/[pcre]/code/trunk/doc/pcretest.txt
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revision 429 by ph10, Tue Sep 1 16:10:16 2009 UTC revision 545 by ph10, Wed Jun 16 10:51:15 2010 UTC
# Line 154  PATTERN MODIFIERS Line 154  PATTERN MODIFIERS
154    
155           /caseless/i           /caseless/i
156    
157         The following table shows additional modifiers for setting PCRE options         The  following  table  shows additional modifiers for setting PCRE com-
158         that do not correspond to anything in Perl:         pile-time options that do not correspond to anything in Perl:
159    
160             /8              PCRE_UTF8
161             /?              PCRE_NO_UTF8_CHECK
162           /A              PCRE_ANCHORED           /A              PCRE_ANCHORED
163           /C              PCRE_AUTO_CALLOUT           /C              PCRE_AUTO_CALLOUT
164           /E              PCRE_DOLLAR_ENDONLY           /E              PCRE_DOLLAR_ENDONLY
# Line 164  PATTERN MODIFIERS Line 166  PATTERN MODIFIERS
166           /J              PCRE_DUPNAMES           /J              PCRE_DUPNAMES
167           /N              PCRE_NO_AUTO_CAPTURE           /N              PCRE_NO_AUTO_CAPTURE
168           /U              PCRE_UNGREEDY           /U              PCRE_UNGREEDY
169             /W              PCRE_UCP
170           /X              PCRE_EXTRA           /X              PCRE_EXTRA
171           /<JS>           PCRE_JAVASCRIPT_COMPAT           /<JS>           PCRE_JAVASCRIPT_COMPAT
172           /<cr>           PCRE_NEWLINE_CR           /<cr>           PCRE_NEWLINE_CR
# Line 174  PATTERN MODIFIERS Line 177  PATTERN MODIFIERS
177           /<bsr_anycrlf>  PCRE_BSR_ANYCRLF           /<bsr_anycrlf>  PCRE_BSR_ANYCRLF
178           /<bsr_unicode>  PCRE_BSR_UNICODE           /<bsr_unicode>  PCRE_BSR_UNICODE
179    
180         Those specifying line ending sequences are literal  strings  as  shown,         The modifiers that are enclosed in angle brackets are  literal  strings
181         but  the  letters  can  be  in either case. This example sets multiline         as  shown,  including  the  angle  brackets,  but the letters can be in
182         matching with CRLF as the line ending sequence:         either case. This example sets multiline matching with CRLF as the line
183           ending sequence:
184    
185           /^abc/m<crlf>           /^abc/m<crlf>
186    
187         Details of the meanings of these PCRE options are given in the  pcreapi         As well as turning on the PCRE_UTF8 option, the /8 modifier also causes
188         documentation.         any non-printing characters in output strings to be printed  using  the
189           \x{hh...}  notation  if they are valid UTF-8 sequences. Full details of
190           the PCRE options are given in the pcreapi documentation.
191    
192     Finding all matches in a string     Finding all matches in a string
193    
194         Searching  for  all  possible matches within each subject string can be         Searching for all possible matches within each subject  string  can  be
195         requested by the /g or /G modifier. After  finding  a  match,  PCRE  is         requested  by  the  /g  or  /G modifier. After finding a match, PCRE is
196         called again to search the remainder of the subject string. The differ-         called again to search the remainder of the subject string. The differ-
197         ence between /g and /G is that the former uses the startoffset argument         ence between /g and /G is that the former uses the startoffset argument
198         to  pcre_exec()  to  start  searching  at a new point within the entire         to pcre_exec() to start searching at a  new  point  within  the  entire
199         string (which is in effect what Perl does), whereas the  latter  passes         string  (which  is in effect what Perl does), whereas the latter passes
200         over  a  shortened  substring.  This makes a difference to the matching         over a shortened substring. This makes a  difference  to  the  matching
201         process if the pattern begins with a lookbehind assertion (including \b         process if the pattern begins with a lookbehind assertion (including \b
202         or \B).         or \B).
