/[pcre]/code/trunk/doc/pcretest.txt
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revision 77 by nigel, Sat Feb 24 21:40:45 2007 UTC revision 91 by nigel, Sat Feb 24 21:41:34 2007 UTC
# Line 1  Line 1 
1  PCRETEST(1)                                                        PCRETEST(1)  PCRETEST(1)                                                        PCRETEST(1)
2    
3    
   
4  NAME  NAME
5         pcretest - a program for testing Perl-compatible regular expressions.         pcretest - a program for testing Perl-compatible regular expressions.
6    
7    
8  SYNOPSIS  SYNOPSIS
9    
10         pcretest [-C] [-d] [-dfa] [-i] [-m] [-o osize] [-p] [-t] [source]         pcretest [options] [source] [destination]
             [destination]  
11    
12         pcretest  was written as a test program for the PCRE regular expression         pcretest  was written as a test program for the PCRE regular expression
13         library itself, but it can also be used for experimenting with  regular         library itself, but it can also be used for experimenting with  regular
# Line 50  OPTIONS Line 49  OPTIONS
49                   per  API  is used to call PCRE. None of the other options has                   per  API  is used to call PCRE. None of the other options has
50                   any effect when -p is set.                   any effect when -p is set.
51    
52           -q        Do not output the version number of pcretest at the start  of
53                     execution.
54    
55           -S size   On  Unix-like  systems,  set the size of the runtime stack to
56                     size megabytes.
57    
58         -t        Run each compile, study, and match many times with  a  timer,         -t        Run each compile, study, and match many times with  a  timer,
59                   and  output resulting time per compile or match (in millisec-                   and  output resulting time per compile or match (in millisec-
60                   onds). Do not set -m with -t, because you will then  get  the                   onds). Do not set -m with -t, because you will then  get  the
# Line 71  DESCRIPTION Line 76  DESCRIPTION
76         ber of data lines to be matched against the pattern.         ber of data lines to be matched against the pattern.
77    
78         Each  data line is matched separately and independently. If you want to         Each  data line is matched separately and independently. If you want to
79         do multiple-line matches, you have to use the \n escape sequence  in  a         do multi-line matches, you have to use the \n escape sequence (or \r or
80         single  line  of  input  to  encode the newline characters. The maximum         \r\n,  depending  on  the newline setting) in a single line of input to
81         length of data line is 30,000 characters.         encode the newline characters. There is no limit on the length of  data
82           lines; the input buffer is automatically extended if it is too small.
83         An empty line signals the end of the data lines, at which point  a  new  
84         regular  expression is read. The regular expressions are given enclosed         An  empty  line signals the end of the data lines, at which point a new
85         in any non-alphanumeric delimiters other than backslash, for example         regular expression is read. The regular expressions are given  enclosed
86           in any non-alphanumeric delimiters other than backslash, for example:
87    
88           /(a|bc)x+yz/           /(a|bc)x+yz/
89    
90         White space before the initial delimiter is ignored. A regular  expres-         White  space before the initial delimiter is ignored. A regular expres-
91         sion  may be continued over several input lines, in which case the new-         sion may be continued over several input lines, in which case the  new-
92         line characters are included within it. It is possible to  include  the         line  characters  are included within it. It is possible to include the
93         delimiter within the pattern by escaping it, for example         delimiter within the pattern by escaping it, for example
94    
95           /abc\/def/           /abc\/def/
96    
97         If  you  do  so, the escape and the delimiter form part of the pattern,         If you do so, the escape and the delimiter form part  of  the  pattern,
98         but since delimiters are always non-alphanumeric, this does not  affect         but  since delimiters are always non-alphanumeric, this does not affect
99         its  interpretation.   If the terminating delimiter is immediately fol-         its interpretation.  If the terminating delimiter is  immediately  fol-
100         lowed by a backslash, for example,         lowed by a backslash, for example,
101    
102           /abc/\           /abc/\
103    
104         then a backslash is added to the end of the pattern. This  is  done  to         then  a  backslash  is added to the end of the pattern. This is done to
105         provide  a  way of testing the error condition that arises if a pattern         provide a way of testing the error condition that arises if  a  pattern
106         finishes with a backslash, because         finishes with a backslash, because
107    
108           /abc\/           /abc\/
109    
110         is interpreted as the first line of a pattern that starts with  "abc/",         is  interpreted as the first line of a pattern that starts with "abc/",
111         causing pcretest to read the next line as a continuation of the regular         causing pcretest to read the next line as a continuation of the regular
112         expression.         expression.
