, which disables all calling out. - Within a regular expression, (?C) indicates the points at which the - external function is to be called. If you want to identify different - callout points, you can put a number less than 256 after the letter C. - The default value is zero. For example, this pattern has two callout + Within a regular expression, (?C) indicates the points at which the + external function is to be called. If you want to identify different + callout points, you can put a number less than 256 after the letter C. + The default value is zero. For example, this pattern has two callout points: (?C1)abc(?C2)def If the PCRE_AUTO_CALLOUT flag is passed to pcre_compile(), callouts are - automatically installed before each item in the pattern. They are all + automatically installed before each item in the pattern. They are all numbered 255. During matching, when PCRE reaches a callout point (and pcre_callout is - set), the external function is called. It is provided with the number - of the callout, the position in the pattern, and, optionally, one item - of data originally supplied by the caller of pcre_exec(). The callout - function may cause matching to proceed, to backtrack, or to fail alto- + set), the external function is called. It is provided with the number + of the callout, the position in the pattern, and, optionally, one item + of data originally supplied by the caller of pcre_exec(). The callout + function may cause matching to proceed, to backtrack, or to fail alto- gether. A complete description of the interface to the callout function is given in the pcrecallout documentation. BACKTRACKING CONTROL - Perl 5.10 introduced a number of "Special Backtracking Control Verbs", + Perl 5.10 introduced a number of "Special Backtracking Control Verbs", which are described in the Perl documentation as "experimental and sub- - ject to change or removal in a future version of Perl". It goes on to - say: "Their usage in production code should be noted to avoid problems + ject to change or removal in a future version of Perl". It goes on to + say: "Their usage in production code should be noted to avoid problems during upgrades." The same remarks apply to the PCRE features described in this section. - Since these verbs are specifically related to backtracking, most of - them can be used only when the pattern is to be matched using + Since these verbs are specifically related to backtracking, most of + them can be used only when the pattern is to be matched using pcre_exec(), which uses a backtracking algorithm. With the exception of (*FAIL), which behaves like a failing negative assertion, they cause an error if encountered by pcre_dfa_exec(). If any of these verbs are used in an assertion or subroutine subpattern - (including recursive subpatterns), their effect is confined to that - subpattern; it does not extend to the surrounding pattern. Note that - such subpatterns are processed as anchored at the point where they are + (including recursive subpatterns), their effect is confined to that + subpattern; it does not extend to the surrounding pattern. Note that + such subpatterns are processed as anchored at the point where they are tested. - The new verbs make use of what was previously invalid syntax: an open- + The new verbs make use of what was previously invalid syntax: an open- ing parenthesis followed by an asterisk. They are generally of the form - (*VERB) or (*VERB:NAME). Some may take either form, with differing be- + (*VERB) or (*VERB:NAME). Some may take either form, with differing be- haviour, depending on whether or not an argument is present. An name is - a sequence of letters, digits, and underscores. If the name is empty, - that is, if the closing parenthesis immediately follows the colon, the + a sequence of letters, digits, and underscores. If the name is empty, + that is, if the closing parenthesis immediately follows the colon, the effect is as if the colon were not there. Any number of these verbs may occur in a pattern. - PCRE contains some optimizations that are used to speed up matching by + PCRE contains some optimizations that are used to speed up matching by running some checks at the start of each match attempt. For example, it - may know the minimum length of matching subject, or that a particular - character must be present. When one of these optimizations suppresses - the running of a match, any included backtracking verbs will not, of + may know the minimum length of matching subject, or that a particular + character must be present. When one of these optimizations suppresses + the running of a match, any included backtracking verbs will not, of course, be processed. You can suppress the start-of-match optimizations by setting the PCRE_NO_START_OPTIMIZE option when calling pcre_exec(). Verbs that act immediately - The following verbs act as soon as they are encountered. They may not + The following verbs act as soon as they are encountered. They may not be followed by a name. (*ACCEPT) - This verb causes the match to end successfully, skipping the remainder - of the pattern. When inside a recursion, only the innermost pattern is - ended immediately. If (*ACCEPT) is inside capturing parentheses, the - data so far is captured. (This feature was added to PCRE at release + This verb causes the match to end successfully, skipping the remainder + of the pattern. When inside a recursion, only the innermost pattern is + ended immediately. If (*ACCEPT) is inside capturing parentheses, the + data so far is captured. (This feature was added to PCRE at release 8.00.) For example: A((?:A|B(*ACCEPT)|C)D) - This matches "AB", "AAD", or "ACD"; when it matches "AB", "B" is cap- + This matches "AB", "AAD", or "ACD"; when it matches "AB", "B" is cap- tured by the outer parentheses. (*FAIL) or (*F) - This verb causes the match to fail, forcing backtracking to occur. It - is equivalent to (?!) but easier to read. The Perl documentation notes - that it is probably useful only when combined with (?{}) or (??{}). - Those are, of course, Perl features that are not present in PCRE. The - nearest equivalent is the callout feature, as for example in this pat- + This verb causes the match to fail, forcing backtracking to occur. It + is equivalent to (?!) but easier to read. The Perl documentation notes + that it is probably useful only when combined with (?{}) or (??{}). + Those are, of course, Perl features that are not present in PCRE. The + nearest equivalent is the callout feature, as for example in this pat- tern: a+(?C)(*FAIL) - A match with the string "aaaa" always fails, but the callout is taken + A match with the string "aaaa" always fails, but the callout is taken before each backtrack happens (in this example, 10 times). Recording which path was taken - There is one verb whose main purpose is to track how a match was - arrived at, though it also has a secondary use in conjunction with + There is one verb whose main purpose is to track how a match was + arrived at, though it also has a secondary use in conjunction with advancing the match starting point (see (*SKIP) below). (*MARK:NAME) or (*:NAME) - A name is always required with this verb. There may be as many - instances of (*MARK) as you like in a pattern, and their names do not + A name is always required with this verb. There may be as many + instances of (*MARK) as you like in a pattern, and their names do not have to be unique. - When a match succeeds, the name of the last-encountered (*MARK) is - passed back to the caller via the pcre_extra data structure, as + When a match succeeds, the name of the last-encountered (*MARK) is + passed back to the caller via the pcre_extra data structure, as described in the section on pcre_extra in the pcreapi documentation. No - data is returned for a partial match. Here is an example of pcretest - output, where the /K modifier requests the retrieval and outputting of + data is returned for a partial match. Here is an example of pcretest + output, where the /K modifier requests the retrieval and outputting of (*MARK) data: /X(*MARK:A)Y|X(*MARK:B)Z/K @@ -5237,13 +5278,13 @@ BACKTRACKING CONTROL MK: B The (*MARK) name is tagged with "MK:" in this output, and in this exam- - ple it indicates which of the two alternatives matched. This is a more - efficient way of obtaining this information than putting each alterna- + ple it indicates which of the two alternatives matched. This is a more + efficient way of obtaining this information than putting each alterna- tive in its own capturing parentheses. - A name may also be returned after a failed match if the final path - through the pattern involves (*MARK). However, unless (*MARK) used in - conjunction with (*COMMIT), this is unlikely to happen for an unan- + A name may also be returned after a failed match if the final path + through the pattern involves (*MARK). However, unless (*MARK) used in + conjunction with (*COMMIT), this is unlikely to happen for an unan- chored pattern because, as the starting point for matching is advanced, the final check is often with an empty string, causing a failure before (*MARK) is reached. For example: @@ -5253,56 +5294,56 @@ BACKTRACKING CONTROL No match There are three potential starting points for this match (starting with - X, starting with P, and with an empty string). If the pattern is + X, starting with P, and with an empty string). If the pattern is anchored, the result is different: /^X(*MARK:A)Y|^X(*MARK:B)Z/K XP No match, mark = B - PCRE's start-of-match optimizations can also interfere with this. For - example, if, as a result of a call to pcre_study(), it knows the mini- - mum subject length for a match, a shorter subject will not be scanned + PCRE's start-of-match optimizations can also interfere with this. For + example, if, as a result of a call to pcre_study(), it knows the mini- + mum subject length for a match, a shorter subject will not be scanned at all. Note that similar anomalies (though different in detail) exist in Perl, - no doubt for the same reasons. The use of (*MARK) data after a failed - match of an unanchored pattern is not recommended, unless (*COMMIT) is + no doubt for the same reasons. The use of (*MARK) data after a failed + match of an unanchored pattern is not recommended, unless (*COMMIT) is involved. Verbs that act after backtracking The following verbs do nothing when they are encountered. Matching con- - tinues with what follows, but if there is no subsequent match, causing - a backtrack to the verb, a failure is forced. That is, backtracking - cannot pass to the left of the verb. However, when one of these verbs - appears inside an atomic group, its effect is confined to that group, - because once the group has been matched, there is never any backtrack- - ing into it. In this situation, backtracking can "jump back" to the - left of the entire atomic group. (Remember also, as stated above, that + tinues with what follows, but if there is no subsequent match, causing + a backtrack to the verb, a failure is forced. That is, backtracking + cannot pass to the left of the verb. However, when one of these verbs + appears inside an atomic group, its effect is confined to that group, + because once the group has been matched, there is never any backtrack- + ing into it. In this situation, backtracking can "jump back" to the + left of the entire atomic group. (Remember also, as stated above, that this localization also applies in subroutine calls and assertions.) - These verbs differ in exactly what kind of failure occurs when back- + These verbs differ in exactly what kind of failure occurs when back- tracking reaches them. (*COMMIT) - This verb, which may not be followed by a name, causes the whole match + This verb, which may not be followed by a name, causes the whole match to fail outright if the rest of the pattern does not match. Even if the pattern is unanchored, no further attempts to find a match by advancing the starting point take place. Once (*COMMIT) has been passed, - pcre_exec() is committed to finding a match at the current starting + pcre_exec() is committed to finding a match at the current starting point, or not at all. For example: a+(*COMMIT)b - This matches "xxaab" but not "aacaab". It can be thought of as a kind + This matches "xxaab" but not "aacaab". It can be thought of as a kind of dynamic anchor, or "I've started, so I must finish." The name of the - most recently passed (*MARK) in the path is passed back when (*COMMIT) + most recently passed (*MARK) in the path is passed back when (*COMMIT) forces a match failure. - Note that (*COMMIT) at the start of a pattern is not the same as an - anchor, unless PCRE's start-of-match optimizations are turned off, as + Note that (*COMMIT) at the start of a pattern is not the same as an + anchor, unless PCRE's start-of-match optimizations are turned off, as shown in this pcretest example: /(*COMMIT)abc/ @@ -5311,71 +5352,71 @@ BACKTRACKING CONTROL xyzabc\Y No match - PCRE knows that any match must start with "a", so the optimization - skips along the subject to "a" before running the first match attempt, - which succeeds. When the optimization is disabled by the \Y escape in + PCRE knows that any match must start with "a", so the optimization + skips along the subject to "a" before running the first match attempt, + which succeeds. When the optimization is disabled by the \Y escape in the second subject, the match starts at "x" and so the (*COMMIT) causes it to fail without trying any other starting points. (*PRUNE) or (*PRUNE:NAME) - This verb causes the match to fail at the current starting position in - the subject if the rest of the pattern does not match. If the pattern - is unanchored, the normal "bumpalong" advance to the next starting - character then happens. Backtracking can occur as usual to the left of - (*PRUNE), before it is reached, or when matching to the right of - (*PRUNE), but if there is no match to the right, backtracking cannot - cross (*PRUNE). In simple cases, the use of (*PRUNE) is just an alter- - native to an atomic group or possessive quantifier, but there are some + This verb causes the match to fail at the current starting position in + the subject if the rest of the pattern does not match. If the pattern + is unanchored, the normal "bumpalong" advance to the next starting + character then happens. Backtracking can occur as usual to the left of + (*PRUNE), before it is reached, or when matching to the right of + (*PRUNE), but if there is no match to the right, backtracking cannot + cross (*PRUNE). In simple cases, the use of (*PRUNE) is just an alter- + native to an atomic group or possessive quantifier, but there are some uses of (*PRUNE) that cannot be expressed in any other way. The behav- - iour of (*PRUNE:NAME) is the same as (*MARK:NAME)(*PRUNE) when the - match fails completely; the name is passed back if this is the final - attempt. (*PRUNE:NAME) does not pass back a name if the match suc- - ceeds. In an anchored pattern (*PRUNE) has the same effect as (*COM- + iour of (*PRUNE:NAME) is the same as (*MARK:NAME)(*PRUNE) when the + match fails completely; the name is passed back if this is the final + attempt. (*PRUNE:NAME) does