203    
204         If  any  call  to  pcre_exec()  in a /g or /G sequence matches an empty         If any call to pcre_exec() in a /g or  /G  sequence  matches  an  empty
205         string, the next call is done with the PCRE_NOTEMPTY and  PCRE_ANCHORED         string,  the  next  call  is  done  with  the PCRE_NOTEMPTY_ATSTART and
206         flags  set in order to search for another, non-empty, match at the same         PCRE_ANCHORED flags set in order  to  search  for  another,  non-empty,
207         point.  If this second match fails, the start  offset  is  advanced  by         match  at  the same point. If this second match fails, the start offset
208         one,  and  the normal match is retried. This imitates the way Perl han-         is advanced by one character, and the normal  match  is  retried.  This
209         dles such cases when using the /g modifier or the split() function.         imitates  the way Perl handles such cases when using the /g modifier or
210           the split() function.
211    
212     Other modifiers     Other modifiers
213    
# Line 218  PATTERN MODIFIERS Line 225  PATTERN MODIFIERS
225         feature for use in the automatic test scripts; it ensures that the same         feature for use in the automatic test scripts; it ensures that the same
226         output is generated for different internal link sizes.         output is generated for different internal link sizes.
227    
        The /L modifier must be followed directly by the name of a locale,  for  
        example,  
   
          /pattern/Lfr_FR  
   
        For this reason, it must be the last modifier. The given locale is set,  
        pcre_maketables() is called to build a set of character tables for  the  
        locale,  and  this  is then passed to pcre_compile() when compiling the  
        regular expression. Without an /L  modifier,  NULL  is  passed  as  the  
        tables  pointer; that is, /L applies only to the expression on which it  
        appears.  
   
        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.  
   
228         The /D modifier is a PCRE debugging feature, and is equivalent to  /BI,         The /D modifier is a PCRE debugging feature, and is equivalent to  /BI,
229         that is, both the /B and the /I modifiers.         that is, both the /B and the /I modifiers.
230    
# Line 247  PATTERN MODIFIERS Line 236  PATTERN MODIFIERS
236         used, that is, when the /P pattern modifier is specified. See also  the         used, that is, when the /P pattern modifier is specified. See also  the
237         section about saving and reloading compiled patterns below.         section about saving and reloading compiled patterns below.
238    
239         The  /S  modifier causes pcre_study() to be called after the expression         The  /I  modifier  requests  that pcretest output information about the
240         has been compiled, and the results used when the expression is matched.         compiled pattern (whether it is anchored, has a fixed first  character,
241           and  so  on). It does this by calling pcre_fullinfo() after compiling a
242           pattern. If the pattern is studied, the results of that are  also  out-
243           put.
244    
245           The  /K modifier requests pcretest to show names from backtracking con-
246           trol verbs that are returned  from  calls  to  pcre_exec().  It  causes
247           pcretest  to create a pcre_extra block if one has not already been cre-
248           ated by a call to pcre_study(), and to set the PCRE_EXTRA_MARK flag and
249           the mark field within it, every time that pcre_exec() is called. If the
250           variable that the mark field points to is non-NULL for  a  match,  non-
251           match, or partial match, pcretest prints the string to which it points.
252           For a match, this is shown on a line by itself, tagged with "MK:".  For
253           a non-match it is added to the message.
254    
255         The /M modifier causes the size of memory block used to hold  the  com-         The  /L modifier must be followed directly by the name of a locale, for
256           example,
257    
258             /pattern/Lfr_FR
259    
260           For this reason, it must be the last modifier. The given locale is set,
261           pcre_maketables()  is called to build a set of character tables for the
262           locale, and this is then passed to pcre_compile()  when  compiling  the
263           regular  expression.  Without an /L (or /T) modifier, NULL is passed as
264           the tables pointer; that is, /L applies only to the expression on which
265           it appears.
266    
267           The  /M  modifier causes the size of memory block used to hold the com-
268         piled pattern to be output.         piled pattern to be output.
269    
270           The /S modifier causes pcre_study() to be called after  the  expression
271           has been compiled, and the results used when the expression is matched.
