/[pcre]/code/trunk/doc/pcretest.txt
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revision 567 by ph10, Sat Nov 6 17:10:00 2010 UTC revision 572 by ph10, Wed Nov 17 17:55:57 2010 UTC
# Line 322  DATA LINES Line 322  DATA LINES
322           \t         tab (\x09)           \t         tab (\x09)
323           \v         vertical tab (\x0b)           \v         vertical tab (\x0b)
324           \nnn       octal character (up to 3 octal digits)           \nnn       octal character (up to 3 octal digits)
325           \xhh       hexadecimal character (up to 2 hex digits)                        always a byte unless > 255 in UTF-8 mode
326             \xhh       hexadecimal byte (up to 2 hex digits)
327           \x{hh...}  hexadecimal character, any number of digits           \x{hh...}  hexadecimal character, any number of digits
328                        in UTF-8 mode                        in UTF-8 mode
329           \A         pass the PCRE_ANCHORED option to pcre_exec()           \A         pass the PCRE_ANCHORED option to pcre_exec()
# Line 386  DATA LINES Line 387  DATA LINES
387           \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()           \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()
388                        or pcre_dfa_exec()                        or pcre_dfa_exec()
389    
390         The  escapes  that  specify  line ending sequences are literal strings,         Note  that  \xhh  always  specifies  one byte, even in UTF-8 mode; this
391           makes it possible to construct invalid UTF-8 sequences for testing pur-
392           poses. On the other hand, \x{hh} is interpreted as a UTF-8 character in
393           UTF-8 mode, generating more than one byte if the value is greater  than
394           127. When not in UTF-8 mode, it generates one byte for values less than
395           256, and causes an error for greater values.
396    
397           The escapes that specify line ending  sequences  are  literal  strings,
398         exactly as shown. No more than one newline setting should be present in         exactly as shown. No more than one newline setting should be present in
399         any data line.         any data line.
400    
401         A  backslash  followed by anything else just escapes the anything else.         A backslash followed by anything else just escapes the  anything  else.
402         If the very last character is a backslash, it is ignored. This gives  a         If  the very last character is a backslash, it is ignored. This gives a
403         way  of  passing  an empty line as data, since a real empty line termi-         way of passing an empty line as data, since a real  empty  line  termi-
404         nates the data input.         nates the data input.
405    
406         If \M is present, pcretest calls pcre_exec() several times,  with  dif-         If  \M  is present, pcretest calls pcre_exec() several times, with dif-
407         ferent  values  in  the match_limit and match_limit_recursion fields of         ferent values in the match_limit and  match_limit_recursion  fields  of
408         the pcre_extra data structure, until it finds the minimum  numbers  for         the  pcre_extra  data structure, until it finds the minimum numbers for
409         each parameter that allow pcre_exec() to complete. The match_limit num-         each parameter that allow pcre_exec() to complete. The match_limit num-
410         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
411         checking it out can be instructive. For most simple matches, the number         checking it out can be instructive. For most simple matches, the number
412         is quite small, but for patterns with very large  numbers  of  matching         is  quite  small,  but for patterns with very large numbers of matching
413         possibilities,  it can become large very quickly with increasing length         possibilities, it can become large very quickly with increasing  length
414         of subject string. The match_limit_recursion number is a measure of how         of subject string. The match_limit_recursion number is a measure of how
415         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)
416         memory is needed to complete the match attempt.         memory is needed to complete the match attempt.
417    
418         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
419         size set by the -O command line option (or defaulted to 45); \O applies         size set by the -O command line option (or defaulted to 45); \O applies
420         only to the call of pcre_exec() for the line in which it appears.         only to the call of pcre_exec() for the line in which it appears.
421    
422         If the /P modifier was present on the pattern, causing the POSIX  wrap-         If  the /P modifier was present on the pattern, causing the POSIX wrap-
423         per  API  to  be  used, the only option-setting sequences that have any         per API to be used, the only option-setting  sequences  that  have  any
424         effect are \B,  \N,  and  \Z,  causing  REG_NOTBOL,  REG_NOTEMPTY,  and         effect  are  \B,  \N,  and  \Z,  causing  REG_NOTBOL, REG_NOTEMPTY, and
425         REG_NOTEOL, respectively, to be passed to regexec().         REG_NOTEOL, respectively, to be passed to regexec().
426    
427         The  use of \x{hh...} to represent UTF-8 characters is not dependent on         The use of \x{hh...} to represent UTF-8 characters is not dependent  on
428         the use of the /8 modifier on the pattern.  It  is  recognized  always.         the  use  of  the  /8 modifier on the pattern. It is recognized always.