113    
114    
115  PATTERN MODIFIERS  PATTERN MODIFIERS
116    
117         A pattern may be followed by any number of modifiers, which are  mostly         A  pattern may be followed by any number of modifiers, which are mostly
118         single  characters.  Following  Perl usage, these are referred to below         single characters. Following Perl usage, these are  referred  to  below
119         as, for example, "the /i modifier", even though the  delimiter  of  the         as,  for  example,  "the /i modifier", even though the delimiter of the
120         pattern  need  not always be a slash, and no slash is used when writing         pattern need not always be a slash, and no slash is used  when  writing
121         modifiers. Whitespace may appear between the  final  pattern  delimiter         modifiers.  Whitespace  may  appear between the final pattern delimiter
122         and the first modifier, and between the modifiers themselves.         and the first modifier, and between the modifiers themselves.
123    
124         The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,         The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,
125         PCRE_DOTALL, or PCRE_EXTENDED  options,  respectively,  when  pcre_com-         PCRE_DOTALL,  or  PCRE_EXTENDED  options,  respectively, when pcre_com-
126         pile()  is  called. These four modifier letters have the same effect as         pile() is called. These four modifier letters have the same  effect  as
127         they do in Perl. For example:         they do in Perl. For example:
128    
129           /caseless/i           /caseless/i
# Line 125  PATTERN MODIFIERS Line 131  PATTERN MODIFIERS
131         The following table shows additional modifiers for setting PCRE options         The following table shows additional modifiers for setting PCRE options
132         that do not correspond to anything in Perl:         that do not correspond to anything in Perl:
133    
134           /A    PCRE_ANCHORED           /A       PCRE_ANCHORED
135           /C    PCRE_AUTO_CALLOUT           /C       PCRE_AUTO_CALLOUT
136           /E    PCRE_DOLLAR_ENDONLY           /E       PCRE_DOLLAR_ENDONLY
137           /f    PCRE_FIRSTLINE           /f       PCRE_FIRSTLINE
138           /N    PCRE_NO_AUTO_CAPTURE           /J       PCRE_DUPNAMES
139           /U    PCRE_UNGREEDY           /N       PCRE_NO_AUTO_CAPTURE
140           /X    PCRE_EXTRA           /U       PCRE_UNGREEDY
141             /X       PCRE_EXTRA
142             /<cr>    PCRE_NEWLINE_CR
143             /<lf>    PCRE_NEWLINE_LF
144             /<crlf>  PCRE_NEWLINE_CRLF
145    
146           Those specifying line endings are literal strings as shown. Details  of
147           the  meanings of these PCRE options are given in the pcreapi documenta-
148           tion.
149    
150         Searching  for  all  possible matches within each subject string can be     Finding all matches in a string
151         requested by the /g or /G modifier. After  finding  a  match,  PCRE  is  
152           Searching for all possible matches within each subject  string  can  be
153           requested  by  the  /g  or  /G modifier. After finding a match, PCRE is
154         called again to search the remainder of the subject string. The differ-         called again to search the remainder of the subject string. The differ-
155         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
156         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
157         string (which is in effect what Perl does), whereas the  latter  passes         string  (which  is in effect what Perl does), whereas the latter passes
158         over  a  shortened  substring.  This makes a difference to the matching         over a shortened substring. This makes a  difference  to  the  matching
159         process if the pattern begins with a lookbehind assertion (including \b         process if the pattern begins with a lookbehind assertion (including \b
160         or \B).         or \B).
