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1 PCRETEST(1) PCRETEST(1)
2
3
4 NAME
5 pcretest - a program for testing Perl-compatible regular expressions.
6
7
8 SYNOPSIS
9
10 pcretest [options] [source] [destination]
11
12 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
14 expressions. This document describes the features of the test program;
15 for details of the regular expressions themselves, see the pcrepattern
16 documentation. For details of the PCRE library function calls and their
17 options, see the pcreapi documentation.
18
19
20 OPTIONS
21
22 -b Behave as if each regex has the /B (show bytecode) modifier;
23 the internal form is output after compilation.
24
25 -C Output the version number of the PCRE library, and all avail-
26 able information about the optional features that are
27 included, and then exit.
28
29 -d Behave as if each regex has the /D (debug) modifier; the
30 internal form and information about the compiled pattern is
31 output after compilation; -d is equivalent to -b -i.
32
33 -dfa Behave as if each data line contains the \D escape sequence;
34 this causes the alternative matching function,
35 pcre_dfa_exec(), to be used instead of the standard
36 pcre_exec() function (more detail is given below).
37
38 -help Output a brief summary these options and then exit.
39
40 -i Behave as if each regex has the /I modifier; information
41 about the compiled pattern is given after compilation.
42
43 -M Behave as if each data line contains the \M escape sequence;
44 this causes PCRE to discover the minimum MATCH_LIMIT and
45 MATCH_LIMIT_RECURSION settings by calling pcre_exec() repeat-
46 edly with different limits.
47
48 -m Output the size of each compiled pattern after it has been
49 compiled. This is equivalent to adding /M to each regular
50 expression. For compatibility with earlier versions of
51 pcretest, -s is a synonym for -m.
52
53 -o osize Set the number of elements in the output vector that is used
54 when calling pcre_exec() or pcre_dfa_exec() to be osize. The
55 default value is 45, which is enough for 14 capturing subex-
56 pressions for pcre_exec() or 22 different matches for
57 pcre_dfa_exec(). The vector size can be changed for individ-
58 ual matching calls by including \O in the data line (see
59 below).
60
61 -p Behave as if each regex has the /P modifier; the POSIX wrap-
62 per API is used to call PCRE. None of the other options has
63 any effect when -p is set.
64
65 -q Do not output the version number of pcretest at the start of
66 execution.
67
68 -S size On Unix-like systems, set the size of the runtime stack to
69 size megabytes.
70
71 -t Run each compile, study, and match many times with a timer,
72 and output resulting time per compile or match (in millisec-
73 onds). Do not set -m with -t, because you will then get the
74 size output a zillion times, and the timing will be dis-
75 torted. You can control the number of iterations that are
76 used for timing by following -t with a number (as a separate
77 item on the command line). For example, "-t 1000" would iter-
78 ate 1000 times. The default is to iterate 500000 times.
79
80 -tm This is like -t except that it times only the matching phase,
81 not the compile or study phases.
82
83
84 DESCRIPTION
85
86 If pcretest is given two filename arguments, it reads from the first
87 and writes to the second. If it is given only one filename argument, it
88 reads from that file and writes to stdout. Otherwise, it reads from
89 stdin and writes to stdout, and prompts for each line of input, using
90 "re>" to prompt for regular expressions, and "data>" to prompt for data
91 lines.
92
93 When pcretest is built, a configuration option can specify that it
94 should be linked with the libreadline library. When this is done, if
95 the input is from a terminal, it is read using the readline() function.
96 This provides line-editing and history facilities. The output from the
97 -help option states whether or not readline() will be used.
98
99 The program handles any number of sets of input on a single input file.
100 Each set starts with a regular expression, and continues with any num-
101 ber of data lines to be matched against the pattern.
