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diff --git a/doc/pcretest.txt b/doc/pcretest.txt index 999ee0c..3835f48 100644 --- a/doc/pcretest.txt +++ b/doc/pcretest.txt @@ -305,30 +305,33 @@ PATTERN MODIFIERS it appears. The /M modifier causes the size of memory block used to hold the com- - piled pattern to be output. - - If the /S modifier appears once, it causes pcre_study() to be called - after the expression has been compiled, and the results used when the - expression is matched. If /S appears twice, it suppresses studying, + piled pattern to be output. This does not include the size of the pcre + block; it is just the actual compiled data. If the pattern is success- + fully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the + JIT compiled code is also output. + + If the /S modifier appears once, it causes pcre_study() to be called + after the expression has been compiled, and the results used when the + expression is matched. If /S appears twice, it suppresses studying, even if it was requested externally by the -s command line option. This - makes it possible to specify that certain patterns are always studied, + makes it possible to specify that certain patterns are always studied, and others are never studied, independently of -s. This feature is used in the test files in a few cases where the output is different when the pattern is studied. - If the /S modifier is immediately followed by a + character, the call - to pcre_study() is made with the PCRE_STUDY_JIT_COMPILE option, - requesting just-in-time optimization support if it is available. Note - that there is also a /+ modifier; it must not be given immediately - after /S because this will be misinterpreted. If JIT studying is suc- - cessful, it will automatically be used when pcre_exec() is run, except - when incompatible run-time options are specified. These include the + If the /S modifier is immediately followed by a + character, the call + to pcre_study() is made with the PCRE_STUDY_JIT_COMPILE option, + requesting just-in-time optimization support if it is available. Note + that there is also a /+ modifier; it must not be given immediately + after /S because this will be misinterpreted. If JIT studying is suc- + cessful, it will automatically be used when pcre_exec() is run, except + when incompatible run-time options are specified. These include the partial matching options; a complete list is given in the pcrejit docu- - mentation. See also the \J escape sequence below for a way of setting + mentation. See also the \J escape sequence below for a way of setting the size of the JIT stack. - The /T modifier must be followed by a single digit. It causes a spe- - cific set of built-in character tables to be passed to pcre_compile(). + The /T modifier must be followed by a single digit. It causes a spe- + cific set of built-in character tables to be passed to pcre_compile(). It is used in the standard PCRE tests to check behaviour with different character tables. The digit specifies the tables as follows: @@ -336,12 +339,12 @@ PATTERN MODIFIERS pcre_chartables.c.dist 1 a set of tables defining ISO 8859 characters - In table 1, some characters whose codes are greater than 128 are iden- + In table 1, some characters whose codes are greater than 128 are iden- tified as letters, digits, spaces, etc. Using the POSIX wrapper API - The /P modifier causes pcretest to call PCRE via the POSIX wrapper API + The /P modifier causes pcretest to call PCRE via the POSIX wrapper API rather than its native API. When /P is set, the following modifiers set options for the regcomp() function: @@ -353,17 +356,17 @@ PATTERN MODIFIERS /W REG_UCP ) the POSIX standard /8 REG_UTF8 ) - The /+ modifier works as described above. All other modifiers are + The /+ modifier works as described above. All other modifiers are ignored. DATA LINES - Before each data line is passed to pcre_exec(), leading and trailing - white space 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 + white space 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) @@ -444,95 +447,95 @@ DATA LINES \<any> pass the PCRE_NEWLINE_ANY option to pcre_exec() or pcre_dfa_exec() - Note that \xhh always specifies one byte, even in UTF-8 mode; this + Note that \xhh always specifies one byte, even in UTF-8 mode; this makes it possible to construct invalid UTF-8 sequences for testing pur- poses. On the other hand, \x{hh} is interpreted as a UTF-8 character in - UTF-8 mode, generating more than one byte if the value is greater than + UTF-8 mode, generating more than one byte if the value is greater than 127. When not in UTF-8 mode, it generates one byte for values less than 256, and causes an error for greater values. - 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. - The \J escape provides a way of setting the maximum stack size that is - used by the just-in-time optimization code. It is ignored if JIT opti- - mization is not being used. Providing a stack that is larger than the + The \J escape provides a way of setting the maximum stack size that is + used by the just-in-time optimization code. It is ignored if JIT opti- + mization is not being used. Providing a stack that is larger than the default 32K is necessary only for very complicated patterns. - 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 without error. - Because this is testing a specific feature of the normal interpretive - pcre_exec() execution, the use of any JIT optimization that might have + 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 without error. + Because this is testing a specific feature of the normal interpretive + pcre_exec() execution, the use of any JIT optimization that might have been set up by the /S+ qualifier of -s+ option is disabled. - The match_limit number 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 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) memory