429         There  may  be  any number of hexadecimal digits inside the braces. The         There may be any number of hexadecimal digits inside  the  braces.  The
430         result is from one to six bytes,  encoded  according  to  the  original         result  is  from  one  to  six bytes, encoded according to the original
431         UTF-8  rules  of  RFC  2279.  This  allows for values in the range 0 to         UTF-8 rules of RFC 2279. This allows for  values  in  the  range  0  to
432         0x7FFFFFFF. Note that not all of those are valid Unicode  code  points,         0x7FFFFFFF.  Note  that not all of those are valid Unicode code points,
433         or  indeed  valid  UTF-8 characters according to the later rules in RFC         or indeed valid UTF-8 characters according to the later  rules  in  RFC
434         3629.         3629.
435    
436    
437  THE ALTERNATIVE MATCHING FUNCTION  THE ALTERNATIVE MATCHING FUNCTION
438    
439         By  default,  pcretest  uses  the  standard  PCRE  matching   function,         By   default,  pcretest  uses  the  standard  PCRE  matching  function,
440         pcre_exec() to match each data line. From release 6.0, PCRE supports an         pcre_exec() to match each data line. From release 6.0, PCRE supports an
441         alternative matching function, pcre_dfa_test(),  which  operates  in  a         alternative  matching  function,  pcre_dfa_test(),  which operates in a
442         different  way,  and has some restrictions. The differences between the         different way, and has some restrictions. The differences  between  the
443         two functions are described in the pcrematching documentation.         two functions are described in the pcrematching documentation.
444    
445         If a data line contains the \D escape sequence, or if the command  line         If  a data line contains the \D escape sequence, or if the command line
446         contains  the -dfa option, the alternative matching function is called.         contains the -dfa option, the alternative matching function is  called.
447         This function finds all possible matches at a given point. If, however,         This function finds all possible matches at a given point. If, however,
448         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
449         first match is found. This is always the shortest possible match.         first match is found. This is always the shortest possible match.
450    
451    
452  DEFAULT OUTPUT FROM PCRETEST  DEFAULT OUTPUT FROM PCRETEST
453    
454         This section describes the output when the  normal  matching  function,         This  section  describes  the output when the normal matching function,
455         pcre_exec(), is being used.         pcre_exec(), is being used.
456    
457         When a match succeeds, pcretest outputs the list of captured substrings         When a match succeeds, pcretest outputs the list of captured substrings
458         that pcre_exec() returns, starting with number 0 for  the  string  that         that  pcre_exec()  returns,  starting with number 0 for the string that
459         matched  the  whole  pattern. Otherwise, it outputs "No match" when the         matched the whole pattern. Otherwise, it outputs "No  match"  when  the
460         return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the par-         return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the par-
461         tially  matching substring when pcre_exec() returns PCRE_ERROR_PARTIAL.         tially matching substring when pcre_exec() returns  PCRE_ERROR_PARTIAL.
462         (Note that this is the entire substring that was inspected  during  the         (Note  that  this is the entire substring that was inspected during the
463         partial  match; it may include characters before the actual match start         partial match; it may include characters before the actual match  start
464         if a lookbehind assertion, \K, \b, or \B was involved.) For  any  other         if  a  lookbehind assertion, \K, \b, or \B was involved.) For any other
465         returns,  it outputs the PCRE negative error number. Here is an example         returns, it outputs the PCRE negative error number. Here is an  example
466         of an interactive pcretest run.         of an interactive pcretest run.
467    
468           $ pcretest           $ pcretest
# Line 467  DEFAULT OUTPUT FROM PCRETEST Line 475  DEFAULT OUTPUT FROM PCRETEST
475           data> xyz           data> xyz
476           No match           No match
477    
478         Note that unset capturing substrings that are not followed by one  that         Note  that unset capturing substrings that are not followed by one that
479         is  set are not returned by pcre_exec(), and are not shown by pcretest.         is set are not returned by pcre_exec(), and are not shown by  pcretest.
480         In the following example, there are two capturing substrings, but  when         In  the following example, there are two capturing substrings, but when
481         the  first  data  line  is  matched, the second, unset substring is not         the first data line is matched, the  second,  unset  substring  is  not
482         shown. An "internal" unset substring is shown as "<unset>", as for  the         shown.  An "internal" unset substring is shown as "<unset>", as for the
483         second data line.         second data line.
