/[pcre]/code/trunk/doc/pcretest.txt
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revision 210 by ph10, Tue Apr 24 13:36:11 2007 UTC revision 211 by ph10, Thu Aug 9 09:52:43 2007 UTC
# Line 369  DATA LINES Line 369  DATA LINES
369         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
370         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.
371         There may be any number of hexadecimal digits inside  the  braces.  The         There may be any number of hexadecimal digits inside  the  braces.  The
372         result  is from one to six bytes, encoded according to the UTF-8 rules.         result  is  from  one  to  six bytes, encoded according to the original
373           UTF-8 rules of RFC 2279. This allows for  values  in  the  range  0  to
374           0x7FFFFFFF.  Note  that not all of those are valid Unicode code points,
375           or indeed valid UTF-8 characters according to the later  rules  in  RFC
376           3629.
377    
378    
379  THE ALTERNATIVE MATCHING FUNCTION  THE ALTERNATIVE MATCHING FUNCTION
380    
381         By  default,  pcretest  uses  the  standard  PCRE  matching   function,         By   default,  pcretest  uses  the  standard  PCRE  matching  function,
382         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
383         alternative matching function, pcre_dfa_test(),  which  operates  in  a         alternative  matching  function,  pcre_dfa_test(),  which operates in a
384         different  way,  and has some restrictions. The differences between the         different way, and has some restrictions. The differences  between  the
385         two functions are described in the pcrematching documentation.         two functions are described in the pcrematching documentation.
386    
387         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
388         contains  the -dfa option, the alternative matching function is called.         contains the -dfa option, the alternative matching function is  called.
389         This function finds all possible matches at a given point. If, however,         This function finds all possible matches at a given point. If, however,
390         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
391         first match is found. This is always the shortest possible match.         first match is found. This is always the shortest possible match.
392    
393    
394  DEFAULT OUTPUT FROM PCRETEST  DEFAULT OUTPUT FROM PCRETEST
395    
396         This section describes the output when the  normal  matching  function,         This  section  describes  the output when the normal matching function,
397         pcre_exec(), is being used.         pcre_exec(), is being used.
398    
399         When a match succeeds, pcretest outputs the list of captured substrings         When a match succeeds, pcretest outputs the list of captured substrings
400         that pcre_exec() returns, starting with number 0 for  the  string  that         that  pcre_exec()  returns,  starting with number 0 for the string that
401         matched the whole pattern. Otherwise, it outputs "No match" or "Partial         matched the whole pattern. Otherwise, it outputs "No match" or "Partial
402         match" when pcre_exec() returns PCRE_ERROR_NOMATCH  or  PCRE_ERROR_PAR-         match"  when  pcre_exec() returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PAR-
403         TIAL,  respectively, and otherwise the PCRE negative error number. Here         TIAL, respectively, and otherwise the PCRE negative error number.  Here
404         is an example of an interactive pcretest run.         is an example of an interactive pcretest run.
405    
406           $ pcretest           $ pcretest
# Line 409  DEFAULT OUTPUT FROM PCRETEST Line 413  DEFAULT OUTPUT FROM PCRETEST
413           data> xyz           data> xyz
414           No match           No match
415    
416         If the strings contain any non-printing characters, they are output  as         If  the strings contain any non-printing characters, they are output as
417         \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
418         the pattern. See below for the definition of  non-printing  characters.         the  pattern.  See below for the definition of non-printing characters.
419         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-
420         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
421         this:         this:
422    
423             re> /cat/+             re> /cat/+
# Line 421  DEFAULT OUTPUT FROM PCRETEST Line 425  DEFAULT OUTPUT FROM PCRETEST
425            0: cat            0: cat
426            0+ aract            0+ aract
427    
428         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
429         matching attempts are output in sequence, like this:         matching attempts are output in sequence, like this:
430    
431             re> /\Bi(\w\w)/g             re> /\Bi(\w\w)/g
# Line 435  DEFAULT OUTPUT FROM PCRETEST Line 439  DEFAULT OUTPUT FROM PCRETEST
439    
440         "No match" is output only if the first match attempt fails.         "No match" is output only if the first match attempt fails.
441    
442         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
443         is  successfully  matched,  the substrings extracted by the convenience         is successfully matched, the substrings extracted  by  the  convenience
444         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
445         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
446         (that is, the return from the extraction function) is given  in  paren-         (that  is,  the return from the extraction function) is given in paren-
447         theses after each string for \C and \G.         theses after each string for \C and \G.