not pass back a name if the match suc- + ceeds. In an anchored pattern (*PRUNE) has the same effect as (*COM- MIT). (*SKIP) - This verb, when given without a name, is like (*PRUNE), except that if - the pattern is unanchored, the "bumpalong" advance is not to the next + This verb, when given without a name, is like (*PRUNE), except that if + the pattern is unanchored, the "bumpalong" advance is not to the next character, but to the position in the subject where (*SKIP) was encoun- - tered. (*SKIP) signifies that whatever text was matched leading up to + tered. (*SKIP) signifies that whatever text was matched leading up to it cannot be part of a successful match. Consider: a+(*SKIP)b - If the subject is "aaaac...", after the first match attempt fails - (starting at the first character in the string), the starting point + If the subject is "aaaac...", after the first match attempt fails + (starting at the first character in the string), the starting point skips on to start the next attempt at "c". Note that a possessive quan- - tifer does not have the same effect as this example; although it would - suppress backtracking during the first match attempt, the second - attempt would start at the second character instead of skipping on to + tifer does not have the same effect as this example; although it would + suppress backtracking during the first match attempt, the second + attempt would start at the second character instead of skipping on to "c". (*SKIP:NAME) - When (*SKIP) has an associated name, its behaviour is modified. If the + When (*SKIP) has an associated name, its behaviour is modified. If the following pattern fails to match, the previous path through the pattern - is searched for the most recent (*MARK) that has the same name. If one - is found, the "bumpalong" advance is to the subject position that cor- - responds to that (*MARK) instead of to where (*SKIP) was encountered. - If no (*MARK) with a matching name is found, normal "bumpalong" of one + is searched for the most recent (*MARK) that has the same name. If one + is found, the "bumpalong" advance is to the subject position that cor- + responds to that (*MARK) instead of to where (*SKIP) was encountered. + If no (*MARK) with a matching name is found, normal "bumpalong" of one character happens (the (*SKIP) is ignored). (*THEN) or (*THEN:NAME) This verb causes a skip to the next alternation if the rest of the pat- tern does not match. That is, it cancels pending backtracking, but only - within the current alternation. Its name comes from the observation + within the current alternation. Its name comes from the observation that it can be used for a pattern-based if-then-else block: ( COND1 (*THEN) FOO | COND2 (*THEN) BAR | COND3 (*THEN) BAZ ) ... - If the COND1 pattern matches, FOO is tried (and possibly further items - after the end of the group if FOO succeeds); on failure the matcher - skips to the second alternative and tries COND2, without backtracking - into COND1. The behaviour of (*THEN:NAME) is exactly the same as - (*MARK:NAME)(*THEN) if the overall match fails. If (*THEN) is not + If the COND1 pattern matches, FOO is tried (and possibly further items + after the end of the group if FOO succeeds); on failure the matcher + skips to the second alternative and tries COND2, without backtracking + into COND1. The behaviour of (*THEN:NAME) is exactly the same as + (*MARK:NAME)(*THEN) if the overall match fails. If (*THEN) is not directly inside an alternation, it acts like (*PRUNE). @@ -5393,11 +5434,11 @@ AUTHOR REVISION - Last updated: 27 March 2010 + Last updated: 05 May 2010 Copyright (c) 1997-2010 University of Cambridge. ------------------------------------------------------------------------------ - - + + PCRESYNTAX(3) PCRESYNTAX(3) @@ -5441,6 +5482,7 @@ CHARACTER TYPES \D a character that is not a decimal digit \h a horizontal whitespace character \H a character that is not a horizontal whitespace character + \N a character that is not a newline \p{xx} a character with the xx property \P{xx} a character without the xx property \R a newline sequence @@ -5455,7 +5497,7 @@ CHARACTER TYPES In PCRE, \d, \D, \s, \S, \w, and \W recognize only ASCII characters. -GENERAL CATEGORY PROPERTY CODES FOR \p and \P +GENERAL CATEGORY PROPERTIES FOR \p and \P C Other Cc Control @@ -5503,6 +5545,14 @@ GENERAL CATEGORY PROPERTY CODES FOR \p and \P Zs Space separator +PCRE SPECIAL CATEGORY PROPERTIES FOR \p and \P + + Xan Alphanumeric: union of properties L and N + Xps POSIX space: property Z or tab, NL, VT, FF, CR + Xsp Perl space: property Z or tab, NL, FF, CR + Xwd Perl word: property Xan or underscore + + SCRIPT NAMES FOR \p AND \P Arabic, Armenian, Avestan, Balinese, Bamum, Bengali, Bopomofo, Braille, @@ -5749,11 +5799,11 @@ AUTHOR REVISION - Last updated: 01 March 2010 + Last updated: 05 May 2010 Copyright (c) 1997-2010 University of Cambridge. ------------------------------------------------------------------------------ - - + + PCREPARTIAL(3) PCREPARTIAL(3) @@ -6134,8 +6184,8 @@ REVISION Last updated: 19 October 2009 Copyright (c) 1997-2009 University of Cambridge. ------------------------------------------------------------------------------ - - + + PCREPRECOMPILE(3) PCREPRECOMPILE(3) @@ -6258,8 +6308,8 @@ REVISION Last updated: 13 June 2007 Copyright (c) 1997-2007 University of Cambridge. ------------------------------------------------------------------------------ - - + + PCREPERFORM(3) PCREPERFORM(3) @@ -6418,8 +6468,8 @@ REVISION Last updated: 07 March 2010 Copyright (c) 1997-2010 University of Cambridge. ------------------------------------------------------------------------------ - - + + PCREPOSIX(3) PCREPOSIX(3) @@ -6674,8 +6724,8 @@ REVISION Last updated: 02 September 2009 Copyright (c) 1997-2009 University of Cambridge. ------------------------------------------------------------------------------ - - + + PCRECPP(3) PCRECPP(3) @@ -7015,8 +7065,8 @@ REVISION Last updated: 17 March 2009 ------------------------------------------------------------------------------ - - + + PCRESAMPLE(3) PCRESAMPLE(3) @@ -7245,5 +7295,5 @@ REVISION Last updated: 03 January 2010 Copyright (c) 1997-2010 University of Cambridge. ------------------------------------------------------------------------------ - - + + diff --git a/doc/pcre_compile.3 b/doc/pcre_compile.3 index e64288a..f0861d7 100644 --- a/doc/pcre_compile.3 +++ b/doc/pcre_compile.3 @@ -55,11 +55,12 @@ The option bits are: PCRE_NO_UTF8_CHECK Do not check the pattern for UTF-8 validity (only relevant if PCRE_UTF8 is set) + PCRE_UCP Use Unicode properties for \ed, \ew, etc. PCRE_UNGREEDY Invert greediness of quantifiers PCRE_UTF8 Run in UTF-8 mode .sp PCRE must be built with UTF-8 support in order to use PCRE_UTF8 and -PCRE_NO_UTF8_CHECK. +PCRE_NO_UTF8_CHECK, and with UCP support if PCRE_UCP is used. .P The yield of the function is a pointer to a private data structure that contains the compiled pattern, or NULL if an error was detected. Note that diff --git a/doc/pcre_compile2.3 b/doc/pcre_compile2.3 index b358cd4..907e8ff 100644 --- a/doc/pcre_compile2.3 +++ b/doc/pcre_compile2.3 @@ -59,11 +59,12 @@ The option bits are: PCRE_NO_UTF8_CHECK Do not check the pattern for UTF-8 validity (only relevant if PCRE_UTF8 is set) + PCRE_UCP Use Unicode properties for \ed, \ew, etc. PCRE_UNGREEDY Invert greediness of quantifiers PCRE_UTF8 Run in UTF-8 mode .sp PCRE must be built with UTF-8 support in order to use PCRE_UTF8 and -PCRE_NO_UTF8_CHECK. +PCRE_NO_UTF8_CHECK, and with UCP support if PCRE_UCP is used. .P The yield of the function is a pointer to a private data structure that contains the compiled pattern, or NULL if an error was detected. Note that diff --git a/doc/pcreapi.3 b/doc/pcreapi.3 index 90c28ac..724dd98 100644 --- a/doc/pcreapi.3 +++ b/doc/pcreapi.3 @@ -636,6 +636,24 @@ were followed by ?: but named parentheses can still be used for capturing (and they acquire numbers in the usual way). There is no equivalent of this option in Perl. .sp + PCRE_UCP +.sp +This option changes the way PCRE processes \eb, \ed, \es, \ew, and some of the +POSIX character classes. By default, only ASCII characters are recognized, but +if PCRE_UCP is set, Unicode properties are used instead to classify characters. +More details are given in the section on +.\" HTML <a href="pcre.html#genericchartypes"> +.\" </a> +generic character types +.\" +in the +.\" HREF +\fBpcrepattern\fP +.\" +page. If you set PCRE_UCP, matching one of the items it affects takes much +longer. The option is available only if PCRE has been compiled with Unicode +property support. +.sp PCRE_UNGREEDY .sp This option inverts the "greediness" of the quantifiers so that they are not @@ -756,6 +774,7 @@ out of use. To avoid confusion, they have not been re-used. 64 ] is an invalid data character in JavaScript compatibility mode 65 different names for subpatterns of the same number are not allowed 66 (*MARK) must have an argument + 67 this version of PCRE is not compiled with PCRE_UCP support .sp The numbers 32 and 10000 in errors 48 and 49 are defaults; different values may be used if the limits were changed when PCRE was built. @@ -830,11 +849,13 @@ matching. PCRE handles caseless matching, and determines whether characters are letters, digits, or whatever, by reference to a set of tables, indexed by character value. When running in UTF-8 mode, this applies only to characters with codes -less than 128. Higher-valued codes never match escapes such as \ew or \ed, but -can be tested with \ep if PCRE is built with Unicode character property -support. The use of locales with Unicode is discouraged. If you are handling -characters with codes greater than 128, you should either use UTF-8 and -Unicode, or use locales, but not try to mix the two. +less than 128. By default, higher-valued codes never match escapes such as \ew +or \ed, but they can be tested with \ep if PCRE is built with Unicode character +property support. Alternatively, the PCRE_UCP option can be set at compile +time; this causes \ew and friends to use Unicode property support instead of +built-in tables. The use of locales with Unicode is discouraged. If you are +handling characters with codes greater than 128, you should either use UTF-8 +and Unicode, or use locales, but not try to mix the two. .P PCRE contains an internal set of tables that are used when the final argument of \fBpcre_compile()\fP is NULL. These are sufficient for many applications. @@ -2100,6 +2121,6 @@ Cambridge CB2 3QH, England. .rs .sp .nf -Last updated: 03 May 2010 +Last updated: 16 May 2010 Copyright (c) 1997-2010 University of Cambridge. .fi diff --git a/doc/pcrecompat.3 b/doc/pcrecompat.3 index e5c683c..6c1adda 100644 --- a/doc/pcrecompat.3 +++ b/doc/pcrecompat.3 @@ -6,7 +6,7 @@ PCRE - Perl-compatible regular expressions .sp This document describes the differences in the ways that PCRE and Perl handle regular expressions. The differences described here are with respect to Perl -5.10. +5.10/5.11. .P 1. PCRE has only a subset of Perl's UTF-8 and Unicode support. Details of what it does have are given in the @@ -93,11 +93,7 @@ page. strings when part of a pattern is repeated. For example, matching "aba" against the pattern /^(a(b)?)+$/ in Perl leaves $2 unset, but in PCRE it is set to "b". .P -11. PCRE does support Perl 5.10's backtracking verbs (*ACCEPT), (*FAIL), (*F), -(*COMMIT), (*PRUNE), (*SKIP), and (*THEN), but only in the forms without an -argument. PCRE does not support (*MARK). -.P -12. PCRE's handling of duplicate subpattern numbers and duplicate subpattern +11. PCRE's handling of duplicate subpattern numbers and duplicate subpattern names is not as general as Perl's. This is a consequence of the fact the PCRE works internally just with numbers, using an external table to translate between numbers and names. In particular, a pattern such as (?|(?<a>A)|(?<b)B), @@ -107,7 +103,7 @@ would not be possible to distinguish which parentheses matched, because both names map to capturing subpattern number 1. To avoid this confusing situation, an error is given at compile time. .P -13. PCRE provides some extensions to the Perl regular expression facilities. +12. PCRE provides some extensions to the Perl regular expression facilities. Perl 5.10 includes new features that are not in earlier versions of Perl, some of which (such as named parentheses) have been in PCRE for some time. This list is with respect to Perl 5.10: @@ -164,6 +160,6 @@ Cambridge CB2 3QH, England. .rs .sp .nf -Last updated: 04 October 2009 -Copyright (c) 1997-2009 University of Cambridge. +Last updated: 12 May 2010 +Copyright (c) 1997-2010 University of Cambridge. .fi diff --git a/doc/pcrepattern.3 b/doc/pcrepattern.3 index 4552c59..1ec6b80 100644 --- a/doc/pcrepattern.3 +++ b/doc/pcrepattern.3 @@ -42,6 +42,16 @@ in the main .\" page. .P +Another special sequence that may appear at the start of a pattern or in +combination with (*UTF8) is: +.sp + (*UCP) +.sp +This has the same effect as setting the PCRE_UCP option: it causes sequences +such as \ed and \ew to use Unicode properties to determine character types, +instead of recognizing only characters with codes less than 128 via a lookup +table. +.P The remainder of this document discusses the patterns that are supported by PCRE when its main matching function, \fBpcre_exec()\fP, is used. From release 6.0, PCRE offers a second matching function, @@ -340,6 +350,7 @@ subroutine call. . . +.\" HTML <a name="genericchartypes"></a> .SS "Generic character types" .rs .sp @@ -366,11 +377,9 @@ when PCRE_DOTALL is not set. .P Each pair of lower and upper case escape sequences partitions the complete set of characters into two disjoint sets. Any given character matches one, and only -one, of each pair. -.P -These character type sequences can appear both inside and outside character +one, of each pair. The sequences can appear both inside and outside character classes. They each match one character of the appropriate type. If the current -matching point is at the end of the subject string, all of them fail, since +matching point is at the end of the subject string, all of them fail, because there is no character to match. .P For compatibility with Perl, \es does not match the VT character (code 11). @@ -379,16 +388,44 @@ are HT (9), LF (10), FF (12), CR (13), and space (32). If "use locale;" is included in a Perl script, \es may match the VT character. In PCRE, it never does. .P -In UTF-8 mode, characters with values greater than 128 never match \ed, \es, or -\ew, and always match \eD, \eS, and \eW. This is true even when Unicode -character property support is available. These sequences retain their original -meanings from before UTF-8 support was available, mainly for efficiency -reasons. Note that this also affects \eb, because it is defined in terms of \ew -and \eW. +A "word" character is an underscore or any character that is a letter or digit. +By default, the definition of letters and digits is controlled by PCRE's +low-valued character tables, and may vary if locale-specific matching is taking +place (see +.\" HTML <a href="pcreapi.html#localesupport"> +.\" </a> +"Locale support" +.\" +in the +.\" HREF +\fBpcreapi\fP +.