272    
273           The  /T  modifier  must be followed by a single digit. It causes a spe-
274           cific set of built-in character tables to be passed to  pcre_compile().
275           It is used in the standard PCRE tests to check behaviour with different
276           character tables. The digit specifies the tables as follows:
277    
278             0   the default ASCII tables, as distributed in
279                   pcre_chartables.c.dist
280             1   a set of tables defining ISO 8859 characters
281    
282           In table 1, some characters whose codes are greater than 128 are  iden-
283           tified as letters, digits, spaces, etc.
284    
285       Using the POSIX wrapper API
286    
287         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
288         rather than its native API. When this  is  done,  all  other  modifiers         rather than its native API. When /P is set, the following modifiers set
289         except  /i,  /m, and /+ are ignored. REG_ICASE is set if /i is present,         options for the regcomp() function:
290         and REG_NEWLINE is set if /m is present. The  wrapper  functions  force  
291         PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set.           /i    REG_ICASE
292             /m    REG_NEWLINE
293         The  /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option           /N    REG_NOSUB
294         set. This turns on support for UTF-8 character handling in  PCRE,  pro-           /s    REG_DOTALL     )
295         vided  that  it  was  compiled with this support enabled. This modifier           /U    REG_UNGREEDY   ) These options are not part of
296         also causes any non-printing characters in output strings to be printed           /W    REG_UCP        )   the POSIX standard
297         using the \x{hh...} notation if they are valid UTF-8 sequences.           /8    REG_UTF8       )
298    
299         If  the  /?  modifier  is  used  with  /8,  it  causes pcretest to call         The  /+  modifier  works  as  described  above. All other modifiers are
300         pcre_compile() with the  PCRE_NO_UTF8_CHECK  option,  to  suppress  the         ignored.
        checking of the string for UTF-8 validity.  
301    
302    
303  DATA LINES  DATA LINES
304    
305         Before  each  data  line is passed to pcre_exec(), leading and trailing         Before each data line is passed to pcre_exec(),  leading  and  trailing
306         whitespace is removed, and it is then scanned for \  escapes.  Some  of         whitespace  is  removed,  and it is then scanned for \ escapes. Some of
307         these  are  pretty esoteric features, intended for checking out some of         these are pretty esoteric features, intended for checking out  some  of
308         the more complicated features of PCRE. If you are just  testing  "ordi-         the  more  complicated features of PCRE. If you are just testing "ordi-
309         nary"  regular  expressions,  you probably don't need any of these. The         nary" regular expressions, you probably don't need any  of  these.  The
310         following escapes are recognized:         following escapes are recognized:
311    
312           \a         alarm (BEL, \x07)           \a         alarm (BEL, \x07)
# Line 323  DATA LINES Line 353  DATA LINES
353           \M         discover the minimum MATCH_LIMIT and           \M         discover the minimum MATCH_LIMIT and
354                        MATCH_LIMIT_RECURSION settings                        MATCH_LIMIT_RECURSION settings
355           \N         pass the PCRE_NOTEMPTY option to pcre_exec()           \N         pass the PCRE_NOTEMPTY option to pcre_exec()
356                        or pcre_dfa_exec()                        or pcre_dfa_exec(); if used twice, pass the
357                          PCRE_NOTEMPTY_ATSTART option
358           \Odd       set the size of the output vector passed to           \Odd       set the size of the output vector passed to
359                        pcre_exec() to dd (any number of digits)                        pcre_exec() to dd (any number of digits)
360           \P         pass the PCRE_PARTIAL_SOFT option to pcre_exec()           \P         pass the PCRE_PARTIAL_SOFT option to pcre_exec()
# Line 333  DATA LINES Line 364  DATA LINES
364                        (any number of digits)                        (any number of digits)
365           \R         pass the PCRE_DFA_RESTART option to pcre_dfa_exec()           \R         pass the PCRE_DFA_RESTART option to pcre_dfa_exec()
366           \S         output details of memory get/free calls during matching           \S         output details of memory get/free calls during matching
367             \Y         pass the PCRE_NO_START_OPTIMIZE option to pcre_exec()
368                          or pcre_dfa_exec()
369           \Z         pass the PCRE_NOTEOL option to pcre_exec()           \Z         pass the PCRE_NOTEOL option to pcre_exec()
370                        or pcre_dfa_exec()                        or pcre_dfa_exec()
371           \?         pass the PCRE_NO_UTF8_CHECK option to           \?         pass the PCRE_NO_UTF8_CHECK option to
# Line 351  DATA LINES Line 384  DATA LINES
384           \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()           \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()
385                        or pcre_dfa_exec()                        or pcre_dfa_exec()
386    
387         The escapes that specify line ending  sequences  are  literal  strings,         The  escapes  that  specify  line ending sequences are literal strings,
388         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
389         any data line.         any data line.