is needed to complete the match + The match_limit number 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 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) 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, \N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and + 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, \N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, 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. - (Note that this is the entire substring that was inspected during the - partial match; it may include characters before the actual match start - if a lookbehind assertion, \K, \b, or \B was involved.) For any other - return, pcretest outputs the PCRE negative error number and a short - descriptive phrase. If the error is a failed UTF-8 string check, the - byte offset of the start of the failing character and the reason code - are also output, provided that the size of the output vector is at + tially matching substring when pcre_exec() returns PCRE_ERROR_PARTIAL. + (Note that this is the entire substring that was inspected during the + partial match; it may include characters before the actual match start + if a lookbehind assertion, \K, \b, or \B was involved.) For any other + return, pcretest outputs the PCRE negative error number and a short + descriptive phrase. If the error is a failed UTF-8 string check, the + byte offset of the start of the failing character and the reason code + are also output, provided that the size of the output vector is at least two. Here is an example of an interactive pcretest run. $ pcretest @@ -547,9 +550,9 @@ DEFAULT OUTPUT FROM PCRETEST 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 fol- - lowing 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 + lowing 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)/ @@ -561,11 +564,11 @@ 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/+ @@ -573,7 +576,7 @@ 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 @@ -585,32 +588,32 @@ DEFAULT OUTPUT FROM PCRETEST 0: ipp 1: pp - "No match" is output only if the first match attempt fails. Here is an - example of a failure message (the offset 4 that is specified by \>4 is + "No match" is output only if the first match attempt fails. Here is an + example of a failure message (the offset 4 that is specified by \>4 is past the end of the subject string): re> /xyz/ data> xyz\>4 Error -24 (bad offset value) - 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)/ @@ -619,11 +622,11 @@ 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. (Note that this is the - entire substring that was inspected during the partial match; it may + lowed by the partially matching substring. (Note that this is the + entire substring that was inspected during the partial match; it may include characters before the actual match start if a lookbehind asser- tion, \K, \b, or \B was involved.) @@ -639,16 +642,16 @@ 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$/ @@ -657,30 +660,30 @@ 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 @@ -693,7 +696,7 @@ CALLOUTS 0: E* If a pattern contains (*MARK) items, an additional line is output when- - ever a change of latest mark is passed to the callout function. For + ever a change of latest mark is passed to the callout function. For example: re> /a(*MARK:X)bc/C @@ -707,59 +710,59 @@ CALLOUTS +12 ^ ^ 0: abc - The mark changes between matching "a" and "b", but stays the same for - the rest of the match, so nothing more is output. If, as a result of - backtracking, the mark reverts to being unset, the text "<unset>" is + The mark changes between matching "a" and "b", but stays the same for + the rest of the match, so nothing more is output. If, as a result of + backtracking, the mark reverts to being unset, the text "<unset>" is output. - 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 and other parameters of the callout. - 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 - POSIX interface to PCRE is being used, that is, when the /P pattern + The facilities described in this section are not available when the + POSIX interface to PCRE is being used, that is, when the /P pattern modifier 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 - re-using compiled patterns. Note that if the pattern was successfully + See the pcreprecompile documentation for a discussion about saving and + re-using compiled patterns. Note that if the pattern was successfully studied with JIT optimization, the JIT data cannot be saved. - 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 - compiled pattern. If there is additional study data, this (excluding - any JIT data) follows immediately after the compiled pattern. After + ond length is zero. The lengths are followed by an exact copy of the + compiled pattern. If there is additional study data, this (excluding + any JIT data) follows immediately after the compiled pattern. After writing the file, pcretest expects to read a new pattern. - A saved pattern can be reloaded into pcretest by specifying < and a + A saved pattern can be reloaded into pcretest by specifying < 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 delimited by < characters. For example: @@ -768,27 +771,27 @@ SAVING AND RELOADING COMPILED PATTERNS Compiled pattern loaded from /some/file No study data - If the pattern was previously studied with the JIT optimization, the - JIT information cannot be saved and restored, and so is lost. When the - pattern has been loaded, pcretest proceeds to read data lines in the + If the pattern was previously studied with the JIT optimization, the + JIT information cannot be saved and restored, and so is lost. 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. @@ -807,5 +810,5 @@ AUTHOR REVISION - Last updated: 26 August 2011 + Last updated: 02 December 2011 Copyright (c) 1997-2011 University of Cambridge. |