102
103 Each data line is matched separately and independently. If you want to
104 do multi-line matches, you have to use the \n escape sequence (or \r or
105 \r\n, etc., depending on the newline setting) in a single line of input
106 to encode the newline sequences. There is no limit on the length of
107 data lines; the input buffer is automatically extended if it is too
108 small.
109
110 An empty line signals the end of the data lines, at which point a new
111 regular expression is read. The regular expressions are given enclosed
112 in any non-alphanumeric delimiters other than backslash, for example:
113
114 /(a|bc)x+yz/
115
116 White space before the initial delimiter is ignored. A regular expres-
117 sion may be continued over several input lines, in which case the new-
118 line characters are included within it. It is possible to include the
119 delimiter within the pattern by escaping it, for example
120
121 /abc\/def/
122
123 If you do so, the escape and the delimiter form part of the pattern,
124 but since delimiters are always non-alphanumeric, this does not affect
125 its interpretation. If the terminating delimiter is immediately fol-
126 lowed by a backslash, for example,
127
128 /abc/\
129
130 then a backslash is added to the end of the pattern. This is done to
131 provide a way of testing the error condition that arises if a pattern
132 finishes with a backslash, because
133
134 /abc\/
135
136 is interpreted as the first line of a pattern that starts with "abc/",
137 causing pcretest to read the next line as a continuation of the regular
138 expression.
139
140
141 PATTERN MODIFIERS
142
143 A pattern may be followed by any number of modifiers, which are mostly
144 single characters. Following Perl usage, these are referred to below
145 as, for example, "the /i modifier", even though the delimiter of the
146 pattern need not always be a slash, and no slash is used when writing
147 modifiers. Whitespace may appear between the final pattern delimiter
148 and the first modifier, and between the modifiers themselves.
149
150 The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,
151 PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when pcre_com-
152 pile() is called. These four modifier letters have the same effect as
153 they do in Perl. For example:
154
155 /caseless/i
156
157 The following table shows additional modifiers for setting PCRE com-
158 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
163 /C PCRE_AUTO_CALLOUT
164 /E PCRE_DOLLAR_ENDONLY
165 /f PCRE_FIRSTLINE
166 /J PCRE_DUPNAMES
167 /N PCRE_NO_AUTO_CAPTURE
168 /U PCRE_UNGREEDY
169 /W PCRE_UCP
170 /X PCRE_EXTRA
171 /<JS> PCRE_JAVASCRIPT_COMPAT
172 /<cr> PCRE_NEWLINE_CR
173 /<lf> PCRE_NEWLINE_LF
174 /<crlf> PCRE_NEWLINE_CRLF
175 /<anycrlf> PCRE_NEWLINE_ANYCRLF
176 /<any> PCRE_NEWLINE_ANY
177 /<bsr_anycrlf> PCRE_BSR_ANYCRLF
178 /<bsr_unicode> PCRE_BSR_UNICODE
179
180 The modifiers that are enclosed in angle brackets are literal strings
181 as shown, including the angle brackets, but the letters can be in
182 either case. This example sets multiline matching with CRLF as the line
183 ending sequence:
184
185 /^abc/m<crlf>
186
187 As well as turning on the PCRE_UTF8 option, the /8 modifier also causes
188 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
193
194 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
196 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
198 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
200 over a shortened substring. This makes a difference to the matching
201 process if the pattern begins with a lookbehind assertion (including \b
202 or \B).
203
204 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_ATSTART and
206 PCRE_ANCHORED flags set in order to search for another, non-empty,
207 match at the same point. If this second match fails, the start offset
208 is advanced by one character, and the normal match is retried. This
209 imitates the way Perl handles such cases when using the /g modifier or
210 the split() function.
211
212 Other modifiers
213
214 There are yet more modifiers for controlling the way pcretest operates.
215
216 The /+ modifier requests that as well as outputting the substring that
217 matched the entire pattern, pcretest should in addition output the
218 remainder of the subject string. This is useful for tests where the
219 subject contains multiple copies of the same substring.