\" +page). For example, in a French locale such as "fr_FR" in Unix-like systems, +or "french" in Windows, some character codes greater than 128 are used for +accented letters, and these are then matched by \ew. The use of locales with +Unicode is discouraged. +.P +By default, in UTF-8 mode, characters with values greater than 128 never match +\ed, \es, or \ew, and always match \eD, \eS, and \eW. These sequences retain +their original meanings from before UTF-8 support was available, mainly for +efficiency reasons. However, if PCRE is compiled with Unicode property support, +and the PCRE_UCP option is set, the behaviour is changed so that Unicode +properties are used to determine character types, as follows: +.sp + \ed any character that \ep{Nd} matches (decimal digit) + \es any character that \ep{Z} matches, plus HT, LF, FF, CR + \ew any character that \ep{L} or \ep{N} matches, plus underscore +.sp +The upper case escapes match the inverse sets of characters. Note that \ed +matches only decimal digits, whereas \ew matches any Unicode digit, as well as +any Unicode letter, and underscore. Note also that PCRE_UCP affects \eb, and +\eB because they are defined in terms of \ew and \eW. Matching these sequences +is noticeably slower when PCRE_UCP is set. .P The sequences \eh, \eH, \ev, and \eV are Perl 5.10 features. In contrast to the -other sequences, these do match certain high-valued codepoints in UTF-8 mode. -The horizontal space characters are: +other sequences, which match only ASCII characters by default, these always +match certain high-valued codepoints in UTF-8 mode, whether or not PCRE_UCP is +set. The horizontal space characters are: .sp U+0009 Horizontal tab U+0020 Space @@ -419,23 +456,6 @@ The vertical space characters are: U+0085 Next line U+2028 Line separator U+2029 Paragraph separator -.P -A "word" character is an underscore or any character less than 256 that is a -letter or digit. The definition of letters and digits is controlled by PCRE's -low-valued character tables, and may vary if locale-specific matching is taking -place (see -.\" HTML <a href="pcreapi.html#localesupport"> -.\" </a> -"Locale support" -.\" -in the -.\" HREF -\fBpcreapi\fP -.\" -page). For example, in a French locale such as "fr_FR" in Unix-like systems, -or "french" in Windows, some character codes greater than 128 are used for -accented letters, and these are matched by \ew. The use of locales with Unicode -is discouraged. . . .\" HTML <a name="newlineseq"></a> @@ -481,13 +501,13 @@ These override the default and the options given to \fBpcre_compile()\fP or which are not Perl-compatible, are recognized only at the very start of a pattern, and that they must be in upper case. If more than one of them is present, the last one is used. They can be combined with a change of newline -convention, for example, a pattern can start with: +convention; for example, a pattern can start with: .sp (*ANY)(*BSR_ANYCRLF) .sp -Inside a character class, \eR is treated as an unrecognized escape sequence, -and so matches the letter "R" by default, but causes an error if PCRE_EXTRA is -set. +They can also be combined with the (*UTF8) or (*UCP) special sequences. Inside +a character class, \eR is treated as an unrecognized escape sequence, and so +matches the letter "R" by default, but causes an error if PCRE_EXTRA is set. . . .\" HTML <a name="uniextseq"></a> @@ -721,7 +741,9 @@ non-UTF-8 mode \eX matches any one character. Matching characters by Unicode property is not fast, because PCRE has to search a structure that contains data for over fifteen thousand characters. That is why the traditional escape sequences such as \ed and \ew do not use Unicode -properties in PCRE. +properties in PCRE by default, though you can make them do so by setting the +PCRE_UCP option for \fBpcre_compile()\fP or by starting the pattern with +(*UCP). . . .\" HTML <a name="extraprops"></a> @@ -731,7 +753,8 @@ properties in PCRE. As well as the standard Unicode properties described in the previous section, PCRE supports four more that make it possible to convert traditional escape sequences such as \ew and \es and POSIX character classes to use Unicode -properties. These are: +properties. PCRE uses these non-standard, non-Perl properties internally when +PCRE_UCP is set. They are: .sp Xan Any alphanumeric character Xps Any POSIX space character @@ -810,10 +833,12 @@ escape sequence" error is generated instead. A word boundary is a position in the subject string where the current character and the previous character do not both match \ew or \eW (i.e. one matches \ew and the other matches \eW), or the start or end of the string if the -first or last character matches \ew, respectively. Neither PCRE nor Perl has a -separte "start of word" or "end of word" metasequence. However, whatever -follows \eb normally determines which it is. For example, the fragment -\eba matches "a" at the start of a word. +first or last character matches \ew, respectively. In UTF-8 mode, the meanings +of \ew and \eW can be changed by setting the PCRE_UCP option. When this is +done, it also affects \eb and \eB. Neither PCRE nor Perl has a separate "start +of word" or "end of word" metasequence. However, whatever follows \eb normally +determines which it is. For example, the fragment \eba matches "a" at the start +of a word. .P The \eA, \eZ, and \ez assertions differ from the traditional circumflex and dollar (described in the next section) in that they only ever match at the very @@ -1018,12 +1043,12 @@ characters in both cases. In UTF-8 mode, PCRE supports the concept of case for characters with values greater than 128 only when it is compiled with Unicode property support. .P -The character types \ed, \eD, \ep, \eP, \es, \eS, \ew, and \eW may also appear -in a character class, and add the characters that they match to the class. For -example, [\edABCDEF] matches any hexadecimal digit. A circumflex can -conveniently be used with the upper case character types to specify a more -restricted set of characters than the matching lower case type. For example, -the class [^\eW_] matches any letter or digit, but not underscore. +The character types \ed, \eD, \eh, \eH, \ep, \eP, \es, \eS, \ev, \eV, \ew, and +\eW may also appear in a character class, and add the characters that they +match to the class. For example, [\edABCDEF] matches any hexadecimal digit. A +circumflex can conveniently be used with the upper case character types to +specify a more restricted set of characters than the matching lower case type. +For example, the class [^\eW_] matches any letter or digit, but not underscore. .P The only metacharacters that are recognized in character classes are backslash, hyphen (only where it can be interpreted as specifying a range), circumflex @@ -1043,7 +1068,7 @@ this notation. For example, [01[:alpha:]%] .sp matches "0", "1", any alphabetic character, or "%". The supported class names -are +are: .sp alnum letters and digits alpha letters @@ -1054,7 +1079,7 @@ are graph printing characters, excluding space lower lower case letters print printing characters, including space - punct printing characters, excluding letters and digits + punct printing characters, excluding letters and digits and space space white space (not quite the same as \es) upper upper case letters word "word" characters (same as \ew) @@ -1075,8 +1100,24 @@ matches "1", "2", or any non-digit. PCRE (and Perl) also recognize the POSIX syntax [.ch.] and [=ch=] where "ch" is a "collating element", but these are not supported, and an error is given if they are encountered. .P -In UTF-8 mode, characters with values greater than 128 do not match any of -the POSIX character classes. +By default, in UTF-8 mode, characters with values greater than 128 do not match +any of the POSIX character classes. However, if the PCRE_UCP option is passed +to \fBpcre_compile()\fP, some of the classes are changed so that Unicode +character properties are used. This is achieved by replacing the POSIX classes +by other sequences, as follows: +.sp + [:alnum:] becomes \ep{Xan} + [:alpha:] becomes \ep{L} + [:blank:] becomes \eh + [:digit:] becomes \ep{Nd} + [:lower:] becomes \ep{Ll} + [:space:] becomes \ep{Xps} + [:upper:] becomes \ep{Lu} + [:word:] becomes \ep{Xwd} +.sp +Negated versions, such as [:^alpha:] use \eP instead of \ep. The other POSIX +classes are unchanged, and match only characters with code points less than +128. . . .SH "VERTICAL BAR" @@ -1155,8 +1196,9 @@ section entitled .\" </a> "Newline sequences" .\" -above. There is also the (*UTF8) leading sequence that can be used to set UTF-8 -mode; this is equivalent to setting the PCRE_UTF8 option. +above. There are also the (*UTF8) and (*UCP) leading sequences that can be used +to set UTF-8 and Unicode property modes; they are equivalent to setting the +PCRE_UTF8 and the PCRE_UCP options, respectively. . . .\" HTML <a name="subpattern"></a> @@ -2624,6 +2666,6 @@ Cambridge CB2 3QH, England. .rs .sp .nf -Last updated: 05 May 2010 +Last updated: 18 May 2010 Copyright (c) 1997-2010 University of Cambridge. .fi diff --git a/doc/pcreperform.3 b/doc/pcreperform.3 index 59b63b8..ed42cd2 100644 --- a/doc/pcreperform.3 +++ b/doc/pcreperform.3 @@ -96,6 +96,14 @@ thousand characters whenever it needs a character's property. If you can find an alternative pattern that does not use character properties, it will probably be faster. .P +By default, the escape sequences \eb, \ed, \es, and \ew, and the POSIX +character classes such as [:alpha:] do not use Unicode properties, partly for +backwards compatibility, and partly for performance reasons. However, you can +set PCRE_UCP if you want Unicode character properties to be used. This can +double the matching time for items such as \ed, when matched with +\fBpcre_exec()\fP; the performance loss is less with \fBpcre_dfa_exec()\fP, and +in both cases there is not much difference for \eb. +.P When a pattern begins with .* not in parentheses, or in parentheses that are not the subject of a backreference, and the PCRE_DOTALL option is set, the pattern is implicitly anchored by PCRE, since it can match only at the start of @@ -164,6 +172,6 @@ Cambridge CB2 3QH, England. .rs .sp .nf -Last updated: 07 March 2010 +Last updated: 16 May 2010 Copyright (c) 1997-2010 University of Cambridge. .fi diff --git a/doc/pcreposix.3 b/doc/pcreposix.3 index c6092ac..2a164aa 100644 --- a/doc/pcreposix.3 +++ b/doc/pcreposix.3 @@ -63,7 +63,8 @@ structure types, \fIregex_t\fP for compiled internal forms, and \fIregmatch_t\fP for returning captured substrings. It also defines some constants whose names start with "REG_"; these are used for setting options and identifying error codes. -.P +. +. .SH "COMPILING A PATTERN" .rs .sp @@ -101,6 +102,13 @@ compiled with this flag is passed to \fBregexec()\fP for matching, the \fInmatch\fP and \fIpmatch\fP arguments are ignored, and no captured strings are returned. .sp + REG_UCP +.sp +The PCRE_UCP option is set when the regular expression is passed for +compilation to the native function. This causes PCRE to use Unicode properties +when matchine \ed, \ew, etc., instead of just recognizing ASCII values. Note +that REG_UTF8 is not part of the POSIX standard. +.sp REG_UNGREEDY .sp The PCRE_UNGREEDY option is set when the regular expression is passed for @@ -256,6 +264,6 @@ Cambridge CB2 3QH, England. .rs .sp .nf -Last updated: 02 September 2009 -Copyright (c) 1997-2009 University of Cambridge. +Last updated: 16 May 2010 +Copyright (c) 1997-2010 University of Cambridge. .fi diff --git a/doc/pcresyntax.3 b/doc/pcresyntax.3 index 9de639e..3c23373 100644 --- a/doc/pcresyntax.3 +++ b/doc/pcresyntax.3 @@ -57,7 +57,9 @@ syntax. \eW a "non-word" character \eX an extended Unicode sequence .sp -In PCRE, \ed, \eD, \es, \eS, \ew, and \eW recognize only ASCII characters. +In PCRE, by default, \ed, \eD, \es, \eS, \ew, and \eW recognize only ASCII +characters, even in UTF-8 mode. However, this can be changed by setting the +PCRE_UCP option. . . .SH "GENERAL CATEGORY PROPERTIES FOR \ep and \eP" @@ -239,7 +241,8 @@ Yi. word same as \ew xdigit hexadecimal digit .sp -In PCRE, POSIX character set names recognize only ASCII characters. You can use +In PCRE, POSIX character set names recognize only ASCII characters by default, +but some of them use Unicode properties if PCRE_UCP is set. You can use \eQ...\eE inside a character class. . . @@ -267,7 +270,7 @@ In PCRE, POSIX character set names recognize only ASCII characters. You can use .SH "ANCHORS AND SIMPLE ASSERTIONS" .rs .sp - \eb word boundary (only ASCII letters recognized) + \eb word boundary \eB not a word boundary ^ start of subject also after internal newline in multiline mode @@ -330,10 +333,11 @@ In PCRE, POSIX character set names recognize only ASCII characters. You can use (?x) extended (ignore white space) (?-...) unset option(s) .sp -The following is recognized only at the start of a pattern or after one of the +The following are recognized only at the start of a pattern or after one of the newline-setting options with similar syntax: .sp - (*UTF8) set UTF-8 mode + (*UTF8) set UTF-8 mode (PCRE_UTF8) + (*UCP) set PCRE_UCP (use Unicode properties for \ed etc) . . .SH "LOOKAHEAD AND LOOKBEHIND ASSERTIONS" @@ -422,7 +426,7 @@ pattern is not anchored. .rs .sp These are recognized only at the very start of the pattern or after a -(*BSR_...) or (*UTF8) option. +(*BSR_...) or (*UTF8) or (*UCP) option. .sp (*CR) carriage return only (*LF) linefeed only @@ -435,7 +439,7 @@ These are recognized only at the very start of the pattern or after a .rs .sp These are recognized only at the very start of the pattern or after a -(*...) option that sets the newline convention or UTF-8 mode. +(*...) option that sets the newline convention or UTF-8 or UCP mode. .sp (*BSR_ANYCRLF) CR, LF, or CRLF (*BSR_UNICODE) any Unicode newline sequence @@ -469,6 +473,6 @@ Cambridge CB2 3QH, England. .rs .sp .nf -Last updated: 05 May 2010 +Last updated: 12 May 2010 Copyright (c) 1997-2010 University of Cambridge. .fi diff --git a/doc/pcretest.1 b/doc/pcretest.1 index e7e90e6..8c439c7 100644 --- a/doc/pcretest.1 +++ b/doc/pcretest.1 @@ -165,9 +165,11 @@ effect as they do in Perl. For example: .sp /caseless/i .sp -The following table shows additional modifiers for setting PCRE options that do -not correspond to anything in Perl: +The following table shows additional modifiers for setting PCRE compile-time +options that do not correspond to anything in Perl: .sp + \fB/8\fP PCRE_UTF8 + \fB/?\fP PCRE_NO_UTF8_CHECK \fB/A\fP PCRE_ANCHORED \fB/C\fP PCRE_AUTO_CALLOUT \fB/E\fP PCRE_DOLLAR_ENDONLY @@ -175,6 +177,7 @@ not correspond to anything in Perl: \fB/J\fP PCRE_DUPNAMES \fB/N\fP PCRE_NO_AUTO_CAPTURE \fB/U\fP PCRE_UNGREEDY + \fB/W\fP PCRE_UCP \fB/X\fP PCRE_EXTRA \fB/<JS>\fP PCRE_JAVASCRIPT_COMPAT \fB/<cr>\fP PCRE_NEWLINE_CR @@ -185,17 +188,20 @@ not correspond to anything in Perl: \fB/<bsr_anycrlf>\fP PCRE_BSR_ANYCRLF \fB/<bsr_unicode>\fP PCRE_BSR_UNICODE .sp -Those specifying line ending sequences are literal strings as shown, but the -letters can be in either case. This example sets multiline matching with CRLF -as the line ending sequence: +The modifiers that are enclosed in angle brackets are literal strings as shown, +including the angle brackets, but the letters can be in either case. This +example sets multiline matching with CRLF as the line ending sequence: .sp /^abc/m<crlf> .sp -Details of the meanings of these PCRE options are given in the +As well as turning on the PCRE_UTF8 option, the \fB/8\fP modifier also causes +any non-printing characters in output strings to be printed using the +\ex{hh...