484    
485             re> /(a)|(b)/             re> /(a)|(b)/
# Line 483  DEFAULT OUTPUT FROM PCRETEST Line 491  DEFAULT OUTPUT FROM PCRETEST
491            1: <unset>            1: <unset>
492            2: b            2: b
493    
494         If  the strings contain any non-printing characters, they are output as         If the strings contain any non-printing characters, they are output  as
495         \0x escapes, or as \x{...} escapes if the /8 modifier  was  present  on         \0x  escapes,  or  as \x{...} escapes if the /8 modifier was present on
496         the  pattern.  See below for the definition of non-printing characters.         the pattern. See below for the definition of  non-printing  characters.
497         If the pattern has the /+ modifier, the output for substring 0 is  fol-         If  the pattern has the /+ modifier, the output for substring 0 is fol-
498         lowed  by  the  the rest of the subject string, identified by "0+" like         lowed by the the rest of the subject string, identified  by  "0+"  like
499         this:         this:
500    
501             re> /cat/+             re> /cat/+
# Line 495  DEFAULT OUTPUT FROM PCRETEST Line 503  DEFAULT OUTPUT FROM PCRETEST
503            0: cat            0: cat
504            0+ aract            0+ aract
505    
506         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
507         matching attempts are output in sequence, like this:         matching attempts are output in sequence, like this:
508    
509             re> /\Bi(\w\w)/g             re> /\Bi(\w\w)/g
# Line 509  DEFAULT OUTPUT FROM PCRETEST Line 517  DEFAULT OUTPUT FROM PCRETEST
517    
518         "No match" is output only if the first match attempt fails.         "No match" is output only if the first match attempt fails.
519    
520         If  any  of the sequences \C, \G, or \L are present in a data line that         If any of the sequences \C, \G, or \L are present in a data  line  that
521         is successfully matched, the substrings extracted  by  the  convenience         is  successfully  matched,  the substrings extracted by the convenience
522         functions are output with C, G, or L after the string number instead of         functions are output with C, G, or L after the string number instead of
523         a colon. This is in addition to the normal full list. The string length         a colon. This is in addition to the normal full list. The string length
524         (that  is,  the return from the extraction function) is given in paren-         (that is, the return from the extraction function) is given  in  paren-
525         theses after each string for \C and \G.         theses after each string for \C and \G.
526    
527         Note that whereas patterns can be continued over several lines (a plain         Note that whereas patterns can be continued over several lines (a plain
528         ">" prompt is used for continuations), data lines may not. However new-         ">" prompt is used for continuations), data lines may not. However new-
529         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,
530         etc., depending on the newline sequence setting).         etc., depending on the newline sequence setting).
531    
532    
533  OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION  OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
534    
535         When  the  alternative  matching function, pcre_dfa_exec(), is used (by         When the alternative matching function, pcre_dfa_exec(),  is  used  (by
536         means of the \D escape sequence or the -dfa command line  option),  the         means  of  the \D escape sequence or the -dfa command line option), the
537         output  consists  of  a list of all the matches that start at the first         output consists of a list of all the matches that start  at  the  first
538         point in the subject where there is at least one match. For example:         point in the subject where there is at least one match. For example:
539    
540             re> /(tang|tangerine|tan)/             re> /(tang|tangerine|tan)/
# Line 535  OUTPUT FROM THE ALTERNATIVE MATCHING FUN Line 543  OUTPUT FROM THE ALTERNATIVE MATCHING FUN
543            1: tang            1: tang
544            2: tan            2: tan
545    
546         (Using the normal matching function on this data  finds  only  "tang".)         (Using  the  normal  matching function on this data finds only "tang".)
547         The  longest matching string is always given first (and numbered zero).         The longest matching string is always given first (and numbered  zero).
548         After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-         After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-
549         lowed  by  the  partially  matching  substring.  (Note that this is the         lowed by the partially matching  substring.  (Note  that  this  is  the
550         entire substring that was inspected during the partial  match;  it  may         entire  substring  that  was inspected during the partial match; it may
551         include characters before the actual match start if a lookbehind asser-         include characters before the actual match start if a lookbehind asser-
552         tion, \K, \b, or \B was involved.)         tion, \K, \b, or \B was involved.)
553    
# Line 555  OUTPUT FROM THE ALTERNATIVE MATCHING FUN Line 563  OUTPUT FROM THE ALTERNATIVE MATCHING FUN
563            1: tan            1: tan
564            0: tan            0: tan
565    
566         Since  the  matching  function  does not support substring capture, the         Since the matching function does not  support  substring  capture,  the
567         escape sequences that are concerned with captured  substrings  are  not         escape  sequences  that  are concerned with captured substrings are not
568         relevant.         relevant.
