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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">INPUT DATA FORMAT</a>
18 <li><a name="TOC3" href="#SEC3">PCRE's 8-BIT, 16-BIT AND 32-BIT LIBRARIES</a>
19 <li><a name="TOC4" href="#SEC4">COMMAND LINE OPTIONS</a>
20 <li><a name="TOC5" href="#SEC5">DESCRIPTION</a>
21 <li><a name="TOC6" href="#SEC6">PATTERN MODIFIERS</a>
22 <li><a name="TOC7" href="#SEC7">DATA LINES</a>
23 <li><a name="TOC8" href="#SEC8">THE ALTERNATIVE MATCHING FUNCTION</a>
24 <li><a name="TOC9" href="#SEC9">DEFAULT OUTPUT FROM PCRETEST</a>
25 <li><a name="TOC10" href="#SEC10">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a>
26 <li><a name="TOC11" href="#SEC11">RESTARTING AFTER A PARTIAL MATCH</a>
27 <li><a name="TOC12" href="#SEC12">CALLOUTS</a>
28 <li><a name="TOC13" href="#SEC13">NON-PRINTING CHARACTERS</a>
29 <li><a name="TOC14" href="#SEC14">SAVING AND RELOADING COMPILED PATTERNS</a>
30 <li><a name="TOC15" href="#SEC15">SEE ALSO</a>
31 <li><a name="TOC16" href="#SEC16">AUTHOR</a>
32 <li><a name="TOC17" href="#SEC17">REVISION</a>
33 </ul>
34 <br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br>
35 <P>
36 <b>pcretest [options] [input file [output file]]</b>
37 <br>
38 <br>
39 <b>pcretest</b> was written as a test program for the PCRE regular expression
40 library itself, but it can also be used for experimenting with regular
41 expressions. This document describes the features of the test program; for
42 details of the regular expressions themselves, see the
43 <a href="pcrepattern.html"><b>pcrepattern</b></a>
44 documentation. For details of the PCRE library function calls and their
45 options, see the
46 <a href="pcreapi.html"><b>pcreapi</b></a>
47 ,
48 <a href="pcre16.html"><b>pcre16</b></a>
49 and
50 <a href="pcre32.html"><b>pcre32</b></a>
51 documentation.
52 </P>
53 <P>
54 The input for <b>pcretest</b> is a sequence of regular expression patterns and
55 strings to be matched, as described below. The output shows the result of each
56 match. Options on the command line and the patterns control PCRE options and
57 exactly what is output.
58 </P>
59 <P>
60 As PCRE has evolved, it has acquired many different features, and as a result,
61 <b>pcretest</b> now has rather a lot of obscure options for testing every
62 possible feature. Some of these options are specifically designed for use in
63 conjunction with the test script and data files that are distributed as part of
64 PCRE, and are unlikely to be of use otherwise. They are all documented here,
65 but without much justification.
66 </P>
67 <br><a name="SEC2" href="#TOC1">INPUT DATA FORMAT</a><br>
68 <P>
69 Input to <b>pcretest</b> is processed line by line, either by calling the C
70 library's <b>fgets()</b> function, or via the <b>libreadline</b> library (see
71 below). In Unix-like environments, <b>fgets()</b> treats any bytes other than
72 newline as data characters. However, in some Windows environments character 26
73 (hex 1A) causes an immediate end of file, and no further data is read. For
74 maximum portability, therefore, it is safest to use only ASCII characters in
75 <b>pcretest</b> input files.
76 </P>
77 <br><a name="SEC3" href="#TOC1">PCRE's 8-BIT, 16-BIT AND 32-BIT LIBRARIES</a><br>
78 <P>
79 From release 8.30, two separate PCRE libraries can be built. The original one
80 supports 8-bit character strings, whereas the newer 16-bit library supports
81 character strings encoded in 16-bit units. From release 8.32, a third library
82 can be built, supporting character strings encoded in 32-bit units. The
83 <b>pcretest</b> program can be used to test all three libraries. However, it is
84 itself still an 8-bit program, reading 8-bit input and writing 8-bit output.
85 When testing the 16-bit or 32-bit library, the patterns and data strings are
86 converted to 16- or 32-bit format before being passed to the PCRE library
87 functions. Results are converted to 8-bit for output.
88 </P>
89 <P>
90 References to functions and structures of the form <b>pcre[16|32]_xx</b> below
91 mean "<b>pcre_xx</b> when using the 8-bit library, <b>pcre16_xx</b> when using
92 the 16-bit library, or <b>pcre32_xx</b> when using the 32-bit library".
93 </P>
94 <br><a name="SEC4" href="#TOC1">COMMAND LINE OPTIONS</a><br>
95 <P>
96 <b>-8</b>
97 If both the 8-bit library has been built, this option causes the 8-bit library
98 to be used (which is the default); if the 8-bit library has not been built,
99 this option causes an error.
100 </P>
101 <P>
102 <b>-16</b>
103 If both the 8-bit or the 32-bit, and the 16-bit libraries have been built, this
104 option causes the 16-bit library to be used. If only the 16-bit library has been
105 built, this is the default (so has no effect). If only the 8-bit or the 32-bit
106 library has been built, this option causes an error.
107 </P>
108 <P>
109 <b>-32</b>
110 If both the 8-bit or the 16-bit, and the 32-bit libraries have been built, this
111 option causes the 32-bit library to be used. If only the 32-bit library has been
112 built, this is the default (so has no effect). If only the 8-bit or the 16-bit
113 library has been built, this option causes an error.
114 </P>
115 <P>
116 <b>-b</b>
117 Behave as if each pattern has the <b>/B</b> (show byte code) modifier; the
118 internal form is output after compilation.
119 </P>
120 <P>
121 <b>-C</b>
122 Output the version number of the PCRE library, and all available information
123 about the optional features that are included, and then exit with zero exit
124 code. All other options are ignored.
125 </P>
126 <P>
127 <b>-C</b> <i>option</i>
128 Output information about a specific build-time option, then exit. This
129 functionality is intended for use in scripts such as <b>RunTest</b>. The
130 following options output the value and set the exit code as indicated:
131 <pre>
132 ebcdic-nl the code for LF (= NL) in an EBCDIC environment:
133 0x15 or 0x25
134 0 if used in an ASCII environment
135 exit code is always 0
136 linksize the configured internal link size (2, 3, or 4)
137 exit code is set to the link size
138 newline the default newline setting:
139 CR, LF, CRLF, ANYCRLF, or ANY
140 exit code is always 0
141 </pre>
142 The following options output 1 for true or 0 for false, and set the exit code
143 to the same value:
144 <pre>
145 ebcdic compiled for an EBCDIC environment
146 jit just-in-time support is available
147 pcre16 the 16-bit library was built
148 pcre32 the 32-bit library was built
149 pcre8 the 8-bit library was built
150 ucp Unicode property support is available
151 utf UTF-8 and/or UTF-16 and/or UTF-32 support
152 is available
153 </pre>
154 If an unknown option is given, an error message is output; the exit code is 0.
155 </P>
156 <P>
157 <b>-d</b>
158 Behave as if each pattern has the <b>/D</b> (debug) modifier; the internal
159 form and information about the compiled pattern is output after compilation;
160 <b>-d</b> is equivalent to <b>-b -i</b>.
