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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 options
158 that do not correspond to anything in Perl:
159
160 /A PCRE_ANCHORED
161 /C PCRE_AUTO_CALLOUT
162 /E PCRE_DOLLAR_ENDONLY
163 /f PCRE_FIRSTLINE
164 /J PCRE_DUPNAMES
165 /N PCRE_NO_AUTO_CAPTURE
166 /U PCRE_UNGREEDY
167 /X PCRE_EXTRA
168 /<JS> PCRE_JAVASCRIPT_COMPAT
169 /<cr> PCRE_NEWLINE_CR
170 /<lf> PCRE_NEWLINE_LF
171 /<crlf> PCRE_NEWLINE_CRLF
172 /<anycrlf> PCRE_NEWLINE_ANYCRLF
173 /<any> PCRE_NEWLINE_ANY
174 /<bsr_anycrlf> PCRE_BSR_ANYCRLF
175 /<bsr_unicode> PCRE_BSR_UNICODE
176
177 Those specifying line ending sequences are literal strings as shown,
178 but the letters can be in either case. This example sets multiline
179 matching with CRLF as the line ending sequence:
180
181 /^abc/m<crlf>
182
183 Details of the meanings of these PCRE options are given in the pcreapi
184 documentation.
185
186 Finding all matches in a string
187
188 Searching for all possible matches within each subject string can be
189 requested by the /g or /G modifier. After finding a match, PCRE is
190 called again to search the remainder of the subject string. The differ-
191 ence between /g and /G is that the former uses the startoffset argument
192 to pcre_exec() to start searching at a new point within the entire
193 string (which is in effect what Perl does), whereas the latter passes
194 over a shortened substring. This makes a difference to the matching
195 process if the pattern begins with a lookbehind assertion (including \b
196 or \B).
197
198 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_ATSTART and
200 PCRE_ANCHORED flags set in order to search for another, non-empty,
201 match at the same point. If this second match fails, the start offset
202 is advanced by one character, and the normal match is retried. This
203 imitates the way Perl handles such cases when using the /g modifier or
204 the split() function.
205
206 Other modifiers
207
208 There are yet more modifiers for controlling the way pcretest operates.
209
210 The /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option
211 set. This turns on support for UTF-8 character handling in PCRE, pro-
212 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.
224
225 The /B modifier is a debugging feature. It requests that pcretest out-
226 put a representation of the compiled byte code after compilation. Nor-
227 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
229 feature for use in the automatic test scripts; it ensures that the same
230 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
260 example,
261
262 /pattern/Lfr_FR
263
264 For this reason, it must be the last modifier. The given locale is set,
265 pcre_maketables() is called to build a set of character tables for the
266 locale, and this is then passed to pcre_compile() when compiling the
267 regular expression. Without an /L modifier, NULL is passed as the
268 tables pointer; that is, /L applies only to the expression on which it
269 appears.
270
271 The /M modifier causes the size of memory block used to hold the com-
272 piled pattern to be output.
273
274 The /P modifier causes pcretest to call PCRE via the POSIX wrapper API
275 rather than its native API. When this is done, all other modifiers
276 except /i, /m, and /+ are ignored. REG_ICASE is set if /i is present,
277 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.
279
280 The /S modifier causes pcre_study() to be called after the expression
281 has been compiled, and the results used when the expression is matched.
