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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 bsr the default setting for what \R matches:
142 ANYCRLF or ANY
143 exit code is always 0
144 </pre>
145 The following options output 1 for true or 0 for false, and set the exit code
146 to the same value:
147 <pre>
148 ebcdic compiled for an EBCDIC environment
149 jit just-in-time support is available
150 pcre16 the 16-bit library was built
151 pcre32 the 32-bit library was built
152 pcre8 the 8-bit library was built
153 ucp Unicode property support is available
154 utf UTF-8 and/or UTF-16 and/or UTF-32 support
155 is available
156 </pre>
157 If an unknown option is given, an error message is output; the exit code is 0.
158 </P>
159 <P>
160 <b>-d</b>
161 Behave as if each pattern has the <b>/D</b> (debug) modifier; the internal
162 form and information about the compiled pattern is output after compilation;
163 <b>-d</b> is equivalent to <b>-b -i</b>.
164 </P>
165 <P>
166 <b>-dfa</b>
167 Behave as if each data line contains the \D escape sequence; this causes the
168 alternative matching function, <b>pcre[16|32]_dfa_exec()</b>, to be used instead
169 of the standard <b>pcre[16|32]_exec()</b> function (more detail is given below).
170 </P>
171 <P>
172 <b>-help</b>
173 Output a brief summary these options and then exit.
174 </P>
175 <P>
176 <b>-i</b>
177 Behave as if each pattern has the <b>/I</b> modifier; information about the
178 compiled pattern is given after compilation.
179 </P>
180 <P>
181 <b>-M</b>
182 Behave as if each data line contains the \M escape sequence; this causes
183 PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
184 calling <b>pcre[16|32]_exec()</b> repeatedly with different limits.
185 </P>
186 <P>
187 <b>-m</b>
188 Output the size of each compiled pattern after it has been compiled. This is
189 equivalent to adding <b>/M</b> to each regular expression. The size is given in
190 bytes for both libraries.
191 </P>
192 <P>
193 <b>-O</b>
194 Behave as if each pattern has the <b>/O</b> modifier, that is disable
195 auto-possessification for all patterns.
196 </P>
197 <P>
198 <b>-o</b> <i>osize</i>
199 Set the number of elements in the output vector that is used when calling
200 <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b> to be <i>osize</i>. The
201 default value is 45, which is enough for 14 capturing subexpressions for
202 <b>pcre[16|32]_exec()</b> or 22 different matches for
203 <b>pcre[16|32]_dfa_exec()</b>.
204 The vector size can be changed for individual matching calls by including \O
205 in the data line (see below).
206 </P>
207 <P>
208 <b>-p</b>
209 Behave as if each pattern has the <b>/P</b> modifier; the POSIX wrapper API is
210 used to call PCRE. None of the other options has any effect when <b>-p</b> is
211 set. This option can be used only with the 8-bit library.
212 </P>
213 <P>
214 <b>-q</b>
215 Do not output the version number of <b>pcretest</b> at the start of execution.
216 </P>
217 <P>
218 <b>-S</b> <i>size</i>
219 On Unix-like systems, set the size of the run-time stack to <i>size</i>
220 megabytes.
221 </P>
222 <P>
223 <b>-s</b> or <b>-s+</b>
224 Behave as if each pattern has the <b>/S</b> modifier; in other words, force each
225 pattern to be studied. If <b>-s+</b> is used, all the JIT compile options are
226 passed to <b>pcre[16|32]_study()</b>, causing just-in-time optimization to be set
227 up if it is available, for both full and partial matching. Specific JIT compile
228 options can be selected by following <b>-s+</b> with a digit in the range 1 to
229 7, which selects the JIT compile modes as follows:
230 <pre>
231 1 normal match only
232 2 soft partial match only
233 3 normal match and soft partial match
234 4 hard partial match only
235 6 soft and hard partial match
236 7 all three modes (default)
237 </pre>
238 If <b>-s++</b> is used instead of <b>-s+</b> (with or without a following digit),
239 the text "(JIT)" is added to the first output line after a match or no match
240 when JIT-compiled code was actually used.
241 <br>
242 <br>
243 Note that there are pattern options that can override <b>-s</b>, either
244 specifying no studying at all, or suppressing JIT compilation.
245 <br>
246 <br>
247 If the <b>/I</b> or <b>/D</b> option is present on a pattern (requesting output
248 about the compiled pattern), information about the result of studying is not
249 included when studying is caused only by <b>-s</b> and neither <b>-i</b> nor
250 <b>-d</b> is present on the command line. This behaviour means that the output
251 from tests that are run with and without <b>-s</b> should be identical, except
252 when options that output information about the actual running of a match are
253 set.
254 <br>
255 <br>
256 The <b>-M</b>, <b>-t</b>, and <b>-tm</b> options, which give information about
257 resources used, are likely to produce different output with and without
258 <b>-s</b>. Output may also differ if the <b>/C</b> option is present on an
259 individual pattern. This uses callouts to trace the the matching process, and
260 this may be different between studied and non-studied patterns. If the pattern
261 contains (*MARK) items there may also be differences, for the same reason. The
262 <b>-s</b> command line option can be overridden for specific patterns that
263 should never be studied (see the <b>/S</b> pattern modifier below).
264 </P>
265 <P>
266 <b>-t</b>
267 Run each compile, study, and match many times with a timer, and output the
268 resulting times per compile, study, or match (in milliseconds). Do not set
269 <b>-m</b> with <b>-t</b>, because you will then get the size output a zillion
270 times, and the timing will be distorted. You can control the number of
271 iterations that are used for timing by following <b>-t</b> with a number (as a
272 separate item on the command line). For example, "-t 1000" iterates 1000 times.
273 The default is to iterate 500000 times.
274 </P>
275 <P>
276 <b>-tm</b>
277 This is like <b>-t</b> except that it times only the matching phase, not the
278 compile or study phases.
279 </P>
280 <P>
281 <b>-T</b> <b>-TM</b>
282 These behave like <b>-t</b> and <b>-tm</b>, but in addition, at the end of a run,
283 the total times for all compiles, studies, and matches are output.
