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diff --git a/doc/pcretest.txt b/doc/pcretest.txt index 0e9cd13..7da6889 100644 --- a/doc/pcretest.txt +++ b/doc/pcretest.txt @@ -6,24 +6,25 @@ NAME pcretest - a program for testing Perl-compatible regular expressions. SYNOPSIS - pcretest [-d] [-i] [-m] [-o osize] [-p] [-t] [source] [destination] + + pcretest [-C] [-d] [-i] [-m] [-o osize] [-p] [-t] [source] + [destination] pcretest was written as a test program for the PCRE regular expression library itself, but it can also be used for experimenting with regular expressions. This document describes the features of the test program; for details of the regular expressions themselves, see the pcrepattern - documentation. For details of PCRE and its options, see the pcreapi - documentation. + documentation. For details of the PCRE library function calls and their + options, see the pcreapi documentation. OPTIONS - -C Output the version number of the PCRE library, and all avail- able information about the optional features that are included, and then exit. - -d Behave as if each regex had the /D modifier (see below); the + -d Behave as if each regex had the /D (debug) modifier; the internal form is output after compilation. -i Behave as if each regex had the /I modifier; information @@ -35,10 +36,10 @@ OPTIONS pcretest, -s is a synonym for -m. -o osize Set the number of elements in the output vector that is used - when calling PCRE to be osize. The default value is 45, which - is enough for 14 capturing subexpressions. The vector size - can be changed for individual matching calls by including \O - in the data line (see below). + when calling pcre_exec() to be osize. The default value is + 45, which is enough for 14 capturing subexpressions. The vec- + tor size can be changed for individual matching calls by + including \O in the data line (see below). -p Behave as if each regex has /P modifier; the POSIX wrapper API is used to call PCRE. None of the other options has any @@ -46,176 +47,171 @@ OPTIONS -t Run each compile, study, and match many times with a timer, and output resulting time per compile or match (in millisec- - onds). Do not set -t with -m, because you will then get the - size output 20000 times and the timing will be distorted. + onds). Do not set -m with -t, because you will then get the + size output a zillion times, and the timing will be dis- + torted. DESCRIPTION - If pcretest is given two filename arguments, it reads from the first + If pcretest is given two filename arguments, it reads from the first and writes to the second. If it is given only one filename argument, it - reads from that file and writes to stdout. Otherwise, it reads from - stdin and writes to stdout, and prompts for each line of input, using + reads from that file and writes to stdout. Otherwise, it reads from + stdin and writes to stdout, and prompts for each line of input, using "re>" to prompt for regular expressions, and "data>" to prompt for data lines. The program handles any number of sets of input on a single input file. - Each set starts with a regular expression, and continues with any num- + Each set starts with a regular expression, and continues with any num- ber of data lines to be matched against the pattern. - Each line is matched separately and independently. If you want to do - multiple-line matches, you have to use the \n escape sequence in a sin- - gle line of input to encode the newline characters. The maximum length - of data line is 30,000 characters. + Each data line is matched separately and independently. If you want to + do multiple-line matches, you have to use the \n escape sequence in a + single line of input to encode the newline characters. The maximum + length of data line is 30,000 characters. - An empty line signals the end of the data lines, at which point a new - regular expression is read. The regular expressions are given enclosed - in any non-alphameric delimiters other than backslash, for example + An empty line signals the end of the data lines, at which point a new + regular expression is read. The regular expressions are given enclosed + in any non-alphanumeric delimiters other than backslash, for example /(a|bc)x+yz/ - White space before the initial delimiter is ignored. A regular expres- - sion may be continued over several input lines, in which case the new- - line characters are included within it. It is possible to include the + White space before the initial delimiter is ignored. A regular expres- + sion may be continued over several input lines, in which case the new- + line characters are included within it. It is possible to include the delimiter within the pattern by escaping it, for example /abc\/def/ - If you do so, the escape and the delimiter form part of the pattern, - but since delimiters are always non-alphameric, this does not affect - its interpretation. If the terminating delimiter is immediately fol- + If you do so, the escape and the delimiter form part of the pattern, + but since delimiters are always non-alphanumeric, this does not affect + its interpretation. If the terminating delimiter is immediately fol- lowed by a backslash, for example, /abc/\ - then a backslash is added to the end of the pattern. This is done to - provide a way of testing the error condition that arises if a pattern + then a backslash