390    
391         A backslash followed by anything else just escapes the  anything  else.         A  backslash  followed by anything else just escapes the anything else.
392         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
393         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-
394         nates the data input.         nates the data input.
395    
396         If  \M  is present, pcretest calls pcre_exec() several times, with dif-         If \M is present, pcretest calls pcre_exec() several times,  with  dif-
397         ferent values in the match_limit and  match_limit_recursion  fields  of         ferent  values  in  the match_limit and match_limit_recursion fields of
398         the  pcre_extra  data structure, until it finds the minimum numbers for         the pcre_extra data structure, until it finds the minimum  numbers  for
399         each parameter that allow pcre_exec() to complete. The match_limit num-         each parameter that allow pcre_exec() to complete. The match_limit num-
400         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
401         checking it out can be instructive. For most simple matches, the number         checking it out can be instructive. For most simple matches, the number
402         is  quite  small,  but for patterns with very large numbers of matching         is quite small, but for patterns with very large  numbers  of  matching
403         possibilities, it can become large very quickly with increasing  length         possibilities,  it can become large very quickly with increasing length
404         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
405         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)
406         memory is needed to complete the match attempt.         memory is needed to complete the match attempt.
407    
408         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
409         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
410         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.
411    
412         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-
413         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
414         effect  are \B and \Z, causing REG_NOTBOL and REG_NOTEOL, respectively,         effect are \B,  \N,  and  \Z,  causing  REG_NOTBOL,  REG_NOTEMPTY,  and
415         to be passed to regexec().         REG_NOTEOL, respectively, to be passed to regexec().
416    
417         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
418         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.
419         There may be any number of hexadecimal digits inside  the  braces.  The         There  may  be  any number of hexadecimal digits inside the braces. The
420         result  is  from  one  to  six bytes, encoded according to the original         result is from one to six bytes,  encoded  according  to  the  original
421         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
422         0x7FFFFFFF.  Note  that not all of those are valid Unicode code points,         0x7FFFFFFF. Note that not all of those are valid Unicode  code  points,
423         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
424         3629.         3629.
425    
426    
427  THE ALTERNATIVE MATCHING FUNCTION  THE ALTERNATIVE MATCHING FUNCTION
428    
429         By   default,  pcretest  uses  the  standard  PCRE  matching  function,         By  default,  pcretest  uses  the  standard  PCRE  matching   function,
430         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
431         alternative  matching  function,  pcre_dfa_test(),  which operates in a         alternative matching function, pcre_dfa_test(),  which  operates  in  a
432         different way, and has some restrictions. The differences  between  the         different  way,  and has some restrictions. The differences between the
433         two functions are described in the pcrematching documentation.         two functions are described in the pcrematching documentation.
434    
435         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
436         contains the -dfa option, the alternative matching function is  called.         contains  the -dfa option, the alternative matching function is called.
437         This function finds all possible matches at a given point. If, however,         This function finds all possible matches at a given point. If, however,
438         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
439         first match is found. This is always the shortest possible match.         first match is found. This is always the shortest possible match.
440    
441    
442  DEFAULT OUTPUT FROM PCRETEST  DEFAULT OUTPUT FROM PCRETEST
443    
444         This  section  describes  the output when the normal matching function,         This section describes the output when the  normal  matching  function,
445         pcre_exec(), is being used.         pcre_exec(), is being used.