284 </P>
285 <br><a name="SEC5" href="#TOC1">DESCRIPTION</a><br>
286 <P>
287 If <b>pcretest</b> is given two filename arguments, it reads from the first and
288 writes to the second. If it is given only one filename argument, it reads from
289 that file and writes to stdout. Otherwise, it reads from stdin and writes to
290 stdout, and prompts for each line of input, using "re&#62;" to prompt for regular
291 expressions, and "data&#62;" to prompt for data lines.
292 </P>
293 <P>
294 When <b>pcretest</b> is built, a configuration option can specify that it should
295 be linked with the <b>libreadline</b> library. When this is done, if the input
296 is from a terminal, it is read using the <b>readline()</b> function. This
297 provides line-editing and history facilities. The output from the <b>-help</b>
298 option states whether or not <b>readline()</b> will be used.
299 </P>
300 <P>
301 The program handles any number of sets of input on a single input file. Each
302 set starts with a regular expression, and continues with any number of data
303 lines to be matched against that pattern.
304 </P>
305 <P>
306 Each data line is matched separately and independently. If you want to do
307 multi-line matches, you have to use the \n escape sequence (or \r or \r\n,
308 etc., depending on the newline setting) in a single line of input to encode the
309 newline sequences. There is no limit on the length of data lines; the input
310 buffer is automatically extended if it is too small.
311 </P>
312 <P>
313 An empty line signals the end of the data lines, at which point a new regular
314 expression is read. The regular expressions are given enclosed in any
315 non-alphanumeric delimiters other than backslash, for example:
316 <pre>
317 /(a|bc)x+yz/
318 </pre>
319 White space before the initial delimiter is ignored. A regular expression may
320 be continued over several input lines, in which case the newline characters are
321 included within it. It is possible to include the delimiter within the pattern
322 by escaping it, for example
323 <pre>
324 /abc\/def/
325 </pre>
326 If you do so, the escape and the delimiter form part of the pattern, but since
327 delimiters are always non-alphanumeric, this does not affect its interpretation.
328 If the terminating delimiter is immediately followed by a backslash, for
329 example,
330 <pre>
331 /abc/\
332 </pre>
333 then a backslash is added to the end of the pattern. This is done to provide a
334 way of testing the error condition that arises if a pattern finishes with a
335 backslash, because
336 <pre>
337 /abc\/
338 </pre>
339 is interpreted as the first line of a pattern that starts with "abc/", causing
340 pcretest to read the next line as a continuation of the regular expression.
341 </P>
342 <br><a name="SEC6" href="#TOC1">PATTERN MODIFIERS</a><br>
343 <P>
344 A pattern may be followed by any number of modifiers, which are mostly single
345 characters, though some of these can be qualified by further characters.
346 Following Perl usage, these are referred to below as, for example, "the
347 <b>/i</b> modifier", even though the delimiter of the pattern need not always be
348 a slash, and no slash is used when writing modifiers. White space may appear
349 between the final pattern delimiter and the first modifier, and between the
350 modifiers themselves. For reference, here is a complete list of modifiers. They
351 fall into several groups that are described in detail in the following
352 sections.
353 <pre>
354 <b>/8</b> set UTF mode
355 <b>/9</b> set PCRE_NEVER_UTF (locks out UTF mode)
356 <b>/?</b> disable UTF validity check
357 <b>/+</b> show remainder of subject after match
358 <b>/=</b> show all captures (not just those that are set)
359
360 <b>/A</b> set PCRE_ANCHORED
361 <b>/B</b> show compiled code
362 <b>/C</b> set PCRE_AUTO_CALLOUT
363 <b>/D</b> same as <b>/B</b> plus <b>/I</b>
364 <b>/E</b> set PCRE_DOLLAR_ENDONLY
365 <b>/F</b> flip byte order in compiled pattern
366 <b>/f</b> set PCRE_FIRSTLINE
367 <b>/G</b> find all matches (shorten string)
368 <b>/g</b> find all matches (use startoffset)
369 <b>/I</b> show information about pattern
370 <b>/i</b> set PCRE_CASELESS
371 <b>/J</b> set PCRE_DUPNAMES
372 <b>/K</b> show backtracking control names
373 <b>/L</b> set locale
374 <b>/M</b> show compiled memory size
375 <b>/m</b> set PCRE_MULTILINE
376 <b>/N</b> set PCRE_NO_AUTO_CAPTURE
377 <b>/O</b> set PCRE_NO_AUTO_POSSESS
378 <b>/P</b> use the POSIX wrapper
379 <b>/Q</b> test external stack check function
380 <b>/S</b> study the pattern after compilation
381 <b>/s</b> set PCRE_DOTALL
382 <b>/T</b> select character tables
383 <b>/U</b> set PCRE_UNGREEDY
384 <b>/W</b> set PCRE_UCP
385 <b>/X</b> set PCRE_EXTRA
386 <b>/x</b> set PCRE_EXTENDED
387 <b>/Y</b> set PCRE_NO_START_OPTIMIZE
388 <b>/Z</b> don't show lengths in <b>/B</b> output
389
390 <b>/&#60;any&#62;</b> set PCRE_NEWLINE_ANY
391 <b>/&#60;anycrlf&#62;</b> set PCRE_NEWLINE_ANYCRLF
392 <b>/&#60;cr&#62;</b> set PCRE_NEWLINE_CR
393 <b>/&#60;crlf&#62;</b> set PCRE_NEWLINE_CRLF
394 <b>/&#60;lf&#62;</b> set PCRE_NEWLINE_LF
395 <b>/&#60;bsr_anycrlf&#62;</b> set PCRE_BSR_ANYCRLF
396 <b>/&#60;bsr_unicode&#62;</b> set PCRE_BSR_UNICODE
397 <b>/&#60;JS&#62;</b> set PCRE_JAVASCRIPT_COMPAT
398
399 </PRE>
400 </P>
401 <br><b>
402 Perl-compatible modifiers
403 </b><br>
404 <P>
