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1 <html>
2 <head>
3 <title>pcretest specification</title>
4 </head>
5 <body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB">
6 <h1>pcretest man page</h1>
7 <p>
8 Return to the <a href="index.html">PCRE index page</a>.
9 </p>
10 <p>
11 This page is part of the PCRE HTML documentation. It was generated automatically
12 from the original man page. If there is any nonsense in it, please consult the
13 man page, in case the conversion went wrong.
14 <br>
15 <ul>
16 <li><a name="TOC1" href="#SEC1">SYNOPSIS</a>
17 <li><a name="TOC2" href="#SEC2">OPTIONS</a>
18 <li><a name="TOC3" href="#SEC3">DESCRIPTION</a>
19 <li><a name="TOC4" href="#SEC4">PATTERN MODIFIERS</a>
20 <li><a name="TOC5" href="#SEC5">DATA LINES</a>
21 <li><a name="TOC6" href="#SEC6">THE ALTERNATIVE MATCHING FUNCTION</a>
22 <li><a name="TOC7" href="#SEC7">DEFAULT OUTPUT FROM PCRETEST</a>
23 <li><a name="TOC8" href="#SEC8">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a>
24 <li><a name="TOC9" href="#SEC9">RESTARTING AFTER A PARTIAL MATCH</a>
25 <li><a name="TOC10" href="#SEC10">CALLOUTS</a>
26 <li><a name="TOC11" href="#SEC11">SAVING AND RELOADING COMPILED PATTERNS</a>
27 <li><a name="TOC12" href="#SEC12">AUTHOR</a>
28 </ul>
29 <br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br>
30 <P>
31 <b>pcretest [-C] [-d] [-dfa] [-i] [-m] [-o osize] [-p] [-t] [source]</b>
32 <b>[destination]</b>
33 </P>
34 <P>
35 <b>pcretest</b> was written as a test program for the PCRE regular expression
36 library itself, but it can also be used for experimenting with regular
37 expressions. This document describes the features of the test program; for
38 details of the regular expressions themselves, see the
39 <a href="pcrepattern.html"><b>pcrepattern</b></a>
40 documentation. For details of the PCRE library function calls and their
41 options, see the
42 <a href="pcreapi.html"><b>pcreapi</b></a>
43 documentation.
44 </P>
45 <br><a name="SEC2" href="#TOC1">OPTIONS</a><br>
46 <P>
47 <b>-C</b>
48 Output the version number of the PCRE library, and all available information
49 about the optional features that are included, and then exit.
50 </P>
51 <P>
52 <b>-d</b>
53 Behave as if each regex has the <b>/D</b> (debug) modifier; the internal
54 form is output after compilation.
55 </P>
56 <P>
57 <b>-dfa</b>
58 Behave as if each data line contains the \D escape sequence; this causes the
59 alternative matching function, <b>pcre_dfa_exec()</b>, to be used instead of the
60 standard <b>pcre_exec()</b> function (more detail is given below).
61 </P>
62 <P>
63 <b>-i</b>
64 Behave as if each regex has the <b>/I</b> modifier; information about the
65 compiled pattern is given after compilation.
66 </P>
67 <P>
68 <b>-m</b>
69 Output the size of each compiled pattern after it has been compiled. This is
70 equivalent to adding <b>/M</b> to each regular expression. For compatibility
71 with earlier versions of pcretest, <b>-s</b> is a synonym for <b>-m</b>.
72 </P>
73 <P>
74 <b>-o</b> <i>osize</i>
75 Set the number of elements in the output vector that is used when calling
76 <b>pcre_exec()</b> to be <i>osize</i>. The default value is 45, which is enough
77 for 14 capturing subexpressions. The vector size can be changed for individual
78 matching calls by including \O in the data line (see below).
79 </P>
80 <P>
81 <b>-p</b>
82 Behave as if each regex has the <b>/P</b> modifier; the POSIX wrapper API is
83 used to call PCRE. None of the other options has any effect when <b>-p</b> is
84 set.
85 </P>
86 <P>
87 \fP-q\fP
88 Do not output the version number of <b>pcretest</b> at the start of execution.
89 </P>
90 <P>
91 <b>-t</b>
92 Run each compile, study, and match many times with a timer, and output
93 resulting time per compile or match (in milliseconds). Do not set <b>-m</b> with
94 <b>-t</b>, because you will then get the size output a zillion times, and the
95 timing will be distorted.