282
283
284 DATA LINES
285
286 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
288 these are pretty esoteric features, intended for checking out some of
289 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
291 following escapes are recognized:
292
293 \a alarm (BEL, \x07)
294 \b backspace (\x08)
295 \e escape (\x27)
296 \f formfeed (\x0c)
297 \n newline (\x0a)
298 \qdd set the PCRE_MATCH_LIMIT limit to dd
299 (any number of digits)
300 \r carriage return (\x0d)
301 \t tab (\x09)
302 \v vertical tab (\x0b)
303 \nnn octal character (up to 3 octal digits)
304 \xhh hexadecimal character (up to 2 hex digits)
305 \x{hh...} hexadecimal character, any number of digits
306 in UTF-8 mode
307 \A pass the PCRE_ANCHORED option to pcre_exec()
308 or pcre_dfa_exec()
309 \B pass the PCRE_NOTBOL option to pcre_exec()
310 or pcre_dfa_exec()
311 \Cdd call pcre_copy_substring() for substring dd
312 after a successful match (number less than 32)
313 \Cname call pcre_copy_named_substring() for substring
314 "name" after a successful match (name termin-
315 ated by next non alphanumeric character)
316 \C+ show the current captured substrings at callout
317 time
318 \C- do not supply a callout function
319 \C!n return 1 instead of 0 when callout number n is
320 reached
321 \C!n!m return 1 instead of 0 when callout number n is
322 reached for the nth time
323 \C*n pass the number n (may be negative) as callout
324 data; this is used as the callout return value
325 \D use the pcre_dfa_exec() match function
326 \F only shortest match for pcre_dfa_exec()
327 \Gdd call pcre_get_substring() for substring dd
328 after a successful match (number less than 32)
329 \Gname call pcre_get_named_substring() for substring
330 "name" after a successful match (name termin-
331 ated by next non-alphanumeric character)
332 \L call pcre_get_substringlist() after a
333 successful match
334 \M discover the minimum MATCH_LIMIT and
335 MATCH_LIMIT_RECURSION settings
336 \N pass the PCRE_NOTEMPTY option to pcre_exec()
337 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
340 pcre_exec() to dd (any number of digits)
341 \P pass the PCRE_PARTIAL_SOFT option to pcre_exec()
342 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
345 (any number of digits)
346 \R pass the PCRE_DFA_RESTART option to pcre_dfa_exec()
347 \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()
351 or pcre_dfa_exec()
352 \? pass the PCRE_NO_UTF8_CHECK option to
353 pcre_exec() or pcre_dfa_exec()
354 \>dd start the match at offset dd (any number of digits);
355 this sets the startoffset argument for pcre_exec()
356 or pcre_dfa_exec()
357 \<cr> pass the PCRE_NEWLINE_CR option to pcre_exec()
358 or pcre_dfa_exec()
359 \<lf> pass the PCRE_NEWLINE_LF option to pcre_exec()
360 or pcre_dfa_exec()
361 \<crlf> pass the PCRE_NEWLINE_CRLF option to pcre_exec()
362 or pcre_dfa_exec()
363 \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to pcre_exec()
364 or pcre_dfa_exec()
365 \<any> pass the PCRE_NEWLINE_ANY option to pcre_exec()
366 or pcre_dfa_exec()
367
368 The escapes that specify line ending sequences are literal strings,
369 exactly as shown. No more than one newline setting should be present in
370 any data line.
371
372 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
374 way of passing an empty line as data, since a real empty line termi-
375 nates the data input.
376
377 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
379 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-
381 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
383 is quite small, but for patterns with very large numbers of matching
384 possibilities, it can become large very quickly with increasing length
385 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)
387 memory is needed to complete the match attempt.
388
389 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
391 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-
394 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,
396 to be passed to regexec().
397
398 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.
400 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
402 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,
404 or indeed valid UTF-8 characters according to the later rules in RFC
405 3629.
406
407
408 THE ALTERNATIVE MATCHING FUNCTION
409
410 By default, pcretest uses the standard PCRE matching function,
411 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
413 different way, and has some restrictions. The differences between the
414 two functions are described in the pcrematching documentation.
415
416 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.
418 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
420 first match is found. This is always the shortest possible match.
421
422
423 DEFAULT OUTPUT FROM PCRETEST
424
425 This section describes the output when the normal matching function,
426 pcre_exec(), is being used.
427
428 When a match succeeds, pcretest outputs the list of captured substrings
429 that pcre_exec() returns, starting with number 0 for the string that
430 matched the whole pattern. Otherwise, it outputs "No match" when the
431 return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the par-
432 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.