} notation if they are valid UTF-8 sequences. Full details of the PCRE +options are given in the .\" HREF \fBpcreapi\fP .\" -documentation. +documentation. . . .SS "Finding all matches in a string" @@ -224,16 +230,6 @@ such cases when using the \fB/g\fP modifier or the \fBsplit()\fP function. There are yet more modifiers for controlling the way \fBpcretest\fP operates. .P -The \fB/8\fP modifier causes \fBpcretest\fP to call PCRE with the PCRE_UTF8 -option set. This turns on support for UTF-8 character handling in PCRE, -provided that it was compiled with this support enabled. This modifier also -causes any non-printing characters in output strings to be printed using the -\ex{hh...} notation if they are valid UTF-8 sequences. -.P -If the \fB/?\fP modifier is used with \fB/8\fP, it causes \fBpcretest\fP to -call \fBpcre_compile()\fP with the PCRE_NO_UTF8_CHECK option, to suppress the -checking of the string for UTF-8 validity. -.P The \fB/+\fP modifier requests that as well as outputting the substring that matched the entire pattern, pcretest should in addition output the remainder of the subject string. This is useful for tests where the subject contains @@ -286,17 +282,30 @@ pointer; that is, \fB/L\fP applies only to the expression on which it appears. The \fB/M\fP modifier causes the size of memory block used to hold the compiled pattern to be output. .P -The \fB/P\fP modifier causes \fBpcretest\fP to call PCRE via the POSIX wrapper -API rather than its native API. When this is done, all other modifiers except -\fB/i\fP, \fB/m\fP, and \fB/+\fP are ignored. REG_ICASE is set if \fB/i\fP is -present, and REG_NEWLINE is set if \fB/m\fP is present. The wrapper functions -force PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set. -.P The \fB/S\fP modifier causes \fBpcre_study()\fP to be called after the expression has been compiled, and the results used when the expression is matched. . . +.SS "Using the POSIX wrapper API" +.rs +.sp +The \fB/P\fP modifier causes \fBpcretest\fP to call PCRE via the POSIX wrapper +API rather than its native API. When \fB/P\fP is set, the following modifiers +set options for the \fBregcomp()\fP function: +.sp + /i REG_ICASE + /m REG_NEWLINE + /N REG_NOSUB + /s REG_DOTALL ) + /U REG_UNGREEDY ) These options are not part of + /W REG_UCP ) the POSIX standard + /8 REG_UTF8 ) +.sp +The \fB/+\fP modifier works as described above. All other modifiers are +ignored. +. +. .SH "DATA LINES" .rs .sp @@ -434,9 +443,9 @@ by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to the call of \fBpcre_exec()\fP for the line in which it appears. .P If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper -API to be used, the only option-setting sequences that have any effect are \eB -and \eZ, causing REG_NOTBOL and REG_NOTEOL, respectively, to be passed to -\fBregexec()\fP. +API to be used, the only option-setting sequences that have any effect are \eB, +\eN, and \eZ, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively, +to be passed to \fBregexec()\fP. .P The use of \ex{hh...} to represent UTF-8 characters is not dependent on the use of the \fB/8\fP modifier on the pattern. It is recognized always. There may be @@ -741,6 +750,6 @@ Cambridge CB2 3QH, England. .rs .sp .nf -Last updated: 26 March 2010 +Last updated: 16 May 2010 Copyright (c) 1997-2010 University of Cambridge. .fi diff --git a/doc/pcretest.txt b/doc/pcretest.txt index 7a9523c..2855437 100644 --- a/doc/pcretest.txt +++ b/doc/pcretest.txt @@ -157,6 +157,8 @@ PATTERN MODIFIERS The following table shows additional modifiers for setting PCRE options that do not correspond to anything in Perl: + /8 PCRE_UTF8 + /? PCRE_NO_UTF8_CHECK /A PCRE_ANCHORED /C PCRE_AUTO_CALLOUT /E PCRE_DOLLAR_ENDONLY @@ -164,6 +166,7 @@ PATTERN MODIFIERS /J PCRE_DUPNAMES /N PCRE_NO_AUTO_CAPTURE /U PCRE_UNGREEDY + /W PCRE_UCP /X PCRE_EXTRA /<JS> PCRE_JAVASCRIPT_COMPAT /<cr> PCRE_NEWLINE_CR @@ -174,120 +177,113 @@ PATTERN MODIFIERS /<bsr_anycrlf> PCRE_BSR_ANYCRLF /<bsr_unicode> PCRE_BSR_UNICODE - Those specifying line ending sequences are literal strings as shown, - but the letters can be in either case. This example sets multiline - matching with CRLF as the line ending sequence: + The modifiers that are enclosed in angle brackets are literal strings + as shown, including the angle brackets, but the letters can be in + either case. This example sets multiline matching with CRLF as the line + ending sequence: /^abc/m<crlf> - Details of the meanings of these PCRE options are given in the pcreapi - documentation. + As well as turning on the PCRE_UTF8 option, the /8 modifier also causes + any non-printing characters in output strings to be printed using the + \x{hh...} notation if they are valid UTF-8 sequences. Full details of + the PCRE options are given in the pcreapi documentation. Finding all matches in a string - Searching for all possible matches within each subject string can be - requested by the /g or /G modifier. After finding a match, PCRE is + Searching for all possible matches within each subject string can be + requested by the /g or /G modifier. After finding a match, PCRE is called again to search the remainder of the subject string. The differ- ence between /g and /G is that the former uses the startoffset argument - to pcre_exec() to start searching at a new point within the entire - string (which is in effect what Perl does), whereas the latter passes - over a shortened substring. This makes a difference to the matching + to pcre_exec() to start searching at a new point within the entire + string (which is in effect what Perl does), whereas the latter passes + over a shortened substring. This makes a difference to the matching process if the pattern begins with a lookbehind assertion (including \b or \B). - If any call to pcre_exec() in a /g or /G sequence matches an empty - string, the next call is done with the PCRE_NOTEMPTY_ATSTART and - PCRE_ANCHORED flags set in order to search for another, non-empty, - match at the same point. If this second match fails, the start offset - is advanced by one character, and the normal match is retried. This - imitates the way Perl handles such cases when using the /g modifier or + If any call to pcre_exec() in a /g or /G sequence matches an empty + string, the next call is done with the PCRE_NOTEMPTY_ATSTART and + PCRE_ANCHORED flags set in order to search for another, non-empty, + match at the same point. If this second match fails, the start offset + is advanced by one character, and the normal match is retried. This + imitates the way Perl handles such cases when using the /g modifier or the split() function. Other modifiers There are yet more modifiers for controlling the way pcretest operates. - The /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option - set. This turns on support for UTF-8 character handling in PCRE, pro- - vided that it was compiled with this support enabled. This modifier - also causes any non-printing characters in output strings to be printed - using the \x{hh...} notation if they are valid UTF-8 sequences. - - If the /? modifier is used with /8, it causes pcretest to call - pcre_compile() with the PCRE_NO_UTF8_CHECK option, to suppress the - checking of the string for UTF-8 validity. - - The /+ modifier requests that as well as outputting the substring that - matched the entire pattern, pcretest should in addition output the - remainder of the subject string. This is useful for tests where the + The /+ modifier requests that as well as outputting the substring that + matched the entire pattern, pcretest should in addition output the + remainder of the subject string. This is useful for tests where the subject contains multiple copies of the same substring. - The /B modifier is a debugging feature. It requests that pcretest out- - put a representation of the compiled byte code after compilation. Nor- - mally this information contains length and offset values; however, if - /Z is also present, this data is replaced by spaces. This is a special + The /B modifier is a debugging feature. It requests that pcretest out- + put a representation of the compiled byte code after compilation. Nor- + mally this information contains length and offset values; however, if + /Z is also present, this data is replaced by spaces. This is a special feature for use in the automatic test scripts; it ensures that the same output is generated for different internal link sizes. - The /D modifier is a PCRE debugging feature, and is equivalent to /BI, + The /D modifier is a PCRE debugging feature, and is equivalent to /BI, that is, both the /B and the /I modifiers. The /F modifier causes pcretest to flip the byte order of the fields in - the compiled pattern that contain 2-byte and 4-byte numbers. This - facility is for testing the feature in PCRE that allows it to execute + the compiled pattern that contain 2-byte and 4-byte numbers. This + facility is for testing the feature in PCRE that allows it to execute patterns that were compiled on a host with a different endianness. This - feature is not available when the POSIX interface to PCRE is being - used, that is, when the /P pattern modifier is specified. See also the + feature is not available when the POSIX interface to PCRE is being + used, that is, when the /P pattern modifier is specified. See also the section about saving and reloading compiled patterns below. - The /I modifier requests that pcretest output information about the - compiled pattern (whether it is anchored, has a fixed first character, - and so on). It does this by calling pcre_fullinfo() after compiling a - pattern. If the pattern is studied, the results of that are also out- + The /I modifier requests that pcretest output information about the + compiled pattern (whether it is anchored, has a fixed first character, + and so on). It does this by calling pcre_fullinfo() after compiling a + pattern. If the pattern is studied, the results of that are also out- put. - The /K modifier requests pcretest to show names from backtracking con- - trol verbs that are returned from calls to pcre_exec(). It causes - pcretest to create a pcre_extra block if one has not already been cre- + The /K modifier requests pcretest to show names from backtracking con- + trol verbs that are returned from calls to pcre_exec(). It causes + pcretest to create a pcre_extra block if one has not already been cre- ated by a call to pcre_study(), and to set the PCRE_EXTRA_MARK flag and the mark field within it, every time that pcre_exec() is called. If the - variable that the mark field points to is non-NULL for a match, non- + variable that the mark field points to is non-NULL for a match, non- match, or partial match, pcretest prints the string to which it points. For a match, this is shown on a line by itself, tagged with "MK:". For a non-match it is added to the message. - The /L modifier must be followed directly by the name of a locale, for + The /L modifier must be followed directly by the name of a locale, for example, /pattern/Lfr_FR For this reason, it must be the last modifier. The given locale is set, - pcre_maketables() is called to build a set of character tables for the - locale, and this is then passed to pcre_compile() when compiling the - regular expression. Without an /L modifier, NULL is passed as the - tables pointer; that is, /L applies only to the expression on which it + pcre_maketables() is called to build a set of character tables for the + locale, and this is then passed to pcre_compile() when compiling the + regular expression. Without an /L modifier, NULL is passed as the + tables pointer; that is, /L applies only to the expression on which it appears. - The /M modifier causes the size of memory block used to hold the com- + The /M modifier causes the size of memory block used to hold the com- piled pattern to be output. - The /P modifier causes pcretest to call PCRE via the POSIX wrapper API - rather than its native API. When this is done, all other modifiers - except /i, /m, and /+ are ignored. REG_ICASE is set if /i is present, - and REG_NEWLINE is set if /m is present. The wrapper functions force + The /P modifier causes pcretest to call PCRE via the POSIX wrapper API + rather than its native API. When this is done, all other modifiers + except /i, /m, and /+ are ignored. REG_ICASE is set if /i is present, + and REG_NEWLINE is set if /m is present. The wrapper functions force PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set. - The /S modifier causes pcre_study() to be called after the expression + The /S modifier causes pcre_study() to be called after the expression has been compiled, and the results used when the expression is matched. DATA LINES - Before each data line is passed to pcre_exec(), leading and trailing - whitespace is removed, and it is then scanned for \ escapes. Some of - these are pretty esoteric features, intended for checking out some of - the more complicated features of PCRE. If you are just testing "ordi- - nary" regular expressions, you probably don't need any of these. The + Before each data line is passed to pcre_exec(), leading and trailing + whitespace is removed, and it is then scanned for \ escapes. Some of + these are pretty esoteric features, intended for checking out some of + the more complicated features of PCRE. If you are just testing "ordi- + nary" regular expressions, you probably don't need any of these. The following escapes are recognized: \a alarm (BEL, \x07) @@ -365,72 +361,72 @@ DATA LINES \<any> pass the PCRE_NEWLINE_ANY option to pcre_exec() or pcre_dfa_exec() - The escapes that specify line ending sequences are literal strings, + The escapes that specify line ending sequences are literal strings, exactly as shown. No more than one newline setting should be present in any data line. - A backslash followed by anything else just escapes the anything else. - If the very last character is a backslash, it is ignored. This gives a - way of passing an empty line as data, since a real empty line termi- + A backslash followed by anything else just escapes the anything else. + If the very last character is a backslash, it is ignored. This gives a + way of passing an empty line as data, since a real empty line termi- nates the data input. - If \M is present, pcretest calls pcre_exec() several times, with dif- - ferent values in the match_limit and match_limit_recursion fields of - the pcre_extra data structure, until it finds the minimum numbers for + If \M is present, pcretest calls pcre_exec() several times, with dif- + ferent values in the match_limit and match_limit_recursion fields of + the pcre_extra data structure, until it finds the minimum numbers for each parameter that allow pcre_exec() to complete. The match_limit num- - ber is a measure of the amount of backtracking that takes place, and + ber is a measure of the amount of backtracking that takes place, and checking it out can be instructive. For most simple matches, the number - is quite small, but for patterns with very large numbers of matching - possibilities, it can become large very quickly with increasing length + is quite small, but for patterns with very large numbers of matching + possibilities, it can become large very quickly with increasing length of subject string. The match_limit_recursion number is a measure of how - much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) + much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is needed to complete the match attempt. - When \O is used, the value specified may be higher or lower than the + When \O is used, the value specified may be higher or lower than the size set by the -O command line option (or defaulted to 45); \O applies only to the call of pcre_exec() for the line in which it appears. - If the /P modifier was present on the pattern, causing the POSIX wrap- - per API to be used, the only option-setting sequences that have any - effect are \B and \Z, causing REG_NOTBOL and REG_NOTEOL, respectively, + If the /P modifier was present on the pattern, causing the POSIX wrap- + per API to be used, the only option-setting sequences that have any + effect are \B and \Z, causing REG_NOTBOL and REG_NOTEOL, respectively, to be passed to regexec(). - The use of \x{hh...