96 </P>
97 <br><a name="SEC3" href="#TOC1">DESCRIPTION</a><br>
98 <P>
99 If <b>pcretest</b> is given two filename arguments, it reads from the first and
100 writes to the second. If it is given only one filename argument, it reads from
101 that file and writes to stdout. Otherwise, it reads from stdin and writes to
102 stdout, and prompts for each line of input, using "re&#62;" to prompt for regular
103 expressions, and "data&#62;" to prompt for data lines.
104 </P>
105 <P>
106 The program handles any number of sets of input on a single input file. Each
107 set starts with a regular expression, and continues with any number of data
108 lines to be matched against the pattern.
109 </P>
110 <P>
111 Each data line is matched separately and independently. If you want to do
112 multiple-line matches, you have to use the \n escape sequence in a single line
113 of input to encode the newline characters. The maximum length of data line is
114 30,000 characters.
115 </P>
116 <P>
117 An empty line signals the end of the data lines, at which point a new regular
118 expression is read. The regular expressions are given enclosed in any
119 non-alphanumeric delimiters other than backslash, for example
120 <pre>
121 /(a|bc)x+yz/
122 </pre>
123 White space before the initial delimiter is ignored. A regular expression may
124 be continued over several input lines, in which case the newline characters are
125 included within it. It is possible to include the delimiter within the pattern
126 by escaping it, for example
127 <pre>
128 /abc\/def/
129 </pre>
130 If you do so, the escape and the delimiter form part of the pattern, but since
131 delimiters are always non-alphanumeric, this does not affect its interpretation.
132 If the terminating delimiter is immediately followed by a backslash, for
133 example,
134 <pre>
135 /abc/\
136 </pre>
137 then a backslash is added to the end of the pattern. This is done to provide a
138 way of testing the error condition that arises if a pattern finishes with a
139 backslash, because
140 <pre>
141 /abc\/
142 </pre>
143 is interpreted as the first line of a pattern that starts with "abc/", causing
144 pcretest to read the next line as a continuation of the regular expression.
145 </P>
146 <br><a name="SEC4" href="#TOC1">PATTERN MODIFIERS</a><br>
147 <P>
148 A pattern may be followed by any number of modifiers, which are mostly single
149 characters. Following Perl usage, these are referred to below as, for example,
150 "the <b>/i</b> modifier", even though the delimiter of the pattern need not
151 always be a slash, and no slash is used when writing modifiers. Whitespace may
152 appear between the final pattern delimiter and the first modifier, and between
153 the modifiers themselves.
154 </P>
155 <P>
156 The <b>/i</b>, <b>/m</b>, <b>/s</b>, and <b>/x</b> modifiers set the PCRE_CASELESS,
157 PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
158 <b>pcre_compile()</b> is called. These four modifier letters have the same
159 effect as they do in Perl. For example:
160 <pre>
161 /caseless/i
162 </pre>
163 The following table shows additional modifiers for setting PCRE options that do
164 not correspond to anything in Perl:
165 <pre>
166 <b>/A</b> PCRE_ANCHORED
167 <b>/C</b> PCRE_AUTO_CALLOUT
168 <b>/E</b> PCRE_DOLLAR_ENDONLY
169 <b>/f</b> PCRE_FIRSTLINE
170 <b>/N</b> PCRE_NO_AUTO_CAPTURE
171 <b>/U</b> PCRE_UNGREEDY
172 <b>/X</b> PCRE_EXTRA
173 </pre>
174 Searching for all possible matches within each subject string can be requested
175 by the <b>/g</b> or <b>/G</b> modifier. After finding a match, PCRE is called
176 again to search the remainder of the subject string. The difference between
177 <b>/g</b> and <b>/G</b> is that the former uses the <i>startoffset</i> argument to
178 <b>pcre_exec()</b> to start searching at a new point within the entire string
179 (which is in effect what Perl does), whereas the latter passes over a shortened
180 substring. This makes a difference to the matching process if the pattern
181 begins with a lookbehind assertion (including \b or \B).
182 </P>
183 <P>
184 If any call to <b>pcre_exec()</b> in a <b>/g</b> or <b>/G</b> sequence matches an
185 empty string, the next call is done with the PCRE_NOTEMPTY and PCRE_ANCHORED
186 flags set in order to search for another, non-empty, match at the same point.
187 If this second match fails, the start offset is advanced by one, and the normal
188 match is retried. This imitates the way Perl handles such cases when using the
189 <b>/g</b> modifier or the <b>split()</b> function.
190 </P>
191 <P>
192 There are yet more modifiers for controlling the way <b>pcretest</b>
193 operates.
