/[pcre]/code/trunk/doc/pcretest.txt
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revision 518 by ph10, Tue May 18 15:47:01 2010 UTC revision 579 by ph10, Wed Nov 24 17:39:25 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           /8              PCRE_UTF8
161           /?              PCRE_NO_UTF8_CHECK           /?              PCRE_NO_UTF8_CHECK
# Line 168  PATTERN MODIFIERS Line 168  PATTERN MODIFIERS
168           /U              PCRE_UNGREEDY           /U              PCRE_UNGREEDY
169           /W              PCRE_UCP           /W              PCRE_UCP
170           /X              PCRE_EXTRA           /X              PCRE_EXTRA
171             /Y              PCRE_NO_START_OPTIMIZE
172           /<JS>           PCRE_JAVASCRIPT_COMPAT           /<JS>           PCRE_JAVASCRIPT_COMPAT
173           /<cr>           PCRE_NEWLINE_CR           /<cr>           PCRE_NEWLINE_CR
174           /<lf>           PCRE_NEWLINE_LF           /<lf>           PCRE_NEWLINE_LF
# Line 205  PATTERN MODIFIERS Line 206  PATTERN MODIFIERS
206         string,  the  next  call  is  done  with  the PCRE_NOTEMPTY_ATSTART and         string,  the  next  call  is  done  with  the PCRE_NOTEMPTY_ATSTART and
207         PCRE_ANCHORED flags set in order  to  search  for  another,  non-empty,         PCRE_ANCHORED flags set in order  to  search  for  another,  non-empty,
208         match  at  the same point. If this second match fails, the start offset         match  at  the same point. If this second match fails, the start offset
209         is advanced by one character, and the normal  match  is  retried.  This         is advanced, and the normal match is retried.  This  imitates  the  way
210         imitates  the way Perl handles such cases when using the /g modifier or         Perl handles such cases when using the /g modifier or the split() func-
211         the split() function.         tion. Normally, the start offset is advanced by one character,  but  if
212           the  newline  convention  recognizes CRLF as a newline, and the current
213           character is CR followed by LF, an advance of two is used.
214    
215     Other modifiers     Other modifiers
216    
# Line 260  PATTERN MODIFIERS Line 263  PATTERN MODIFIERS
263         For this reason, it must be the last modifier. The given locale is set,         For this reason, it must be the last modifier. The given locale is set,
264         pcre_maketables()  is called to build a set of character tables for the         pcre_maketables()  is called to build a set of character tables for the
265         locale, and this is then passed to pcre_compile()  when  compiling  the         locale, and this is then passed to pcre_compile()  when  compiling  the
266         regular  expression.  Without  an  /L  modifier,  NULL is passed as the         regular  expression.  Without an /L (or /T) modifier, NULL is passed as
267         tables pointer; that is, /L applies only to the expression on which  it         the tables pointer; that is, /L applies only to the expression on which
268         appears.         it appears.
269    
270         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-
271         piled pattern to be output.         piled pattern to be output.
272    
        The /P modifier causes pcretest to call PCRE via the POSIX wrapper  API  
        rather  than  its  native  API.  When this is done, all other modifiers  
        except /i, /m, and /+ are ignored. REG_ICASE is set if /i  is  present,  
        and  REG_NEWLINE  is  set if /m is present. The wrapper functions force  
        PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set.  
   
273         The /S modifier causes pcre_study() to be called after  the  expression         The /S modifier causes pcre_study() to be called after  the  expression
274         has been compiled, and the results used when the expression is matched.         has been compiled, and the results used when the expression is matched.
275    
276           The  /T  modifier  must be followed by a single digit. It causes a spe-
277           cific set of built-in character tables to be passed to  pcre_compile().
278           It is used in the standard PCRE tests to check behaviour with different
279           character tables. The digit specifies the tables as follows:
280    
281             0   the default ASCII tables, as distributed in
282                   pcre_chartables.c.dist
283             1   a set of tables defining ISO 8859 characters
284    
285           In table 1, some characters whose codes are greater than 128 are  iden-
286           tified as letters, digits, spaces, etc.
287    
288       Using the POSIX wrapper API
289    
290           The  /P modifier causes pcretest to call PCRE via the POSIX wrapper API
291           rather than its native API. When /P is set, the following modifiers set
292           options for the regcomp() function:
293    
294             /i    REG_ICASE
295             /m    REG_NEWLINE
296             /N    REG_NOSUB
297             /s    REG_DOTALL     )
298             /U    REG_UNGREEDY   ) These options are not part of
299             /W    REG_UCP        )   the POSIX standard
300             /8    REG_UTF8       )
301    
302           The  /+  modifier  works  as  described  above. All other modifiers are
303           ignored.