405 The <b>/i</b>, <b>/m</b>, <b>/s</b>, and <b>/x</b> modifiers set the PCRE_CASELESS,
406 PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
407 <b>pcre[16|32]_compile()</b> is called. These four modifier letters have the same
408 effect as they do in Perl. For example:
409 <pre>
410 /caseless/i
411
412 </PRE>
413 </P>
414 <br><b>
415 Modifiers for other PCRE options
416 </b><br>
417 <P>
418 The following table shows additional modifiers for setting PCRE compile-time
419 options that do not correspond to anything in Perl:
420 <pre>
421 <b>/8</b> PCRE_UTF8 ) when using the 8-bit
422 <b>/?</b> PCRE_NO_UTF8_CHECK ) library
423
424 <b>/8</b> PCRE_UTF16 ) when using the 16-bit
425 <b>/?</b> PCRE_NO_UTF16_CHECK ) library
426
427 <b>/8</b> PCRE_UTF32 ) when using the 32-bit
428 <b>/?</b> PCRE_NO_UTF32_CHECK ) library
429
430 <b>/9</b> PCRE_NEVER_UTF
431 <b>/A</b> PCRE_ANCHORED
432 <b>/C</b> PCRE_AUTO_CALLOUT
433 <b>/E</b> PCRE_DOLLAR_ENDONLY
434 <b>/f</b> PCRE_FIRSTLINE
435 <b>/J</b> PCRE_DUPNAMES
436 <b>/N</b> PCRE_NO_AUTO_CAPTURE
437 <b>/O</b> PCRE_NO_AUTO_POSSESS
438 <b>/U</b> PCRE_UNGREEDY
439 <b>/W</b> PCRE_UCP
440 <b>/X</b> PCRE_EXTRA
441 <b>/Y</b> PCRE_NO_START_OPTIMIZE
442 <b>/&#60;any&#62;</b> PCRE_NEWLINE_ANY
443 <b>/&#60;anycrlf&#62;</b> PCRE_NEWLINE_ANYCRLF
444 <b>/&#60;cr&#62;</b> PCRE_NEWLINE_CR
445 <b>/&#60;crlf&#62;</b> PCRE_NEWLINE_CRLF
446 <b>/&#60;lf&#62;</b> PCRE_NEWLINE_LF
447 <b>/&#60;bsr_anycrlf&#62;</b> PCRE_BSR_ANYCRLF
448 <b>/&#60;bsr_unicode&#62;</b> PCRE_BSR_UNICODE
449 <b>/&#60;JS&#62;</b> PCRE_JAVASCRIPT_COMPAT
450 </pre>
451 The modifiers that are enclosed in angle brackets are literal strings as shown,
452 including the angle brackets, but the letters within can be in either case.
453 This example sets multiline matching with CRLF as the line ending sequence:
454 <pre>
455 /^abc/m&#60;CRLF&#62;
456 </pre>
457 As well as turning on the PCRE_UTF8/16/32 option, the <b>/8</b> modifier causes
458 all non-printing characters in output strings to be printed using the
459 \x{hh...} notation. Otherwise, those less than 0x100 are output in hex without
460 the curly brackets.
461 </P>
462 <P>
463 Full details of the PCRE options are given in the
464 <a href="pcreapi.html"><b>pcreapi</b></a>
465 documentation.
466 </P>
467 <br><b>
468 Finding all matches in a string
469 </b><br>
470 <P>
471 Searching for all possible matches within each subject string can be requested
472 by the <b>/g</b> or <b>/G</b> modifier. After finding a match, PCRE is called
473 again to search the remainder of the subject string. The difference between
474 <b>/g</b> and <b>/G</b> is that the former uses the <i>startoffset</i> argument to
475 <b>pcre[16|32]_exec()</b> to start searching at a new point within the entire
476 string (which is in effect what Perl does), whereas the latter passes over a
477 shortened substring. This makes a difference to the matching process if the
478 pattern begins with a lookbehind assertion (including \b or \B).
479 </P>
480 <P>
481 If any call to <b>pcre[16|32]_exec()</b> in a <b>/g</b> or <b>/G</b> sequence matches
482 an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
483 PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
484 same point. If this second match fails, the start offset is advanced, and the
485 normal match is retried. This imitates the way Perl handles such cases when
486 using the <b>/g</b> modifier or the <b>split()</b> function. Normally, the start
487 offset is advanced by one character, but if the newline convention recognizes
488 CRLF as a newline, and the current character is CR followed by LF, an advance
489 of two is used.
490 </P>
491 <br><b>
492 Other modifiers
493 </b><br>
494 <P>
495 There are yet more modifiers for controlling the way <b>pcretest</b>
496 operates.
497 </P>
498 <P>
499 The <b>/+</b> modifier requests that as well as outputting the substring that
500 matched the entire pattern, <b>pcretest</b> should in addition output the
501 remainder of the subject string. This is useful for tests where the subject
502 contains multiple copies of the same substring. If the <b>+</b> modifier appears
503 twice, the same action is taken for captured substrings. In each case the
504 remainder is output on the following line with a plus character following the
505 capture number. Note that this modifier must not immediately follow the /S
506 modifier because /S+ and /S++ have other meanings.
507 </P>
508 <P>
509 The <b>/=</b> modifier requests that the values of all potential captured
510 parentheses be output after a match. By default, only those up to the highest
511 one actually used in the match are output (corresponding to the return code
512 from <b>pcre[16|32]_exec()</b>). Values in the offsets vector corresponding to
513 higher numbers should be set to -1, and these are output as "&#60;unset&#62;". This
514 modifier gives a way of checking that this is happening.
515 </P>
516 <P>
517 The <b>/B</b> modifier is a debugging feature. It requests that <b>pcretest</b>
518 output a representation of the compiled code after compilation. Normally this
519 information contains length and offset values; however, if <b>/Z</b> is also
520 present, this data is replaced by spaces. This is a special feature for use in
521 the automatic test scripts; it ensures that the same output is generated for
522 different internal link sizes.