194 </P>
195 <P>
196 The <b>/+</b> modifier requests that as well as outputting the substring that
197 matched the entire pattern, pcretest should in addition output the remainder of
198 the subject string. This is useful for tests where the subject contains
199 multiple copies of the same substring.
200 </P>
201 <P>
202 The <b>/L</b> modifier must be followed directly by the name of a locale, for
203 example,
204 <pre>
205 /pattern/Lfr_FR
206 </pre>
207 For this reason, it must be the last modifier. The given locale is set,
208 <b>pcre_maketables()</b> is called to build a set of character tables for the
209 locale, and this is then passed to <b>pcre_compile()</b> when compiling the
210 regular expression. Without an <b>/L</b> modifier, NULL is passed as the tables
211 pointer; that is, <b>/L</b> applies only to the expression on which it appears.
212 </P>
213 <P>
214 The <b>/I</b> modifier requests that <b>pcretest</b> output information about the
215 compiled pattern (whether it is anchored, has a fixed first character, and
216 so on). It does this by calling <b>pcre_fullinfo()</b> after compiling a
217 pattern. If the pattern is studied, the results of that are also output.
218 </P>
219 <P>
220 The <b>/D</b> modifier is a PCRE debugging feature, which also assumes <b>/I</b>.
221 It causes the internal form of compiled regular expressions to be output after
222 compilation. If the pattern was studied, the information returned is also
223 output.
224 </P>
225 <P>
226 The <b>/F</b> modifier causes <b>pcretest</b> to flip the byte order of the
227 fields in the compiled pattern that contain 2-byte and 4-byte numbers. This
228 facility is for testing the feature in PCRE that allows it to execute patterns
229 that were compiled on a host with a different endianness. This feature is not
230 available when the POSIX interface to PCRE is being used, that is, when the
231 <b>/P</b> pattern modifier is specified. See also the section about saving and
232 reloading compiled patterns below.
233 </P>
234 <P>
235 The <b>/S</b> modifier causes <b>pcre_study()</b> to be called after the
236 expression has been compiled, and the results used when the expression is
237 matched.
238 </P>
239 <P>
240 The <b>/M</b> modifier causes the size of memory block used to hold the compiled
241 pattern to be output.
242 </P>
243 <P>
244 The <b>/P</b> modifier causes <b>pcretest</b> to call PCRE via the POSIX wrapper
245 API rather than its native API. When this is done, all other modifiers except
246 <b>/i</b>, <b>/m</b>, and <b>/+</b> are ignored. REG_ICASE is set if <b>/i</b> is
247 present, and REG_NEWLINE is set if <b>/m</b> is present. The wrapper functions
248 force PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set.
249 </P>
250 <P>
251 The <b>/8</b> modifier causes <b>pcretest</b> to call PCRE with the PCRE_UTF8
252 option set. This turns on support for UTF-8 character handling in PCRE,
253 provided that it was compiled with this support enabled. This modifier also
254 causes any non-printing characters in output strings to be printed using the
255 \x{hh...} notation if they are valid UTF-8 sequences.
256 </P>
257 <P>
258 If the <b>/?</b> modifier is used with <b>/8</b>, it causes <b>pcretest</b> to
259 call <b>pcre_compile()</b> with the PCRE_NO_UTF8_CHECK option, to suppress the
260 checking of the string for UTF-8 validity.