} to represent UTF-8 characters is not dependent on - the use of the /8 modifier on the pattern. It is recognized always. - There may be any number of hexadecimal digits inside the braces. The - result is from one to six bytes, encoded according to the original - UTF-8 rules of RFC 2279. This allows for values in the range 0 to - 0x7FFFFFFF. Note that not all of those are valid Unicode code points, - or indeed valid UTF-8 characters according to the later rules in RFC + The use of \x{hh...} to represent UTF-8 characters is not dependent on + the use of the /8 modifier on the pattern. It is recognized always. + There may be any number of hexadecimal digits inside the braces. The + result is from one to six bytes, encoded according to the original + UTF-8 rules of RFC 2279. This allows for values in the range 0 to + 0x7FFFFFFF. Note that not all of those are valid Unicode code points, + or indeed valid UTF-8 characters according to the later rules in RFC 3629. THE ALTERNATIVE MATCHING FUNCTION - By default, pcretest uses the standard PCRE matching function, + By default, pcretest uses the standard PCRE matching function, pcre_exec() to match each data line. From release 6.0, PCRE supports an - alternative matching function, pcre_dfa_test(), which operates in a - different way, and has some restrictions. The differences between the + alternative matching function, pcre_dfa_test(), which operates in a + different way, and has some restrictions. The differences between the two functions are described in the pcrematching documentation. - If a data line contains the \D escape sequence, or if the command line - contains the -dfa option, the alternative matching function is called. + If a data line contains the \D escape sequence, or if the command line + contains the -dfa option, the alternative matching function is called. This function finds all possible matches at a given point. If, however, - the \F escape sequence is present in the data line, it stops after the + the \F escape sequence is present in the data line, it stops after the first match is found. This is always the shortest possible match. DEFAULT OUTPUT FROM PCRETEST - This section describes the output when the normal matching function, + This section describes the output when the normal matching function, pcre_exec(), is being used. When a match succeeds, pcretest outputs the list of captured substrings - that pcre_exec() returns, starting with number 0 for the string that - matched the whole pattern. Otherwise, it outputs "No match" when the + that pcre_exec() returns, starting with number 0 for the string that + matched the whole pattern. Otherwise, it outputs "No match" when the return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the par- - tially matching substring when pcre_exec() returns PCRE_ERROR_PARTIAL. - For any other returns, it outputs the PCRE negative error number. Here + tially matching substring when pcre_exec() returns PCRE_ERROR_PARTIAL. + For any other returns, it outputs the PCRE negative error number. Here is an example of an interactive pcretest run. $ pcretest @@ -443,11 +439,11 @@ DEFAULT OUTPUT FROM PCRETEST data> xyz No match - Note that unset capturing substrings that are not followed by one that - is set are not returned by pcre_exec(), and are not shown by pcretest. - In the following example, there are two capturing substrings, but when - the first data line is matched, the second, unset substring is not - shown. An "internal" unset substring is shown as "<unset>", as for the + Note that unset capturing substrings that are not followed by one that + is set are not returned by pcre_exec(), and are not shown by pcretest. + In the following example, there are two capturing substrings, but when + the first data line is matched, the second, unset substring is not + shown. An "internal" unset substring is shown as "<unset>", as for the second data line. re> /(a)|(b)/ @@ -459,11 +455,11 @@ DEFAULT OUTPUT FROM PCRETEST 1: <unset> 2: b - If the strings contain any non-printing characters, they are output as - \0x escapes, or as \x{...} escapes if the /8 modifier was present on - the pattern. See below for the definition of non-printing characters. - If the pattern has the /+ modifier, the output for substring 0 is fol- - lowed by the the rest of the subject string, identified by "0+" like + If the strings contain any non-printing characters, they are output as + \0x escapes, or as \x{...} escapes if the /8 modifier was present on + the pattern. See below for the definition of non-printing characters. + If the pattern has the /+ modifier, the output for substring 0 is fol- + lowed by the the rest of the subject string, identified by "0+" like this: re> /cat/+ @@ -471,7 +467,7 @@ DEFAULT OUTPUT FROM PCRETEST 0: cat 0+ aract - If the pattern has the /g or /G modifier, the results of successive + If the pattern has the /g or /G modifier, the results of successive matching attempts are output in sequence, like this: re> /\Bi(\w\w)/g @@ -485,24 +481,24 @@ DEFAULT OUTPUT FROM PCRETEST "No match" is output only if the first match attempt fails. - If any of the sequences \C, \G, or \L are present in a data line that - is successfully matched, the substrings extracted by the convenience + If any of the sequences \C, \G, or \L are present in a data line that + is successfully matched, the substrings extracted by the convenience functions are output with C, G, or L after the string number instead of a colon. This is in addition to the normal full list. The string length - (that is, the return from the extraction function) is given in paren- + (that is, the return from the extraction function) is given in paren- theses after each string for \C and \G. Note that whereas patterns can be continued over several lines (a plain ">" prompt is used for continuations), data lines may not. However new- - lines can be included in data by means of the \n escape (or \r, \r\n, + lines can be included in data by means of the \n escape (or \r, \r\n, etc., depending on the newline sequence setting). OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION - When the alternative matching function, pcre_dfa_exec(), is used (by - means of the \D escape sequence or the -dfa command line option), the - output consists of a list of all the matches that start at the first + When the alternative matching function, pcre_dfa_exec(), is used (by + means of the \D escape sequence or the -dfa command line option), the + output consists of a list of all the matches that start at the first point in the subject where there is at least one match. For example: re> /(tang|tangerine|tan)/ @@ -511,8 +507,8 @@ OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION 1: tang 2: tan - (Using the normal matching function on this data finds only "tang".) - The longest matching string is always given first (and numbered zero). + (Using the normal matching function on this data finds only "tang".) + The longest matching string is always given first (and numbered zero). After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol- lowed by the partially matching substring. @@ -528,16 +524,16 @@ OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION 1: tan 0: tan - Since the matching function does not support substring capture, the - escape sequences that are concerned with captured substrings are not + Since the matching function does not support substring capture, the + escape sequences that are concerned with captured substrings are not relevant. RESTARTING AFTER A PARTIAL MATCH When the alternative matching function has given the PCRE_ERROR_PARTIAL - return, indicating that the subject partially matched the pattern, you - can restart the match with additional subject data by means of the \R + return, indicating that the subject partially matched the pattern, you + can restart the match with additional subject data by means of the \R escape sequence. For example: re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/ @@ -546,30 +542,30 @@ RESTARTING AFTER A PARTIAL MATCH data> n05\R\D 0: n05 - For further information about partial matching, see the pcrepartial + For further information about partial matching, see the pcrepartial documentation. CALLOUTS - If the pattern contains any callout requests, pcretest's callout func- - tion is called during matching. This works with both matching func- + If the pattern contains any callout requests, pcretest's callout func- + tion is called during matching. This works with both matching func- tions. By default, the called function displays the callout number, the - start and current positions in the text at the callout time, and the + start and current positions in the text at the callout time, and the next pattern item to be tested. For example, the output --->pqrabcdef 0 ^ ^ \d - indicates that callout number 0 occurred for a match attempt starting - at the fourth character of the subject string, when the pointer was at - the seventh character of the data, and when the next pattern item was - \d. Just one circumflex is output if the start and current positions + indicates that callout number 0 occurred for a match attempt starting + at the fourth character of the subject string, when the pointer was at + the seventh character of the data, and when the next pattern item was + \d. Just one circumflex is output if the start and current positions are the same. Callouts numbered 255 are assumed to be automatic callouts, inserted as - a result of the /C pattern modifier. In this case, instead of showing - the callout number, the offset in the pattern, preceded by a plus, is + a result of the /C pattern modifier. In this case, instead of showing + the callout number, the offset in the pattern, preceded by a plus, is output. For example: re> /\d?[A-E]\*/C @@ -581,86 +577,86 @@ CALLOUTS +10 ^ ^ 0: E* - The callout function in pcretest returns zero (carry on matching) by - default, but you can use a \C item in a data line (as described above) + The callout function in pcretest returns zero (carry on matching) by + default, but you can use a \C item in a data line (as described above) to change this. - Inserting callouts can be helpful when using pcretest to check compli- - cated regular expressions. For further information about callouts, see + Inserting callouts can be helpful when using pcretest to check compli- + cated regular expressions. For further information about callouts, see the pcrecallout documentation. NON-PRINTING CHARACTERS - When pcretest is outputting text in the compiled version of a pattern, - bytes other than 32-126 are always treated as non-printing characters + When pcretest is outputting text in the compiled version of a pattern, + bytes other than 32-126 are always treated as non-printing characters are are therefore shown as hex escapes. - When pcretest is outputting text that is a matched part of a subject - string, it behaves in the same way, unless a different locale has been - set for the pattern (using the /L modifier). In this case, the + When pcretest is outputting text that is a matched part of a subject + string, it behaves in the same way, unless a different locale has been + set for the pattern (using the /L modifier). In this case, the isprint() function to distinguish printing and non-printing characters. SAVING AND RELOADING COMPILED PATTERNS - The facilities described in this section are not available when the + The facilities described in this section are not available when the POSIX inteface to PCRE is being used, that is, when the /P pattern mod- ifier is specified. When the POSIX interface is not in use, you can cause pcretest to write - a compiled pattern to a file, by following the modifiers with > and a + a compiled pattern to a file, by following the modifiers with > and a file name. For example: /pattern/im >/some/file - See the pcreprecompile documentation for a discussion about saving and + See the pcreprecompile documentation for a discussion about saving and re-using compiled patterns. - The data that is written is binary. The first eight bytes are the - length of the compiled pattern data followed by the length of the - optional study data, each written as four bytes in big-endian order - (most significant byte first). If there is no study data (either the + The data that is written is binary. The first eight bytes are the + length of the compiled pattern data followed by the length of the + optional study data, each written as four bytes in big-endian order + (most significant byte first). If there is no study data (either the pattern was not studied, or studying did not return any data), the sec- - ond length is zero. The lengths are followed by an exact copy of the + ond length is zero. The lengths are followed by an exact copy of the compiled pattern. If there is additional study data, this follows imme- - diately after the compiled pattern. After writing the file, pcretest + diately after the compiled pattern. After writing the file, pcretest expects to read a new pattern. A saved pattern can be reloaded into pcretest by specifing < and a file - name instead of a pattern. The name of the file must not contain a < - character, as otherwise pcretest will interpret the line as a pattern + name instead of a pattern. The name of the file must not contain a < + character, as otherwise pcretest will interpret the line as a pattern delimited by < characters. For example: re> </some/file Compiled regex loaded from /some/file No study data - When the pattern has been loaded, pcretest proceeds to read data lines + When the pattern has been loaded, pcretest proceeds to read data lines in the usual way. - You can copy a file written by pcretest to a different host and reload - it there, even if the new host has opposite