161 </P>
162 <P>
163 <b>-dfa</b>
164 Behave as if each data line contains the \D escape sequence; this causes the
165 alternative matching function, <b>pcre[16|32]_dfa_exec()</b>, to be used instead
166 of the standard <b>pcre[16|32]_exec()</b> function (more detail is given below).
167 </P>
168 <P>
169 <b>-help</b>
170 Output a brief summary these options and then exit.
171 </P>
172 <P>
173 <b>-i</b>
174 Behave as if each pattern has the <b>/I</b> modifier; information about the
175 compiled pattern is given after compilation.
176 </P>
177 <P>
178 <b>-M</b>
179 Behave as if each data line contains the \M escape sequence; this causes
180 PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
181 calling <b>pcre[16|32]_exec()</b> repeatedly with different limits.
182 </P>
183 <P>
184 <b>-m</b>
185 Output the size of each compiled pattern after it has been compiled. This is
186 equivalent to adding <b>/M</b> to each regular expression. The size is given in
187 bytes for both libraries.
188 </P>
189 <P>
190 <b>-O</b>
191 Behave as if each pattern has the <b>/O</b> modifier, that is disable
192 auto-possessification for all patterns.
193 </P>
194 <P>
195 <b>-o</b> <i>osize</i>
196 Set the number of elements in the output vector that is used when calling
197 <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b> to be <i>osize</i>. The
198 default value is 45, which is enough for 14 capturing subexpressions for
199 <b>pcre[16|32]_exec()</b> or 22 different matches for
200 <b>pcre[16|32]_dfa_exec()</b>.
201 The vector size can be changed for individual matching calls by including \O
202 in the data line (see below).
203 </P>
204 <P>
205 <b>-p</b>
206 Behave as if each pattern has the <b>/P</b> modifier; the POSIX wrapper API is
207 used to call PCRE. None of the other options has any effect when <b>-p</b> is
208 set. This option can be used only with the 8-bit library.
209 </P>
210 <P>
211 <b>-q</b>
212 Do not output the version number of <b>pcretest</b> at the start of execution.
213 </P>
214 <P>
215 <b>-S</b> <i>size</i>
216 On Unix-like systems, set the size of the run-time stack to <i>size</i>
217 megabytes.
218 </P>
219 <P>
220 <b>-s</b> or <b>-s+</b>
221 Behave as if each pattern has the <b>/S</b> modifier; in other words, force each
222 pattern to be studied. If <b>-s+</b> is used, all the JIT compile options are
223 passed to <b>pcre[16|32]_study()</b>, causing just-in-time optimization to be set
224 up if it is available, for both full and partial matching. Specific JIT compile
225 options can be selected by following <b>-s+</b> with a digit in the range 1 to
226 7, which selects the JIT compile modes as follows:
227 <pre>
228 1 normal match only
229 2 soft partial match only
230 3 normal match and soft partial match
231 4 hard partial match only
232 6 soft and hard partial match
233 7 all three modes (default)
234 </pre>
235 If <b>-s++</b> is used instead of <b>-s+</b> (with or without a following digit),
236 the text "(JIT)" is added to the first output line after a match or no match
237 when JIT-compiled code was actually used.
238 <br>
239 <br>
240 Note that there are pattern options that can override <b>-s</b>, either
241 specifying no studying at all, or suppressing JIT compilation.
242 <br>
243 <br>
244 If the <b>/I</b> or <b>/D</b> option is present on a pattern (requesting output
245 about the compiled pattern), information about the result of studying is not
246 included when studying is caused only by <b>-s</b> and neither <b>-i</b> nor
247 <b>-d</b> is present on the command line. This behaviour means that the output
248 from tests that are run with and without <b>-s</b> should be identical, except
249 when options that output information about the actual running of a match are
250 set.
251 <br>
252 <br>
253 The <b>-M</b>, <b>-t</b>, and <b>-tm</b> options, which give information about
254 resources used, are likely to produce different output with and without
255 <b>-s</b>. Output may also differ if the <b>/C</b> option is present on an
256 individual pattern. This uses callouts to trace the the matching process, and
257 this may be different between studied and non-studied patterns. If the pattern
258 contains (*MARK) items there may also be differences, for the same reason. The
259 <b>-s</b> command line option can be overridden for specific patterns that
260 should never be studied (see the <b>/S</b> pattern modifier below).
261 </P>
262 <P>
263 <b>-t</b>
264 Run each compile, study, and match many times with a timer, and output the
265 resulting times per compile, study, or match (in milliseconds). Do not set
266 <b>-m</b> with <b>-t</b>, because you will then get the size output a zillion
267 times, and the timing will be distorted. You can control the number of
268 iterations that are used for timing by following <b>-t</b> with a number (as a
269 separate item on the command line). For example, "-t 1000" iterates 1000 times.
270 The default is to iterate 500000 times.
271 </P>
272 <P>
273 <b>-tm</b>
274 This is like <b>-t</b> except that it times only the matching phase, not the
275 compile or study phases.
276 </P>
277 <P>
278 <b>-T</b> <b>-TM</b>
279 These behave like <b>-t</b> and <b>-tm</b>, but in addition, at the end of a run,
280 the total times for all compiles, studies, and matches are output.
281 </P>
282 <br><a name="SEC5" href="#TOC1">DESCRIPTION</a><br>
283 <P>
284 If <b>pcretest</b> is given two filename arguments, it reads from the first and
285 writes to the second. If it is given only one filename argument, it reads from
286 that file and writes to stdout. Otherwise, it reads from stdin and writes to
287 stdout, and prompts for each line of input, using "re&#62;" to prompt for regular
288 expressions, and "data&#62;" to prompt for data lines.
289 </P>
290 <P>
291 When <b>pcretest</b> is built, a configuration option can specify that it should
292 be linked with the <b>libreadline</b> library. When this is done, if the input
293 is from a terminal, it is read using the <b>readline()</b> function. This
294 provides line-editing and history facilities. The output from the <b>-help</b>
295 option states whether or not <b>readline()</b> will be used.
296 </P>
297 <P>
298 The program handles any number of sets of input on a single input file. Each
299 set starts with a regular expression, and continues with any number of data
300 lines to be matched against that pattern.