220
221 The /B modifier is a debugging feature. It requests that pcretest out-
222 put a representation of the compiled byte code after compilation. Nor-
223 mally this information contains length and offset values; however, if
224 /Z is also present, this data is replaced by spaces. This is a special
225 feature for use in the automatic test scripts; it ensures that the same
226 output is generated for different internal link sizes.
227
228 The /D modifier is a PCRE debugging feature, and is equivalent to /BI,
229 that is, both the /B and the /I modifiers.
230
231 The /F modifier causes pcretest to flip the byte order of the fields in
232 the compiled pattern that contain 2-byte and 4-byte numbers. This
233 facility is for testing the feature in PCRE that allows it to execute
234 patterns that were compiled on a host with a different endianness. This
235 feature is not available when the POSIX interface to PCRE is being
236 used, that is, when the /P pattern modifier is specified. See also the
237 section about saving and reloading compiled patterns below.
238
239 The /I modifier requests that pcretest output information about the
240 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 /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.
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
288 rather than its native API. When /P is set, the following modifiers set
289 options for the regcomp() function:
290
291 /i REG_ICASE
292 /m REG_NEWLINE
293 /N REG_NOSUB
294 /s REG_DOTALL )
295 /U REG_UNGREEDY ) These options are not part of
296 /W REG_UCP ) the POSIX standard
297 /8 REG_UTF8 )
298
299 The /+ modifier works as described above. All other modifiers are
300 ignored.
301
302
303 DATA LINES
304
305 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
307 these are pretty esoteric features, intended for checking out some of
308 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
310 following escapes are recognized:
311
312 \a alarm (BEL, \x07)
313 \b backspace (\x08)
314 \e escape (\x27)
315 \f formfeed (\x0c)
316 \n newline (\x0a)
317 \qdd set the PCRE_MATCH_LIMIT limit to dd
318 (any number of digits)
319 \r carriage return (\x0d)
320 \t tab (\x09)
321 \v vertical tab (\x0b)
322 \nnn octal character (up to 3 octal digits)
323 \xhh hexadecimal character (up to 2 hex digits)
324 \x{hh...} hexadecimal character, any number of digits
325 in UTF-8 mode
326 \A pass the PCRE_ANCHORED option to pcre_exec()
327 or pcre_dfa_exec()
328 \B pass the PCRE_NOTBOL option to pcre_exec()
329 or pcre_dfa_exec()
330 \Cdd call pcre_copy_substring() for substring dd
331 after a successful match (number less than 32)
332 \Cname call pcre_copy_named_substring() for substring
333 "name" after a successful match (name termin-
334 ated by next non alphanumeric character)
335 \C+ show the current captured substrings at callout
336 time
337 \C- do not supply a callout function
338 \C!n return 1 instead of 0 when callout number n is
339 reached
340 \C!n!m return 1 instead of 0 when callout number n is
341 reached for the nth time
342 \C*n pass the number n (may be negative) as callout
343 data; this is used as the callout return value
344 \D use the pcre_dfa_exec() match function
345 \F only shortest match for pcre_dfa_exec()
346 \Gdd call pcre_get_substring() for substring dd
347 after a successful match (number less than 32)
348 \Gname call pcre_get_named_substring() for substring
349 "name" after a successful match (name termin-
350 ated by next non-alphanumeric character)
351 \L call pcre_get_substringlist() after a
352 successful match
353 \M discover the minimum MATCH_LIMIT and
354 MATCH_LIMIT_RECURSION settings
355 \N pass the PCRE_NOTEMPTY option to pcre_exec()
356 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
359 pcre_exec() to dd (any number of digits)
360 \P pass the PCRE_PARTIAL_SOFT option to pcre_exec()
361 or pcre_dfa_exec(); if used twice, pass the
362 PCRE_PARTIAL_HARD option
363 \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd
364 (any number of digits)
365 \R pass the PCRE_DFA_RESTART option to pcre_dfa_exec()
366 \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()
370 or pcre_dfa_exec()
371 \? pass the PCRE_NO_UTF8_CHECK option to
372 pcre_exec() or pcre_dfa_exec()
373 \>dd start the match at offset dd (any number of digits);
374 this sets the startoffset argument for pcre_exec()
375 or pcre_dfa_exec()
376 \<cr> pass the PCRE_NEWLINE_CR option to pcre_exec()
377 or pcre_dfa_exec()
378 \<lf> pass the PCRE_NEWLINE_LF option to pcre_exec()
379 or pcre_dfa_exec()
380 \<crlf> pass the PCRE_NEWLINE_CRLF option to pcre_exec()
381 or pcre_dfa_exec()
382 \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to pcre_exec()
383 or pcre_dfa_exec()
384 \<any> pass the PCRE_NEWLINE_ANY option to pcre_exec()
385 or pcre_dfa_exec()
386
387 The escapes that specify line ending sequences are literal strings,
388 exactly as shown. No more than one newline setting should be present in
389 any data line.