endianness to the one on - which the pattern was compiled. For example, you can compile on an i86 + You can copy a file written by pcretest to a different host and reload + it there, even if the new host has opposite endianness to the one on + which the pattern was compiled. For example, you can compile on an i86 machine and run on a SPARC machine. - File names for saving and reloading can be absolute or relative, but - note that the shell facility of expanding a file name that starts with + File names for saving and reloading can be absolute or relative, but + note that the shell facility of expanding a file name that starts with a tilde (~) is not available. - The ability to save and reload files in pcretest is intended for test- - ing and experimentation. It is not intended for production use because - only a single pattern can be written to a file. Furthermore, there is - no facility for supplying custom character tables for use with a - reloaded pattern. If the original pattern was compiled with custom - tables, an attempt to match a subject string using a reloaded pattern - is likely to cause pcretest to crash. Finally, if you attempt to load + The ability to save and reload files in pcretest is intended for test- + ing and experimentation. It is not intended for production use because + only a single pattern can be written to a file. Furthermore, there is + no facility for supplying custom character tables for use with a + reloaded pattern. If the original pattern was compiled with custom + tables, an attempt to match a subject string using a reloaded pattern + is likely to cause pcretest to crash. Finally, if you attempt to load a file that is not in the correct format, the result is undefined. SEE ALSO - pcre(3), pcreapi(3), pcrecallout(3), pcrematching(3), pcrepartial(d), + pcre(3), pcreapi(3), pcrecallout(3), pcrematching(3), pcrepartial(d), pcrepattern(3), pcreprecompile(3). @@ -673,5 +669,5 @@ AUTHOR REVISION - Last updated: 26 March 2010 + Last updated: 12 May 2010 Copyright (c) 1997-2010 University of Cambridge. @@ -5,7 +5,7 @@ /* This is the public header file for the PCRE library, to be #included by applications that call the PCRE functions. - Copyright (c) 1997-2009 University of Cambridge + Copyright (c) 1997-2010 University of Cambridge ----------------------------------------------------------------------------- Redistribution and use in source and binary forms, with or without @@ -131,6 +131,7 @@ both, so we keep them all distinct. */ #define PCRE_NO_START_OPTIMISE 0x04000000 #define PCRE_PARTIAL_HARD 0x08000000 #define PCRE_NOTEMPTY_ATSTART 0x10000000 +#define PCRE_UCP 0x20000000 /* Exec-time and get/set-time error codes */ diff --git a/pcre_compile.c b/pcre_compile.c index e4a529e..d48bac5 100644 --- a/pcre_compile.c +++ b/pcre_compile.c @@ -261,6 +261,53 @@ static const int posix_class_maps[] = { cbit_xdigit,-1, 0 /* xdigit */ }; +/* Table of substitutes for \d etc when PCRE_UCP is set. The POSIX class +substitutes must be in the order of the names, defined above, and there are +both positive and negative cases. NULL means no substitute. */ + +#ifdef SUPPORT_UCP +static const uschar *substitutes[] = { + (uschar *)"\\P{Nd}", /* \D */ + (uschar *)"\\p{Nd}", /* \d */ + (uschar *)"\\P{Xsp}", /* \S */ /* NOTE: Xsp is Perl space */ + (uschar *)"\\p{Xsp}", /* \s */ + (uschar *)"\\P{Xwd}", /* \W */ + (uschar *)"\\p{Xwd}" /* \w */ +}; + +static const uschar *posix_substitutes[] = { + (uschar *)"\\p{L}", /* alpha */ + (uschar *)"\\p{Ll}", /* lower */ + (uschar *)"\\p{Lu}", /* upper */ + (uschar *)"\\p{Xan}", /* alnum */ + NULL, /* ascii */ + (uschar *)"\\h", /* blank */ + NULL, /* cntrl */ + (uschar *)"\\p{Nd}", /* digit */ + NULL, /* graph */ + NULL, /* print */ + NULL, /* punct */ + (uschar *)"\\p{Xps}", /* space */ /* NOTE: Xps is POSIX space */ + (uschar *)"\\p{Xwd}", /* word */ + NULL, /* xdigit */ + /* Negated cases */ + (uschar *)"\\P{L}", /* ^alpha */ + (uschar *)"\\P{Ll}", /* ^lower */ + (uschar *)"\\P{Lu}", /* ^upper */ + (uschar *)"\\P{Xan}", /* ^alnum */ + NULL, /* ^ascii */ + (uschar *)"\\H", /* ^blank */ + NULL, /* ^cntrl */ + (uschar *)"\\P{Nd}", /* ^digit */ + NULL, /* ^graph */ + NULL, /* ^print */ + NULL, /* ^punct */ + (uschar *)"\\P{Xps}", /* ^space */ /* NOTE: Xps is POSIX space */ + (uschar *)"\\P{Xwd}", /* ^word */ + NULL /* ^xdigit */ +}; +#define POSIX_SUBSIZE (sizeof(posix_substitutes)/sizeof(uschar *)) +#endif #define STRING(a) # a #define XSTRING(s) STRING(s) @@ -360,6 +407,7 @@ static const char error_texts[] = /* 65 */ "different names for subpatterns of the same number are not allowed\0" "(*MARK) must have an argument\0" + "this version of PCRE is not compiled with PCRE_UCP support\0" ; /* Table to identify digits and hex digits. This is used when compiling @@ -829,12 +877,19 @@ else break; } } - -/* Perl supports \N{name} for character names, as well as plain \N for "not + +/* Perl supports \N{name} for character names, as well as plain \N for "not newline". PCRE does not support \N{name}. */ if (c == -ESC_N && ptr[1] == CHAR_LEFT_CURLY_BRACKET) - *errorcodeptr = ERR37; + *errorcodeptr = ERR37; + +/* If PCRE_UCP is set, we change the values for \d etc. */ + +if ((options & PCRE_UCP) != 0 && c <= -ESC_D && c >= -ESC_w) + c -= (ESC_DU - ESC_D); + +/* Set the pointer to the final character before returning. */ *ptrptr = ptr; return c; @@ -2725,6 +2780,7 @@ BOOL inescq = FALSE; BOOL groupsetfirstbyte = FALSE; const uschar *ptr = *ptrptr; const uschar *tempptr; +const uschar *nestptr = NULL; uschar *previous = NULL; uschar *previous_callout = NULL; uschar *save_hwm = NULL; @@ -2795,6 +2851,16 @@ for (;; ptr++) c = *ptr; + /* If we are at the end of a nested substitution, revert to the outer level + string. Nesting only happens one level deep. */ + + if (c == 0 && nestptr != NULL) + { + ptr = nestptr; + nestptr = NULL; + c = *ptr; + } + /* If we are in the pre-compile phase, accumulate the length used for the previous cycle of this loop. */ @@ -3092,7 +3158,7 @@ for (;; ptr++) { /* Braces are required because the */ GETCHARLEN(c, ptr, ptr); /* macro generates multiple statements */ } - + /* In the pre-compile phase, accumulate the length of any UTF-8 extra data and reset the pointer. This is so that very large classes that contain a zillion UTF-8 characters no longer overwrite the work space @@ -3161,11 +3227,26 @@ for (;; ptr++) if ((options & PCRE_CASELESS) != 0 && posix_class <= 2) posix_class = 0; - - /* We build the bit map for the POSIX class in a chunk of local store - because we may be adding and subtracting from it, and we don't want to - subtract bits that may be in the main map already. At the end we or the - result into the bit map that is being built. */ + + /* When PCRE_UCP is set, some of the POSIX classes are converted to + different escape sequences that use Unicode properties. */ + +#ifdef SUPPORT_UCP + if ((options & PCRE_UCP) != 0) + { + int pc = posix_class + ((local_negate)? POSIX_SUBSIZE/2 : 0); + if (posix_substitutes[pc] != NULL) + { + nestptr = tempptr + 1; + ptr = posix_substitutes[pc] - 1; + continue; + } + } +#endif + /* In the non-UCP case, we build the bit map for the POSIX class in a + chunk of local store because we may be adding and subtracting from it, + and we don't want to subtract bits that may be in the main map already. + At the end we or the result into the bit map that is being built. */ posix_class *= 3; @@ -3237,10 +3318,20 @@ for (;; ptr++) register const uschar *cbits = cd->cbits; class_charcount += 2; /* Greater than 1 is what matters */ - /* Save time by not doing this in the pre-compile phase. */ - - if (lengthptr == NULL) switch (-c) + switch (-c) { +#ifdef SUPPORT_UCP + case ESC_du: /* These are the values given for \d etc */ + case ESC_DU: /* when PCRE_UCP is set. We replace the */ + case ESC_wu: /* escape sequence with an appropriate \p */ + case ESC_WU: /* or \P to test Unicode properties instead */ + case ESC_su: /* of the default ASCII testing. */ + case ESC_SU: + nestptr = ptr; + ptr = substitutes[-c - ESC_DU] - 1; /* Just before substitute */ + class_charcount -= 2; /* Undo! */ + continue; +#endif case ESC_d: for (c = 0; c < 32; c++) classbits[c] |= cbits[c+cbit_digit]; continue; @@ -3270,20 +3361,7 @@ for (;; ptr++) classbits[1] |= 0x08; /* Perl 5.004 onwards omits VT from \s */ continue; - default: /* Not recognized; fall through */ - break; /* Need "default" setting to stop compiler warning. */ - } - - /* In the pre-compile phase, just do the recognition. */ - - else if (c == -ESC_d || c == -ESC_D || c == -ESC_w || - c == -ESC_W || c == -ESC_s || c == -ESC_S) continue; - - /* We need to deal with \H, \h, \V, and \v in both phases because - they use extra memory. */ - - if (-c == ESC_h) - { + case ESC_h: SETBIT(classbits, 0x09); /* VT */ SETBIT(classbits, 0x20); /* SPACE */ SETBIT(classbits, 0xa0); /* NSBP */ @@ -3307,10 +3385,8 @@ for (;; ptr++) } #endif continue; - } - if (-c == ESC_H) - { + case ESC_H: for (c = 0; c < 32; c++) { int x = 0xff; @@ -3352,10 +3428,8 @@ for (;; ptr++) } #endif continue; - } - if (-c == ESC_v) - { + case ESC_v: SETBIT(classbits, 0x0a); /* LF */ SETBIT(classbits, 0x0b); /* VT */ SETBIT(classbits, 0x0c); /* FF */ @@ -3371,10 +3445,8 @@ for (;; ptr++) } #endif continue; - } - if (-c == ESC_V) - { + case ESC_V: for (c = 0; c < 32; c++) { int x = 0xff; @@ -3404,38 +3476,38 @@ for (;; ptr++) } #endif continue; - } - - /* We need to deal with \P and \p in both phases. */ #ifdef SUPPORT_UCP - if (-c == ESC_p || -c == ESC_P) - { - BOOL negated; - int pdata; - int ptype = get_ucp(&ptr, &negated, &pdata, errorcodeptr); - if (ptype < 0) goto FAILED; - class_utf8 = TRUE; - *class_utf8data++ = ((-c == ESC_p) != negated)? - XCL_PROP : XCL_NOTPROP; - *class_utf8data++ = ptype; - *class_utf8data++ = pdata; - class_charcount -= 2; /* Not a < 256 character */ - continue; - } + case ESC_p: + case ESC_P: + { + BOOL negated; + int pdata; + int ptype = get_ucp(&ptr, &negated, &pdata, errorcodeptr); + if (ptype < 0) goto FAILED; + class_utf8 = TRUE; + *class_utf8data++ = ((-c == ESC_p) != negated)? + XCL_PROP : XCL_NOTPROP; + *class_utf8data++ = ptype; + *class_utf8data++ = pdata; + class_charcount -= 2; /* Not a < 256 character */ + continue; + } #endif - /* Unrecognized escapes are faulted if PCRE is running in its - strict mode. By default, for compatibility with Perl, they are - treated as literals. */ + /* Unrecognized escapes are faulted if PCRE is running in its + strict mode. By default, for compatibility with Perl, they are + treated as literals. */ - if ((options & PCRE_EXTRA) != 0) - { - *errorcodeptr = ERR7; - goto FAILED; + default: + if ((options & PCRE_EXTRA) != 0) + { + *errorcodeptr = ERR7; + goto FAILED; + } + class_charcount -= 2; /* Undo the default count from above */ + c = *ptr; /* Get the final character and fall through */ + break; } - - class_charcount -= 2; /* Undo the default count from above */ - c = *ptr; /* Get the final character and fall through */ } /* Fall through if we have a single character (c >= 0). This may be @@ -3675,35 +3747,23 @@ for (;; ptr++) } } - /* Loop until ']' reached. This "while" is the end of the "do" above. */ + /* Loop until ']' reached. This "while" is the end of the "do" far above. + If we are at the end of an internal nested string, revert to the outer + string. */ - while ((c = *(++ptr)) != 0 && (c != CHAR_RIGHT_SQUARE_BRACKET || inescq)); + while (((c = *(++ptr)) != 0 || + (nestptr != NULL && + (ptr = nestptr, nestptr = NULL, c = *(++ptr)) != 0)) && + (c != CHAR_RIGHT_SQUARE_BRACKET || inescq)); - if (c == 0) /* Missing terminating ']' */ + /* Check for missing terminating ']' */ + + if (c == 0) { *errorcodeptr = ERR6; goto FAILED; } - -/* This code has been disabled because it would mean that \s counts as -an explicit \r or \n reference, and that's not really what is wanted. Now -we set the flag only if there is a literal "\r" or "\n" in the class. */ - -#if 0 - /* Remember whether \r or \n are in this class */ - - if (negate_class) - { - if ((classbits[1] & 0x24) != 0x24) cd->external_flags |= PCRE_HASCRORLF; - } - else - { - if ((classbits[1] & 0x24) != 0) cd->external_flags |= PCRE_HASCRORLF; - } -#endif - - /* If class_charcount is 1, we saw precisely one character whose value is less than 256. As long as there were no characters >= 128 and there was no use of \p or \P, in other words, no use of any XCLASS features, we can @@ -3720,7 +3780,7 @@ we set the flag only if there is a literal "\r" or "\n" in the class. */ can cause firstbyte to be set. Otherwise, there can be no first char if this item is first, whatever repeat count may follow. In the case of reqbyte, save the previous value for reinstating. */ - + #ifdef SUPPORT_UTF8 if (class_charcount == 1 && !class_utf8 && (!utf8 || !negate_class || class_lastchar < 128)) @@ -3767,13 +3827,14 @@ we set the flag only if there is a literal "\r" or "\n" in the class. */ /* If there are characters with values > 255, we have to compile an extended class, with its own opcode, unless there was a negated special - such as \S in the class, because in that case all characters > 255 are in - the class, so any that were explicitly given as well can be ignored. If - (when there are explicit characters > 255 that must be listed) there are no - characters < 256, we can omit the bitmap in the actual compiled code. */ + such as \S in the class, and PCRE_UCP is not set, because in that case all + characters > 255 are in the class, so any that were explicitly given as + well can be ignored. If (when there are explicit characters > 255 that must + be listed) there are no characters < 256, we can omit the bitmap in the + actual compiled code. */ #ifdef SUPPORT_UTF8 - if (class_utf8 && !should_flip_negation) + if (class_utf8 && (!should_flip_negation || (options & PCRE_UCP) != 0)) { *class_utf8data++ = XCL_END; /* Marks the end of extra data */ *code++ = OP_XCLASS; @@ -3799,10 +3860,11 @@ we set the flag only if there is a literal "\r" or "\n" in the class. */ } #endif - /* If there are no characters > 255, set the opcode to OP_CLASS or - OP_NCLASS, depending on whether the whole class was negated and whether - there were negative specials such as \S in the class. Then copy the 32-byte - map into the code vector, negating it if necessary. */ + /* If there are no characters > 255, or they are all to be included or + excluded, set the opcode to OP_CLASS or OP_NCLASS, depending on whether the + whole class was negated and whether there were negative specials such as \S + (non-UCP) in the class. Then copy the 32-byte map into the code vector, + negating it if necessary. */ *code++ = (negate_class == should_flip_negation) ? OP_CLASS : OP_NCLASS; if (negate_class) @@ -5603,11 +5665,12 @@ we set the flag only if there is a literal "\r" or "\n" in the class. */ /* ===================================================================*/ /* Handle metasequences introduced by \. For ones like \d, the ESC_ values - are arranged to be the negation of the corresponding OP_values. For the - back references, the values are ESC_REF plus the reference number. Only - back references and those types that consume a character may be repeated. - We can test for values between ESC_b