301 </P>
302 <P>
303 Each data line is matched separately and independently. If you want to do
304 multi-line matches, you have to use the \n escape sequence (or \r or \r\n,
305 etc., depending on the newline setting) in a single line of input to encode the
306 newline sequences. There is no limit on the length of data lines; the input
307 buffer is automatically extended if it is too small.
308 </P>
309 <P>
310 An empty line signals the end of the data lines, at which point a new regular
311 expression is read. The regular expressions are given enclosed in any
312 non-alphanumeric delimiters other than backslash, for example:
313 <pre>
314 /(a|bc)x+yz/
315 </pre>
316 White space before the initial delimiter is ignored. A regular expression may
317 be continued over several input lines, in which case the newline characters are
318 included within it. It is possible to include the delimiter within the pattern
319 by escaping it, for example
320 <pre>
321 /abc\/def/
322 </pre>
323 If you do so, the escape and the delimiter form part of the pattern, but since
324 delimiters are always non-alphanumeric, this does not affect its interpretation.
325 If the terminating delimiter is immediately followed by a backslash, for
326 example,
327 <pre>
328 /abc/\
329 </pre>
330 then a backslash is added to the end of the pattern. This is done to provide a
331 way of testing the error condition that arises if a pattern finishes with a
332 backslash, because
333 <pre>
334 /abc\/
335 </pre>
336 is interpreted as the first line of a pattern that starts with "abc/", causing
337 pcretest to read the next line as a continuation of the regular expression.
338 </P>
339 <br><a name="SEC6" href="#TOC1">PATTERN MODIFIERS</a><br>
340 <P>
341 A pattern may be followed by any number of modifiers, which are mostly single
342 characters, though some of these can be qualified by further characters.
343 Following Perl usage, these are referred to below as, for example, "the
344 <b>/i</b> modifier", even though the delimiter of the pattern need not always be
345 a slash, and no slash is used when writing modifiers. White space may appear
346 between the final pattern delimiter and the first modifier, and between the
347 modifiers themselves. For reference, here is a complete list of modifiers. They
348 fall into several groups that are described in detail in the following
349 sections.
350 <pre>
351 <b>/8</b> set UTF mode
352 <b>/9</b> set PCRE_NEVER_UTF (locks out UTF mode)
353 <b>/?</b> disable UTF validity check
354 <b>/+</b> show remainder of subject after match
355 <b>/=</b> show all captures (not just those that are set)
356
357 <b>/A</b> set PCRE_ANCHORED
358 <b>/B</b> show compiled code
359 <b>/C</b> set PCRE_AUTO_CALLOUT
360 <b>/D</b> same as <b>/B</b> plus <b>/I</b>
361 <b>/E</b> set PCRE_DOLLAR_ENDONLY
362 <b>/F</b> flip byte order in compiled pattern
363 <b>/f</b> set PCRE_FIRSTLINE
364 <b>/G</b> find all matches (shorten string)
365 <b>/g</b> find all matches (use startoffset)
366 <b>/I</b> show information about pattern
367 <b>/i</b> set PCRE_CASELESS
368 <b>/J</b> set PCRE_DUPNAMES
369 <b>/K</b> show backtracking control names
370 <b>/L</b> set locale
371 <b>/M</b> show compiled memory size
372 <b>/m</b> set PCRE_MULTILINE
373 <b>/N</b> set PCRE_NO_AUTO_CAPTURE
374 <b>/O</b> set PCRE_NO_AUTO_POSSESS
375 <b>/P</b> use the POSIX wrapper
376 <b>/S</b> study the pattern after compilation
377 <b>/s</b> set PCRE_DOTALL
378 <b>/T</b> select character tables
379 <b>/U</b> set PCRE_UNGREEDY
380 <b>/W</b> set PCRE_UCP
381 <b>/X</b> set PCRE_EXTRA
382 <b>/x</b> set PCRE_EXTENDED
383 <b>/Y</b> set PCRE_NO_START_OPTIMIZE
384 <b>/Z</b> don't show lengths in <b>/B</b> output
385
386 <b>/&#60;any&#62;</b> set PCRE_NEWLINE_ANY
387 <b>/&#60;anycrlf&#62;</b> set PCRE_NEWLINE_ANYCRLF
388 <b>/&#60;cr&#62;</b> set PCRE_NEWLINE_CR
389 <b>/&#60;crlf&#62;</b> set PCRE_NEWLINE_CRLF
390 <b>/&#60;lf&#62;</b> set PCRE_NEWLINE_LF
391 <b>/&#60;bsr_anycrlf&#62;</b> set PCRE_BSR_ANYCRLF
392 <b>/&#60;bsr_unicode&#62;</b> set PCRE_BSR_UNICODE
393 <b>/&#60;JS&#62;</b> set PCRE_JAVASCRIPT_COMPAT
394
395 </PRE>
396 </P>
397 <br><b>
398 Perl-compatible modifiers
399 </b><br>
400 <P>
401 The <b>/i</b>, <b>/m</b>, <b>/s</b>, and <b>/x</b> modifiers set the PCRE_CASELESS,
402 PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
403 <b>pcre[16|32]_compile()</b> is called. These four modifier letters have the same
404 effect as they do in Perl. For example:
405 <pre>
406 /caseless/i
407
408 </PRE>
409 </P>
410 <br><b>
411 Modifiers for other PCRE options
412 </b><br>
413 <P>
414 The following table shows additional modifiers for setting PCRE compile-time
415 options that do not correspond to anything in Perl:
416 <pre>
417 <b>/8</b> PCRE_UTF8 ) when using the 8-bit
418 <b>/?</b> PCRE_NO_UTF8_CHECK ) library
419
420 <b>/8</b> PCRE_UTF16 ) when using the 16-bit
421 <b>/?</b> PCRE_NO_UTF16_CHECK ) library
422
423 <b>/8</b> PCRE_UTF32 ) when using the 32-bit
424 <b>/?</b> PCRE_NO_UTF32_CHECK ) library
425
426 <b>/9</b> PCRE_NEVER_UTF
427 <b>/A</b> PCRE_ANCHORED
428 <b>/C</b> PCRE_AUTO_CALLOUT
429 <b>/E</b> PCRE_DOLLAR_ENDONLY
430 <b>/f</b> PCRE_FIRSTLINE
431 <b>/J</b> PCRE_DUPNAMES
432 <b>/N</b> PCRE_NO_AUTO_CAPTURE
433 <b>/O</b> PCRE_NO_AUTO_POSSESS
434 <b>/U</b> PCRE_UNGREEDY
435 <b>/W</b> PCRE_UCP
436 <b>/X</b> PCRE_EXTRA
437 <b>/Y</b> PCRE_NO_START_OPTIMIZE
438 <b>/&#60;any&#62;</b> PCRE_NEWLINE_ANY
439 <b>/&#60;anycrlf&#62;</b> PCRE_NEWLINE_ANYCRLF
440 <b>/&#60;cr&#62;</b> PCRE_NEWLINE_CR
441 <b>/&#60;crlf&#62;</b> PCRE_NEWLINE_CRLF
442 <b>/&#60;lf&#62;</b> PCRE_NEWLINE_LF
443 <b>/&#60;bsr_anycrlf&#62;</b> PCRE_BSR_ANYCRLF
444 <b>/&#60;bsr_unicode&#62;</b> PCRE_BSR_UNICODE
445 <b>/&#60;JS&#62;</b> PCRE_JAVASCRIPT_COMPAT
446 </pre>
447 The modifiers that are enclosed in angle brackets are literal strings as shown,
448 including the angle brackets, but the letters within can be in either case.