161    
162         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
163         string, the next call is done with the PCRE_NOTEMPTY and  PCRE_ANCHORED         string,  the next call is done with the PCRE_NOTEMPTY and PCRE_ANCHORED
164         flags  set in order to search for another, non-empty, match at the same         flags set in order to search for another, non-empty, match at the  same
165         point.  If this second match fails, the start  offset  is  advanced  by         point.   If  this  second  match fails, the start offset is advanced by
166         one,  and  the normal match is retried. This imitates the way Perl han-         one, and the normal match is retried. This imitates the way  Perl  han-
167         dles such cases when using the /g modifier or the split() function.         dles such cases when using the /g modifier or the split() function.
168    
169       Other modifiers
170    
171         There are yet more modifiers for controlling the way pcretest operates.         There are yet more modifiers for controlling the way pcretest operates.
172    
173         The  /+ modifier requests that as well as outputting the substring that         The /+ modifier requests that as well as outputting the substring  that
174         matched the entire pattern, pcretest  should  in  addition  output  the         matched  the  entire  pattern,  pcretest  should in addition output the
175         remainder  of  the  subject  string. This is useful for tests where the         remainder of the subject string. This is useful  for  tests  where  the
176         subject contains multiple copies of the same substring.         subject contains multiple copies of the same substring.
177    
178         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
179         example,         example,
180    
181           /pattern/Lfr_FR           /pattern/Lfr_FR
182    
183         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,
184         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
185         locale,  and  this  is then passed to pcre_compile() when compiling the         locale, and this is then passed to pcre_compile()  when  compiling  the
186         regular expression. Without an /L  modifier,  NULL  is  passed  as  the         regular  expression.  Without  an  /L  modifier,  NULL is passed as the
187         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
188         appears.         appears.
189    
190         The /I modifier requests that pcretest  output  information  about  the         The  /I  modifier  requests  that pcretest output information about the
191         compiled  pattern (whether it is anchored, has a fixed first character,         compiled pattern (whether it is anchored, has a fixed first  character,
192         and so on). It does this by calling pcre_fullinfo() after  compiling  a         and  so  on). It does this by calling pcre_fullinfo() after compiling a
193         pattern.  If  the pattern is studied, the results of that are also out-         pattern. If the pattern is studied, the results of that are  also  out-
194         put.         put.
195    
196         The /D modifier is a PCRE debugging feature, which also assumes /I.  It         The /D modifier is a PCRE debugging feature, which also assumes /I.  It
197         causes  the  internal form of compiled regular expressions to be output         causes the internal form of compiled regular expressions to  be  output
198         after compilation. If the pattern was studied, the information returned         after compilation. If the pattern was studied, the information returned
199         is also output.         is also output.
200    
201         The /F modifier causes pcretest to flip the byte order of the fields in         The /F modifier causes pcretest to flip the byte order of the fields in
202         the compiled pattern that  contain  2-byte  and  4-byte  numbers.  This         the  compiled  pattern  that  contain  2-byte  and 4-byte numbers. This
203         facility  is  for testing the feature in PCRE that allows it to execute         facility is for testing the feature in PCRE that allows it  to  execute
204         patterns that were compiled on a host with a different endianness. This         patterns that were compiled on a host with a different endianness. This
205         feature  is  not  available  when  the POSIX interface to PCRE is being         feature is not available when the POSIX  interface  to  PCRE  is  being
206         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
207         section about saving and reloading compiled patterns below.         section about saving and reloading compiled patterns below.
208    
209         The  /S  modifier causes pcre_study() to be called after the expression         The /S modifier causes pcre_study() to be called after  the  expression
210         has been compiled, and the results used when the expression is matched.         has been compiled, and the results used when the expression is matched.
211    
212         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-
213         piled pattern to be output.         piled pattern to be output.
214    
215         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
216         rather  than  its  native  API.  When this is done, all other modifiers         rather than its native API. When this  is  done,  all  other  modifiers
217         except /i, /m, and /+ are ignored. REG_ICASE is set if /i  is  present,         except  /i,  /m, and /+ are ignored. REG_ICASE is set if /i is present,
218         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
219         PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is  set.         PCRE_DOLLAR_ENDONLY  always, and PCRE_DOTALL unless REG_NEWLINE is set.