523 </P>
524 <P>
525 The <b>/D</b> modifier is a PCRE debugging feature, and is equivalent to
526 <b>/BI</b>, that is, both the <b>/B</b> and the <b>/I</b> modifiers.
527 </P>
528 <P>
529 The <b>/F</b> modifier causes <b>pcretest</b> to flip the byte order of the
530 2-byte and 4-byte fields in the compiled pattern. This facility is for testing
531 the feature in PCRE that allows it to execute patterns that were compiled on a
532 host with a different endianness. This feature is not available when the POSIX
533 interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is
534 specified. See also the section about saving and reloading compiled patterns
535 below.
536 </P>
537 <P>
538 The <b>/I</b> modifier requests that <b>pcretest</b> output information about the
539 compiled pattern (whether it is anchored, has a fixed first character, and
540 so on). It does this by calling <b>pcre[16|32]_fullinfo()</b> after compiling a
541 pattern. If the pattern is studied, the results of that are also output. In
542 this output, the word "char" means a non-UTF character, that is, the value of a
543 single data item (8-bit, 16-bit, or 32-bit, depending on the library that is
544 being tested).
545 </P>
546 <P>
547 The <b>/K</b> modifier requests <b>pcretest</b> to show names from backtracking
548 control verbs that are returned from calls to <b>pcre[16|32]_exec()</b>. It causes
549 <b>pcretest</b> to create a <b>pcre[16|32]_extra</b> block if one has not already
550 been created by a call to <b>pcre[16|32]_study()</b>, and to set the
551 PCRE_EXTRA_MARK flag and the <b>mark</b> field within it, every time that
552 <b>pcre[16|32]_exec()</b> is called. If the variable that the <b>mark</b> field
553 points to is non-NULL for a match, non-match, or partial match, <b>pcretest</b>
554 prints the string to which it points. For a match, this is shown on a line by
555 itself, tagged with "MK:". For a non-match it is added to the message.
556 </P>
557 <P>
558 The <b>/L</b> modifier must be followed directly by the name of a locale, for
559 example,
560 <pre>
561 /pattern/Lfr_FR
562 </pre>
563 For this reason, it must be the last modifier. The given locale is set,
564 <b>pcre[16|32]_maketables()</b> is called to build a set of character tables for
565 the locale, and this is then passed to <b>pcre[16|32]_compile()</b> when compiling
566 the regular expression. Without an <b>/L</b> (or <b>/T</b>) modifier, NULL is
567 passed as the tables pointer; that is, <b>/L</b> applies only to the expression
568 on which it appears.
569 </P>
570 <P>
571 The <b>/M</b> modifier causes the size in bytes of the memory block used to hold
572 the compiled pattern to be output. This does not include the size of the
573 <b>pcre[16|32]</b> block; it is just the actual compiled data. If the pattern is
574 successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the
575 JIT compiled code is also output.
576 </P>
577 <P>
578 The <b>/Q</b> modifier is used to test the use of <b>pcre_stack_guard</b>. It
579 must be followed by '0' or '1', specifying the return code to be given from an
580 external function that is passed to PCRE and used for stack checking during
581 compilation (see the
582 <a href="pcreapi.html"><b>pcreapi</b></a>
583 documentation for details).
584 </P>
585 <P>
586 The <b>/S</b> modifier causes <b>pcre[16|32]_study()</b> to be called after the
587 expression has been compiled, and the results used when the expression is
588 matched. There are a number of qualifying characters that may follow <b>/S</b>.
589 They may appear in any order.
590 </P>
591 <P>
592 If <b>/S</b> is followed by an exclamation mark, <b>pcre[16|32]_study()</b> is
593 called with the PCRE_STUDY_EXTRA_NEEDED option, causing it always to return a
594 <b>pcre_extra</b> block, even when studying discovers no useful information.
595 </P>
596 <P>
597 If <b>/S</b> is followed by a second S character, it suppresses studying, even
598 if it was requested externally by the <b>-s</b> command line option. This makes
599 it possible to specify that certain patterns are always studied, and others are
600 never studied, independently of <b>-s</b>. This feature is used in the test
601 files in a few cases where the output is different when the pattern is studied.
602 </P>
603 <P>
604 If the <b>/S</b> modifier is followed by a + character, the call to
605 <b>pcre[16|32]_study()</b> is made with all the JIT study options, requesting
606 just-in-time optimization support if it is available, for both normal and
607 partial matching. If you want to restrict the JIT compiling modes, you can
608 follow <b>/S+</b> with a digit in the range 1 to 7:
609 <pre>
610 1 normal match only
611 2 soft partial match only
612 3 normal match and soft partial match
613 4 hard partial match only
614 6 soft and hard partial match
615 7 all three modes (default)
616 </pre>
617 If <b>/S++</b> is used instead of <b>/S+</b> (with or without a following digit),
618 the text "(JIT)" is added to the first output line after a match or no match
619 when JIT-compiled code was actually used.
620 </P>
621 <P>
622 Note that there is also an independent <b>/+</b> modifier; it must not be given
623 immediately after <b>/S</b> or <b>/S+</b> because this will be misinterpreted.
624 </P>
625 <P>
626 If JIT studying is successful, the compiled JIT code will automatically be used
627 when <b>pcre[16|32]_exec()</b> is run, except when incompatible run-time options
628 are specified. For more details, see the
629 <a href="pcrejit.html"><b>pcrejit</b></a>
630 documentation. See also the <b>\J</b> escape sequence below for a way of
631 setting the size of the JIT stack.
632 </P>
633 <P>
634 Finally, if <b>/S</b> is followed by a minus character, JIT compilation is
635 suppressed, even if it was requested externally by the <b>-s</b> command line
636 option. This makes it possible to specify that JIT is never to be used for
637 certain patterns.