569    
570    
571  RESTARTING AFTER A PARTIAL MATCH  RESTARTING AFTER A PARTIAL MATCH
572    
573         When the alternative matching function has given the PCRE_ERROR_PARTIAL         When the alternative matching function has given the PCRE_ERROR_PARTIAL
574         return, indicating that the subject partially matched the pattern,  you         return,  indicating that the subject partially matched the pattern, you
575         can  restart  the match with additional subject data by means of the \R         can restart the match with additional subject data by means of  the  \R
576         escape sequence. For example:         escape sequence. For example:
577    
578             re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/             re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
# Line 573  RESTARTING AFTER A PARTIAL MATCH Line 581  RESTARTING AFTER A PARTIAL MATCH
581           data> n05\R\D           data> n05\R\D
582            0: n05            0: n05
583    
584         For further information about partial  matching,  see  the  pcrepartial         For  further  information  about  partial matching, see the pcrepartial
585         documentation.         documentation.
586    
587    
588  CALLOUTS  CALLOUTS
589    
590         If  the pattern contains any callout requests, pcretest's callout func-         If the pattern contains any callout requests, pcretest's callout  func-
591         tion is called during matching. This works  with  both  matching  func-         tion  is  called  during  matching. This works with both matching func-
592         tions. By default, the called function displays the callout number, the         tions. By default, the called function displays the callout number, the
593         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
594         next pattern item to be tested. For example, the output         next pattern item to be tested. For example, the output
595    
596           --->pqrabcdef           --->pqrabcdef
597             0    ^  ^     \d             0    ^  ^     \d
598    
599         indicates  that  callout number 0 occurred for a match attempt starting         indicates that callout number 0 occurred for a match  attempt  starting
600         at the fourth character of the subject string, when the pointer was  at         at  the fourth character of the subject string, when the pointer was at
601         the  seventh  character of the data, and when the next pattern item was         the seventh character of the data, and when the next pattern  item  was
602         \d. Just one circumflex is output if the start  and  current  positions         \d.  Just  one  circumflex is output if the start and current positions
603         are the same.         are the same.
604    
605         Callouts numbered 255 are assumed to be automatic callouts, inserted as         Callouts numbered 255 are assumed to be automatic callouts, inserted as
606         a result of the /C pattern modifier. In this case, instead  of  showing         a  result  of the /C pattern modifier. In this case, instead of showing
607         the  callout  number, the offset in the pattern, preceded by a plus, is         the callout number, the offset in the pattern, preceded by a  plus,  is
608         output. For example:         output. For example:
609    
610             re> /\d?[A-E]\*/C             re> /\d?[A-E]\*/C
# Line 608  CALLOUTS Line 616  CALLOUTS
616           +10 ^ ^           +10 ^ ^
617            0: E*            0: E*
618    
619         The callout function in pcretest returns zero (carry  on  matching)  by         The  callout  function  in pcretest returns zero (carry on matching) by
620         default,  but you can use a \C item in a data line (as described above)         default, but you can use a \C item in a data line (as described  above)
621         to change this.         to change this.
622    
623         Inserting callouts can be helpful when using pcretest to check  compli-         Inserting  callouts can be helpful when using pcretest to check compli-
624         cated  regular expressions. For further information about callouts, see         cated regular expressions. For further information about callouts,  see
625         the pcrecallout documentation.         the pcrecallout documentation.
626    
627    
628  NON-PRINTING CHARACTERS  NON-PRINTING CHARACTERS
629    
630         When pcretest is outputting text in the compiled version of a  pattern,         When  pcretest is outputting text in the compiled version of a pattern,
631         bytes  other  than 32-126 are always treated as non-printing characters         bytes other than 32-126 are always treated as  non-printing  characters
632         are are therefore shown as hex escapes.         are are therefore shown as hex escapes.
633    
634         When pcretest is outputting text that is a matched part  of  a  subject         When  pcretest  is  outputting text that is a matched part of a subject
635         string,  it behaves in the same way, unless a different locale has been         string, it behaves in the same way, unless a different locale has  been
636         set for the  pattern  (using  the  /L  modifier).  In  this  case,  the         set  for  the  pattern  (using  the  /L  modifier).  In  this case, the
637         isprint() function to distinguish printing and non-printing characters.         isprint() function to distinguish printing and non-printing characters.
638    
639    
640  SAVING AND RELOADING COMPILED PATTERNS  SAVING AND RELOADING COMPILED PATTERNS
641    
642         The  facilities  described  in  this section are not available when the         The facilities described in this section are  not  available  when  the
643         POSIX inteface to PCRE is being used, that is, when the /P pattern mod-         POSIX inteface to PCRE is being used, that is, when the /P pattern mod-
644         ifier is specified.         ifier is specified.