448    
449         Note that whereas patterns can be continued over several lines (a plain         Note that whereas patterns can be continued over several lines (a plain
450         ">" prompt is used for continuations), data lines may not. However new-         ">" prompt is used for continuations), data lines may not. However new-
451         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,
452         etc., depending on the newline sequence setting).         etc., depending on the newline sequence setting).
453    
454    
455  OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION  OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
456    
457         When the alternative matching function, pcre_dfa_exec(),  is  used  (by         When  the  alternative  matching function, pcre_dfa_exec(), is used (by
458         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
459         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
460         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:
461    
462             re> /(tang|tangerine|tan)/             re> /(tang|tangerine|tan)/
# Line 461  OUTPUT FROM THE ALTERNATIVE MATCHING FUN Line 465  OUTPUT FROM THE ALTERNATIVE MATCHING FUN
465            1: tang            1: tang
466            2: tan            2: tan
467    
468         (Using  the  normal  matching function on this data finds only "tang".)         (Using the normal matching function on this data  finds  only  "tang".)
469         The longest matching string is always given first (and numbered  zero).         The  longest matching string is always given first (and numbered zero).
470    
471         If /g is present on the pattern, the search for further matches resumes         If /g is present on the pattern, the search for further matches resumes
472         at the end of the longest match. For example:         at the end of the longest match. For example:
# Line 476  OUTPUT FROM THE ALTERNATIVE MATCHING FUN Line 480  OUTPUT FROM THE ALTERNATIVE MATCHING FUN
480            1: tan            1: tan
481            0: tan            0: tan
482    
483         Since the matching function does not  support  substring  capture,  the         Since  the  matching  function  does not support substring capture, the
484         escape  sequences  that  are concerned with captured substrings are not         escape sequences that are concerned with captured  substrings  are  not
485         relevant.         relevant.
486    
487    
488  RESTARTING AFTER A PARTIAL MATCH  RESTARTING AFTER A PARTIAL MATCH
489    
490         When the alternative matching function has given the PCRE_ERROR_PARTIAL         When the alternative matching function has given the PCRE_ERROR_PARTIAL
491         return,  indicating that the subject partially matched the pattern, you         return, indicating that the subject partially matched the pattern,  you
492         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
493         escape sequence. For example:         escape sequence. For example:
494    
495             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 494  RESTARTING AFTER A PARTIAL MATCH Line 498  RESTARTING AFTER A PARTIAL MATCH
498           data> n05\R\D           data> n05\R\D
499            0: n05            0: n05
500    
501         For  further  information  about  partial matching, see the pcrepartial         For further information about partial  matching,  see  the  pcrepartial
502         documentation.         documentation.
503    
504    
505  CALLOUTS  CALLOUTS
506    
507         If the pattern contains any callout requests, pcretest's callout  func-         If  the pattern contains any callout requests, pcretest's callout func-
508         tion  is  called  during  matching. This works with both matching func-         tion is called during matching. This works  with  both  matching  func-
509         tions. By default, the called function displays the callout number, the         tions. By default, the called function displays the callout number, the
510         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
511         next pattern item to be tested. For example, the output         next pattern item to be tested. For example, the output
512    
513           --->pqrabcdef           --->pqrabcdef
514             0    ^  ^     \d             0    ^  ^     \d
515    
516         indicates that callout number 0 occurred for a match  attempt  starting         indicates  that  callout number 0 occurred for a match attempt starting
517         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
518         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
519         \d.  Just  one  circumflex is output if the start and current positions         \d. Just one circumflex is output if the start  and  current  positions
520         are the same.         are the same.
521    
522         Callouts numbered 255 are assumed to be automatic callouts, inserted as         Callouts numbered 255 are assumed to be automatic callouts, inserted as
523         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
524         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
525         output. For example:         output. For example:
526    
527             re> /\d?[A-E]\*/C             re> /\d?[A-E]\*/C
# Line 529  CALLOUTS Line 533  CALLOUTS
533           +10 ^ ^           +10 ^ ^
534            0: E*            0: E*
535    
536         The  callout  function  in pcretest returns zero (carry on matching) by         The callout function in pcretest returns zero (carry  on  matching)  by
537         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)
538         to change this.         to change this.