220    
221         The  /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option         The /8 modifier causes pcretest to call PCRE with the PCRE_UTF8  option
222         set. This turns on support for UTF-8 character handling in  PCRE,  pro-         set.  This  turns on support for UTF-8 character handling in PCRE, pro-
223         vided  that  it  was  compiled with this support enabled. This modifier         vided that it was compiled with this  support  enabled.  This  modifier
224         also causes any non-printing characters in output strings to be printed         also causes any non-printing characters in output strings to be printed
225         using the \x{hh...} notation if they are valid UTF-8 sequences.         using the \x{hh...} notation if they are valid UTF-8 sequences.
226    
227         If  the  /?  modifier  is  used  with  /8,  it  causes pcretest to call         If the /? modifier  is  used  with  /8,  it  causes  pcretest  to  call
228         pcre_compile() with the  PCRE_NO_UTF8_CHECK  option,  to  suppress  the         pcre_compile()  with  the  PCRE_NO_UTF8_CHECK  option,  to suppress the
229         checking of the string for UTF-8 validity.         checking of the string for UTF-8 validity.
230    
231    
232  DATA LINES  DATA LINES
233    
234         Before  each  data  line is passed to pcre_exec(), leading and trailing         Before each data line is passed to pcre_exec(),  leading  and  trailing
235         whitespace is removed, and it is then scanned for \  escapes.  Some  of         whitespace  is  removed,  and it is then scanned for \ escapes. Some of
236         these  are  pretty esoteric features, intended for checking out some of         these are pretty esoteric features, intended for checking out  some  of
237         the more complicated features of PCRE. If you are just  testing  "ordi-         the  more  complicated features of PCRE. If you are just testing "ordi-
238         nary"  regular  expressions,  you probably don't need any of these. The         nary" regular expressions, you probably don't need any  of  these.  The
239         following escapes are recognized:         following escapes are recognized:
240    
241           \a         alarm (= BEL)           \a         alarm (= BEL)
# Line 225  DATA LINES Line 243  DATA LINES
243           \e         escape           \e         escape
244           \f         formfeed           \f         formfeed
245           \n         newline           \n         newline
246             \qdd       set the PCRE_MATCH_LIMIT limit to dd
247                          (any number of digits)
248           \r         carriage return           \r         carriage return
249           \t         tab           \t         tab
250           \v         vertical tab           \v         vertical tab
# Line 233  DATA LINES Line 253  DATA LINES
253           \x{hh...}  hexadecimal character, any number of digits           \x{hh...}  hexadecimal character, any number of digits
254                        in UTF-8 mode                        in UTF-8 mode
255           \A         pass the PCRE_ANCHORED option to pcre_exec()           \A         pass the PCRE_ANCHORED option to pcre_exec()
256                          or pcre_dfa_exec()
257           \B         pass the PCRE_NOTBOL option to pcre_exec()           \B         pass the PCRE_NOTBOL option to pcre_exec()
258                          or pcre_dfa_exec()
259           \Cdd       call pcre_copy_substring() for substring dd           \Cdd       call pcre_copy_substring() for substring dd
260                        after a successful match (number less than 32)                        after a successful match (number less than 32)
261           \Cname     call pcre_copy_named_substring() for substring           \Cname     call pcre_copy_named_substring() for substring
# Line 257  DATA LINES Line 279  DATA LINES
279                        ated by next non-alphanumeric character)                        ated by next non-alphanumeric character)
280           \L         call pcre_get_substringlist() after a           \L         call pcre_get_substringlist() after a
281                        successful match                        successful match
282           \M         discover the minimum MATCH_LIMIT setting           \M         discover the minimum MATCH_LIMIT and
283                          MATCH_LIMIT_RECURSION settings
284           \N         pass the PCRE_NOTEMPTY option to pcre_exec()           \N         pass the PCRE_NOTEMPTY option to pcre_exec()
285                          or pcre_dfa_exec()
286           \Odd       set the size of the output vector passed to           \Odd       set the size of the output vector passed to