304    
305    
306  DATA LINES  DATA LINES
307    
308         Before  each  data  line is passed to pcre_exec(), leading and trailing         Before each data line is passed to pcre_exec(),  leading  and  trailing
309         whitespace is removed, and it is then scanned for \  escapes.  Some  of         whitespace  is  removed,  and it is then scanned for \ escapes. Some of
310         these  are  pretty esoteric features, intended for checking out some of         these are pretty esoteric features, intended for checking out  some  of
311         the more complicated features of PCRE. If you are just  testing  "ordi-         the  more  complicated features of PCRE. If you are just testing "ordi-
312         nary"  regular  expressions,  you probably don't need any of these. The         nary" regular expressions, you probably don't need any  of  these.  The
313         following escapes are recognized:         following escapes are recognized:
314    
315           \a         alarm (BEL, \x07)           \a         alarm (BEL, \x07)
# Line 297  DATA LINES Line 323  DATA LINES
323           \t         tab (\x09)           \t         tab (\x09)
324           \v         vertical tab (\x0b)           \v         vertical tab (\x0b)
325           \nnn       octal character (up to 3 octal digits)           \nnn       octal character (up to 3 octal digits)
326           \xhh       hexadecimal character (up to 2 hex digits)                        always a byte unless > 255 in UTF-8 mode
327             \xhh       hexadecimal byte (up to 2 hex digits)
328           \x{hh...}  hexadecimal character, any number of digits           \x{hh...}  hexadecimal character, any number of digits
329                        in UTF-8 mode                        in UTF-8 mode
330           \A         pass the PCRE_ANCHORED option to pcre_exec()           \A         pass the PCRE_ANCHORED option to pcre_exec()
# Line 347  DATA LINES Line 374  DATA LINES
374                        or pcre_dfa_exec()                        or pcre_dfa_exec()
375           \?         pass the PCRE_NO_UTF8_CHECK option to           \?         pass the PCRE_NO_UTF8_CHECK option to
376                        pcre_exec() or pcre_dfa_exec()                        pcre_exec() or pcre_dfa_exec()
377           \>dd       start the match at offset dd (any number of digits);           \>dd       start the match at offset dd (optional "-"; then
378                        this sets the startoffset argument for pcre_exec()                        any number of digits); this sets the startoffset
379                        or pcre_dfa_exec()                        argument for pcre_exec() or pcre_dfa_exec()
380           \<cr>      pass the PCRE_NEWLINE_CR option to pcre_exec()           \<cr>      pass the PCRE_NEWLINE_CR option to pcre_exec()
381                        or pcre_dfa_exec()                        or pcre_dfa_exec()
382           \<lf>      pass the PCRE_NEWLINE_LF option to pcre_exec()           \<lf>      pass the PCRE_NEWLINE_LF option to pcre_exec()
# Line 361  DATA LINES Line 388  DATA LINES
388           \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()           \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()
389                        or pcre_dfa_exec()                        or pcre_dfa_exec()
390    
391           Note  that  \xhh  always  specifies  one byte, even in UTF-8 mode; this
392           makes it possible to construct invalid UTF-8 sequences for testing pur-
393           poses. On the other hand, \x{hh} is interpreted as a UTF-8 character in
394           UTF-8 mode, generating more than one byte if the value is greater  than
395           127. When not in UTF-8 mode, it generates one byte for values less than
396           256, and causes an error for greater values.
397    
398         The escapes that specify line ending  sequences  are  literal  strings,         The escapes that specify line ending  sequences  are  literal  strings,
399         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
400         any data line.         any data line.
# Line 388  DATA LINES Line 422  DATA LINES
422    
423         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-
424         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
425         effect  are \B and \Z, causing REG_NOTBOL and REG_NOTEOL, respectively,         effect  are  \B,  \N,  and  \Z,  causing  REG_NOTBOL, REG_NOTEMPTY, and
426         to be passed to regexec().         REG_NOTEOL, respectively, to be passed to regexec().
427    
428         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
429         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.
# Line 426  DEFAULT OUTPUT FROM PCRETEST Line 460  DEFAULT OUTPUT FROM PCRETEST
460         matched the whole pattern. Otherwise, it outputs "No  match"  when  the         matched the whole pattern. Otherwise, it outputs "No  match"  when  the
461         return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the par-         return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the par-
462         tially matching substring when pcre_exec() returns  PCRE_ERROR_PARTIAL.         tially matching substring when pcre_exec() returns  PCRE_ERROR_PARTIAL.