261 </P>
262 <br><a name="SEC5" href="#TOC1">DATA LINES</a><br>
263 <P>
264 Before each data line is passed to <b>pcre_exec()</b>, leading and trailing
265 whitespace is removed, and it is then scanned for \ escapes. Some of these are
266 pretty esoteric features, intended for checking out some of the more
267 complicated features of PCRE. If you are just testing "ordinary" regular
268 expressions, you probably don't need any of these. The following escapes are
269 recognized:
270 <pre>
271 \a alarm (= BEL)
272 \b backspace
273 \e escape
274 \f formfeed
275 \n newline
276 \r carriage return
277 \t tab
278 \v vertical tab
279 \nnn octal character (up to 3 octal digits)
280 \xhh hexadecimal character (up to 2 hex digits)
281 \x{hh...} hexadecimal character, any number of digits in UTF-8 mode
282 \A pass the PCRE_ANCHORED option to <b>pcre_exec()</b>
283 \B pass the PCRE_NOTBOL option to <b>pcre_exec()</b>
284 \Cdd call pcre_copy_substring() for substring dd after a successful match (number less than 32)
285 \Cname call pcre_copy_named_substring() for substring "name" after a successful match (name termin-
286 ated by next non alphanumeric character)
287 \C+ show the current captured substrings at callout time
288 \C- do not supply a callout function
289 \C!n return 1 instead of 0 when callout number n is reached
290 \C!n!m return 1 instead of 0 when callout number n is reached for the nth time
291 \C*n pass the number n (may be negative) as callout data; this is used as the callout return value
292 \D use the <b>pcre_dfa_exec()</b> match function
293 \F only shortest match for <b>pcre_dfa_exec()</b>
294 \Gdd call pcre_get_substring() for substring dd after a successful match (number less than 32)
295 \Gname call pcre_get_named_substring() for substring "name" after a successful match (name termin-
296 ated by next non-alphanumeric character)
297 \L call pcre_get_substringlist() after a successful match
298 \M discover the minimum MATCH_LIMIT and
299 MATCH_LIMIT_RECURSION settings
300 \N pass the PCRE_NOTEMPTY option to <b>pcre_exec()</b>
301 \Odd set the size of the output vector passed to <b>pcre_exec()</b> to dd (any number of digits)
302 \P pass the PCRE_PARTIAL option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
303 \R pass the PCRE_DFA_RESTART option to <b>pcre_dfa_exec()</b>
304 \S output details of memory get/free calls during matching
305 \Z pass the PCRE_NOTEOL option to <b>pcre_exec()</b>
306 \? pass the PCRE_NO_UTF8_CHECK option to <b>pcre_exec()</b>
307 \&#62;dd start the match at offset dd (any number of digits);
308 this sets the <i>startoffset</i> argument for <b>pcre_exec()</b>
309 </pre>
310 A backslash followed by anything else just escapes the anything else. If the
311 very last character is a backslash, it is ignored. This gives a way of passing
312 an empty line as data, since a real empty line terminates the data input.
313 </P>
314 <P>
315 If \M is present, <b>pcretest</b> calls <b>pcre_exec()</b> several times, with
316 different values in the <i>match_limit</i> and <i>match_limit_recursion</i>
317 fields of the <b>pcre_extra</b> data structure, until it finds the minimum
318 numbers for each parameter that allow <b>pcre_exec()</b> to complete. The
319 <i>match_limit</i> number is a measure of the amount of backtracking that takes
320 place, and checking it out can be instructive. For most simple matches, the
321 number is quite small, but for patterns with very large numbers of matching
322 possibilities, it can become large very quickly with increasing length of
323 subject string. The <i>match_limit_recursion</i> number is a measure of how much
324 stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is needed
325 to complete the match attempt.
326 </P>
327 <P>
328 When \O is used, the value specified may be higher or lower than the size set
329 by the <b>-O</b> command line option (or defaulted to 45); \O applies only to
330 the call of <b>pcre_exec()</b> for the line in which it appears.
331 </P>
332 <P>
333 If the <b>/P</b> modifier was present on the pattern, causing the POSIX wrapper
334 API to be used, the only option-setting sequences that have any effect are \B
335 and \Z, causing REG_NOTBOL and REG_NOTEOL, respectively, to be passed to
336 <b>regexec()</b>.
337 </P>
338 <P>
339 The use of \x{hh...} to represent UTF-8 characters is not dependent on the use
340 of the <b>/8</b> modifier on the pattern. It is recognized always. There may be
341 any number of hexadecimal digits inside the braces. The result is from one to
342 six bytes, encoded according to the UTF-8 rules.
343 </P>
344 <br><a name="SEC6" href="#TOC1">THE ALTERNATIVE MATCHING FUNCTION</a><br>
345 <P>
346 By default, <b>pcretest</b> uses the standard PCRE matching function,
347 <b>pcre_exec()</b> to match each data line. From release 6.0, PCRE supports an
348 alternative matching function, <b>pcre_dfa_test()</b>, which operates in a
349 different way, and has some restrictions. The differences between the two
350 functions are described in the
351 <a href="pcrematching.html"><b>pcrematching</b></a>
352 documentation.
353 </P>
354 <P>
355 If a data line contains the \D escape sequence, or if the command line
356 contains the <b>-dfa</b> option, the alternative matching function is called.
357 This function finds all possible matches at a given point. If, however, the \F
358 escape sequence is present in the data line, it stops after the first match is
359 found. This is always the shortest possible match.