539    
540         Inserting  callouts can be helpful when using pcretest to check compli-         Inserting callouts can be helpful when using pcretest to check  compli-
541         cated regular expressions. For further information about callouts,  see         cated  regular expressions. For further information about callouts, see
542         the pcrecallout documentation.         the pcrecallout documentation.
543    
544    
545  NON-PRINTING CHARACTERS  NON-PRINTING CHARACTERS
546    
547         When  pcretest is outputting text in the compiled version of a pattern,         When pcretest is outputting text in the compiled version of a  pattern,
548         bytes other than 32-126 are always treated as  non-printing  characters         bytes  other  than 32-126 are always treated as non-printing characters
549         are are therefore shown as hex escapes.         are are therefore shown as hex escapes.
550    
551         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
552         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
553         set  for  the  pattern  (using  the  /L  modifier).  In  this case, the         set for the  pattern  (using  the  /L  modifier).  In  this  case,  the
554         isprint() function to distinguish printing and non-printing characters.         isprint() function to distinguish printing and non-printing characters.
555    
556    
557  SAVING AND RELOADING COMPILED PATTERNS  SAVING AND RELOADING COMPILED PATTERNS
558    
559         The  facilities  described  in  this section are not available when the         The facilities described in this section are  not  available  when  the
560         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-
561         ifier is specified.         ifier is specified.
562    
563         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
564         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
565         file name.  For example:         file name.  For example:
566    
567           /pattern/im >/some/file           /pattern/im >/some/file
568    
569         See  the pcreprecompile documentation for a discussion about saving and         See the pcreprecompile documentation for a discussion about saving  and
570         re-using compiled patterns.         re-using compiled patterns.
571    
572         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
573         length  of  the  compiled  pattern  data  followed by the length of the         length of the compiled pattern data  followed  by  the  length  of  the
574         optional study data, each written as four  bytes  in  big-endian  order         optional  study  data,  each  written as four bytes in big-endian order
575         (most  significant  byte  first). If there is no study data (either the         (most significant byte first). If there is no study  data  (either  the
576         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-
577         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
578         compiled pattern. If there is additional study data, this follows imme-         compiled pattern. If there is additional study data, this follows imme-
579         diately  after  the  compiled pattern. After writing the file, pcretest         diately after the compiled pattern. After writing  the  file,  pcretest
580         expects to read a new pattern.         expects to read a new pattern.
581    
582         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
583         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  <
584         character, as otherwise pcretest will interpret the line as  a  pattern         character,  as  otherwise pcretest will interpret the line as a pattern
585         delimited by < characters.  For example:         delimited by < characters.  For example:
586    
587            re> </some/file            re> </some/file
588           Compiled regex loaded from /some/file           Compiled regex loaded from /some/file
589           No study data           No study data
590    
591         When  the pattern has been loaded, pcretest proceeds to read data lines         When the pattern has been loaded, pcretest proceeds to read data  lines
592         in the usual way.         in the usual way.
593    
594         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
595         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
596         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
597         machine and run on a SPARC machine.         machine and run on a SPARC machine.
598    
599         File  names  for  saving and reloading can be absolute or relative, but         File names for saving and reloading can be absolute  or  relative,  but
600         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
601         a tilde (~) is not available.         a tilde (~) is not available.
602    
603         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-
604         ing and experimentation. It is not intended for production use  because         ing  and experimentation. It is not intended for production use because
605         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
606         no facility for supplying  custom  character  tables  for  use  with  a         no  facility  for  supplying  custom  character  tables  for use with a
607         reloaded  pattern.  If  the  original  pattern was compiled with custom         reloaded pattern. If the original  pattern  was  compiled  with  custom
608         tables, an attempt to match a subject string using a  reloaded  pattern         tables,  an  attempt to match a subject string using a reloaded pattern
609         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
610         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.
611    
612    
613  SEE ALSO  SEE ALSO
614    
615         pcre(3), pcreapi(3), pcrecallout(3),  pcrematching(3),  pcrepartial(d),         pcre(3),  pcreapi(3),  pcrecallout(3), pcrematching(3), pcrepartial(d),
616         pcrepattern(3), pcreprecompile(3).         pcrepattern(3), pcreprecompile(3).
617    
618    
# Line 621  AUTHOR Line 625  AUTHOR
625    
626  REVISION  REVISION
627    
628         Last updated: 24 April 2007         Last updated: 09 August 2007
629         Copyright (c) 1997-2007 University of Cambridge.         Copyright (c) 1997-2007 University of Cambridge.
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