638 </P>
639 <P>
640 The <b>/T</b> modifier must be followed by a single digit. It causes a specific
641 set of built-in character tables to be passed to <b>pcre[16|32]_compile()</b>. It
642 is used in the standard PCRE tests to check behaviour with different character
643 tables. The digit specifies the tables as follows:
644 <pre>
645 0 the default ASCII tables, as distributed in
646 pcre_chartables.c.dist
647 1 a set of tables defining ISO 8859 characters
648 </pre>
649 In table 1, some characters whose codes are greater than 128 are identified as
650 letters, digits, spaces, etc.
651 </P>
652 <br><b>
653 Using the POSIX wrapper API
654 </b><br>
655 <P>
656 The <b>/P</b> modifier causes <b>pcretest</b> to call PCRE via the POSIX wrapper
657 API rather than its native API. This supports only the 8-bit library. When
658 <b>/P</b> is set, the following modifiers set options for the <b>regcomp()</b>
659 function:
660 <pre>
661 /i REG_ICASE
662 /m REG_NEWLINE
663 /N REG_NOSUB
664 /s REG_DOTALL )
665 /U REG_UNGREEDY ) These options are not part of
666 /W REG_UCP ) the POSIX standard
667 /8 REG_UTF8 )
668 </pre>
669 The <b>/+</b> modifier works as described above. All other modifiers are
670 ignored.
671 </P>
672 <br><b>
673 Locking out certain modifiers
674 </b><br>
675 <P>
676 PCRE can be compiled with or without support for certain features such as
677 UTF-8/16/32 or Unicode properties. Accordingly, the standard tests are split up
678 into a number of different files that are selected for running depending on
679 which features are available. When updating the tests, it is all too easy to
680 put a new test into the wrong file by mistake; for example, to put a test that
681 requires UTF support into a file that is used when it is not available. To help
682 detect such mistakes as early as possible, there is a facility for locking out
683 specific modifiers. If an input line for <b>pcretest</b> starts with the string
684 "&#60; forbid " the following sequence of characters is taken as a list of
685 forbidden modifiers. For example, in the test files that must not use UTF or
686 Unicode property support, this line appears:
687 <pre>
688 &#60; forbid 8W
689 </pre>
690 This locks out the /8 and /W modifiers. An immediate error is given if they are
691 subsequently encountered. If the character string contains &#60; but not &#62;, all the
692 multi-character modifiers that begin with &#60; are locked out. Otherwise, such
693 modifiers must be explicitly listed, for example:
694 <pre>
695 &#60; forbid &#60;JS&#62;&#60;cr&#62;
696 </pre>
697 There must be a single space between &#60; and "forbid" for this feature to be
698 recognised. If there is not, the line is interpreted either as a request to
699 re-load a pre-compiled pattern (see "SAVING AND RELOADING COMPILED PATTERNS"
700 below) or, if there is a another &#60; character, as a pattern that uses &#60; as its
701 delimiter.
702 </P>
703 <br><a name="SEC7" href="#TOC1">DATA LINES</a><br>
704 <P>
705 Before each data line is passed to <b>pcre[16|32]_exec()</b>, leading and trailing
706 white space is removed, and it is then scanned for \ escapes. Some of these
707 are pretty esoteric features, intended for checking out some of the more
708 complicated features of PCRE. If you are just testing "ordinary" regular
709 expressions, you probably don't need any of these. The following escapes are
710 recognized:
711 <pre>
712 \a alarm (BEL, \x07)
713 \b backspace (\x08)
714 \e escape (\x27)
715 \f form feed (\x0c)
716 \n newline (\x0a)
717 \qdd set the PCRE_MATCH_LIMIT limit to dd (any number of digits)
718 \r carriage return (\x0d)
719 \t tab (\x09)
720 \v vertical tab (\x0b)
721 \nnn octal character (up to 3 octal digits); always
722 a byte unless &#62; 255 in UTF-8 or 16-bit or 32-bit mode
723 \o{dd...} octal character (any number of octal digits}
724 \xhh hexadecimal byte (up to 2 hex digits)
725 \x{hh...} hexadecimal character (any number of hex digits)
726 \A pass the PCRE_ANCHORED option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
727 \B pass the PCRE_NOTBOL option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
728 \Cdd call pcre[16|32]_copy_substring() for substring dd after a successful match (number less than 32)
729 \Cname call pcre[16|32]_copy_named_substring() for substring "name" after a successful match (name termin-
730 ated by next non alphanumeric character)
731 \C+ show the current captured substrings at callout time
732 \C- do not supply a callout function
733 \C!n return 1 instead of 0 when callout number n is reached
734 \C!n!m return 1 instead of 0 when callout number n is reached for the nth time
735 \C*n pass the number n (may be negative) as callout data; this is used as the callout return value
736 \D use the <b>pcre[16|32]_dfa_exec()</b> match function
737 \F only shortest match for <b>pcre[16|32]_dfa_exec()</b>
738 \Gdd call pcre[16|32]_get_substring() for substring dd after a successful match (number less than 32)
739 \Gname call pcre[16|32]_get_named_substring() for substring "name" after a successful match (name termin-
740 ated by next non-alphanumeric character)
741 \Jdd set up a JIT stack of dd kilobytes maximum (any number of digits)
742 \L call pcre[16|32]_get_substringlist() after a successful match
743 \M discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings
744 \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
745 PCRE_NOTEMPTY_ATSTART option
746 \Odd set the size of the output vector passed to <b>pcre[16|32]_exec()</b> to dd (any number of digits)
747 \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
748 PCRE_PARTIAL_HARD option
749 \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd (any number of digits)
750 \R pass the PCRE_DFA_RESTART option to <b>pcre[16|32]_dfa_exec()</b>
751 \S output details of memory get/free calls during matching
752 \Y pass the PCRE_NO_START_OPTIMIZE option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
753 \Z pass the PCRE_NOTEOL option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
754 \? 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>
755 \&#62;dd start the match at offset dd (optional "-"; then any number of digits); this sets the <i>startoffset</i>
756 argument for <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
757 \&#60;cr&#62; pass the PCRE_NEWLINE_CR option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
758 \&#60;lf&#62; pass the PCRE_NEWLINE_LF option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
759 \&#60;crlf&#62; pass the PCRE_NEWLINE_CRLF option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
760 \&#60;anycrlf&#62; pass the PCRE_NEWLINE_ANYCRLF option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
761 \&#60;any&#62; pass the PCRE_NEWLINE_ANY option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
762 </pre>
763 The use of \x{hh...} is not dependent on the use of the <b>/8</b> modifier on
764 the pattern. It is recognized always. There may be any number of hexadecimal
765 digits inside the braces; invalid values provoke error messages.