446    
447         When a match succeeds, pcretest outputs the list of captured substrings         When a match succeeds, pcretest outputs the list of captured substrings
448         that  pcre_exec()  returns,  starting with number 0 for the string that         that pcre_exec() returns, starting with number 0 for  the  string  that
449         matched the whole pattern. Otherwise, it outputs "No match" or "Partial         matched  the  whole  pattern. Otherwise, it outputs "No match" when the
450         match:"  followed  by the partially matching substring when pcre_exec()         return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the par-
451         returns PCRE_ERROR_NOMATCH  or  PCRE_ERROR_PARTIAL,  respectively,  and         tially  matching substring when pcre_exec() returns PCRE_ERROR_PARTIAL.
452         otherwise  the  PCRE  negative  error  number. Here is an example of an         For any other returns, it outputs the PCRE negative error number.  Here
453         interactive pcretest run.         is an example of an interactive pcretest run.
454    
455           $ pcretest           $ pcretest
456           PCRE version 7.0 30-Nov-2006           PCRE version 7.0 30-Nov-2006
# Line 429  DEFAULT OUTPUT FROM PCRETEST Line 462  DEFAULT OUTPUT FROM PCRETEST
462           data> xyz           data> xyz
463           No match           No match
464    
465         Note that unset capturing substrings that are not followed by one  that         Note  that unset capturing substrings that are not followed by one that
466         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.
467         In the following example, there are two capturing substrings, but  when         In  the following example, there are two capturing substrings, but when
468         the  first  data  line  is  matched, the second, unset substring is not         the first data line is matched, the  second,  unset  substring  is  not
469         shown. An "internal" unset substring is shown as "<unset>", as for  the         shown.  An "internal" unset substring is shown as "<unset>", as for the
470         second data line.         second data line.
471    
472             re> /(a)|(b)/             re> /(a)|(b)/
# Line 445  DEFAULT OUTPUT FROM PCRETEST Line 478  DEFAULT OUTPUT FROM PCRETEST
478            1: <unset>            1: <unset>
479            2: b            2: b
480    
481         If  the strings contain any non-printing characters, they are output as         If the strings contain any non-printing characters, they are output  as
482         \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
483         the  pattern.  See below for the definition of non-printing characters.         the pattern. See below for the definition of  non-printing  characters.
484         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-
485         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
486         this:         this:
487    
488             re> /cat/+             re> /cat/+
# Line 457  DEFAULT OUTPUT FROM PCRETEST Line 490  DEFAULT OUTPUT FROM PCRETEST
490            0: cat            0: cat
491            0+ aract            0+ aract
492    
493         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
494         matching attempts are output in sequence, like this:         matching attempts are output in sequence, like this:
495    
496             re> /\Bi(\w\w)/g             re> /\Bi(\w\w)/g
# Line 471  DEFAULT OUTPUT FROM PCRETEST Line 504  DEFAULT OUTPUT FROM PCRETEST
504    
505         "No match" is output only if the first match attempt fails.         "No match" is output only if the first match attempt fails.
506    
507         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
508         is successfully matched, the substrings extracted  by  the  convenience         is  successfully  matched,  the substrings extracted by the convenience
509         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
510         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
511         (that  is,  the return from the extraction function) is given in paren-         (that is, the return from the extraction function) is given  in  paren-
512         theses after each string for \C and \G.         theses after each string for \C and \G.
513    
514         Note that whereas patterns can be continued over several lines (a plain         Note that whereas patterns can be continued over several lines (a plain
515         ">" prompt is used for continuations), data lines may not. However new-         ">" prompt is used for continuations), data lines may not. However new-
516         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,
517         etc., depending on the newline sequence setting).         etc., depending on the newline sequence setting).