and ESC_Z for the latter; this may - have to change if any new ones are ever created. */ + are arranged to be the negation of the corresponding OP_values in the + default case when PCRE_UCP is not set. For the back references, the values + are ESC_REF plus the reference number. Only back references and those types + that consume a character may be repeated. We can test for values between + ESC_b and ESC_Z for the latter; this may have to change if any new ones are + ever created. */ case CHAR_BACKSLASH: tempptr = ptr; @@ -5767,12 +5830,24 @@ we set the flag only if there is a literal "\r" or "\n" in the class. */ #endif /* For the rest (including \X when Unicode properties are supported), we - can obtain the OP value by negating the escape value. */ + can obtain the OP value by negating the escape value in the default + situation when PCRE_UCP is not set. When it *is* set, we substitute + Unicode property tests. */ else { - previous = (-c > ESC_b && -c < ESC_Z)? code : NULL; - *code++ = -c; +#ifdef SUPPORT_UCP + if (-c >= ESC_DU && -c <= ESC_wu) + { + nestptr = ptr + 1; /* Where to resume */ + ptr = substitutes[-c - ESC_DU] - 1; /* Just before substitute */ + } + else +#endif + { + previous = (-c > ESC_b && -c < ESC_Z)? code : NULL; + *code++ = -c; + } } continue; } @@ -6509,7 +6584,7 @@ int length = 1; /* For final END opcode */ int firstbyte, reqbyte, newline; int errorcode = 0; int skipatstart = 0; -BOOL utf8 = (options & PCRE_UTF8) != 0; +BOOL utf8; size_t size; uschar *code; const uschar *codestart; @@ -6579,6 +6654,8 @@ while (ptr[skipatstart] == CHAR_LEFT_PARENTHESIS && if (strncmp((char *)(ptr+skipatstart+2), STRING_UTF8_RIGHTPAR, 5) == 0) { skipatstart += 7; options |= PCRE_UTF8; continue; } + else if (strncmp((char *)(ptr+skipatstart+2), STRING_UCP_RIGHTPAR, 4) == 0) + { skipatstart += 6; options |= PCRE_UCP; continue; } if (strncmp((char *)(ptr+skipatstart+2), STRING_CR_RIGHTPAR, 3) == 0) { skipatstart += 5; newnl = PCRE_NEWLINE_CR; } @@ -6602,6 +6679,8 @@ while (ptr[skipatstart] == CHAR_LEFT_PARENTHESIS && options = (options & ~(PCRE_BSR_ANYCRLF|PCRE_BSR_UNICODE)) | newbsr; else break; } + +utf8 = (options & PCRE_UTF8) != 0; /* Can't support UTF8 unless PCRE has been compiled to include the code. */ @@ -6620,6 +6699,16 @@ if (utf8) } #endif +/* Can't support UCP unless PCRE has been compiled to include the code. */ + +#ifndef SUPPORT_UCP +if ((options & PCRE_UCP) != 0) + { + errorcode = ERR67; + goto PCRE_EARLY_ERROR_RETURN; + } +#endif + /* Check validity of \R options. */ switch (options & (PCRE_BSR_ANYCRLF|PCRE_BSR_UNICODE)) diff --git a/pcre_dfa_exec.c b/pcre_dfa_exec.c index 88bb1f0..3c4e4b9 100644 --- a/pcre_dfa_exec.c +++ b/pcre_dfa_exec.c @@ -922,13 +922,37 @@ for (;;) if (utf8) BACKCHAR(temp); #endif GETCHARTEST(d, temp); +#ifdef SUPPORT_UCP + if ((md->poptions & PCRE_UCP) != 0) + { + if (d == '_') left_word = TRUE; else + { + int cat = UCD_CATEGORY(d); + left_word = (cat == ucp_L || cat == ucp_N); + } + } + else +#endif left_word = d < 256 && (ctypes[d] & ctype_word) != 0; } - else left_word = 0; + else left_word = FALSE; if (clen > 0) + { +#ifdef SUPPORT_UCP + if ((md->poptions & PCRE_UCP) != 0) + { + if (c == '_') right_word = TRUE; else + { + int cat = UCD_CATEGORY(c); + right_word = (cat == ucp_L || cat == ucp_N); + } + } + else +#endif right_word = c < 256 && (ctypes[c] & ctype_word) != 0; - else right_word = 0; + } + else right_word = FALSE; if ((left_word == right_word) == (codevalue == OP_NOT_WORD_BOUNDARY)) { ADD_ACTIVE(state_offset + 1, 0); } diff --git a/pcre_exec.c b/pcre_exec.c index 42e4f3d..7d95685 100644 --- a/pcre_exec.c +++ b/pcre_exec.c @@ -1718,14 +1718,30 @@ for (;;) #ifdef SUPPORT_UTF8 if (utf8) { + /* Get status of previous character */ + if (eptr == md->start_subject) prev_is_word = FALSE; else { USPTR lastptr = eptr - 1; while((*lastptr & 0xc0) == 0x80) lastptr--; if (lastptr < md->start_used_ptr) md->start_used_ptr = lastptr; GETCHAR(c, lastptr); +#ifdef SUPPORT_UCP + if (md->use_ucp) + { + if (c == '_') prev_is_word = TRUE; else + { + int cat = UCD_CATEGORY(c); + prev_is_word = (cat == ucp_L || cat == ucp_N); + } + } + else +#endif prev_is_word = c < 256 && (md->ctypes[c] & ctype_word) != 0; } + + /* Get status of next character */ + if (eptr >= md->end_subject) { SCHECK_PARTIAL(); @@ -1734,26 +1750,68 @@ for (;;) else { GETCHAR(c, eptr); +#ifdef SUPPORT_UCP + if (md->use_ucp) + { + if (c == '_') cur_is_word = TRUE; else + { + int cat = UCD_CATEGORY(c); + cur_is_word = (cat == ucp_L || cat == ucp_N); + } + } + else +#endif cur_is_word = c < 256 && (md->ctypes[c] & ctype_word) != 0; } } else #endif - /* Not in UTF-8 mode */ + /* Not in UTF-8 mode, but we may still have PCRE_UCP set, and for + consistency with the behaviour of \w we do use it in this case. */ { + /* Get status of previous character */ + if (eptr == md->start_subject) prev_is_word = FALSE; else { if (eptr <= md->start_used_ptr) md->start_used_ptr = eptr - 1; +#ifdef SUPPORT_UCP + if (md->use_ucp) + { + c = eptr[-1]; + if (c == '_') prev_is_word = TRUE; else + { + int cat = UCD_CATEGORY(c); + prev_is_word = (cat == ucp_L || cat == ucp_N); + } + } + else +#endif prev_is_word = ((md->ctypes[eptr[-1]] & ctype_word) != 0); } + + /* Get status of next character */ + if (eptr >= md->end_subject) { SCHECK_PARTIAL(); cur_is_word = FALSE; } - else cur_is_word = ((md->ctypes[*eptr] & ctype_word) != 0); + else +#ifdef SUPPORT_UCP + if (md->use_ucp) + { + c = *eptr; + if (c == '_') cur_is_word = TRUE; else + { + int cat = UCD_CATEGORY(c); + cur_is_word = (cat == ucp_L || cat == ucp_N); + } + } + else +#endif + cur_is_word = ((md->ctypes[*eptr] & ctype_word) != 0); } /* Now see if the situation is what we want */ @@ -5607,6 +5665,7 @@ end_subject = md->end_subject; md->endonly = (re->options & PCRE_DOLLAR_ENDONLY) != 0; utf8 = md->utf8 = (re->options & PCRE_UTF8) != 0; +md->use_ucp = (re->options & PCRE_UCP) != 0; md->jscript_compat = (re->options & PCRE_JAVASCRIPT_COMPAT) != 0; md->notbol = (options & PCRE_NOTBOL) != 0; diff --git a/pcre_internal.h b/pcre_internal.h index f3a3262..a372d6c 100644 --- a/pcre_internal.h +++ b/pcre_internal.h @@ -580,7 +580,7 @@ time, run time, or study time, respectively. */ PCRE_DOTALL|PCRE_DOLLAR_ENDONLY|PCRE_EXTRA|PCRE_UNGREEDY|PCRE_UTF8| \ PCRE_NO_AUTO_CAPTURE|PCRE_NO_UTF8_CHECK|PCRE_AUTO_CALLOUT|PCRE_FIRSTLINE| \ PCRE_DUPNAMES|PCRE_NEWLINE_BITS|PCRE_BSR_ANYCRLF|PCRE_BSR_UNICODE| \ - PCRE_JAVASCRIPT_COMPAT) + PCRE_JAVASCRIPT_COMPAT|PCRE_UCP) #define PUBLIC_EXEC_OPTIONS \ (PCRE_ANCHORED|PCRE_NOTBOL|PCRE_NOTEOL|PCRE_NOTEMPTY|PCRE_NOTEMPTY_ATSTART| \ @@ -905,6 +905,7 @@ so that PCRE works on both ASCII and EBCDIC platforms, in non-UTF-mode only. */ #define STRING_BSR_ANYCRLF_RIGHTPAR "BSR_ANYCRLF)" #define STRING_BSR_UNICODE_RIGHTPAR "BSR_UNICODE)" #define STRING_UTF8_RIGHTPAR "UTF8)" +#define STRING_UCP_RIGHTPAR "UCP)" #else /* SUPPORT_UTF8 */ @@ -1158,6 +1159,7 @@ only. */ #define STRING_BSR_ANYCRLF_RIGHTPAR STR_B STR_S STR_R STR_UNDERSCORE STR_A STR_N STR_Y STR_C STR_R STR_L STR_F STR_RIGHT_PARENTHESIS #define STRING_BSR_UNICODE_RIGHTPAR STR_B STR_S STR_R STR_UNDERSCORE STR_U STR_N STR_I STR_C STR_O STR_D STR_E STR_RIGHT_PARENTHESIS #define STRING_UTF8_RIGHTPAR STR_U STR_T STR_F STR_8 STR_RIGHT_PARENTHESIS +#define STRING_UCP_RIGHTPAR STR_U STR_C STR_P STR_RIGHT_PARENTHESIS #endif /* SUPPORT_UTF8 */ @@ -1218,6 +1220,11 @@ corresponds to "." in DOTALL mode rather than an escape sequence. It is also used for [^] in JavaScript compatibility mode. In non-DOTALL mode, "." behaves like \N. +The special values ESC_DU, ESC_du, etc. are used instead of ESC_D, ESC_d, etc. +when PCRE_UCP is set, when replacement of \d etc by \p sequences is required. +They must be contiguous, and remain in order so that the replacements can be +looked up from a table. + The final escape must be ESC_REF as subsequent values are used for backreferences (\1, \2, \3, etc). There are two tests in the code for an escape greater than ESC_b and less than ESC_Z to detect the types that may be @@ -1227,10 +1234,11 @@ put in between that don't consume a character, that code will have to change. enum { ESC_A = 1, ESC_G, ESC_K, ESC_B, ESC_b, ESC_D, ESC_d, ESC_S, ESC_s, ESC_W, ESC_w, ESC_N, ESC_dum, ESC_C, ESC_P, ESC_p, ESC_R, ESC_H, - ESC_h, ESC_V, ESC_v, ESC_X, ESC_Z, ESC_z, ESC_E, ESC_Q, ESC_g, ESC_k, + ESC_h, ESC_V, ESC_v, ESC_X, ESC_Z, ESC_z, + ESC_E, ESC_Q, ESC_g, ESC_k, + ESC_DU, ESC_du, ESC_SU, ESC_su, ESC_WU, ESC_wu, ESC_REF }; - /* Opcode table: Starting from 1 (i.e. after OP_END), the values up to OP_EOD must correspond in order to the list of escapes immediately above. @@ -1525,7 +1533,7 @@ enum { ERR0, ERR1, ERR2, ERR3, ERR4, ERR5, ERR6, ERR7, ERR8, ERR9, ERR30, ERR31, ERR32, ERR33, ERR34, ERR35, ERR36, ERR37, ERR38, ERR39, ERR40, ERR41, ERR42, ERR43, ERR44, ERR45, ERR46, ERR47, ERR48, ERR49, ERR50, ERR51, ERR52, ERR53, ERR54, ERR55, ERR56, ERR57, ERR58, ERR59, - ERR60, ERR61, ERR62, ERR63, ERR64, ERR65, ERR66, ERRCOUNT }; + ERR60, ERR61, ERR62, ERR63, ERR64, ERR65, ERR66, ERR67, ERRCOUNT }; /* The real format of the start of the pcre block; the index of names and the code vector run on as long as necessary after the end. We store an explicit @@ -1668,6 +1676,7 @@ typedef struct match_data { BOOL noteol; /* NOTEOL flag */ BOOL utf8; /* UTF8 flag */ BOOL jscript_compat; /* JAVASCRIPT_COMPAT flag */ + BOOL use_ucp; /* PCRE_UCP flag */ BOOL endonly; /* Dollar not before final \n */ BOOL notempty; /* Empty string match not wanted */ BOOL notempty_atstart; /* Empty string match at start not wanted */ diff --git a/pcreposix.c b/pcreposix.c index 5b022cc..2400d97 100644 --- a/pcreposix.c +++ b/pcreposix.c @@ -6,7 +6,7 @@ and semantics are as close as possible to those of the Perl 5 language. Written by Philip Hazel - Copyright (c) 1997-2009 University of Cambridge + Copyright (c) 1997-2010 University of Cambridge ----------------------------------------------------------------------------- Redistribution and use in source and binary forms, with or without @@ -145,6 +145,7 @@ static const int eint[] = { /* 65 */ REG_BADPAT, /* different names for subpatterns of the same number are not allowed */ REG_BADPAT, /* (*MARK) must have an argument */ + REG_INVARG, /* this version of PCRE is not compiled with PCRE_UCP support */ }; /* Table of texts corresponding to POSIX error codes */ @@ -248,6 +249,7 @@ if ((cflags & REG_NEWLINE) != 0) options |= PCRE_MULTILINE; if ((cflags & REG_DOTALL) != 0) options |= PCRE_DOTALL; if ((cflags & REG_NOSUB) != 0) options |= PCRE_NO_AUTO_CAPTURE; if ((cflags & REG_UTF8) != 0) options |= PCRE_UTF8; +if ((cflags & REG_UCP) != 0) options |= PCRE_UCP; if ((cflags & REG_UNGREEDY) != 0) options |= PCRE_UNGREEDY; preg->re_pcre = pcre_compile2(pattern, options, &errorcode, &errorptr, diff --git a/pcreposix.h b/pcreposix.h index 8ad58f5..b90e2ec 100644 --- a/pcreposix.h +++ b/pcreposix.h @@ -62,6 +62,7 @@ extern "C" { #define REG_STARTEND 0x0080 /* BSD feature: pass subject string by so,eo */ #define REG_NOTEMPTY 0x0100 /* NOT defined by POSIX; maps to PCRE_NOTEMPTY */ #define REG_UNGREEDY 0x0200 /* NOT defined by POSIX; maps to PCRE_UNGREEDY */ +#define REG_UCP 0x0400 /* NOT defined by POSIX; maps to PCRE_UCP */ /* This is not used by PCRE, but by defining it we make it easier to slot PCRE into existing programs that make POSIX calls. */ @@ -741,9 +741,8 @@ return 0; * Check newline indicator * *************************************************/ -/* This is used both at compile and run-time to check for <xxx> escapes, where -xxx is LF, CR, CRLF, ANYCRLF, or ANY. Print a message and return 0 if there is -no match. +/* This is used both at compile and run-time to check for <xxx> escapes. Print +a message and return 0 if there is no match. Arguments: p points after the leading '<' @@ -1238,6 +1237,7 @@ while (!done) case 'S': do_study = 1; break; case 'U': options |= PCRE_UNGREEDY; break; + case 'W': options |= PCRE_UCP; break; case 'X': options |= PCRE_EXTRA; break; case 'Z': debug_lengths = 0; break; case '8': options |= PCRE_UTF8; use_utf8 = 1; break; @@ -1268,7 +1268,7 @@ while (!done) case '<': { - if (strncmp((char *)pp, "JS>", 3) == 0) + if (strncmpic(pp, (uschar *)"JS>", 3) == 0) { options |= PCRE_JAVASCRIPT_COMPAT; pp += 3; @@ -1309,6 +1309,7 @@ while (!done) if ((options & PCRE_DOTALL) != 0) cflags |= REG_DOTALL; if ((options & PCRE_NO_AUTO_CAPTURE) != 0) cflags |= REG_NOSUB; if ((options & PCRE_UTF8) != 0) cflags |= REG_UTF8; + if ((options & PCRE_UCP) != 0) cflags |= REG_UCP; if ((options & PCRE_UNGREEDY) != 0) cflags |= REG_UNGREEDY; rc = regcomp(&preg, (char *)p, cflags); @@ -1555,7 +1556,7 @@ while (!done) if (do_flip) all_options = byteflip(all_options, sizeof(all_options)); if (get_options == 0) fprintf(outfile, "No options\n"); - else fprintf(outfile, "Options:%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", + else fprintf(outfile, "Options:%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", ((get_options & PCRE_ANCHORED) != 0)? " anchored" : "", ((get_options & PCRE_CASELESS) != 0)? " caseless" : "", ((get_options & PCRE_EXTENDED) != 0)? " extended" : "", @@ -1569,6 +1570,7 @@ while (!done) ((get_options & PCRE_UNGREEDY) != 0)? " ungreedy" : "", ((get_options & PCRE_NO_AUTO_CAPTURE) != 0)? " no_auto_capture" : "", ((get_options & PCRE_UTF8) != 0)? " utf8" : "", + ((get_options & PCRE_UCP) != 0)? " ucp" : "", ((get_options & PCRE_NO_UTF8_CHECK) != 0)? " no_utf8_check" : "", ((get_options & PCRE_DUPNAMES) != 0)? " dupnames" : ""); diff --git a/perltest.pl b/perltest.pl index fba2fa9..424de2d 100755 --- a/perltest.pl +++ b/perltest.pl @@ -99,6 +99,10 @@ for (;;) $pattern =~ s/K(?=[a-zA-Z]*$)//; + # Remove /W from a pattern (asks pcretest to set PCRE_UCP) + + $pattern =~ s/W(?=[a-zA-Z]*$)//; + # Check that the pattern is valid eval "\$_ =~ ${pattern}"; diff --git a/testdata/testinput10 b/testdata/testinput10 index 420c274..99afab8 100644 --- a/testdata/testinput10 +++ b/testdata/testinput10 @@ -1,7 +1,8 @@ /-- These are a few representative patterns whose lengths and offsets are to be shown when the link size is 2. This is just a doublecheck test to ensure the sizes don't go horribly wrong when something is changed. The pattern contents -are all themselves checked in other tests. --/ +are all themselves checked in other tests. Unicode, including property support, +is required for these tests. --/ /((?i)b)/BM @@ -121,4 +122,14 @@ are all themselves checked in other tests. --/ /[^\xaa]/8BM +/[^\d]/8WB + +/[[:^alpha:][:^cntrl:]]+/8WB + +/[[:^cntrl:][:^alpha:]]+/8WB + +/[[:alpha:]]+/8WB + +/[[:^alpha:]\S]+/8WB + /-- End of testinput10 --/ diff --git a/testdata/testinput12 b/testdata/testinput12 index 2f8cb2c..b3d8716 100644 --- a/testdata/testinput12 +++ b/testdata/testinput12 @@ -359,4 +359,124 @@ of case for anything other than the ASCII letters. --/ /^[\p{^Xwd}]+/8 !.+\x{019}\x{35a}AB +/[\D]/WBZ8 + 1\x{3c8}2 + +/[\d]/WBZ8 + >\x{6f4}< + +/[\S]/WBZ8 + \x{1680}\x{6f4}\x{1680} + +/[\s]/WBZ8 + >\x{1680}< + +/[\W]/WBZ8 + A\x{1712}B + +/[\w]/WBZ8 + >\x{1723}< + +/\D/WBZ8 + 1\x{3c8}2 + +/\d/WBZ8 + >\x{6f4}< + +/\S/WBZ8 + \x{1680}\x{6f4}\x{1680} + +/\s/WBZ8 + >\x{1680}> + +/\W/WBZ8 + A\x{1712}B + +/\w/WBZ8 + >\x{1723}< + +/[[:alpha:]]/WBZ + +/[[:lower:]]/WBZ + +/[[:upper:]]/WBZ + +/[[:alnum:]]/WBZ + +/[[:ascii:]]/WBZ + +/[[:blank:]]/WBZ + +/[[:cntrl:]]/WBZ + +/[[:digit:]]/WBZ + +/[[:graph:]]/WBZ + +/[[:print:]]/WBZ + +/[[:punct:]]/WBZ + +/[[:space:]]/WBZ + +/[[:word:]]/WBZ + +/[[:xdigit:]]/WBZ + +/-- Unicode properties for \b abd \B --/ + +/\b...