463         For  any other returns, it outputs the PCRE negative error number. Here         (Note  that  this is the entire substring that was inspected during the
464         is an example of an interactive pcretest run.         partial match; it may include characters before the actual match  start
465           if  a  lookbehind assertion, \K, \b, or \B was involved.) For any other
466           returns, it outputs the PCRE negative error number. Here is an  example
467           of an interactive pcretest run.
468    
469           $ pcretest           $ pcretest
470           PCRE version 7.0 30-Nov-2006           PCRE version 7.0 30-Nov-2006
# Line 439  DEFAULT OUTPUT FROM PCRETEST Line 476  DEFAULT OUTPUT FROM PCRETEST
476           data> xyz           data> xyz
477           No match           No match
478    
479         Note that unset capturing substrings that are not followed by one  that         Note  that unset capturing substrings that are not followed by one that
480         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.
481         In the following example, there are two capturing substrings, but  when         In  the following example, there are two capturing substrings, but when
482         the  first  data  line  is  matched, the second, unset substring is not         the first data line is matched, the  second,  unset  substring  is  not
483         shown. An "internal" unset substring is shown as "<unset>", as for  the         shown.  An "internal" unset substring is shown as "<unset>", as for the
484         second data line.         second data line.
485    
486             re> /(a)|(b)/             re> /(a)|(b)/
# Line 455  DEFAULT OUTPUT FROM PCRETEST Line 492  DEFAULT OUTPUT FROM PCRETEST
492            1: <unset>            1: <unset>
493            2: b            2: b
494    
495         If  the strings contain any non-printing characters, they are output as         If the strings contain any non-printing characters, they are output  as
496         \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
497         the  pattern.  See below for the definition of non-printing characters.         the pattern. See below for the definition of  non-printing  characters.
498         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-
499         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
500         this:         this:
501    
502             re> /cat/+             re> /cat/+
# Line 467  DEFAULT OUTPUT FROM PCRETEST Line 504  DEFAULT OUTPUT FROM PCRETEST
504            0: cat            0: cat
505            0+ aract            0+ aract
506    
507         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
508         matching attempts are output in sequence, like this:         matching attempts are output in sequence, like this:
509    
510             re> /\Bi(\w\w)/g             re> /\Bi(\w\w)/g
# Line 481  DEFAULT OUTPUT FROM PCRETEST Line 518  DEFAULT OUTPUT FROM PCRETEST
518    
519         "No match" is output only if the first match attempt fails.         "No match" is output only if the first match attempt fails.
520    
521         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
522         is successfully matched, the substrings extracted  by  the  convenience         is  successfully  matched,  the substrings extracted by the convenience
523         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
524         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
525         (that  is,  the return from the extraction function) is given in paren-         (that is, the return from the extraction function) is given  in  paren-
526         theses after each string for \C and \G.         theses after each string for \C and \G.
527    
528         Note that whereas patterns can be continued over several lines (a plain         Note that whereas patterns can be continued over several lines (a plain
529         ">" prompt is used for continuations), data lines may not. However new-         ">" prompt is used for continuations), data lines may not. However new-
530         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,
531         etc., depending on the newline sequence setting).         etc., depending on the newline sequence setting).
532    
533    
534  OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION  OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
535    
536         When  the  alternative  matching function, pcre_dfa_exec(), is used (by         When the alternative matching function, pcre_dfa_exec(),  is  used  (by
537         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
538         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
539         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:
540    
541             re> /(tang|tangerine|tan)/             re> /(tang|tangerine|tan)/
# Line 507  OUTPUT FROM THE ALTERNATIVE MATCHING FUN Line 544  OUTPUT FROM THE ALTERNATIVE MATCHING FUN
544            1: tang            1: tang
545            2: tan            2: tan
546    
547         (Using the normal matching function on this data  finds  only  "tang".)         (Using  the  normal  matching function on this data finds only "tang".)
548         The  longest matching string is always given first (and numbered zero).         The longest matching string is always given first (and numbered  zero).
549         After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-         After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-
550         lowed by the partially matching substring.         lowed by the partially matching  substring.  (Note  that  this  is  the
551           entire  substring  that  was inspected during the partial match; it may
552           include characters before the actual match start if a lookbehind asser-
553           tion, \K, \b, or \B was involved.)
554    
555         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
556         at the end of the longest match. For example:         at the end of the longest match. For example:
# Line 669  AUTHOR Line 709  AUTHOR
709    
710  REVISION  REVISION
711    
712         Last updated: 12 May 2010         Last updated: 21 November 2010
713         Copyright (c) 1997-2010 University of Cambridge.         Copyright (c) 1997-2010 University of Cambridge.

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