435
436 $ pcretest
437 PCRE version 7.0 30-Nov-2006
438
439 re> /^abc(\d+)/
440 data> abc123
441 0: abc123
442 1: 123
443 data> xyz
444 No match
445
446 Note that unset capturing substrings that are not followed by one that
447 is set are not returned by pcre_exec(), and are not shown by pcretest.
448 In the following example, there are two capturing substrings, but when
449 the first data line is matched, the second, unset substring is not
450 shown. An "internal" unset substring is shown as "<unset>", as for the
451 second data line.
452
453 re> /(a)|(b)/
454 data> a
455 0: a
456 1: a
457 data> b
458 0: b
459 1: <unset>
460 2: b
461
462 If the strings contain any non-printing characters, they are output as
463 \0x escapes, or as \x{...} escapes if the /8 modifier was present on
464 the pattern. See below for the definition of non-printing characters.
465 If the pattern has the /+ modifier, the output for substring 0 is fol-
466 lowed by the the rest of the subject string, identified by "0+" like
467 this:
468
469 re> /cat/+
470 data> cataract
471 0: cat
472 0+ aract
473
474 If the pattern has the /g or /G modifier, the results of successive
475 matching attempts are output in sequence, like this:
476
477 re> /\Bi(\w\w)/g
478 data> Mississippi
479 0: iss
480 1: ss
481 0: iss
482 1: ss
483 0: ipp
484 1: pp
485
486 "No match" is output only if the first match attempt fails.
487
488 If any of the sequences \C, \G, or \L are present in a data line that
489 is successfully matched, the substrings extracted by the convenience
490 functions are output with C, G, or L after the string number instead of
491 a colon. This is in addition to the normal full list. The string length
492 (that is, the return from the extraction function) is given in paren-
493 theses after each string for \C and \G.
494
495 Note that whereas patterns can be continued over several lines (a plain
496 ">" prompt is used for continuations), data lines may not. However new-
497 lines can be included in data by means of the \n escape (or \r, \r\n,
498 etc., depending on the newline sequence setting).
499
500
501 OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
502
503 When the alternative matching function, pcre_dfa_exec(), is used (by
504 means of the \D escape sequence or the -dfa command line option), the
505 output consists of a list of all the matches that start at the first
506 point in the subject where there is at least one match. For example:
507
508 re> /(tang|tangerine|tan)/
509 data> yellow tangerine\D
510 0: tangerine
511 1: tang
512 2: tan
513
514 (Using the normal matching function on this data finds only "tang".)
515 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
520 at the end of the longest match. For example:
521
522 re> /(tang|tangerine|tan)/g
523 data> yellow tangerine and tangy sultana\D
524 0: tangerine
525 1: tang
526 2: tan
527 0: tang
528 1: tan
529 0: tan
530
531 Since the matching function does not support substring capture, the
532 escape sequences that are concerned with captured substrings are not
533 relevant.
534
535
536 RESTARTING AFTER A PARTIAL MATCH
537
538 When the alternative matching function has given the PCRE_ERROR_PARTIAL
539 return, indicating that the subject partially matched the pattern, you
540 can restart the match with additional subject data by means of the \R
541 escape sequence. For example:
542
543 re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
544 data> 23ja\P\D
545 Partial match: 23ja
546 data> n05\R\D
547 0: n05
548
549 For further information about partial matching, see the pcrepartial
550 documentation.
551
552
553 CALLOUTS
554
555 If the pattern contains any callout requests, pcretest's callout func-
556 tion is called during matching. This works with both matching func-
557 tions. By default, the called function displays the callout number, the
558 start and current positions in the text at the callout time, and the
559 next pattern item to be tested. For example, the output
560
561 --->pqrabcdef
562 0 ^ ^ \d
563
564 indicates that callout number 0 occurred for a match attempt starting
565 at the fourth character of the subject string, when the pointer was at
566 the seventh character of the data, and when the next pattern item was
567 \d. Just one circumflex is output if the start and current positions
568 are the same.