449 This example sets multiline matching with CRLF as the line ending sequence:
450 <pre>
451 /^abc/m&#60;CRLF&#62;
452 </pre>
453 As well as turning on the PCRE_UTF8/16/32 option, the <b>/8</b> modifier causes
454 all non-printing characters in output strings to be printed using the
455 \x{hh...} notation. Otherwise, those less than 0x100 are output in hex without
456 the curly brackets.
457 </P>
458 <P>
459 Full details of the PCRE options are given in the
460 <a href="pcreapi.html"><b>pcreapi</b></a>
461 documentation.
462 </P>
463 <br><b>
464 Finding all matches in a string
465 </b><br>
466 <P>
467 Searching for all possible matches within each subject string can be requested
468 by the <b>/g</b> or <b>/G</b> modifier. After finding a match, PCRE is called
469 again to search the remainder of the subject string. The difference between
470 <b>/g</b> and <b>/G</b> is that the former uses the <i>startoffset</i> argument to
471 <b>pcre[16|32]_exec()</b> to start searching at a new point within the entire
472 string (which is in effect what Perl does), whereas the latter passes over a
473 shortened substring. This makes a difference to the matching process if the
474 pattern begins with a lookbehind assertion (including \b or \B).
475 </P>
476 <P>
477 If any call to <b>pcre[16|32]_exec()</b> in a <b>/g</b> or <b>/G</b> sequence matches
478 an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
479 PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
480 same point. If this second match fails, the start offset is advanced, and the
481 normal match is retried. This imitates the way Perl handles such cases when
482 using the <b>/g</b> modifier or the <b>split()</b> function. Normally, the start
483 offset is advanced by one character, but if the newline convention recognizes
484 CRLF as a newline, and the current character is CR followed by LF, an advance
485 of two is used.
486 </P>
487 <br><b>
488 Other modifiers
489 </b><br>
490 <P>
491 There are yet more modifiers for controlling the way <b>pcretest</b>
492 operates.
493 </P>
494 <P>
495 The <b>/+</b> modifier requests that as well as outputting the substring that
496 matched the entire pattern, <b>pcretest</b> should in addition output the
497 remainder of the subject string. This is useful for tests where the subject
498 contains multiple copies of the same substring. If the <b>+</b> modifier appears
499 twice, the same action is taken for captured substrings. In each case the
500 remainder is output on the following line with a plus character following the
501 capture number. Note that this modifier must not immediately follow the /S
502 modifier because /S+ and /S++ have other meanings.
503 </P>
504 <P>
505 The <b>/=</b> modifier requests that the values of all potential captured
506 parentheses be output after a match. By default, only those up to the highest
507 one actually used in the match are output (corresponding to the return code
508 from <b>pcre[16|32]_exec()</b>). Values in the offsets vector corresponding to
509 higher numbers should be set to -1, and these are output as "&#60;unset&#62;". This
510 modifier gives a way of checking that this is happening.
511 </P>
512 <P>
513 The <b>/B</b> modifier is a debugging feature. It requests that <b>pcretest</b>
514 output a representation of the compiled code after compilation. Normally this
515 information contains length and offset values; however, if <b>/Z</b> is also
516 present, this data is replaced by spaces. This is a special feature for use in
517 the automatic test scripts; it ensures that the same output is generated for
518 different internal link sizes.
519 </P>
520 <P>
521 The <b>/D</b> modifier is a PCRE debugging feature, and is equivalent to
522 <b>/BI</b>, that is, both the <b>/B</b> and the <b>/I</b> modifiers.
523 </P>
524 <P>
525 The <b>/F</b> modifier causes <b>pcretest</b> to flip the byte order of the
526 2-byte and 4-byte fields in the compiled pattern. This facility is for testing
527 the feature in PCRE that allows it to execute patterns that were compiled on a
528 host with a different endianness. This feature is not available when the POSIX
529 interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is
530 specified. See also the section about saving and reloading compiled patterns
531 below.
532 </P>
533 <P>
534 The <b>/I</b> modifier requests that <b>pcretest</b> output information about the
535 compiled pattern (whether it is anchored, has a fixed first character, and
536 so on). It does this by calling <b>pcre[16|32]_fullinfo()</b> after compiling a
537 pattern. If the pattern is studied, the results of that are also output.
538 </P>
539 <P>
540 The <b>/K</b> modifier requests <b>pcretest</b> to show names from backtracking
541 control verbs that are returned from calls to <b>pcre[16|32]_exec()</b>. It causes
542 <b>pcretest</b> to create a <b>pcre[16|32]_extra</b> block if one has not already
543 been created by a call to <b>pcre[16|32]_study()</b>, and to set the
544 PCRE_EXTRA_MARK flag and the <b>mark</b> field within it, every time that
545 <b>pcre[16|32]_exec()</b> is called. If the variable that the <b>mark</b> field
546 points to is non-NULL for a match, non-match, or partial match, <b>pcretest</b>
547 prints the string to which it points. For a match, this is shown on a line by
548 itself, tagged with "MK:". For a non-match it is added to the message.
549 </P>
550 <P>
551 The <b>/L</b> modifier must be followed directly by the name of a locale, for
552 example,
553 <pre>
554 /pattern/Lfr_FR
555 </pre>
556 For this reason, it must be the last modifier. The given locale is set,
557 <b>pcre[16|32]_maketables()</b> is called to build a set of character tables for
558 the locale, and this is then passed to <b>pcre[16|32]_compile()</b> when compiling
559 the regular expression. Without an <b>/L</b> (or <b>/T</b>) modifier, NULL is
560 passed as the tables pointer; that is, <b>/L</b> applies only to the expression
561 on which it appears.