is added to the end of the pattern. This is done to + provide a way of testing the error condition that arises if a pattern finishes with a backslash, because /abc\/ - is interpreted as the first line of a pattern that starts with "abc/", + is interpreted as the first line of a pattern that starts with "abc/", causing pcretest to read the next line as a continuation of the regular expression. PATTERN MODIFIERS - The pattern may be followed by i, m, s, or x to set the PCRE_CASELESS, - PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively. - For example: + A pattern may be followed by any number of modifiers, which are mostly + single characters. Following Perl usage, these are referred to below + as, for example, "the /i modifier", even though the delimiter of the + pattern need not always be a slash, and no slash is used when writing + modifiers. Whitespace may appear between the final pattern delimiter + and the first modifier, and between the modifiers themselves. + + The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE, + PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when pcre_com- + pile() is called. These four modifier letters have the same effect as + they do in Perl. For example: /caseless/i - These modifier letters have the same effect as they do in Perl. There - are others that set PCRE options that do not correspond to anything in - Perl: /A, /E, /N, /U, and /X set PCRE_ANCHORED, PCRE_DOLLAR_ENDONLY, - PCRE_NO_AUTO_CAPTURE, PCRE_UNGREEDY, and PCRE_EXTRA respectively. + The following table shows additional modifiers for setting PCRE options + that do not correspond to anything in Perl: - Searching for all possible matches within each subject string can be - requested by the /g or /G modifier. After finding a match, PCRE is + /A PCRE_ANCHORED + /C PCRE_AUTO_CALLOUT + /E PCRE_DOLLAR_ENDONLY + /N PCRE_NO_AUTO_CAPTURE + /U PCRE_UNGREEDY + /X PCRE_EXTRA + + 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 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, and the normal match is retried. This imitates the way Perl han- + 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 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, and the normal match is retried. This imitates the way Perl han- dles such cases when using the /g modifier or the split() function. - There are a number of other modifiers for controlling the way pcretest - operates. + There are yet more modifiers for controlling the way pcretest operates. - 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 /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 + /pattern/Lfr_FR - For this reason, it must be the last modifier letter. 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 compil- - ing 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. + 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 + appears. - The /I modifier requests that pcretest output information about the - compiled expression (whether it is anchored, has a fixed first charac- - ter, and so on). It does this by calling pcre_fullinfo() after compil- - ing an expression, and outputting the information it gets back. If the - pattern is studied, the results of that are also output. + 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 /D modifier is a PCRE debugging feature, which also assumes /I. It - causes the internal form of compiled regular expressions to be output + causes the internal form of compiled regular expressions to be output after compilation. If the pattern was studied, the information returned is also output. - The /S modifier causes pcre_study() to be called after the expression + 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 + 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 + section about saving and reloading compiled patterns below. + + The /S modifier causes pcre_study() to be called after the expression has been compiled, and the results used when the expression is matched. - 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 - PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set. + 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 /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 + 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 + 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. -CALLOUTS - - If the pattern contains any callout requests, pcretest's callout func- - tion will be called. By default, it displays the callout number, and - the start and current positions in the text at the callout time. For - example, the output - - --->pqrabcdef - 0 ^ ^ - - 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. The callout function returns zero (carry on - matching) by default. - - Inserting callouts may be helpful when using pcretest to check compli- - cated regular expressions. For further information about callouts, see - the pcrecallout documentation. - - For testing the PCRE library, additional control of callout behaviour - is available via escape sequences in the data, as described in the fol- - lowing section. In particular, it is possible to pass in a number as - callout data (the default is zero). If the callout function receives a - non-zero number, it returns that value instead of zero. - - 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) @@ -233,8 +229,7 @@ DATA LINES \A pass the PCRE_ANCHORED option