/[pcre]/code/trunk/doc/pcretest.txt
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revision 392 by ph10, Tue Mar 17 21:30:30 2009 UTC revision 512 by ph10, Tue Mar 30 11:11:52 2010 UTC
# Line 196  PATTERN MODIFIERS Line 196  PATTERN MODIFIERS
196         or \B).         or \B).
197    
198         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
199         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
200         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,
201         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
202         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
203         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
204           the split() function.
205    
206     Other modifiers     Other modifiers
207    
208         There are yet more modifiers for controlling the way pcretest operates.         There are yet more modifiers for controlling the way pcretest operates.
209    
210         The /+ modifier requests that as well as outputting the substring  that         The  /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option
211         matched  the  entire  pattern,  pcretest  should in addition output the         set. This turns on support for UTF-8 character handling in  PCRE,  pro-
212         remainder of the subject string. This is useful  for  tests  where  the         vided  that  it  was  compiled with this support enabled. This modifier
213           also causes any non-printing characters in output strings to be printed
214           using the \x{hh...} notation if they are valid UTF-8 sequences.
215    
216           If  the  /?  modifier  is  used  with  /8,  it  causes pcretest to call
217           pcre_compile() with the  PCRE_NO_UTF8_CHECK  option,  to  suppress  the
218           checking of the string for UTF-8 validity.
219    
220           The  /+ modifier requests that as well as outputting the substring that
221           matched the entire pattern, pcretest  should  in  addition  output  the
222           remainder  of  the  subject  string. This is useful for tests where the
223         subject contains multiple copies of the same substring.         subject contains multiple copies of the same substring.
224    
225         The  /B modifier is a debugging feature. It requests that pcretest out-         The /B modifier is a debugging feature. It requests that pcretest  out-
226         put a representation of the compiled byte code after compilation.  Nor-         put  a representation of the compiled byte code after compilation. Nor-
227         mally  this  information contains length and offset values; however, if         mally this information contains length and offset values;  however,  if
228         /Z is also present, this data is replaced by spaces. This is a  special         /Z  is also present, this data is replaced by spaces. This is a special
229         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
230         output is generated for different internal link sizes.         output is generated for different internal link sizes.
231    
232           The  /D modifier is a PCRE debugging feature, and is equivalent to /BI,
233           that is, both the /B and the /I modifiers.
234    
235           The /F modifier causes pcretest to flip the byte order of the fields in
236           the  compiled  pattern  that  contain  2-byte  and 4-byte numbers. This
237           facility is for testing the feature in PCRE that allows it  to  execute
238           patterns that were compiled on a host with a different endianness. This
239           feature is not available when the POSIX  interface  to  PCRE  is  being
240           used,  that is, when the /P pattern modifier is specified. See also the
241           section about saving and reloading compiled patterns below.
242    
243           The /I modifier requests that pcretest  output  information  about  the
244           compiled  pattern (whether it is anchored, has a fixed first character,
245           and so on). It does this by calling pcre_fullinfo() after  compiling  a
246           pattern.  If  the pattern is studied, the results of that are also out-
247           put.
248    
249           The /K modifier requests pcretest to show names from backtracking  con-
250           trol  verbs  that  are  returned  from  calls to pcre_exec(). It causes
251           pcretest to create a pcre_extra block if one has not already been  cre-
252           ated by a call to pcre_study(), and to set the PCRE_EXTRA_MARK flag and
253           the mark field within it, every time that pcre_exec() is called. If the
254           variable  that  the  mark field points to is non-NULL for a match, non-
255           match, or partial match, pcretest prints the string to which it points.
256           For a match, this is shown on a line by itself, tagged with "MK:".  For
257           a non-match it is added to the message.
258    
259         The /L modifier must be followed directly by the name of a locale,  for         The /L modifier must be followed directly by the name of a locale,  for
260         example,         example,
261    
# Line 230  PATTERN MODIFIERS Line 268  PATTERN MODIFIERS
268         tables  pointer; that is, /L applies only to the expression on which it         tables  pointer; that is, /L applies only to the expression on which it
269         appears.         appears.
270    
        The /I modifier requests that pcretest  output  information  about  the  
        compiled  pattern (whether it is anchored, has a fixed first character,  
        and so on). It does this by calling pcre_fullinfo() after  compiling  a  
        pattern.  If  the pattern is studied, the results of that are also out-  
        put.  
   
        The /D modifier is a PCRE debugging feature, and is equivalent to  /BI,  
        that is, both the /B and the /I modifiers.  
   
        The /F modifier causes pcretest to flip the byte order of the fields in  
        the compiled pattern that  contain  2-byte  and  4-byte  numbers.  This  
        facility  is  for testing the feature in PCRE that allows it to execute  
        patterns that were compiled on a host with a different endianness. This  
        feature  is  not  available  when  the POSIX interface to PCRE is being  
        used, that is, when the /P pattern modifier is specified. See also  the  
        section about saving and reloading compiled patterns below.  
   