562 </P>
563 <P>
564 The <b>/M</b> modifier causes the size in bytes of the memory block used to hold
565 the compiled pattern to be output. This does not include the size of the
566 <b>pcre[16|32]</b> block; it is just the actual compiled data. If the pattern is
567 successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the
568 JIT compiled code is also output.
569 </P>
570 <P>
571 The <b>/S</b> modifier causes <b>pcre[16|32]_study()</b> to be called after the
572 expression has been compiled, and the results used when the expression is
573 matched. There are a number of qualifying characters that may follow <b>/S</b>.
574 They may appear in any order.
575 </P>
576 <P>
577 If <b>/S</b> is followed by an exclamation mark, <b>pcre[16|32]_study()</b> is
578 called with the PCRE_STUDY_EXTRA_NEEDED option, causing it always to return a
579 <b>pcre_extra</b> block, even when studying discovers no useful information.
580 </P>
581 <P>
582 If <b>/S</b> is followed by a second S character, it suppresses studying, even
583 if it was requested externally by the <b>-s</b> command line option. This makes
584 it possible to specify that certain patterns are always studied, and others are
585 never studied, independently of <b>-s</b>. This feature is used in the test
586 files in a few cases where the output is different when the pattern is studied.
587 </P>
588 <P>
589 If the <b>/S</b> modifier is followed by a + character, the call to
590 <b>pcre[16|32]_study()</b> is made with all the JIT study options, requesting
591 just-in-time optimization support if it is available, for both normal and
592 partial matching. If you want to restrict the JIT compiling modes, you can
593 follow <b>/S+</b> with a digit in the range 1 to 7:
594 <pre>
595 1 normal match only
596 2 soft partial match only
597 3 normal match and soft partial match
598 4 hard partial match only
599 6 soft and hard partial match
600 7 all three modes (default)
601 </pre>
602 If <b>/S++</b> is used instead of <b>/S+</b> (with or without a following digit),
603 the text "(JIT)" is added to the first output line after a match or no match
604 when JIT-compiled code was actually used.
605 </P>
606 <P>
607 Note that there is also an independent <b>/+</b> modifier; it must not be given
608 immediately after <b>/S</b> or <b>/S+</b> because this will be misinterpreted.
609 </P>
610 <P>
611 If JIT studying is successful, the compiled JIT code will automatically be used
612 when <b>pcre[16|32]_exec()</b> is run, except when incompatible run-time options
613 are specified. For more details, see the
614 <a href="pcrejit.html"><b>pcrejit</b></a>
615 documentation. See also the <b>\J</b> escape sequence below for a way of
616 setting the size of the JIT stack.
617 </P>
618 <P>
619 Finally, if <b>/S</b> is followed by a minus character, JIT compilation is
620 suppressed, even if it was requested externally by the <b>-s</b> command line
621 option. This makes it possible to specify that JIT is never to be used for
622 certain patterns.
623 </P>
624 <P>
625 The <b>/T</b> modifier must be followed by a single digit. It causes a specific
626 set of built-in character tables to be passed to <b>pcre[16|32]_compile()</b>. It
627 is used in the standard PCRE tests to check behaviour with different character
628 tables. The digit specifies the tables as follows:
629 <pre>
630 0 the default ASCII tables, as distributed in
631 pcre_chartables.c.dist
632 1 a set of tables defining ISO 8859 characters
633 </pre>
634 In table 1, some characters whose codes are greater than 128 are identified as
635 letters, digits, spaces, etc.
636 </P>
637 <br><b>
638 Using the POSIX wrapper API
639 </b><br>
640 <P>
641 The <b>/P</b> modifier causes <b>pcretest</b> to call PCRE via the POSIX wrapper
642 API rather than its native API. This supports only the 8-bit library. When
643 <b>/P</b> is set, the following modifiers set options for the <b>regcomp()</b>
644 function:
645 <pre>
646 /i REG_ICASE
647 /m REG_NEWLINE
648 /N REG_NOSUB
649 /s REG_DOTALL )
650 /U REG_UNGREEDY ) These options are not part of
651 /W REG_UCP ) the POSIX standard
652 /8 REG_UTF8 )
653 </pre>
654 The <b>/+</b> modifier works as described above. All other modifiers are
655 ignored.
656 </P>
657 <br><b>
658 Locking out certain modifiers
659 </b><br>
660 <P>
661 PCRE can be compiled with or without support for certain features such as
662 UTF-8/16/32 or Unicode properties. Accordingly, the standard tests are split up
663 into a number of different files that are selected for running depending on
664 which features are available. When updating the tests, it is all too easy to
665 put a new test into the wrong file by mistake; for example, to put a test that
666 requires UTF support into a file that is used when it is not available. To help
667 detect such mistakes as early as possible, there is a facility for locking out
668 specific modifiers. If an input line for <b>pcretest</b> starts with the string
669 "&#60; forbid " the following sequence of characters is taken as a list of
670 forbidden modifiers. For example, in the test files that must not use UTF or
671 Unicode property support, this line appears:
672 <pre>
673 &#60; forbid 8W
674 </pre>
675 This locks out the /8 and /W modifiers. An immediate error is given if they are
676 subsequently encountered. If the character string contains &#60; but not &#62;, all the
677 multi-character modifiers that begin with &#60; are locked out. Otherwise, such
678 modifiers must be explicitly listed, for example:
679 <pre>
680 &#60; forbid &#60;JS&#62;&#60;cr&#62;
681 </pre>
682 There must be a single space between &#60; and "forbid" for this feature to be
683 recognised. If there is not, the line is interpreted either as a request to
684 re-load a pre-compiled pattern (see "SAVING AND RELOADING COMPILED PATTERNS"
685 below) or, if there is a another &#60; character, as a pattern that uses &#60; as its
686 delimiter.