766 </P>
767 <P>
768 Note that \xhh specifies one byte rather than one character in UTF-8 mode;
769 this makes it possible to construct invalid UTF-8 sequences for testing
770 purposes. On the other hand, \x{hh} is interpreted as a UTF-8 character in
771 UTF-8 mode, generating more than one byte if the value is greater than 127.
772 When testing the 8-bit library not in UTF-8 mode, \x{hh} generates one byte
773 for values less than 256, and causes an error for greater values.
774 </P>
775 <P>
776 In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it
777 possible to construct invalid UTF-16 sequences for testing purposes.
778 </P>
779 <P>
780 In UTF-32 mode, all 4- to 8-digit \x{...} values are accepted. This makes it
781 possible to construct invalid UTF-32 sequences for testing purposes.
782 </P>
783 <P>
784 The escapes that specify line ending sequences are literal strings, exactly as
785 shown. No more than one newline setting should be present in any data line.
786 </P>
787 <P>
788 A backslash followed by anything else just escapes the anything else. If
789 the very last character is a backslash, it is ignored. This gives a way of
790 passing an empty line as data, since a real empty line terminates the data
791 input.
792 </P>
793 <P>
794 The <b>\J</b> escape provides a way of setting the maximum stack size that is
795 used by the just-in-time optimization code. It is ignored if JIT optimization
796 is not being used. Providing a stack that is larger than the default 32K is
797 necessary only for very complicated patterns.
798 </P>
799 <P>
800 If \M is present, <b>pcretest</b> calls <b>pcre[16|32]_exec()</b> several times,
801 with different values in the <i>match_limit</i> and <i>match_limit_recursion</i>
802 fields of the <b>pcre[16|32]_extra</b> data structure, until it finds the minimum
803 numbers for each parameter that allow <b>pcre[16|32]_exec()</b> to complete without
804 error. Because this is testing a specific feature of the normal interpretive
805 <b>pcre[16|32]_exec()</b> execution, the use of any JIT optimization that might
806 have been set up by the <b>/S+</b> qualifier of <b>-s+</b> option is disabled.
807 </P>
808 <P>
809 The <i>match_limit</i> number is a measure of the amount of backtracking
810 that takes place, and checking it out can be instructive. For most simple
811 matches, the number is quite small, but for patterns with very large numbers of
812 matching possibilities, it can become large very quickly with increasing length
813 of subject string. The <i>match_limit_recursion</i> number is a measure of how
814 much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
815 needed to complete the match attempt.
816 </P>
817 <P>
818 When \O is used, the value specified may be higher or lower than the size set
819 by the <b>-O</b> command line option (or defaulted to 45); \O applies only to
820 the call of <b>pcre[16|32]_exec()</b> for the line in which it appears.
821 </P>
822 <P>
823 If the <b>/P</b> modifier was present on the pattern, causing the POSIX wrapper
824 API to be used, the only option-setting sequences that have any effect are \B,
825 \N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
826 to be passed to <b>regexec()</b>.
827 </P>
828 <br><a name="SEC8" href="#TOC1">THE ALTERNATIVE MATCHING FUNCTION</a><br>
829 <P>
830 By default, <b>pcretest</b> uses the standard PCRE matching function,
831 <b>pcre[16|32]_exec()</b> to match each data line. PCRE also supports an
832 alternative matching function, <b>pcre[16|32]_dfa_test()</b>, which operates in a
833 different way, and has some restrictions. The differences between the two
834 functions are described in the
835 <a href="pcrematching.html"><b>pcrematching</b></a>
836 documentation.
837 </P>
838 <P>
839 If a data line contains the \D escape sequence, or if the command line
840 contains the <b>-dfa</b> option, the alternative matching function is used.
841 This function finds all possible matches at a given point. If, however, the \F
842 escape sequence is present in the data line, it stops after the first match is
843 found. This is always the shortest possible match.
844 </P>
845 <br><a name="SEC9" href="#TOC1">DEFAULT OUTPUT FROM PCRETEST</a><br>
846 <P>
847 This section describes the output when the normal matching function,
848 <b>pcre[16|32]_exec()</b>, is being used.
849 </P>
850 <P>
851 When a match succeeds, <b>pcretest</b> outputs the list of captured substrings
852 that <b>pcre[16|32]_exec()</b> returns, starting with number 0 for the string that
853 matched the whole pattern. Otherwise, it outputs "No match" when the return is
854 PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
855 substring when <b>pcre[16|32]_exec()</b> returns PCRE_ERROR_PARTIAL. (Note that
856 this is the entire substring that was inspected during the partial match; it
857 may include characters before the actual match start if a lookbehind assertion,
858 \K, \b, or \B was involved.) For any other return, <b>pcretest</b> outputs
859 the PCRE negative error number and a short descriptive phrase. If the error is
860 a failed UTF string check, the offset of the start of the failing character and
861 the reason code are also output, provided that the size of the output vector is
862 at least two. Here is an example of an interactive <b>pcretest</b> run.
863 <pre>
864 $ pcretest
865 PCRE version 8.13 2011-04-30
866
867 re&#62; /^abc(\d+)/
868 data&#62; abc123
869 0: abc123
870 1: 123
871 data&#62; xyz
872 No match
873 </pre>
874 Unset capturing substrings that are not followed by one that is set are not
875 returned by <b>pcre[16|32]_exec()</b>, and are not shown by <b>pcretest</b>. In the
876 following example, there are two capturing substrings, but when the first data
877 line is matched, the second, unset substring is not shown. An "internal" unset
878 substring is shown as "&#60;unset&#62;", as for the second data line.