390
391 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
393 way of passing an empty line as data, since a real empty line termi-
394 nates the data input.
395
396 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
398 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-
400 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
402 is quite small, but for patterns with very large numbers of matching
403 possibilities, it can become large very quickly with increasing length
404 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)
406 memory is needed to complete the match attempt.
407
408 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
410 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-
413 per API to be used, the only option-setting sequences that have any
414 effect are \B, \N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and
415 REG_NOTEOL, respectively, to be passed to regexec().
416
417 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.
419 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
421 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,
423 or indeed valid UTF-8 characters according to the later rules in RFC
424 3629.
425
426
427 THE ALTERNATIVE MATCHING FUNCTION
428
429 By default, pcretest uses the standard PCRE matching function,
430 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
432 different way, and has some restrictions. The differences between the
433 two functions are described in the pcrematching documentation.
434
435 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.
437 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
439 first match is found. This is always the shortest possible match.
440
441
442 DEFAULT OUTPUT FROM PCRETEST
443
444 This section describes the output when the normal matching function,
445 pcre_exec(), is being used.
446
447 When a match succeeds, pcretest outputs the list of captured substrings
448 that pcre_exec() returns, starting with number 0 for the string that
449 matched the whole pattern. Otherwise, it outputs "No match" when the
450 return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the par-
451 tially matching substring when pcre_exec() returns PCRE_ERROR_PARTIAL.
452 For any other returns, it outputs the PCRE negative error number. Here
453 is an example of an interactive pcretest run.
454
455 $ pcretest
456 PCRE version 7.0 30-Nov-2006
457
458 re> /^abc(\d+)/
459 data> abc123
460 0: abc123
461 1: 123
462 data> xyz
463 No match
464
465 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.
467 In the following example, there are two capturing substrings, but when
468 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
470 second data line.
471
472 re> /(a)|(b)/
473 data> a
474 0: a
475 1: a
476 data> b
477 0: b
478 1: <unset>
479 2: b
480
481 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
483 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-
485 lowed by the the rest of the subject string, identified by "0+" like
486 this:
487
488 re> /cat/+
489 data> cataract
490 0: cat
491 0+ aract
492
493 If the pattern has the /g or /G modifier, the results of successive
494 matching attempts are output in sequence, like this:
495
496 re> /\Bi(\w\w)/g
497 data> Mississippi
498 0: iss
499 1: ss
500 0: iss
501 1: ss
502 0: ipp
503 1: pp
504
505 "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
508 is successfully matched, the substrings extracted by the convenience
509 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
511 (that is, the return from the extraction function) is given in paren-
512 theses after each string for \C and \G.
513
514 Note that whereas patterns can be continued over several lines (a plain
515 ">" 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,
517 etc., depending on the newline sequence setting).