687 </P>
688 <br><a name="SEC7" href="#TOC1">DATA LINES</a><br>
689 <P>
690 Before each data line is passed to <b>pcre[16|32]_exec()</b>, leading and trailing
691 white space is removed, and it is then scanned for \ escapes. Some of these
692 are pretty esoteric features, intended for checking out some of the more
693 complicated features of PCRE. If you are just testing "ordinary" regular
694 expressions, you probably don't need any of these. The following escapes are
695 recognized:
696 <pre>
697 \a alarm (BEL, \x07)
698 \b backspace (\x08)
699 \e escape (\x27)
700 \f form feed (\x0c)
701 \n newline (\x0a)
702 \qdd set the PCRE_MATCH_LIMIT limit to dd (any number of digits)
703 \r carriage return (\x0d)
704 \t tab (\x09)
705 \v vertical tab (\x0b)
706 \nnn octal character (up to 3 octal digits); always
707 a byte unless &#62; 255 in UTF-8 or 16-bit or 32-bit mode
708 \o{dd...} octal character (any number of octal digits}
709 \xhh hexadecimal byte (up to 2 hex digits)
710 \x{hh...} hexadecimal character (any number of hex digits)
711 \A pass the PCRE_ANCHORED option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
712 \B pass the PCRE_NOTBOL option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
713 \Cdd call pcre[16|32]_copy_substring() for substring dd after a successful match (number less than 32)
714 \Cname call pcre[16|32]_copy_named_substring() for substring "name" after a successful match (name termin-
715 ated by next non alphanumeric character)
716 \C+ show the current captured substrings at callout time
717 \C- do not supply a callout function
718 \C!n return 1 instead of 0 when callout number n is reached
719 \C!n!m return 1 instead of 0 when callout number n is reached for the nth time
720 \C*n pass the number n (may be negative) as callout data; this is used as the callout return value
721 \D use the <b>pcre[16|32]_dfa_exec()</b> match function
722 \F only shortest match for <b>pcre[16|32]_dfa_exec()</b>
723 \Gdd call pcre[16|32]_get_substring() for substring dd after a successful match (number less than 32)
724 \Gname call pcre[16|32]_get_named_substring() for substring "name" after a successful match (name termin-
725 ated by next non-alphanumeric character)
726 \Jdd set up a JIT stack of dd kilobytes maximum (any number of digits)
727 \L call pcre[16|32]_get_substringlist() after a successful match
728 \M discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings
729 \N pass the PCRE_NOTEMPTY option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>; if used twice, pass the
730 PCRE_NOTEMPTY_ATSTART option
731 \Odd set the size of the output vector passed to <b>pcre[16|32]_exec()</b> to dd (any number of digits)
732 \P pass the PCRE_PARTIAL_SOFT option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>; if used twice, pass the
733 PCRE_PARTIAL_HARD option
734 \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd (any number of digits)
735 \R pass the PCRE_DFA_RESTART option to <b>pcre[16|32]_dfa_exec()</b>
736 \S output details of memory get/free calls during matching
737 \Y pass the PCRE_NO_START_OPTIMIZE option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
738 \Z pass the PCRE_NOTEOL option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
739 \? pass the PCRE_NO_UTF[8|16|32]_CHECK option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
740 \&#62;dd start the match at offset dd (optional "-"; then any number of digits); this sets the <i>startoffset</i>
741 argument for <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
742 \&#60;cr&#62; pass the PCRE_NEWLINE_CR option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
743 \&#60;lf&#62; pass the PCRE_NEWLINE_LF option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
744 \&#60;crlf&#62; pass the PCRE_NEWLINE_CRLF option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
745 \&#60;anycrlf&#62; pass the PCRE_NEWLINE_ANYCRLF option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
746 \&#60;any&#62; pass the PCRE_NEWLINE_ANY option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
747 </pre>
748 The use of \x{hh...} is not dependent on the use of the <b>/8</b> modifier on
749 the pattern. It is recognized always. There may be any number of hexadecimal
750 digits inside the braces; invalid values provoke error messages.
751 </P>
752 <P>
753 Note that \xhh specifies one byte rather than one character in UTF-8 mode;
754 this makes it possible to construct invalid UTF-8 sequences for testing
755 purposes. On the other hand, \x{hh} is interpreted as a UTF-8 character in
756 UTF-8 mode, generating more than one byte if the value is greater than 127.
757 When testing the 8-bit library not in UTF-8 mode, \x{hh} generates one byte
758 for values less than 256, and causes an error for greater values.
759 </P>
760 <P>
761 In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it
762 possible to construct invalid UTF-16 sequences for testing purposes.
763 </P>
764 <P>
765 In UTF-32 mode, all 4- to 8-digit \x{...} values are accepted. This makes it
766 possible to construct invalid UTF-32 sequences for testing purposes.
767 </P>
768 <P>
769 The escapes that specify line ending sequences are literal strings, exactly as
770 shown. No more than one newline setting should be present in any data line.
771 </P>
772 <P>
773 A backslash followed by anything else just escapes the anything else. If
774 the very last character is a backslash, it is ignored. This gives a way of
775 passing an empty line as data, since a real empty line terminates the data
776 input.
777 </P>
778 <P>
779 The <b>\J</b> escape provides a way of setting the maximum stack size that is
780 used by the just-in-time optimization code. It is ignored if JIT optimization
781 is not being used. Providing a stack that is larger than the default 32K is
782 necessary only for very complicated patterns.
783 </P>
784 <P>
785 If \M is present, <b>pcretest</b> calls <b>pcre[16|32]_exec()</b> several times,
786 with different values in the <i>match_limit</i> and <i>match_limit_recursion</i>
787 fields of the <b>pcre[16|32]_extra</b> data structure, until it finds the minimum
788 numbers for each parameter that allow <b>pcre[16|32]_exec()</b> to complete without
789 error. Because this is testing a specific feature of the normal interpretive
790 <b>pcre[16|32]_exec()</b> execution, the use of any JIT optimization that might
791 have been set up by the <b>/S+</b> qualifier of <b>-s+</b> option is disabled.
792 </P>
793 <P>
794 The <i>match_limit</i> number is a measure of the amount of backtracking
795 that takes place, and checking it out can be instructive. For most simple
796 matches, the number is quite small, but for patterns with very large numbers of
797 matching possibilities, it can become large very quickly with increasing length
798 of subject string. The <i>match_limit_recursion</i> number is a measure of how
799 much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
800 needed to complete the match attempt.
801 </P>
802 <P>
803 When \O is used, the value specified may be higher or lower than the size set
804 by the <b>-O</b> command line option (or defaulted to 45); \O applies only to
805 the call of <b>pcre[16|32]_exec()</b> for the line in which it appears.
806 </P>
807 <P>
808 If the <b>/P</b> modifier was present on the pattern, causing the POSIX wrapper
809 API to be used, the only option-setting sequences that have any effect are \B,
810 \N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
811 to be passed to <b>regexec()</b>.
812 </P>
813 <br><a name="SEC8" href="#TOC1">THE ALTERNATIVE MATCHING FUNCTION</a><br>
814 <P>
815 By default, <b>pcretest</b> uses the standard PCRE matching function,
816 <b>pcre[16|32]_exec()</b> to match each data line. PCRE also supports an
817 alternative matching function, <b>pcre[16|32]_dfa_test()</b>, which operates in a
818 different way, and has some restrictions. The differences between the two
819 functions are described in the
820 <a href="pcrematching.html"><b>pcrematching</b></a>
821 documentation.
822 </P>
823 <P>
824 If a data line contains the \D escape sequence, or if the command line
825 contains the <b>-dfa</b> option, the alternative matching function is used.
826 This function finds all possible matches at a given point. If, however, the \F
827 escape sequence is present in the data line, it stops after the first match is
828 found. This is always the shortest possible match.