to pcre_exec() \B pass the PCRE_NOTBOL option to pcre_exec() \Cdd call pcre_copy_substring() for substring dd - after a successful match (any decimal number - less than 32) + after a successful match (number less than 32) \Cname call pcre_copy_named_substring() for substring "name" after a successful match (name termin- ated by next non alphanumeric character) @@ -246,10 +241,9 @@ DATA LINES \C!n!m return 1 instead of 0 when callout number n is reached for the nth time \C*n pass the number n (may be negative) as callout - data + data; this is used as the callout return value \Gdd call pcre_get_substring() for substring dd - after a successful match (any decimal number - less than 32) + after a successful match (number less than 32) \Gname call pcre_get_named_substring() for substring "name" after a successful match (name termin- ated by next non-alphanumeric character) @@ -258,12 +252,19 @@ DATA LINES \M discover the minimum MATCH_LIMIT setting \N pass the PCRE_NOTEMPTY option to pcre_exec() \Odd set the size of the output vector passed to - pcre_exec() to dd (any number of decimal - digits) + pcre_exec() to dd (any number of digits) + \P pass the PCRE_PARTIAL option to pcre_exec() \S output details of memory get/free calls during matching \Z pass the PCRE_NOTEOL option to pcre_exec() \? pass the PCRE_NO_UTF8_CHECK option to pcre_exec() + \>dd start the match at offset dd (any number of digits); + this sets the startoffset argument for pcre_exec() + + 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 field of the pcre_extra data struc- @@ -274,34 +275,31 @@ DATA LINES with very large numbers of matching possibilities, it can become large very quickly with increasing length of subject string. - When \O is used, it may be higher or lower than the size set by the -O - option (or defaulted to 45); \O applies only to the call of pcre_exec() - for the line in which it appears. + 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. - 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 /P was present on the regex, causing the POSIX wrapper API to be - used, only 0 causing REG_NOTBOL and REG_NOTEOL to be passed to - regexec() respectively. + If the /P modifier was present on the pattern, causing the POSIX wrap- + per API to be used, only \B and \Z have any effect, causing REG_NOTBOL + and REG_NOTEOL to be passed to regexec() respectively. - 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 UTF-8 rules. + 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 UTF-8 rules. OUTPUT FROM PCRETEST 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. Here is an example of an interactive - pcretest run. + that pcre_exec() returns, starting with number 0 for the string that + matched the whole pattern. Otherwise, it outputs "No match" or "Partial + match" when pcre_exec() returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PAR- + TIAL, respectively, and otherwise the PCRE negative error number. Here + is an example of an interactive pcretest run. $ pcretest - PCRE version 4.00 08-Jan-2003 + PCRE version 5.00 07-Sep-2004 re> /^abc(\d+)/ data> abc123 @@ -310,18 +308,18 @@ OUTPUT FROM PCRETEST data> xyz No match - 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. If the pattern has the /+ modifier, then the output for - substring 0 is followed by the the rest of the subject string, identi- - fied by "0+" like this: + 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. If the pattern has the /+ modifier, the output for sub- + string 0 is followed by the the rest of the subject string, identified + by "0+" like this: re> /cat/+ data> cataract 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 @@ -335,23 +333,118 @@ 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 while patterns can be continued over several lines (a plain + Note that while 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. +CALLOUTS + + If the pattern contains any callout requests, pcretest's callout func- + tion is called during matching. By default, it displays the callout + number, 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 + 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 + output. For example: + + re> /\d?[A-E]\*/C + data> E* + --->E* + +0 ^ \d? + +3 ^ [A-E] + +8 ^^ \* + +10 ^ ^ + 0: E* + + The callout function in pcretest returns zero (carry on matching) by + default, but you can use an \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 + the pcrecallout documentation. + + +SAVING AND RELOADING COMPILED PATTERNS + + 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 + file name. For example: + + /pattern/im >/some/file + + 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 + 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 follows imme- + 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 + 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 + 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 + 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 + 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 + a file that is not in the correct format, the result is undefined. + + AUTHOR Philip Hazel <ph10@cam.ac.uk> University Computing Service, Cambridge CB2 3QG, England. -Last updated: 09 December 2003 -Copyright (c) 1997-2003 University of Cambridge. +Last updated: 10 September 2004 +Copyright (c) 1997-2004 University of Cambridge. |