645    
646         When the POSIX interface is not in use, you can cause pcretest to write         When the POSIX interface is not in use, you can cause pcretest to write
647         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
648         file name.  For example:         file name.  For example:
649    
650           /pattern/im >/some/file           /pattern/im >/some/file
651    
652         See  the pcreprecompile documentation for a discussion about saving and         See the pcreprecompile documentation for a discussion about saving  and
653         re-using compiled patterns.         re-using compiled patterns.
654    
655         The data that is written is binary.  The  first  eight  bytes  are  the         The  data  that  is  written  is  binary. The first eight bytes are the
656         length  of  the  compiled  pattern  data  followed by the length of the         length of the compiled pattern data  followed  by  the  length  of  the
657         optional study data, each written as four  bytes  in  big-endian  order         optional  study  data,  each  written as four bytes in big-endian order
658         (most  significant  byte  first). If there is no study data (either the         (most significant byte first). If there is no study  data  (either  the
659         pattern was not studied, or studying did not return any data), the sec-         pattern was not studied, or studying did not return any data), the sec-
660         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
661         compiled pattern. If there is additional study data, this follows imme-         compiled pattern. If there is additional study data, this follows imme-
662         diately  after  the  compiled pattern. After writing the file, pcretest         diately after the compiled pattern. After writing  the  file,  pcretest
663         expects to read a new pattern.         expects to read a new pattern.
664    
665         A saved pattern can be reloaded into pcretest by specifing < and a file         A saved pattern can be reloaded into pcretest by specifing < and a file
666         name  instead  of  a pattern. The name of the file must not contain a <         name instead of a pattern. The name of the file must not  contain  a  <
667         character, as otherwise pcretest will interpret the line as  a  pattern         character,  as  otherwise pcretest will interpret the line as a pattern
668         delimited by < characters.  For example:         delimited by < characters.  For example:
669    
670            re> </some/file            re> </some/file
671           Compiled regex loaded from /some/file           Compiled regex loaded from /some/file
672           No study data           No study data
673    
674         When  the pattern has been loaded, pcretest proceeds to read data lines         When the pattern has been loaded, pcretest proceeds to read data  lines
675         in the usual way.         in the usual way.
676    
677         You can copy a file written by pcretest to a different host and  reload         You  can copy a file written by pcretest to a different host and reload
678         it  there,  even  if the new host has opposite endianness to the one on         it there, even if the new host has opposite endianness to  the  one  on
679         which the pattern was compiled. For example, you can compile on an  i86         which  the pattern was compiled. For example, you can compile on an i86
680         machine and run on a SPARC machine.         machine and run on a SPARC machine.
681    
682         File  names  for  saving and reloading can be absolute or relative, but         File names for saving and reloading can be absolute  or  relative,  but
683         note that the shell facility of expanding a file name that starts  with         note  that the shell facility of expanding a file name that starts with
684         a tilde (~) is not available.         a tilde (~) is not available.
685    
686         The  ability to save and reload files in pcretest is intended for test-         The ability to save and reload files in pcretest is intended for  test-
687         ing and experimentation. It is not intended for production use  because         ing  and experimentation. It is not intended for production use because
688         only  a  single pattern can be written to a file. Furthermore, there is         only a single pattern can be written to a file. Furthermore,  there  is
689         no facility for supplying  custom  character  tables  for  use  with  a         no  facility  for  supplying  custom  character  tables  for use with a
690         reloaded  pattern.  If  the  original  pattern was compiled with custom         reloaded pattern. If the original  pattern  was  compiled  with  custom
691         tables, an attempt to match a subject string using a  reloaded  pattern         tables,  an  attempt to match a subject string using a reloaded pattern
692         is  likely to cause pcretest to crash.  Finally, if you attempt to load         is likely to cause pcretest to crash.  Finally, if you attempt to  load
693         a file that is not in the correct format, the result is undefined.         a file that is not in the correct format, the result is undefined.
694    
695    
696  SEE ALSO  SEE ALSO
697    
698         pcre(3), pcreapi(3), pcrecallout(3),  pcrematching(3),  pcrepartial(d),         pcre(3),  pcreapi(3),  pcrecallout(3), pcrematching(3), pcrepartial(d),
699         pcrepattern(3), pcreprecompile(3).         pcrepattern(3), pcreprecompile(3).
700    
701    
# Line 700  AUTHOR Line 708  AUTHOR
708    
709  REVISION  REVISION
710    
711         Last updated: 06 November 2010         Last updated: 07 November 2010
712         Copyright (c) 1997-2010 University of Cambridge.         Copyright (c) 1997-2010 University of Cambridge.

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