287                        pcre_exec() to dd (any number of digits)                        pcre_exec() to dd (any number of digits)
288           \P         pass the PCRE_PARTIAL option to pcre_exec()           \P         pass the PCRE_PARTIAL option to pcre_exec()
289                        or pcre_dfa_exec()                        or pcre_dfa_exec()
290             \Qdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
291                          (any number of digits)
292           \R         pass the PCRE_DFA_RESTART option to pcre_dfa_exec()           \R         pass the PCRE_DFA_RESTART option to pcre_dfa_exec()
293           \S         output details of memory get/free calls during matching           \S         output details of memory get/free calls during matching
294           \Z         pass the PCRE_NOTEOL option to pcre_exec()           \Z         pass the PCRE_NOTEOL option to pcre_exec()
295                          or pcre_dfa_exec()
296           \?         pass the PCRE_NO_UTF8_CHECK option to           \?         pass the PCRE_NO_UTF8_CHECK option to
297                        pcre_exec()                        pcre_exec() or pcre_dfa_exec()
298           \>dd       start the match at offset dd (any number of digits);           \>dd       start the match at offset dd (any number of digits);
299                        this sets the startoffset argument for pcre_exec()                        this sets the startoffset argument for pcre_exec()
300                          or pcre_dfa_exec()
301             \<cr>      pass the PCRE_NEWLINE_CR option to pcre_exec()
302                          or pcre_dfa_exec()
303             \<lf>      pass the PCRE_NEWLINE_LF option to pcre_exec()
304                          or pcre_dfa_exec()
305             \<crlf>    pass the PCRE_NEWLINE_CRLF option to pcre_exec()
306                          or pcre_dfa_exec()
307    
308         A backslash followed by anything else just escapes the  anything  else.         The  escapes  that specify line endings are literal strings, exactly as
309         If  the very last character is a backslash, it is ignored. This gives a         shown.  A backslash followed by anything else just escapes the anything
310         way of passing an empty line as data, since a real  empty  line  termi-         else.  If  the  very last character is a backslash, it is ignored. This
311         nates the data input.         gives a way of passing an empty line as data, since a real  empty  line
312           terminates the data input.
313    
314         If  \M  is present, pcretest calls pcre_exec() several times, with dif-         If  \M  is present, pcretest calls pcre_exec() several times, with dif-
315         ferent values in the match_limit field of the  pcre_extra  data  struc-         ferent values in the match_limit and  match_limit_recursion  fields  of
316         ture,  until it finds the minimum number that is needed for pcre_exec()         the  pcre_extra  data structure, until it finds the minimum numbers for
317         to complete. This number is a measure of the amount  of  recursion  and         each parameter that allow pcre_exec() to complete. The match_limit num-
318         backtracking  that takes place, and checking it out can be instructive.         ber  is  a  measure of the amount of backtracking that takes place, and
319         For most simple matches, the number is quite small,  but  for  patterns         checking it out can be instructive. For most simple matches, the number
320         with  very large numbers of matching possibilities, it can become large         is  quite  small,  but for patterns with very large numbers of matching
321         very quickly with increasing length of subject string.         possibilities, it can become large very quickly with increasing  length
322           of subject string. The match_limit_recursion number is a measure of how
323           much stack (or, if PCRE is compiled with  NO_RECURSE,  how  much  heap)
324           memory is needed to complete the match attempt.
325    
326         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
327         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
328         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.
329    
330         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-
331         per  API to be used, only \B and \Z have any effect, causing REG_NOTBOL         per API to be used, the only option-setting  sequences  that  have  any
332         and REG_NOTEOL to be passed to regexec() respectively.         effect  are \B and \Z, causing REG_NOTBOL and REG_NOTEOL, respectively,
333           to be passed to regexec().