879 <pre>
880 re&#62; /(a)|(b)/
881 data&#62; a
882 0: a
883 1: a
884 data&#62; b
885 0: b
886 1: &#60;unset&#62;
887 2: b
888 </pre>
889 If the strings contain any non-printing characters, they are output as \xhh
890 escapes if the value is less than 256 and UTF mode is not set. Otherwise they
891 are output as \x{hh...} escapes. See below for the definition of non-printing
892 characters. If the pattern has the <b>/+</b> modifier, the output for substring
893 0 is followed by the the rest of the subject string, identified by "0+" like
894 this:
895 <pre>
896 re&#62; /cat/+
897 data&#62; cataract
898 0: cat
899 0+ aract
900 </pre>
901 If the pattern has the <b>/g</b> or <b>/G</b> modifier, the results of successive
902 matching attempts are output in sequence, like this:
903 <pre>
904 re&#62; /\Bi(\w\w)/g
905 data&#62; Mississippi
906 0: iss
907 1: ss
908 0: iss
909 1: ss
910 0: ipp
911 1: pp
912 </pre>
913 "No match" is output only if the first match attempt fails. Here is an example
914 of a failure message (the offset 4 that is specified by \&#62;4 is past the end of
915 the subject string):
916 <pre>
917 re&#62; /xyz/
918 data&#62; xyz\&#62;4
919 Error -24 (bad offset value)
920 </PRE>
921 </P>
922 <P>
923 If any of the sequences <b>\C</b>, <b>\G</b>, or <b>\L</b> are present in a
924 data line that is successfully matched, the substrings extracted by the
925 convenience functions are output with C, G, or L after the string number
926 instead of a colon. This is in addition to the normal full list. The string
927 length (that is, the return from the extraction function) is given in
928 parentheses after each string for <b>\C</b> and <b>\G</b>.
929 </P>
930 <P>
931 Note that whereas patterns can be continued over several lines (a plain "&#62;"
932 prompt is used for continuations), data lines may not. However newlines can be
933 included in data by means of the \n escape (or \r, \r\n, etc., depending on
934 the newline sequence setting).
935 </P>
936 <br><a name="SEC10" href="#TOC1">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a><br>
937 <P>
938 When the alternative matching function, <b>pcre[16|32]_dfa_exec()</b>, is used (by
939 means of the \D escape sequence or the <b>-dfa</b> command line option), the
940 output consists of a list of all the matches that start at the first point in
941 the subject where there is at least one match. For example:
942 <pre>
943 re&#62; /(tang|tangerine|tan)/
944 data&#62; yellow tangerine\D
945 0: tangerine
946 1: tang
947 2: tan
948 </pre>
949 (Using the normal matching function on this data finds only "tang".) The
950 longest matching string is always given first (and numbered zero). After a
951 PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
952 partially matching substring. (Note that this is the entire substring that was
953 inspected during the partial match; it may include characters before the actual
954 match start if a lookbehind assertion, \K, \b, or \B was involved.)
955 </P>
956 <P>
957 If <b>/g</b> is present on the pattern, the search for further matches resumes
958 at the end of the longest match. For example:
959 <pre>
960 re&#62; /(tang|tangerine|tan)/g
961 data&#62; yellow tangerine and tangy sultana\D
962 0: tangerine
963 1: tang
964 2: tan
965 0: tang
966 1: tan
967 0: tan
968 </pre>
969 Since the matching function does not support substring capture, the escape
970 sequences that are concerned with captured substrings are not relevant.
971 </P>
972 <br><a name="SEC11" href="#TOC1">RESTARTING AFTER A PARTIAL MATCH</a><br>
973 <P>
974 When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
975 indicating that the subject partially matched the pattern, you can restart the
976 match with additional subject data by means of the \R escape sequence. For
977 example:
978 <pre>
979 re&#62; /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
980 data&#62; 23ja\P\D
981 Partial match: 23ja
982 data&#62; n05\R\D
983 0: n05
984 </pre>
985 For further information about partial matching, see the
986 <a href="pcrepartial.html"><b>pcrepartial</b></a>
987 documentation.
988 </P>
989 <br><a name="SEC12" href="#TOC1">CALLOUTS</a><br>
990 <P>
991 If the pattern contains any callout requests, <b>pcretest</b>'s callout function
992 is called during matching. This works with both matching functions. By default,
993 the called function displays the callout number, the start and current
994 positions in the text at the callout time, and the next pattern item to be
995 tested. For example:
996 <pre>
997 ---&#62;pqrabcdef
998 0 ^ ^ \d
999 </pre>
1000 This output indicates that callout number 0 occurred for a match attempt
1001 starting at the fourth character of the subject string, when the pointer was at
1002 the seventh character of the data, and when the next pattern item was \d. Just
1003 one circumflex is output if the start and current positions are the same.
1004 </P>
1005 <P>
1006 Callouts numbered 255 are assumed to be automatic callouts, inserted as a
1007 result of the <b>/C</b> pattern modifier. In this case, instead of showing the
1008 callout number, the offset in the pattern, preceded by a plus, is output. For
1009 example:
1010 <pre>
1011 re&#62; /\d?[A-E]\*/C
1012 data&#62; E*
1013 ---&#62;E*
1014 +0 ^ \d?
1015 +3 ^ [A-E]
1016 +8 ^^ \*
1017 +10 ^ ^
1018 0: E*
1019 </pre>
1020 If a pattern contains (*MARK) items, an additional line is output whenever
1021 a change of latest mark is passed to the callout function. For example:
1022 <pre>
1023 re&#62; /a(*MARK:X)bc/C
1024 data&#62; abc
1025 ---&#62;abc
1026 +0 ^ a
1027 +1 ^^ (*MARK:X)
1028 +10 ^^ b
1029 Latest Mark: X
1030 +11 ^ ^ c
1031 +12 ^ ^
1032 0: abc
1033 </pre>
1034 The mark changes between matching "a" and "b", but stays the same for the rest
1035 of the match, so nothing more is output. If, as a result of backtracking, the
1036 mark reverts to being unset, the text "&#60;unset&#62;" is output.