569
570 Callouts numbered 255 are assumed to be automatic callouts, inserted as
571 a result of the /C pattern modifier. In this case, instead of showing
572 the callout number, the offset in the pattern, preceded by a plus, is
573 output. For example:
574
575 re> /\d?[A-E]\*/C
576 data> E*
577 --->E*
578 +0 ^ \d?
579 +3 ^ [A-E]
580 +8 ^^ \*
581 +10 ^ ^
582 0: E*
583
584 The callout function in pcretest returns zero (carry on matching) by
585 default, but you can use a \C item in a data line (as described above)
586 to change this.
587
588 Inserting callouts can be helpful when using pcretest to check compli-
589 cated regular expressions. For further information about callouts, see
590 the pcrecallout documentation.
591
592
593 NON-PRINTING CHARACTERS
594
595 When pcretest is outputting text in the compiled version of a pattern,
596 bytes other than 32-126 are always treated as non-printing characters
597 are are therefore shown as hex escapes.
598
599 When pcretest is outputting text that is a matched part of a subject
600 string, it behaves in the same way, unless a different locale has been
601 set for the pattern (using the /L modifier). In this case, the
602 isprint() function to distinguish printing and non-printing characters.
603
604
605 SAVING AND RELOADING COMPILED PATTERNS
606
607 The facilities described in this section are not available when the
608 POSIX inteface to PCRE is being used, that is, when the /P pattern mod-
609 ifier is specified.
610
611 When the POSIX interface is not in use, you can cause pcretest to write
612 a compiled pattern to a file, by following the modifiers with > and a
613 file name. For example:
614
615 /pattern/im >/some/file
616
617 See the pcreprecompile documentation for a discussion about saving and
618 re-using compiled patterns.
619
620 The data that is written is binary. The first eight bytes are the
621 length of the compiled pattern data followed by the length of the
622 optional study data, each written as four bytes in big-endian order
623 (most significant byte first). If there is no study data (either the
624 pattern was not studied, or studying did not return any data), the sec-
625 ond length is zero. The lengths are followed by an exact copy of the
626 compiled pattern. If there is additional study data, this follows imme-
627 diately after the compiled pattern. After writing the file, pcretest
628 expects to read a new pattern.
629
630 A saved pattern can be reloaded into pcretest by specifing < and a file
631 name instead of a pattern. The name of the file must not contain a <
632 character, as otherwise pcretest will interpret the line as a pattern
633 delimited by < characters. For example:
634
635 re> </some/file
636 Compiled regex loaded from /some/file
637 No study data
638
639 When the pattern has been loaded, pcretest proceeds to read data lines
640 in the usual way.
641
642 You can copy a file written by pcretest to a different host and reload
643 it there, even if the new host has opposite endianness to the one on
644 which the pattern was compiled. For example, you can compile on an i86
645 machine and run on a SPARC machine.
646
647 File names for saving and reloading can be absolute or relative, but
648 note that the shell facility of expanding a file name that starts with
649 a tilde (~) is not available.
650
651 The ability to save and reload files in pcretest is intended for test-
652 ing and experimentation. It is not intended for production use because
653 only a single pattern can be written to a file. Furthermore, there is
654 no facility for supplying custom character tables for use with a
655 reloaded pattern. If the original pattern was compiled with custom
656 tables, an attempt to match a subject string using a reloaded pattern
657 is likely to cause pcretest to crash. Finally, if you attempt to load
658 a file that is not in the correct format, the result is undefined.
659
660
661 SEE ALSO
662
663 pcre(3), pcreapi(3), pcrecallout(3), pcrematching(3), pcrepartial(d),
664 pcrepattern(3), pcreprecompile(3).
665
666
667 AUTHOR
668
669 Philip Hazel
670 University Computing Service
671 Cambridge CB2 3QH, England.
672
673
674 REVISION
675
676 Last updated: 26 March 2010
677 Copyright (c) 1997-2010 University of Cambridge.

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