360 </P>
361 <br><a name="SEC7" href="#TOC1">DEFAULT OUTPUT FROM PCRETEST</a><br>
362 <P>
363 This section describes the output when the normal matching function,
364 <b>pcre_exec()</b>, is being used.
365 </P>
366 <P>
367 When a match succeeds, pcretest outputs the list of captured substrings that
368 <b>pcre_exec()</b> returns, starting with number 0 for the string that matched
369 the whole pattern. Otherwise, it outputs "No match" or "Partial match"
370 when <b>pcre_exec()</b> returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PARTIAL,
371 respectively, and otherwise the PCRE negative error number. Here is an example
372 of an interactive <b>pcretest</b> run.
373 <pre>
374 $ pcretest
375 PCRE version 5.00 07-Sep-2004
376
377 re&#62; /^abc(\d+)/
378 data&#62; abc123
379 0: abc123
380 1: 123
381 data&#62; xyz
382 No match
383 </pre>
384 If the strings contain any non-printing characters, they are output as \0x
385 escapes, or as \x{...} escapes if the <b>/8</b> modifier was present on the
386 pattern. If the pattern has the <b>/+</b> modifier, the output for substring 0
387 is followed by the the rest of the subject string, identified by "0+" like
388 this:
389 <pre>
390 re&#62; /cat/+
391 data&#62; cataract
392 0: cat
393 0+ aract
394 </pre>
395 If the pattern has the <b>/g</b> or <b>/G</b> modifier, the results of successive
396 matching attempts are output in sequence, like this:
397 <pre>
398 re&#62; /\Bi(\w\w)/g
399 data&#62; Mississippi
400 0: iss
401 1: ss
402 0: iss
403 1: ss
404 0: ipp
405 1: pp
406 </pre>
407 "No match" is output only if the first match attempt fails.
408 </P>
409 <P>
410 If any of the sequences <b>\C</b>, <b>\G</b>, or <b>\L</b> are present in a
411 data line that is successfully matched, the substrings extracted by the
412 convenience functions are output with C, G, or L after the string number
413 instead of a colon. This is in addition to the normal full list. The string
414 length (that is, the return from the extraction function) is given in
415 parentheses after each string for <b>\C</b> and <b>\G</b>.
416 </P>
417 <P>
418 Note that while patterns can be continued over several lines (a plain "&#62;"
419 prompt is used for continuations), data lines may not. However newlines can be
420 included in data by means of the \n escape.
421 </P>
422 <br><a name="SEC8" href="#TOC1">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a><br>
423 <P>
424 When the alternative matching function, <b>pcre_dfa_exec()</b>, is used (by
425 means of the \D escape sequence or the <b>-dfa</b> command line option), the
426 output consists of a list of all the matches that start at the first point in
427 the subject where there is at least one match. For example:
428 <pre>
429 re&#62; /(tang|tangerine|tan)/
430 data&#62; yellow tangerine\D
431 0: tangerine
432 1: tang
433 2: tan
434 </pre>
435 (Using the normal matching function on this data finds only "tang".) The
436 longest matching string is always given first (and numbered zero).
437 </P>
438 <P>
439 If \fB/g\P is present on the pattern, the search for further matches resumes
440 at the end of the longest match. For example:
441 <pre>
442 re&#62; /(tang|tangerine|tan)/g
443 data&#62; yellow tangerine and tangy sultana\D
444 0: tangerine
445 1: tang
446 2: tan
447 0: tang
448 1: tan
449 0: tan
450 </pre>
451 Since the matching function does not support substring capture, the escape
452 sequences that are concerned with captured substrings are not relevant.
453 </P>
454 <br><a name="SEC9" href="#TOC1">RESTARTING AFTER A PARTIAL MATCH</a><br>
455 <P>
456 When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
457 indicating that the subject partially matched the pattern, you can restart the
458 match with additional subject data by means of the \R escape sequence. For
459 example:
460 <pre>
461 re&#62; /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
462 data&#62; 23ja\P\D
463 Partial match: 23ja
464 data&#62; n05\R\D
465 0: n05
466 </pre>
467 For further information about partial matching, see the
468 <a href="pcrepartial.html"><b>pcrepartial</b></a>
469 documentation.
470 </P>
471 <br><a name="SEC10" href="#TOC1">CALLOUTS</a><br>
472 <P>
473 If the pattern contains any callout requests, <b>pcretest</b>'s callout function
474 is called during matching. This works with both matching functions. By default,
475 the called function displays the callout number, the start and current
476 positions in the text at the callout time, and the next pattern item to be
477 tested. For example, the output
478 <pre>
479 ---&#62;pqrabcdef
480 0 ^ ^ \d
481 </pre>
482 indicates that callout number 0 occurred for a match attempt starting at the
483 fourth character of the subject string, when the pointer was at the seventh
484 character of the data, and when the next pattern item was \d. Just one
485 circumflex is output if the start and current positions are the same.