829 </P>
830 <br><a name="SEC9" href="#TOC1">DEFAULT OUTPUT FROM PCRETEST</a><br>
831 <P>
832 This section describes the output when the normal matching function,
833 <b>pcre[16|32]_exec()</b>, is being used.
834 </P>
835 <P>
836 When a match succeeds, <b>pcretest</b> outputs the list of captured substrings
837 that <b>pcre[16|32]_exec()</b> returns, starting with number 0 for the string that
838 matched the whole pattern. Otherwise, it outputs "No match" when the return is
839 PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
840 substring when <b>pcre[16|32]_exec()</b> returns PCRE_ERROR_PARTIAL. (Note that
841 this is the entire substring that was inspected during the partial match; it
842 may include characters before the actual match start if a lookbehind assertion,
843 \K, \b, or \B was involved.) For any other return, <b>pcretest</b> outputs
844 the PCRE negative error number and a short descriptive phrase. If the error is
845 a failed UTF string check, the offset of the start of the failing character and
846 the reason code are also output, provided that the size of the output vector is
847 at least two. Here is an example of an interactive <b>pcretest</b> run.
848 <pre>
849 $ pcretest
850 PCRE version 8.13 2011-04-30
851
852 re&#62; /^abc(\d+)/
853 data&#62; abc123
854 0: abc123
855 1: 123
856 data&#62; xyz
857 No match
858 </pre>
859 Unset capturing substrings that are not followed by one that is set are not
860 returned by <b>pcre[16|32]_exec()</b>, and are not shown by <b>pcretest</b>. In the
861 following example, there are two capturing substrings, but when the first data
862 line is matched, the second, unset substring is not shown. An "internal" unset
863 substring is shown as "&#60;unset&#62;", as for the second data line.
864 <pre>
865 re&#62; /(a)|(b)/
866 data&#62; a
867 0: a
868 1: a
869 data&#62; b
870 0: b
871 1: &#60;unset&#62;
872 2: b
873 </pre>
874 If the strings contain any non-printing characters, they are output as \xhh
875 escapes if the value is less than 256 and UTF mode is not set. Otherwise they
876 are output as \x{hh...} escapes. See below for the definition of non-printing
877 characters. If the pattern has the <b>/+</b> modifier, the output for substring
878 0 is followed by the the rest of the subject string, identified by "0+" like
879 this:
880 <pre>
881 re&#62; /cat/+
882 data&#62; cataract
883 0: cat
884 0+ aract
885 </pre>
886 If the pattern has the <b>/g</b> or <b>/G</b> modifier, the results of successive
887 matching attempts are output in sequence, like this:
888 <pre>
889 re&#62; /\Bi(\w\w)/g
890 data&#62; Mississippi
891 0: iss
892 1: ss
893 0: iss
894 1: ss
895 0: ipp
896 1: pp
897 </pre>
898 "No match" is output only if the first match attempt fails. Here is an example
899 of a failure message (the offset 4 that is specified by \&#62;4 is past the end of
900 the subject string):
901 <pre>
902 re&#62; /xyz/
903 data&#62; xyz\&#62;4
904 Error -24 (bad offset value)
905 </PRE>
906 </P>
907 <P>
908 If any of the sequences <b>\C</b>, <b>\G</b>, or <b>\L</b> are present in a
909 data line that is successfully matched, the substrings extracted by the
910 convenience functions are output with C, G, or L after the string number
911 instead of a colon. This is in addition to the normal full list. The string
912 length (that is, the return from the extraction function) is given in
913 parentheses after each string for <b>\C</b> and <b>\G</b>.
914 </P>
915 <P>
916 Note that whereas patterns can be continued over several lines (a plain "&#62;"
917 prompt is used for continuations), data lines may not. However newlines can be
918 included in data by means of the \n escape (or \r, \r\n, etc., depending on
919 the newline sequence setting).
920 </P>
921 <br><a name="SEC10" href="#TOC1">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a><br>
922 <P>
923 When the alternative matching function, <b>pcre[16|32]_dfa_exec()</b>, is used (by
924 means of the \D escape sequence or the <b>-dfa</b> command line option), the
925 output consists of a list of all the matches that start at the first point in
926 the subject where there is at least one match. For example:
927 <pre>
928 re&#62; /(tang|tangerine|tan)/
929 data&#62; yellow tangerine\D
930 0: tangerine
931 1: tang
932 2: tan
933 </pre>
934 (Using the normal matching function on this data finds only "tang".) The
935 longest matching string is always given first (and numbered zero). After a
936 PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
937 partially matching substring. (Note that this is the entire substring that was
938 inspected during the partial match; it may include characters before the actual
939 match start if a lookbehind assertion, \K, \b, or \B was involved.)
940 </P>
941 <P>
942 If <b>/g</b> is present on the pattern, the search for further matches resumes
943 at the end of the longest match. For example:
944 <pre>
945 re&#62; /(tang|tangerine|tan)/g
946 data&#62; yellow tangerine and tangy sultana\D
947 0: tangerine
948 1: tang
949 2: tan
950 0: tang
951 1: tan
952 0: tan
953 </pre>
954 Since the matching function does not support substring capture, the escape
955 sequences that are concerned with captured substrings are not relevant.
956 </P>
957 <br><a name="SEC11" href="#TOC1">RESTARTING AFTER A PARTIAL MATCH</a><br>
958 <P>
959 When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
960 indicating that the subject partially matched the pattern, you can restart the
961 match with additional subject data by means of the \R escape sequence. For
962 example:
963 <pre>
964 re&#62; /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
965 data&#62; 23ja\P\D
966 Partial match: 23ja
967 data&#62; n05\R\D
968 0: n05
969 </pre>
970 For further information about partial matching, see the
971 <a href="pcrepartial.html"><b>pcrepartial</b></a>
972 documentation.
973 </P>
974 <br><a name="SEC12" href="#TOC1">CALLOUTS</a><br>
975 <P>
976 If the pattern contains any callout requests, <b>pcretest</b>'s callout function
977 is called during matching. This works with both matching functions. By default,
978 the called function displays the callout number, the start and current
979 positions in the text at the callout time, and the next pattern item to be
980 tested. For example:
981 <pre>
982 ---&#62;pqrabcdef
983 0 ^ ^ \d
984 </pre>
985 This output indicates that callout number 0 occurred for a match attempt
986 starting at the fourth character of the subject string, when the pointer was at
987 the seventh character of the data, and when the next pattern item was \d. Just
988 one circumflex is output if the start and current positions are the same.
989 </P>
990 <P>
991 Callouts numbered 255 are assumed to be automatic callouts, inserted as a
992 result of the <b>/C</b> pattern modifier. In this case, instead of showing the
993 callout number, the offset in the pattern, preceded by a plus, is output. For
994 example:
995 <pre>
996 re&#62; /\d?[A-E]\*/C
997 data&#62; E*
998 ---&#62;E*
999 +0 ^ \d?