518    
519    
520  OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION  OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
521    
522         When  the  alternative  matching function, pcre_dfa_exec(), is used (by         When the alternative matching function, pcre_dfa_exec(),  is  used  (by
523         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
524         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
525         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:
526    
527             re> /(tang|tangerine|tan)/             re> /(tang|tangerine|tan)/
# Line 497  OUTPUT FROM THE ALTERNATIVE MATCHING FUN Line 530  OUTPUT FROM THE ALTERNATIVE MATCHING FUN
530            1: tang            1: tang
531            2: tan            2: tan
532    
533         (Using the normal matching function on this data  finds  only  "tang".)         (Using  the  normal  matching function on this data finds only "tang".)
534         The  longest matching string is always given first (and numbered zero).         The longest matching string is always given first (and numbered  zero).
535         After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-         After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-
536         lowed by the partially matching substring.         lowed by the partially matching substring.
537    
# Line 514  OUTPUT FROM THE ALTERNATIVE MATCHING FUN Line 547  OUTPUT FROM THE ALTERNATIVE MATCHING FUN
547            1: tan            1: tan
548            0: tan            0: tan
549    
550         Since the matching function does not  support  substring  capture,  the         Since  the  matching  function  does not support substring capture, the
551         escape  sequences  that  are concerned with captured substrings are not         escape sequences that are concerned with captured  substrings  are  not
552         relevant.         relevant.
553    
554    
555  RESTARTING AFTER A PARTIAL MATCH  RESTARTING AFTER A PARTIAL MATCH
556    
557         When the alternative matching function has given the PCRE_ERROR_PARTIAL         When the alternative matching function has given the PCRE_ERROR_PARTIAL
558         return,  indicating that the subject partially matched the pattern, you         return, indicating that the subject partially matched the pattern,  you
559         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
560         escape sequence. For example:         escape sequence. For example:
561    
562             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 532  RESTARTING AFTER A PARTIAL MATCH Line 565  RESTARTING AFTER A PARTIAL MATCH
565           data> n05\R\D           data> n05\R\D
566            0: n05            0: n05
567    
568         For  further  information  about  partial matching, see the pcrepartial         For further information about partial  matching,  see  the  pcrepartial
569         documentation.         documentation.
570    
571    
572  CALLOUTS  CALLOUTS
573    
574         If the pattern contains any callout requests, pcretest's callout  func-         If  the pattern contains any callout requests, pcretest's callout func-
575         tion  is  called  during  matching. This works with both matching func-         tion is called during matching. This works  with  both  matching  func-
576         tions. By default, the called function displays the callout number, the         tions. By default, the called function displays the callout number, the
577         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
578         next pattern item to be tested. For example, the output         next pattern item to be tested. For example, the output
579    
580           --->pqrabcdef           --->pqrabcdef
581             0    ^  ^     \d             0    ^  ^     \d
582    
583         indicates that callout number 0 occurred for a match  attempt  starting         indicates  that  callout number 0 occurred for a match attempt starting
584         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
585         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
586         \d.  Just  one  circumflex is output if the start and current positions         \d. Just one circumflex is output if the start  and  current  positions
587         are the same.         are the same.
588    
589         Callouts numbered 255 are assumed to be automatic callouts, inserted as         Callouts numbered 255 are assumed to be automatic callouts, inserted as
590         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
591         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
592         output. For example:         output. For example:
593    
594             re> /\d?[A-E]\*/C             re> /\d?[A-E]\*/C
# Line 567  CALLOUTS Line 600  CALLOUTS
600           +10 ^ ^           +10 ^ ^
601            0: E*            0: E*
602    
603         The  callout  function  in pcretest returns zero (carry on matching) by         The callout function in pcretest returns zero (carry  on  matching)  by
604         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)
605         to change this.         to change this.
606    
607         Inserting  callouts can be helpful when using pcretest to check compli-         Inserting callouts can be helpful when using pcretest to check  compli-
608         cated regular expressions. For further information about callouts,  see         cated  regular expressions. For further information about callouts, see
609         the pcrecallout documentation.         the pcrecallout documentation.