1037 </P>
1038 <P>
1039 The callout function in <b>pcretest</b> returns zero (carry on matching) by
1040 default, but you can use a \C item in a data line (as described above) to
1041 change this and other parameters of the callout.
1042 </P>
1043 <P>
1044 Inserting callouts can be helpful when using <b>pcretest</b> to check
1045 complicated regular expressions. For further information about callouts, see
1046 the
1047 <a href="pcrecallout.html"><b>pcrecallout</b></a>
1048 documentation.
1049 </P>
1050 <br><a name="SEC13" href="#TOC1">NON-PRINTING CHARACTERS</a><br>
1051 <P>
1052 When <b>pcretest</b> is outputting text in the compiled version of a pattern,
1053 bytes other than 32-126 are always treated as non-printing characters are are
1054 therefore shown as hex escapes.
1055 </P>
1056 <P>
1057 When <b>pcretest</b> is outputting text that is a matched part of a subject
1058 string, it behaves in the same way, unless a different locale has been set for
1059 the pattern (using the <b>/L</b> modifier). In this case, the <b>isprint()</b>
1060 function to distinguish printing and non-printing characters.
1061 </P>
1062 <br><a name="SEC14" href="#TOC1">SAVING AND RELOADING COMPILED PATTERNS</a><br>
1063 <P>
1064 The facilities described in this section are not available when the POSIX
1065 interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is
1066 specified.
1067 </P>
1068 <P>
1069 When the POSIX interface is not in use, you can cause <b>pcretest</b> to write a
1070 compiled pattern to a file, by following the modifiers with &#62; and a file name.
1071 For example:
1072 <pre>
1073 /pattern/im &#62;/some/file
1074 </pre>
1075 See the
1076 <a href="pcreprecompile.html"><b>pcreprecompile</b></a>
1077 documentation for a discussion about saving and re-using compiled patterns.
1078 Note that if the pattern was successfully studied with JIT optimization, the
1079 JIT data cannot be saved.
1080 </P>
1081 <P>
1082 The data that is written is binary. The first eight bytes are the length of the
1083 compiled pattern data followed by the length of the optional study data, each
1084 written as four bytes in big-endian order (most significant byte first). If
1085 there is no study data (either the pattern was not studied, or studying did not
1086 return any data), the second length is zero. The lengths are followed by an
1087 exact copy of the compiled pattern. If there is additional study data, this
1088 (excluding any JIT data) follows immediately after the compiled pattern. After
1089 writing the file, <b>pcretest</b> expects to read a new pattern.
1090 </P>
1091 <P>
1092 A saved pattern can be reloaded into <b>pcretest</b> by specifying &#60; and a file
1093 name instead of a pattern. There must be no space between &#60; and the file name,
1094 which must not contain a &#60; character, as otherwise <b>pcretest</b> will
1095 interpret the line as a pattern delimited by &#60; characters. For example:
1096 <pre>
1097 re&#62; &#60;/some/file
1098 Compiled pattern loaded from /some/file
1099 No study data
1100 </pre>
1101 If the pattern was previously studied with the JIT optimization, the JIT
1102 information cannot be saved and restored, and so is lost. When the pattern has
1103 been loaded, <b>pcretest</b> proceeds to read data lines in the usual way.
1104 </P>
1105 <P>
1106 You can copy a file written by <b>pcretest</b> to a different host and reload it
1107 there, even if the new host has opposite endianness to the one on which the
1108 pattern was compiled. For example, you can compile on an i86 machine and run on
1109 a SPARC machine. When a pattern is reloaded on a host with different
1110 endianness, the confirmation message is changed to:
1111 <pre>
1112 Compiled pattern (byte-inverted) loaded from /some/file
1113 </pre>
1114 The test suite contains some saved pre-compiled patterns with different
1115 endianness. These are reloaded using "&#60;!" instead of just "&#60;". This suppresses
1116 the "(byte-inverted)" text so that the output is the same on all hosts. It also
1117 forces debugging output once the pattern has been reloaded.
1118 </P>
1119 <P>
1120 File names for saving and reloading can be absolute or relative, but note that
1121 the shell facility of expanding a file name that starts with a tilde (~) is not
1122 available.
1123 </P>
1124 <P>
1125 The ability to save and reload files in <b>pcretest</b> is intended for testing
1126 and experimentation. It is not intended for production use because only a
1127 single pattern can be written to a file. Furthermore, there is no facility for
1128 supplying custom character tables for use with a reloaded pattern. If the
1129 original pattern was compiled with custom tables, an attempt to match a subject
1130 string using a reloaded pattern is likely to cause <b>pcretest</b> to crash.
1131 Finally, if you attempt to load a file that is not in the correct format, the
1132 result is undefined.
1133 </P>
1134 <br><a name="SEC15" href="#TOC1">SEE ALSO</a><br>
1135 <P>
1136 <b>pcre</b>(3), <b>pcre16</b>(3), <b>pcre32</b>(3), <b>pcreapi</b>(3),
1137 <b>pcrecallout</b>(3),
1138 <b>pcrejit</b>, <b>pcrematching</b>(3), <b>pcrepartial</b>(d),
1139 <b>pcrepattern</b>(3), <b>pcreprecompile</b>(3).
1140 </P>
1141 <br><a name="SEC16" href="#TOC1">AUTHOR</a><br>
1142 <P>
1143 Philip Hazel
1144 <br>
1145 University Computing Service
1146 <br>
1147 Cambridge CB2 3QH, England.
1148 <br>
1149 </P>
1150 <br><a name="SEC17" href="#TOC1">REVISION</a><br>
1151 <P>
1152 Last updated: 09 February 2014
1153 <br>
1154 Copyright &copy; 1997-2014 University of Cambridge.
1155 <br>
1156 <p>
1157 Return to the <a href="index.html">PCRE index page</a>.
1158 </p>

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