        The  /S  modifier causes pcre_study() to be called after the expression  
        has been compiled, and the results used when the expression is matched.  
   
271         The /M modifier causes the size of memory block used to hold  the  com-         The /M modifier causes the size of memory block used to hold  the  com-
272         piled pattern to be output.         piled pattern to be output.
273    
# Line 259  PATTERN MODIFIERS Line 277  PATTERN MODIFIERS
277         and REG_NEWLINE is set if /m is present. The  wrapper  functions  force         and REG_NEWLINE is set if /m is present. The  wrapper  functions  force
278         PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set.         PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set.
279    
280         The  /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option         The  /S  modifier causes pcre_study() to be called after the expression
281         set. This turns on support for UTF-8 character handling in  PCRE,  pro-         has been compiled, and the results used when the expression is matched.
        vided  that  it  was  compiled with this support enabled. This modifier  
        also causes any non-printing characters in output strings to be printed  
        using the \x{hh...} notation if they are valid UTF-8 sequences.  
   
        If  the  /?  modifier  is  used  with  /8,  it  causes pcretest to call  
        pcre_compile() with the  PCRE_NO_UTF8_CHECK  option,  to  suppress  the  
        checking of the string for UTF-8 validity.  
282    
283    
284  DATA LINES  DATA LINES
285    
286         Before  each  data  line is passed to pcre_exec(), leading and trailing         Before each data line is passed to pcre_exec(),  leading  and  trailing
287         whitespace is removed, and it is then scanned for \  escapes.  Some  of         whitespace  is  removed,  and it is then scanned for \ escapes. Some of
288         these  are  pretty esoteric features, intended for checking out some of         these are pretty esoteric features, intended for checking out  some  of
289         the more complicated features of PCRE. If you are just  testing  "ordi-         the  more  complicated features of PCRE. If you are just testing "ordi-
290         nary"  regular  expressions,  you probably don't need any of these. The         nary" regular expressions, you probably don't need any  of  these.  The
291         following escapes are recognized:         following escapes are recognized:
292    
293           \a         alarm (BEL, \x07)           \a         alarm (BEL, \x07)
# Line 323  DATA LINES Line 334  DATA LINES
334           \M         discover the minimum MATCH_LIMIT and           \M         discover the minimum MATCH_LIMIT and
335                        MATCH_LIMIT_RECURSION settings                        MATCH_LIMIT_RECURSION settings
336           \N         pass the PCRE_NOTEMPTY option to pcre_exec()           \N         pass the PCRE_NOTEMPTY option to pcre_exec()
337                        or pcre_dfa_exec()                        or pcre_dfa_exec(); if used twice, pass the
338                          PCRE_NOTEMPTY_ATSTART option
339           \Odd       set the size of the output vector passed to           \Odd       set the size of the output vector passed to
340                        pcre_exec() to dd (any number of digits)                        pcre_exec() to dd (any number of digits)
341           \P         pass the PCRE_PARTIAL option to pcre_exec()           \P         pass the PCRE_PARTIAL_SOFT option to pcre_exec()
342                        or pcre_dfa_exec()                        or pcre_dfa_exec(); if used twice, pass the
343                          PCRE_PARTIAL_HARD option
344           \Qdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd           \Qdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
345                        (any number of digits)                        (any number of digits)
346           \R         pass the PCRE_DFA_RESTART option to pcre_dfa_exec()           \R         pass the PCRE_DFA_RESTART option to pcre_dfa_exec()
347           \S         output details of memory get/free calls during matching           \S         output details of memory get/free calls during matching
348             \Y         pass the PCRE_NO_START_OPTIMIZE option to pcre_exec()
349                          or pcre_dfa_exec()
350           \Z         pass the PCRE_NOTEOL option to pcre_exec()           \Z         pass the PCRE_NOTEOL option to pcre_exec()
351                        or pcre_dfa_exec()                        or pcre_dfa_exec()
352           \?         pass the PCRE_NO_UTF8_CHECK option to           \?         pass the PCRE_NO_UTF8_CHECK option to
# Line 350  DATA LINES Line 365  DATA LINES
365           \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()           \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()
366                        or pcre_dfa_exec()                        or pcre_dfa_exec()
367    
368         The escapes that specify line ending  sequences  are  literal  strings,         The  escapes  that  specify  line ending sequences are literal strings,
369         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
370         any data line.         any data line.
371    
372         A backslash followed by anything else just escapes the  anything  else.         A  backslash  followed by anything else just escapes the anything else.
373         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
374         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-
375         nates the data input.         nates the data input.
376    
377         If  \M  is present, pcretest calls pcre_exec() several times, with dif-         If \M is present, pcretest calls pcre_exec() several times,  with  dif-
378         ferent values in the match_limit and  match_limit_recursion  fields  of         ferent  values  in  the match_limit and match_limit_recursion fields of
379         the  pcre_extra  data structure, until it finds the minimum numbers for         the pcre_extra data structure, until it finds the minimum  numbers  for