610    
611    
612  NON-PRINTING CHARACTERS  NON-PRINTING CHARACTERS
613    
614         When  pcretest is outputting text in the compiled version of a pattern,         When pcretest is outputting text in the compiled version of a  pattern,
615         bytes other than 32-126 are always treated as  non-printing  characters         bytes  other  than 32-126 are always treated as non-printing characters
616         are are therefore shown as hex escapes.         are are therefore shown as hex escapes.
617    
618         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
619         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
620         set  for  the  pattern  (using  the  /L  modifier).  In  this case, the         set for the  pattern  (using  the  /L  modifier).  In  this  case,  the
621         isprint() function to distinguish printing and non-printing characters.         isprint() function to distinguish printing and non-printing characters.
622    
623    
624  SAVING AND RELOADING COMPILED PATTERNS  SAVING AND RELOADING COMPILED PATTERNS
625    
626         The facilities described in this section are  not  available  when  the         The  facilities  described  in  this section are not available when the
627         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-
628         ifier is specified.         ifier is specified.
629    
630         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
631         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
632         file name.  For example:         file name.  For example:
633    
634           /pattern/im >/some/file           /pattern/im >/some/file
635    
636         See the pcreprecompile documentation for a discussion about saving  and         See  the pcreprecompile documentation for a discussion about saving and
637         re-using compiled patterns.         re-using compiled patterns.
638    
639         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
640         length of the compiled pattern data  followed  by  the  length  of  the         length  of  the  compiled  pattern  data  followed by the length of the
641         optional  study  data,  each  written as four bytes in big-endian order         optional study data, each written as four  bytes  in  big-endian  order
642         (most significant byte first). If there is no study  data  (either  the         (most  significant  byte  first). If there is no study data (either the
643         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-
644         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
645         compiled pattern. If there is additional study data, this follows imme-         compiled pattern. If there is additional study data, this follows imme-
646         diately after the compiled pattern. After writing  the  file,  pcretest         diately  after  the  compiled pattern. After writing the file, pcretest
647         expects to read a new pattern.         expects to read a new pattern.
648    
649         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
650         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 <
651         character,  as  otherwise pcretest will interpret the line as a pattern         character, as otherwise pcretest will interpret the line as  a  pattern
652         delimited by < characters.  For example:         delimited by < characters.  For example:
653    
654            re> </some/file            re> </some/file
655           Compiled regex loaded from /some/file           Compiled regex loaded from /some/file
656           No study data           No study data
657    
658         When the pattern has been loaded, pcretest proceeds to read data  lines         When  the pattern has been loaded, pcretest proceeds to read data lines
659         in the usual way.         in the usual way.
660    
661         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
662         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
663         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
664         machine and run on a SPARC machine.         machine and run on a SPARC machine.
665    
666         File names for saving and reloading can be absolute  or  relative,  but         File  names  for  saving and reloading can be absolute or relative, but
667         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
668         a tilde (~) is not available.         a tilde (~) is not available.
669    
670         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-
671         ing  and experimentation. It is not intended for production use because         ing and experimentation. It is not intended for production use  because
672         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
673         no  facility  for  supplying  custom  character  tables  for use with a         no facility for supplying  custom  character  tables  for  use  with  a
674         reloaded pattern. If the original  pattern  was  compiled  with  custom         reloaded  pattern.  If  the  original  pattern was compiled with custom
675         tables,  an  attempt to match a subject string using a reloaded pattern         tables, an attempt to match a subject string using a  reloaded  pattern
676         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
677         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.
678    
679    
680  SEE ALSO  SEE ALSO
681    
682         pcre(3),  pcreapi(3),  pcrecallout(3), pcrematching(3), pcrepartial(d),         pcre(3), pcreapi(3), pcrecallout(3),  pcrematching(3),  pcrepartial(d),
683         pcrepattern(3), pcreprecompile(3).         pcrepattern(3), pcreprecompile(3).
684    
685    
# Line 659  AUTHOR Line 692  AUTHOR
692    
693  REVISION  REVISION
694    
695         Last updated: 29 August 2009         Last updated: 14 June 2010
696         Copyright (c) 1997-2009 University of Cambridge.         Copyright (c) 1997-2010 University of Cambridge.

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