334    
335         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
336         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 370  DEFAULT OUTPUT FROM PCRETEST Line 409  DEFAULT OUTPUT FROM PCRETEST
409    
410         Note that while patterns can be continued over several lines  (a  plain         Note that while patterns can be continued over several lines  (a  plain
411         ">" prompt is used for continuations), data lines may not. However new-         ">" prompt is used for continuations), data lines may not. However new-
412         lines can be included in data by means of the \n escape.         lines can be included in data by means of the \n escape (or \r or  \r\n
413           for those newline settings).
414    
415    
416  OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION  OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
417    
418         When the alternative matching function, pcre_dfa_exec(),  is  used  (by         When  the  alternative  matching function, pcre_dfa_exec(), is used (by
419         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
420         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
421         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:
422    
423             re> /(tang|tangerine|tan)/             re> /(tang|tangerine|tan)/
# Line 386  OUTPUT FROM THE ALTERNATIVE MATCHING FUN Line 426  OUTPUT FROM THE ALTERNATIVE MATCHING FUN
426            1: tang            1: tang
427            2: tan            2: tan
428    
429         (Using  the  normal  matching function on this data finds only "tang".)         (Using the normal matching function on this data  finds  only  "tang".)
430         The longest matching string is always given first (and numbered  zero).         The  longest matching string is always given first (and numbered zero).
431    
432         If  /gP  is  present  on  the  pattern,  the search for further matches         If /gP is present on  the  pattern,  the  search  for  further  matches
433         resumes at the end of the longest match. For example:         resumes at the end of the longest match. For example:
434    
435             re> /(tang|tangerine|tan)/g             re> /(tang|tangerine|tan)/g
# Line 401  OUTPUT FROM THE ALTERNATIVE MATCHING FUN Line 441  OUTPUT FROM THE ALTERNATIVE MATCHING FUN
441            1: tan            1: tan
442            0: tan            0: tan
443    
444         Since the matching function does not  support  substring  capture,  the         Since  the  matching  function  does not support substring capture, the
445         escape  sequences  that  are concerned with captured substrings are not         escape sequences that are concerned with captured  substrings  are  not
446         relevant.         relevant.
447    
448    
449  RESTARTING AFTER A PARTIAL MATCH  RESTARTING AFTER A PARTIAL MATCH
450    
451         When the alternative matching function has given the PCRE_ERROR_PARTIAL         When the alternative matching function has given the PCRE_ERROR_PARTIAL
452         return,  indicating that the subject partially matched the pattern, you         return, indicating that the subject partially matched the pattern,  you
453         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
454         escape sequence. For example:         escape sequence. For example:
455    
456             re> /^?(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)$/             re> /^?(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)$/
# Line 419  RESTARTING AFTER A PARTIAL MATCH Line 459  RESTARTING AFTER A PARTIAL MATCH
459           data> n05\R\D           data> n05\R\D
460            0: n05            0: n05
461    
462         For  further  information  about  partial matching, see the pcrepartial         For further information about partial  matching,  see  the  pcrepartial
463         documentation.         documentation.
464    
465    
466  CALLOUTS  CALLOUTS
467    
468         If the pattern contains any callout requests, pcretest's callout  func-         If  the pattern contains any callout requests, pcretest's callout func-
469         tion  is  called  during  matching. This works with both matching func-         tion is called during matching. This works  with  both  matching  func-
470         tions. By default, the called function displays the callout number, the         tions. By default, the called function displays the callout number, the
471         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
472         next pattern item to be tested. For example, the output         next pattern item to be tested. For example, the output
473    
474           --->pqrabcdef           --->pqrabcdef
475             0    ^  ^     \d             0    ^  ^     \d
476    
477         indicates that callout number 0 occurred for a match  attempt  starting         indicates  that  callout number 0 occurred for a match attempt starting
478         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
479         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
480         \d.  Just  one  circumflex is output if the start and current positions         \d. Just one circumflex is output if the start  and  current  positions
481         are the same.         are the same.