\B/8W + abc_ + \x{37e}abc\x{376} + \x{37e}\x{376}\x{371}\x{393}\x{394} + !\x{c0}++\x{c1}\x{c2} + !\x{c0}+++++ + +/-- Without PCRE_UCP, non-ASCII always fail, even if < 256 --/ + +/\b...\B/8 + abc_ + ** Failers + \x{37e}abc\x{376} + \x{37e}\x{376}\x{371}\x{393}\x{394} + !\x{c0}++\x{c1}\x{c2} + !\x{c0}+++++ + +/-- With PCRE_UCP, non-UTF8 chars that are < 256 still check properties --/ + +/\b...\B/W + abc_ + !\x{c0}++\x{c1}\x{c2} + !\x{c0}+++++ + +/-- POSIX interface --/ + +/\w/P + +++\x{c2} + +/\w/WP + +++\x{c2} + +/-- Some of these are silly, but they check various combinations --/ + +/[[:^alpha:][:^cntrl:]]+/8WBZ + 123 + abc + +/[[:^cntrl:][:^alpha:]]+/8WBZ + 123 + abc + +/[[:alpha:]]+/8WBZ + abc + +/[[:^alpha:]\S]+/8WBZ + 123 + abc + +/[^\d]+/8WBZ + abc123 + abc\x{123} + \x{660}abc + /-- End of testinput12 --/ diff --git a/testdata/testinput6 b/testdata/testinput6 index 759018a..9218e5c 100644 --- a/testdata/testinput6 +++ b/testdata/testinput6 @@ -752,4 +752,46 @@ /\p{Avestan}\p{Bamum}\p{Egyptian_Hieroglyphs}\p{Imperial_Aramaic}\p{Inscriptional_Pahlavi}\p{Inscriptional_Parthian}\p{Javanese}\p{Kaithi}\p{Lisu}\p{Meetei_Mayek}\p{Old_South_Arabian}\p{Old_Turkic}\p{Samaritan}\p{Tai_Tham}\p{Tai_Viet}/8 \x{10b00}\x{a6ef}\x{13007}\x{10857}\x{10b78}\x{10b58}\x{a980}\x{110c1}\x{a4ff}\x{abc0}\x{10a7d}\x{10c48}\x{0800}\x{1aad}\x{aac0} +/^\w+/8W + Az_\x{aa}\x{c0}\x{1c5}\x{2b0}\x{3b6}\x{1d7c9}\x{2fa1d}1\x{660}\x{bef}\x{16ee} + +/^[[:xdigit:]]*/8W + 1a\x{660}\x{bef}\x{16ee} + +/^\d+/8W + 1\x{660}\x{bef}\x{16ee} + +/^[[:digit:]]+/8W + 1\x{660}\x{bef}\x{16ee} + +/^>\s+/8W + >\x{20}\x{a0}\x{1680}\x{2028}\x{2029}\x{202f}\x{9}\x{b} + +/^>\pZ+/8W + >\x{20}\x{a0}\x{1680}\x{2028}\x{2029}\x{202f}\x{9}\x{b} + +/^>[[:space:]]*/8W + >\x{20}\x{a0}\x{1680}\x{2028}\x{2029}\x{202f}\x{9}\x{b} + +/^>[[:blank:]]*/8W + >\x{20}\x{a0}\x{1680}\x{180e}\x{2000}\x{202f}\x{9}\x{b}\x{2028} + +/^[[:alpha:]]*/8W + Az\x{aa}\x{c0}\x{1c5}\x{2b0}\x{3b6}\x{1d7c9}\x{2fa1d} + +/^[[:alnum:]]*/8W + Az\x{aa}\x{c0}\x{1c5}\x{2b0}\x{3b6}\x{1d7c9}\x{2fa1d}1\x{660}\x{bef}\x{16ee} + +/^[[:cntrl:]]*/8W + \x{0}\x{09}\x{1f}\x{7f}\x{9f} + +/^[[:graph:]]*/8W + A\x{a1}\x{a0} + +/^[[:print:]]*/8W + A z\x{a0}\x{a1} + +/^[[:punct:]]*/8W + .+\x{a1}\x{a0} + /-- End of testinput6 --/ diff --git a/testdata/testinput9 b/testdata/testinput9 index 6901f20..8d312e0 100644 --- a/testdata/testinput9 +++ b/testdata/testinput9 @@ -960,4 +960,30 @@ /^[\p{Xwd}]+/8 ABCD1234\x{6ca}\x{a6c}\x{10a7}_ +/-- Unicode properties for \b abd \B --/ + +/\b...\B/8W + abc_ + \x{37e}abc\x{376} + \x{37e}\x{376}\x{371}\x{393}\x{394} + !\x{c0}++\x{c1}\x{c2} + !\x{c0}+++++ + +/-- Without PCRE_UCP, non-ASCII always fail, even if < 256 --/ + +/\b...\B/8 + abc_ + ** Failers + \x{37e}abc\x{376} + \x{37e}\x{376}\x{371}\x{393}\x{394} + !\x{c0}++\x{c1}\x{c2} + !\x{c0}+++++ + +/-- With PCRE_UCP, non-UTF8 chars that are < 256 still check properties --/ + +/\b...\B/W + abc_ + !\x{c0}++\x{c1}\x{c2} + !\x{c0}+++++ + /-- End of testinput9 --/ diff --git a/testdata/testoutput10 b/testdata/testoutput10 index a0db640..4994584 100644 --- a/testdata/testoutput10 +++ b/testdata/testoutput10 @@ -1,7 +1,8 @@ /-- These are a few representative patterns whose lengths and offsets are to be shown when the link size is 2. This is just a doublecheck test to ensure the sizes don't go horribly wrong when something is changed. The pattern contents -are all themselves checked in other tests. --/ +are all themselves checked in other tests. Unicode, including property support, +is required for these tests. --/ /((?i)b)/BM Memory allocation (code space): 21 @@ -666,4 +667,44 @@ Memory allocation (code space): 40 39 End ------------------------------------------------------------------ +/[^\d]/8WB +------------------------------------------------------------------ + 0 11 Bra + 3 [^\p{Nd}] + 11 11 Ket + 14 End +------------------------------------------------------------------ + +/[[:^alpha:][:^cntrl:]]+/8WB +------------------------------------------------------------------ + 0 44 Bra + 3 [ -~\x80-\xff\P{L}]+ + 44 44 Ket + 47 End +------------------------------------------------------------------ + +/[[:^cntrl:][:^alpha:]]+/8WB +------------------------------------------------------------------ + 0 44 Bra + 3 [ -~\x80-\xff\P{L}]+ + 44 44 Ket + 47 End +------------------------------------------------------------------ + +/[[:alpha:]]+/8WB +------------------------------------------------------------------ + 0 12 Bra + 3 [\p{L}]+ + 12 12 Ket + 15 End +------------------------------------------------------------------ + +/[[:^alpha:]\S]+/8WB +------------------------------------------------------------------ + 0 15 Bra + 3 [\P{L}\P{Xsp}]+ + 15 15 Ket + 18 End +------------------------------------------------------------------ + /-- End of testinput10 --/ diff --git a/testdata/testoutput12 b/testdata/testoutput12 index 4fe4833..7752d15 100644 --- a/testdata/testoutput12 +++ b/testdata/testoutput12 @@ -703,4 +703,348 @@ No match !.+\x{019}\x{35a}AB 0: !.+\x{19}\x{35a} +/[\D]/WBZ8 +------------------------------------------------------------------ + Bra + [\P{Nd}] + Ket + End +------------------------------------------------------------------ + 1\x{3c8}2 + 0: \x{3c8} + +/[\d]/WBZ8 +------------------------------------------------------------------ + Bra + [\p{Nd}] + Ket + End +------------------------------------------------------------------ + >\x{6f4}< + 0: \x{6f4} + +/[\S]/WBZ8 +------------------------------------------------------------------ + Bra + [\P{Xsp}] + Ket + End +------------------------------------------------------------------ + \x{1680}\x{6f4}\x{1680} + 0: \x{6f4} + +/[\s]/WBZ8 +------------------------------------------------------------------ + Bra + [\p{Xsp}] + Ket + End +------------------------------------------------------------------ + >\x{1680}< + 0: \x{1680} + +/[\W]/WBZ8 +------------------------------------------------------------------ + Bra + [\P{Xwd}] + Ket + End +------------------------------------------------------------------ + A\x{1712}B + 0: \x{1712} + +/[\w]/WBZ8 +------------------------------------------------------------------ + Bra + [\p{Xwd}] + Ket + End +------------------------------------------------------------------ + >\x{1723}< + 0: \x{1723} + +/\D/WBZ8 +------------------------------------------------------------------ + Bra + notprop Nd + Ket + End +------------------------------------------------------------------ + 1\x{3c8}2 + 0: \x{3c8} + +/\d/WBZ8 +------------------------------------------------------------------ + Bra + prop Nd + Ket + End +------------------------------------------------------------------ + >\x{6f4}< + 0: \x{6f4} + +/\S/WBZ8 +------------------------------------------------------------------ + Bra + notprop Xsp + Ket + End +------------------------------------------------------------------ + \x{1680}\x{6f4}\x{1680} + 0: \x{6f4} + +/\s/WBZ8 +------------------------------------------------------------------ + Bra + prop Xsp + Ket + End +------------------------------------------------------------------ + >\x{1680}> + 0: \x{1680} + +/\W/WBZ8 +------------------------------------------------------------------ + Bra + notprop Xwd + Ket + End +------------------------------------------------------------------ + A\x{1712}B + 0: \x{1712} + +/\w/WBZ8 +------------------------------------------------------------------ + Bra + prop Xwd + Ket + End +------------------------------------------------------------------ + >\x{1723}< + 0: \x{1723} + +/[[:alpha:]]/WBZ +------------------------------------------------------------------ + Bra + [\p{L}] + Ket + End +------------------------------------------------------------------ + +/[[:lower:]]/WBZ +------------------------------------------------------------------ + Bra + [\p{Ll}] + Ket + End +------------------------------------------------------------------ + +/[[:upper:]]/WBZ +------------------------------------------------------------------ + Bra + [\p{Lu}] + Ket + End +------------------------------------------------------------------ + +/[[:alnum:]]/WBZ +------------------------------------------------------------------ + Bra + [\p{Xan}] + Ket + End +------------------------------------------------------------------ + +/[[:ascii:]]/WBZ +------------------------------------------------------------------ + Bra + [\x00-\x7f] + Ket + End +------------------------------------------------------------------ + +/[[:blank:]]/WBZ +------------------------------------------------------------------ + Bra + [\x09 \xa0] + Ket + End +------------------------------------------------------------------ + +/[[:cntrl:]]/WBZ +------------------------------------------------------------------ + Bra + [\x00-\x1f\x7f] + Ket + End +------------------------------------------------------------------ + +/[[:digit:]]/WBZ +------------------------------------------------------------------ + Bra + [\p{Nd}] + Ket + End +------------------------------------------------------------------ + +/[[:graph:]]/WBZ +------------------------------------------------------------------ + Bra + [!-~] + Ket + End +------------------------------------------------------------------ + +/[[:print:]]/WBZ +------------------------------------------------------------------ + Bra + [ -~] + Ket + End +------------------------------------------------------------------ + +/[[:punct:]]/WBZ +------------------------------------------------------------------ + Bra + [!-/:-@[-`{-~] + Ket + End +------------------------------------------------------------------ + +/[[:space:]]/WBZ +------------------------------------------------------------------ + Bra + [\p{Xps}] + Ket + End +------------------------------------------------------------------ + +/[[:word:]]/WBZ +------------------------------------------------------------------ + Bra + [\p{Xwd}] + Ket + End +------------------------------------------------------------------ + +/[[:xdigit:]]/WBZ +------------------------------------------------------------------ + Bra + [0-9A-Fa-f] + Ket + End +------------------------------------------------------------------ + +/-- Unicode properties for \b abd \B --/ + +/\b...\B/8W + abc_ + 0: abc + \x{37e}abc\x{376} + 0: abc + \x{37e}\x{376}\x{371}\x{393}\x{394} + 0: \x{376}\x{371}\x{393} + !\x{c0}++\x{c1}\x{c2} + 0: ++\x{c1} + !\x{c0}+++++ + 0: \x{c0}++ + +/-- Without PCRE_UCP, non-ASCII always fail, even if < 256 --/ + +/\b...\B/8 + abc_ + 0: abc + ** Failers + 0: Fai + \x{37e}abc\x{376} +No match + \x{37e}\x{376}\x{371}\x{393}\x{394} +No match + !\x{c0}++\x{c1}\x{c2} +No match + !\x{c0}+++++ +No match + +/-- With PCRE_UCP, non-UTF8 chars that are < 256 still check properties --/ + +/\b...\B/W + abc_ + 0: abc + !\x{c0}++\x{c1}\x{c2} + 0: ++\xc1 + !\x{c0}+++++ + 0: \xc0++ + +/-- POSIX interface --/ + +/\w/P + +++\x{c2} +No match: POSIX code 17: match failed + +/\w/WP + +++\x{c2} + 0: \xc2 + +/-- Some of these are silly, but they check various combinations --/ + +/[[:^alpha:][:^cntrl:]]+/8WBZ +------------------------------------------------------------------ + Bra + [ -~\x80-\xff\P{L}]+ + Ket + End +------------------------------------------------------------------ + 123 + 0: 123 + abc + 0: abc + +/[[:^cntrl:][:^alpha:]]+/8WBZ +------------------------------------------------------------------ + Bra + [ -~\x80-\xff\P{L}]+ + Ket + End +------------------------------------------------------------------ + 123 + 0: 123 + abc + 0: abc + +/[[:alpha:]]+/8WBZ +------------------------------------------------------------------ + Bra + [\p{L}]+ + Ket + End +------------------------------------------------------------------ + abc + 0: abc + +/[[:^alpha:]\S]+/8WBZ +------------------------------------------------------------------ + Bra + [\P{L}\P{Xsp}]+ + Ket + End +------------------------------------------------------------------ + 123 + 0: 123 + abc + 0: abc + +/[^\d]+/8WBZ +------------------------------------------------------------------ + Bra + [^\p{Nd}]+ + Ket + End +------------------------------------------------------------------ + abc123 + 0: abc + abc\x{123} + 0: abc\x{123} + \x{660}abc + 0: abc + /-- End of testinput12 --/ diff --git a/testdata/testoutput6 b/testdata/testoutput6 index b4176eb..c32ea9f 100644 --- a/testdata/testoutput6 +++ b/testdata/testoutput6 @@ -1285,4 +1285,60 @@ No match \x{10b00}\x{a6ef}\x{13007}\x{10857}\x{10b78}\x{10b58}\x{a980}\x{110c1}\x{a4ff}\x{abc0}\x{10a7d}\x{10c48}\x{0800}\x{1aad}\x{aac0} 0: \x{10b00}\x{a6ef}\x{13007}\x{10857}\x{10b78}\x{10b58}\x{a980}\x{110c1}\x{a4ff}\x{abc0}\x{10a7d}\x{10c48}\x{800}\x{1aad}\x{aac0} +/^\w+/8W + Az_\x{aa}\x{c0}\x{1c5}\x{2b0}\x{3b6}\x{1d7c9}\x{2fa1d}1\x{660}\x{bef}\x{16ee} + 0: Az_\x{aa}\x{c0}\x{1c5}\x{2b0}\x{3b6}\x{1d7c9}\x{2fa1d}1\x{660}\x{bef}\x{16ee} + +/^[[:xdigit:]]*/8W + 1a\x{660}\x{bef}\x{16ee} + 0: 1a + +/^\d+/8W + 1\x{660}\x{bef}\x{16ee} + 0: 1\x{660}\x{bef} + +/^[[:digit:]]+/8W + 1\x{660}\x{bef}\x{16ee} + 0: 1\x{660}\x{bef} + +/^>\s+/8W + >\x{20}\x{a0}\x{1680}\x{2028}\x{2029}\x{202f}\x{9}\x{b} + 0: > \x{a0}\x{1680}\x{2028}\x{2029}\x{202f}\x{09} + +/^>\pZ+/8W + >\x{20}\x{a0}\x{1680}\x{2028}\x{2029}\x{202f}\x{9}\x{b} + 0: > \x{a0}\x{1680}\x{2028}\x{2029}\x{202f} + +/^>[[:space:]]*/8W + >\x{20}\x{a0}\x{1680}\x{2028}\x{2029}\x{202f}\x{9}\x{b} + 0: > \x{a0}\x{1680}\x{2028}\x{2029}\x{202f}\x{09}\x{0b} + +/^>[[:blank:]]*/8W + >\x{20}\x{a0}\x{1680}\x{180e}\x{2000}\x{202f}\x{9}\x{b}\x{2028} + 0: > \x{a0}\x{1680}\x{180e}\x{2000}\x{202f}\x{09} + +/^[[:alpha:]]*/8W + Az\x{aa}\x{c0}\x{1c5}\x{2b0}\x{3b6}\x{1d7c9}\x{2fa1d} + 0: Az\x{aa}\x{c0}\x{1c5}\x{2b0}\x{3b6}\x{1d7c9}\x{2fa1d} + +/^[[:alnum:]]*/8W + Az\x{aa}\x{c0}\x{1c5}\x{2b0}\x{3b6}\x{1d7c9}\x{2fa1d}1\x{660}\x{bef}\x{16ee} + 0: Az\x{aa}\x{c0}\x{1c5}\x{2b0}\x{3b6}\x{1d7c9}\x{2fa1d}1\x{660}\x{bef}\x{16ee} + +/^[[:cntrl:]]*/8W + \x{0}\x{09}\x{1f}\x{7f}\x{9f} + 0: \x{00}\x{09}\x{1f}\x{7f} + +/^[[:graph:]]*/8W + A\x{a1}\x{a0} + 0: A + +/^[[:print:]]*/8W + A z\x{a0}\x{a1} + 0: A z + +/^[[:punct:]]*/8W + .+\x{a1}\x{a0} + 0: .+ + /-- End of testinput6 --/ diff --git a/testdata/testoutput9 b/testdata/testoutput9 index e3fdc8d..cb70f1c 100644 --- a/testdata/testoutput9 +++ b/testdata/testoutput9 @@ -1994,4 +1994,44 @@ No match 10: AB 11: A +/-- Unicode properties for \b abd \B --/ + +/\b...\B/8W + abc_ + 0: abc + \x{37e}abc\x{376} + 0: abc + \x{37e}\x{376}\x{371}\x{393}\x{394} + 0: \x{376}\x{371}\x{393} + !\x{c0}++\x{c1}\x{c2} + 0: ++\x{c1} + !\x{c0}+++++ + 0: \x{c0}++ + +/-- Without PCRE_UCP, non-ASCII always fail, even if < 256 --/ + +/\b...\B/8 + abc_ + 0: abc + ** Failers + 0: Fai + \x{37e}abc\x{376} +No match + \x{37e}\x{376}\x{371}\x{393}\x{394} +No match + !\x{c0}++\x{c1}\x{c2} +No match + !\x{c0}+++++ +No match + +/-- With PCRE_UCP, non-UTF8 chars that are < 256 still check properties --/ + +/\b...\B/W + abc_ + 0: abc + !\x{c0}++\x{c1}\x{c2} + 0: ++\xc1 + !\x{c0}+++++ + 0: \xc0++ + /-- End of testinput9 --/ |