518
519
520 OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
521
522 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
524 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:
526
527 re> /(tang|tangerine|tan)/
528 data> yellow tangerine\D
529 0: tangerine
530 1: tang
531 2: tan
532
533 (Using the normal matching function on this data finds only "tang".)
534 The longest matching string is always given first (and numbered zero).
535 After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-
536 lowed by the partially matching substring.
537
538 If /g is present on the pattern, the search for further matches resumes
539 at the end of the longest match. For example:
540
541 re> /(tang|tangerine|tan)/g
542 data> yellow tangerine and tangy sultana\D
543 0: tangerine
544 1: tang
545 2: tan
546 0: tang
547 1: tan
548 0: tan
549
550 Since the matching function does not support substring capture, the
551 escape sequences that are concerned with captured substrings are not
552 relevant.
553
554
555 RESTARTING AFTER A PARTIAL MATCH
556
557 When the alternative matching function has given the PCRE_ERROR_PARTIAL
558 return, indicating that the subject partially matched the pattern, you
559 can restart the match with additional subject data by means of the \R
560 escape sequence. For example:
561
562 re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
563 data> 23ja\P\D
564 Partial match: 23ja
565 data> n05\R\D
566 0: n05
567
568 For further information about partial matching, see the pcrepartial
569 documentation.
570
571
572 CALLOUTS
573
574 If the pattern contains any callout requests, pcretest's callout func-
575 tion is called during matching. This works with both matching func-
576 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
578 next pattern item to be tested. For example, the output
579
580 --->pqrabcdef
581 0 ^ ^ \d
582
583 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
585 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
587 are the same.
588
589 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
591 the callout number, the offset in the pattern, preceded by a plus, is
592 output. For example:
593
594 re> /\d?[A-E]\*/C
595 data> E*
596 --->E*
597 +0 ^ \d?
598 +3 ^ [A-E]
599 +8 ^^ \*
600 +10 ^ ^
601 0: E*
602
603 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)
605 to change this.
606
607 Inserting callouts can be helpful when using pcretest to check compli-
608 cated regular expressions. For further information about callouts, see
609 the pcrecallout documentation.
610
611
612 NON-PRINTING CHARACTERS
613
614 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
616 are are therefore shown as hex escapes.
617
618 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
620 set for the pattern (using the /L modifier). In this case, the
621 isprint() function to distinguish printing and non-printing characters.
622
623
624 SAVING AND RELOADING COMPILED PATTERNS
625
626 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-
628 ifier is specified.
629
630 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
632 file name. For example:
633
634 /pattern/im >/some/file
635
636 See the pcreprecompile documentation for a discussion about saving and
637 re-using compiled patterns.
638
639 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
641 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
643 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
645 compiled pattern. If there is additional study data, this follows imme-
646 diately after the compiled pattern. After writing the file, pcretest
647 expects to read a new pattern.
648
649 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 <
651 character, as otherwise pcretest will interpret the line as a pattern
652 delimited by < characters. For example:
653
654 re> </some/file
655 Compiled regex loaded from /some/file
656 No study data
657
658 When the pattern has been loaded, pcretest proceeds to read data lines
659 in the usual way.
660
661 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
663 which the pattern was compiled. For example, you can compile on an i86
664 machine and run on a SPARC machine.
665
666 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
668 a tilde (~) is not available.
669
670 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
672 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
674 reloaded pattern. If the original pattern was compiled with custom
675 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
677 a file that is not in the correct format, the result is undefined.
678
679
680 SEE ALSO
681
682 pcre(3), pcreapi(3), pcrecallout(3), pcrematching(3), pcrepartial(d),
683 pcrepattern(3), pcreprecompile(3).
684
685
686 AUTHOR
687
688 Philip Hazel
689 University Computing Service
690 Cambridge CB2 3QH, England.
691
692
693 REVISION
694
695 Last updated: 14 June 2010
696 Copyright (c) 1997-2010 University of Cambridge.

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