482    
483         Callouts numbered 255 are assumed to be automatic callouts, inserted as         Callouts numbered 255 are assumed to be automatic callouts, inserted as
484         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
485         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
486         output. For example:         output. For example:
487    
488             re> /\d?[A-E]\*/C             re> /\d?[A-E]\*/C
# Line 454  CALLOUTS Line 494  CALLOUTS
494           +10 ^ ^           +10 ^ ^
495            0: E*            0: E*
496    
497         The  callout  function  in pcretest returns zero (carry on matching) by         The callout function in pcretest returns zero (carry  on  matching)  by
498         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)
499         to change this.         to change this.
500    
501         Inserting  callouts can be helpful when using pcretest to check compli-         Inserting callouts can be helpful when using pcretest to check  compli-
502         cated regular expressions. For further information about callouts,  see         cated  regular expressions. For further information about callouts, see
503         the pcrecallout documentation.         the pcrecallout documentation.
504    
505    
506  SAVING AND RELOADING COMPILED PATTERNS  SAVING AND RELOADING COMPILED PATTERNS
507    
508         The  facilities  described  in  this section are not available when the         The facilities described in this section are  not  available  when  the
509         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-
510         ifier is specified.         ifier is specified.
511    
512         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
513         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
514         file name.  For example:         file name.  For example:
515    
516           /pattern/im >/some/file           /pattern/im >/some/file
517    
518         See  the pcreprecompile documentation for a discussion about saving and         See the pcreprecompile documentation for a discussion about saving  and
519         re-using compiled patterns.         re-using compiled patterns.
520    
521         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
522         length  of  the  compiled  pattern  data  followed by the length of the         length of the compiled pattern data  followed  by  the  length  of  the
523         optional study data, each written as four  bytes  in  big-endian  order         optional  study  data,  each  written as four bytes in big-endian order
524         (most  significant  byte  first). If there is no study data (either the         (most significant byte first). If there is no study  data  (either  the
525         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-
526         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
527         compiled pattern. If there is additional study data, this follows imme-         compiled pattern. If there is additional study data, this follows imme-
528         diately  after  the  compiled pattern. After writing the file, pcretest         diately after the compiled pattern. After writing  the  file,  pcretest
529         expects to read a new pattern.         expects to read a new pattern.
530    
531         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
532         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  <
533         character, as otherwise pcretest will interpret the line as  a  pattern         character,  as  otherwise pcretest will interpret the line as a pattern
534         delimited by < characters.  For example:         delimited by < characters.  For example:
535    
536            re> </some/file            re> </some/file
537           Compiled regex loaded from /some/file           Compiled regex loaded from /some/file
538           No study data           No study data
539    
540         When  the pattern has been loaded, pcretest proceeds to read data lines         When the pattern has been loaded, pcretest proceeds to read data  lines
541         in the usual way.         in the usual way.
542    
543         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
544         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
545         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
546         machine and run on a SPARC machine.         machine and run on a SPARC machine.
547    
548         File  names  for  saving and reloading can be absolute or relative, but         File names for saving and reloading can be absolute  or  relative,  but
549         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
550         a tilde (~) is not available.         a tilde (~) is not available.
551    
552         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-
553         ing and experimentation. It is not intended for production use  because         ing  and experimentation. It is not intended for production use because
554         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
555         no facility for supplying  custom  character  tables  for  use  with  a         no  facility  for  supplying  custom  character  tables  for use with a
556         reloaded  pattern.  If  the  original  pattern was compiled with custom         reloaded pattern. If the original  pattern  was  compiled  with  custom
557         tables, an attempt to match a subject string using a  reloaded  pattern         tables,  an  attempt to match a subject string using a reloaded pattern
558         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
559         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.
560    
561    
# Line 525  AUTHOR Line 565  AUTHOR
565         University Computing Service,         University Computing Service,
566         Cambridge CB2 3QG, England.         Cambridge CB2 3QG, England.
567    
568  Last updated: 28 February 2005  Last updated: 29 June 2006
569  Copyright (c) 1997-2005 University of Cambridge.  Copyright (c) 1997-2006 University of Cambridge.

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