1000 +3 ^ [A-E]
1001 +8 ^^ \*
1002 +10 ^ ^
1003 0: E*
1004 </pre>
1005 If a pattern contains (*MARK) items, an additional line is output whenever
1006 a change of latest mark is passed to the callout function. For example:
1007 <pre>
1008 re&#62; /a(*MARK:X)bc/C
1009 data&#62; abc
1010 ---&#62;abc
1011 +0 ^ a
1012 +1 ^^ (*MARK:X)
1013 +10 ^^ b
1014 Latest Mark: X
1015 +11 ^ ^ c
1016 +12 ^ ^
1017 0: abc
1018 </pre>
1019 The mark changes between matching "a" and "b", but stays the same for the rest
1020 of the match, so nothing more is output. If, as a result of backtracking, the
1021 mark reverts to being unset, the text "&#60;unset&#62;" is output.
1022 </P>
1023 <P>
1024 The callout function in <b>pcretest</b> returns zero (carry on matching) by
1025 default, but you can use a \C item in a data line (as described above) to
1026 change this and other parameters of the callout.
1027 </P>
1028 <P>
1029 Inserting callouts can be helpful when using <b>pcretest</b> to check
1030 complicated regular expressions. For further information about callouts, see
1031 the
1032 <a href="pcrecallout.html"><b>pcrecallout</b></a>
1033 documentation.
1034 </P>
1035 <br><a name="SEC13" href="#TOC1">NON-PRINTING CHARACTERS</a><br>
1036 <P>
1037 When <b>pcretest</b> is outputting text in the compiled version of a pattern,
1038 bytes other than 32-126 are always treated as non-printing characters are are
1039 therefore shown as hex escapes.
1040 </P>
1041 <P>
1042 When <b>pcretest</b> is outputting text that is a matched part of a subject
1043 string, it behaves in the same way, unless a different locale has been set for
1044 the pattern (using the <b>/L</b> modifier). In this case, the <b>isprint()</b>
1045 function to distinguish printing and non-printing characters.
1046 </P>
1047 <br><a name="SEC14" href="#TOC1">SAVING AND RELOADING COMPILED PATTERNS</a><br>
1048 <P>
1049 The facilities described in this section are not available when the POSIX
1050 interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is
1051 specified.
1052 </P>
1053 <P>
1054 When the POSIX interface is not in use, you can cause <b>pcretest</b> to write a
1055 compiled pattern to a file, by following the modifiers with &#62; and a file name.
1056 For example:
1057 <pre>
1058 /pattern/im &#62;/some/file
1059 </pre>
1060 See the
1061 <a href="pcreprecompile.html"><b>pcreprecompile</b></a>
1062 documentation for a discussion about saving and re-using compiled patterns.
1063 Note that if the pattern was successfully studied with JIT optimization, the
1064 JIT data cannot be saved.
1065 </P>
1066 <P>
1067 The data that is written is binary. The first eight bytes are the length of the
1068 compiled pattern data followed by the length of the optional study data, each
1069 written as four bytes in big-endian order (most significant byte first). If
1070 there is no study data (either the pattern was not studied, or studying did not
1071 return any data), the second length is zero. The lengths are followed by an
1072 exact copy of the compiled pattern. If there is additional study data, this
1073 (excluding any JIT data) follows immediately after the compiled pattern. After
1074 writing the file, <b>pcretest</b> expects to read a new pattern.
1075 </P>
1076 <P>
1077 A saved pattern can be reloaded into <b>pcretest</b> by specifying &#60; and a file
1078 name instead of a pattern. There must be no space between &#60; and the file name,
1079 which must not contain a &#60; character, as otherwise <b>pcretest</b> will
1080 interpret the line as a pattern delimited by &#60; characters. For example:
1081 <pre>
1082 re&#62; &#60;/some/file
1083 Compiled pattern loaded from /some/file
1084 No study data
1085 </pre>
1086 If the pattern was previously studied with the JIT optimization, the JIT
1087 information cannot be saved and restored, and so is lost. When the pattern has
1088 been loaded, <b>pcretest</b> proceeds to read data lines in the usual way.
1089 </P>
1090 <P>
1091 You can copy a file written by <b>pcretest</b> to a different host and reload it
1092 there, even if the new host has opposite endianness to the one on which the
1093 pattern was compiled. For example, you can compile on an i86 machine and run on
1094 a SPARC machine. When a pattern is reloaded on a host with different
1095 endianness, the confirmation message is changed to:
1096 <pre>
1097 Compiled pattern (byte-inverted) loaded from /some/file
1098 </pre>
1099 The test suite contains some saved pre-compiled patterns with different
1100 endianness. These are reloaded using "&#60;!" instead of just "&#60;". This suppresses
1101 the "(byte-inverted)" text so that the output is the same on all hosts. It also
1102 forces debugging output once the pattern has been reloaded.
1103 </P>
1104 <P>
1105 File names for saving and reloading can be absolute or relative, but note that
1106 the shell facility of expanding a file name that starts with a tilde (~) is not
1107 available.
1108 </P>
1109 <P>
1110 The ability to save and reload files in <b>pcretest</b> is intended for testing
1111 and experimentation. It is not intended for production use because only a
1112 single pattern can be written to a file. Furthermore, there is no facility for
1113 supplying custom character tables for use with a reloaded pattern. If the
1114 original pattern was compiled with custom tables, an attempt to match a subject
1115 string using a reloaded pattern is likely to cause <b>pcretest</b> to crash.
1116 Finally, if you attempt to load a file that is not in the correct format, the
1117 result is undefined.
1118 </P>
1119 <br><a name="SEC15" href="#TOC1">SEE ALSO</a><br>
1120 <P>
1121 <b>pcre</b>(3), <b>pcre16</b>(3), <b>pcre32</b>(3), <b>pcreapi</b>(3),
1122 <b>pcrecallout</b>(3),
1123 <b>pcrejit</b>, <b>pcrematching</b>(3), <b>pcrepartial</b>(d),
1124 <b>pcrepattern</b>(3), <b>pcreprecompile</b>(3).
1125 </P>
1126 <br><a name="SEC16" href="#TOC1">AUTHOR</a><br>
1127 <P>
1128 Philip Hazel
1129 <br>
1130 University Computing Service
1131 <br>
1132 Cambridge CB2 3QH, England.
1133 <br>
1134 </P>
1135 <br><a name="SEC17" href="#TOC1">REVISION</a><br>
1136 <P>
1137 Last updated: 12 November 2013
1138 <br>
1139 Copyright &copy; 1997-2013 University of Cambridge.
1140 <br>
1141 <p>
1142 Return to the <a href="index.html">PCRE index page</a>.
1143 </p>

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