380         each parameter that allow pcre_exec() to complete. The match_limit num-         each parameter that allow pcre_exec() to complete. The match_limit num-
381         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
382         checking it out can be instructive. For most simple matches, the number         checking it out can be instructive. For most simple matches, the number
383         is  quite  small,  but for patterns with very large numbers of matching         is quite small, but for patterns with very large  numbers  of  matching
384         possibilities, it can become large very quickly with increasing  length         possibilities,  it can become large very quickly with increasing length
385         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
386         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)
387         memory is needed to complete the match attempt.         memory is needed to complete the match attempt.
388    
389         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
390         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
391         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.
392    
393         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-
394         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
395         effect  are \B and \Z, causing REG_NOTBOL and REG_NOTEOL, respectively,         effect are \B and \Z, causing REG_NOTBOL and REG_NOTEOL,  respectively,
396         to be passed to regexec().         to be passed to regexec().
397    
398         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
399         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.
400         There may be any number of hexadecimal digits inside  the  braces.  The         There  may  be  any number of hexadecimal digits inside the braces. The
401         result  is  from  one  to  six bytes, encoded according to the original         result is from one to six bytes,  encoded  according  to  the  original
402         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
403         0x7FFFFFFF.  Note  that not all of those are valid Unicode code points,         0x7FFFFFFF. Note that not all of those are valid Unicode  code  points,
404         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
405         3629.         3629.
406    
407    
408  THE ALTERNATIVE MATCHING FUNCTION  THE ALTERNATIVE MATCHING FUNCTION
409    
410         By   default,  pcretest  uses  the  standard  PCRE  matching  function,         By  default,  pcretest  uses  the  standard  PCRE  matching   function,
411         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
412         alternative  matching  function,  pcre_dfa_test(),  which operates in a         alternative matching function, pcre_dfa_test(),  which  operates  in  a
413         different way, and has some restrictions. The differences  between  the         different  way,  and has some restrictions. The differences between the
414         two functions are described in the pcrematching documentation.         two functions are described in the pcrematching documentation.
415    
416         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
417         contains the -dfa option, the alternative matching function is  called.         contains  the -dfa option, the alternative matching function is called.
418         This function finds all possible matches at a given point. If, however,         This function finds all possible matches at a given point. If, however,
419         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
420         first match is found. This is always the shortest possible match.         first match is found. This is always the shortest possible match.
421    
422    
423  DEFAULT OUTPUT FROM PCRETEST  DEFAULT OUTPUT FROM PCRETEST
424    
425         This  section  describes  the output when the normal matching function,         This section describes the output when the  normal  matching  function,
426         pcre_exec(), is being used.         pcre_exec(), is being used.
427    
428         When a match succeeds, pcretest outputs the list of captured substrings         When a match succeeds, pcretest outputs the list of captured substrings
429         that  pcre_exec()  returns,  starting with number 0 for the string that         that pcre_exec() returns, starting with number 0 for  the  string  that
430         matched the whole pattern. Otherwise, it outputs "No match" or "Partial         matched  the  whole  pattern. Otherwise, it outputs "No match" when the
431         match"  when  pcre_exec() returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PAR-         return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the par-
432         TIAL, respectively, and otherwise the PCRE negative error number.  Here         tially  matching substring when pcre_exec() returns PCRE_ERROR_PARTIAL.
433           For any other returns, it outputs the PCRE negative error number.  Here
434         is an example of an interactive pcretest run.         is an example of an interactive pcretest run.
435    
436           $ pcretest           $ pcretest
# Line 496  OUTPUT FROM THE ALTERNATIVE MATCHING FUN Line 512  OUTPUT FROM THE ALTERNATIVE MATCHING FUN
512            2: tan            2: tan
513    
514         (Using  the  normal  matching function on this data finds only "tang".)         (Using  the  normal  matching function on this data finds only "tang".)
515         The longest matching string is always given first (and numbered zero).         The longest matching string is always given first (and numbered  zero).
516           After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-
517           lowed by the partially matching substring.
518    
519         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
520         at the end of the longest match. For example:         at the end of the longest match. For example:
# Line 655  AUTHOR Line 673  AUTHOR
673    
674  REVISION  REVISION
675    
676         Last updated: 10 March 2009         Last updated: 26 March 2010
677         Copyright (c) 1997-2009 University of Cambridge.         Copyright (c) 1997-2010 University of Cambridge.

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