486 </P>
487 <P>
488 Callouts numbered 255 are assumed to be automatic callouts, inserted as a
489 result of the <b>/C</b> pattern modifier. In this case, instead of showing the
490 callout number, the offset in the pattern, preceded by a plus, is output. For
491 example:
492 <pre>
493 re&#62; /\d?[A-E]\*/C
494 data&#62; E*
495 ---&#62;E*
496 +0 ^ \d?
497 +3 ^ [A-E]
498 +8 ^^ \*
499 +10 ^ ^
500 0: E*
501 </pre>
502 The callout function in <b>pcretest</b> returns zero (carry on matching) by
503 default, but you can use a \C item in a data line (as described above) to
504 change this.
505 </P>
506 <P>
507 Inserting callouts can be helpful when using <b>pcretest</b> to check
508 complicated regular expressions. For further information about callouts, see
509 the
510 <a href="pcrecallout.html"><b>pcrecallout</b></a>
511 documentation.
512 </P>
513 <br><a name="SEC11" href="#TOC1">SAVING AND RELOADING COMPILED PATTERNS</a><br>
514 <P>
515 The facilities described in this section are not available when the POSIX
516 inteface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is
517 specified.
518 </P>
519 <P>
520 When the POSIX interface is not in use, you can cause <b>pcretest</b> to write a
521 compiled pattern to a file, by following the modifiers with &#62; and a file name.
522 For example:
523 <pre>
524 /pattern/im &#62;/some/file
525 </pre>
526 See the
527 <a href="pcreprecompile.html"><b>pcreprecompile</b></a>
528 documentation for a discussion about saving and re-using compiled patterns.
529 </P>
530 <P>
531 The data that is written is binary. The first eight bytes are the length of the
532 compiled pattern data followed by the length of the optional study data, each
533 written as four bytes in big-endian order (most significant byte first). If
534 there is no study data (either the pattern was not studied, or studying did not
535 return any data), the second length is zero. The lengths are followed by an
536 exact copy of the compiled pattern. If there is additional study data, this
537 follows immediately after the compiled pattern. After writing the file,
538 <b>pcretest</b> expects to read a new pattern.
539 </P>
540 <P>
541 A saved pattern can be reloaded into <b>pcretest</b> by specifing &#60; and a file
542 name instead of a pattern. The name of the file must not contain a &#60; character,
543 as otherwise <b>pcretest</b> will interpret the line as a pattern delimited by &#60;
544 characters.
545 For example:
546 <pre>
547 re&#62; &#60;/some/file
548 Compiled regex loaded from /some/file
549 No study data
550 </pre>
551 When the pattern has been loaded, <b>pcretest</b> proceeds to read data lines in
552 the usual way.
553 </P>
554 <P>
555 You can copy a file written by <b>pcretest</b> to a different host and reload it
556 there, even if the new host has opposite endianness to the one on which the
557 pattern was compiled. For example, you can compile on an i86 machine and run on
558 a SPARC machine.
559 </P>
560 <P>
561 File names for saving and reloading can be absolute or relative, but note that
562 the shell facility of expanding a file name that starts with a tilde (~) is not
563 available.
564 </P>
565 <P>
566 The ability to save and reload files in <b>pcretest</b> is intended for testing
567 and experimentation. It is not intended for production use because only a
568 single pattern can be written to a file. Furthermore, there is no facility for
569 supplying custom character tables for use with a reloaded pattern. If the
570 original pattern was compiled with custom tables, an attempt to match a subject
571 string using a reloaded pattern is likely to cause <b>pcretest</b> to crash.
572 Finally, if you attempt to load a file that is not in the correct format, the
573 result is undefined.
574 </P>
575 <br><a name="SEC12" href="#TOC1">AUTHOR</a><br>
576 <P>
577 Philip Hazel
578 <br>
579 University Computing Service,
580 <br>
581 Cambridge CB2 3QG, England.
582 </P>
583 <P>
584 Last updated: 18 January 2006
585 <br>
586 Copyright &copy; 1997-2006 University of Cambridge.
587 <p>
588 Return to the <a href="index.html">PCRE index page</a>.
589 </p>

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