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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">PCRE's 8-BIT and 16-BIT LIBRARIES</a>
18 <li><a name="TOC3" href="#SEC3">COMMAND LINE OPTIONS</a>
19 <li><a name="TOC4" href="#SEC4">DESCRIPTION</a>
20 <li><a name="TOC5" href="#SEC5">PATTERN MODIFIERS</a>
21 <li><a name="TOC6" href="#SEC6">DATA LINES</a>
22 <li><a name="TOC7" href="#SEC7">THE ALTERNATIVE MATCHING FUNCTION</a>
23 <li><a name="TOC8" href="#SEC8">DEFAULT OUTPUT FROM PCRETEST</a>
25 <li><a name="TOC10" href="#SEC10">RESTARTING AFTER A PARTIAL MATCH</a>
26 <li><a name="TOC11" href="#SEC11">CALLOUTS</a>
27 <li><a name="TOC12" href="#SEC12">NON-PRINTING CHARACTERS</a>
29 <li><a name="TOC14" href="#SEC14">SEE ALSO</a>
30 <li><a name="TOC15" href="#SEC15">AUTHOR</a>
31 <li><a name="TOC16" href="#SEC16">REVISION</a>
32 </ul>
33 <br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br>
34 <P>
35 <b>pcretest [options] [input file [output file]]</b>
36 <br>
37 <br>
38 <b>pcretest</b> was written as a test program for the PCRE regular expression
39 library itself, but it can also be used for experimenting with regular
40 expressions. This document describes the features of the test program; for
41 details of the regular expressions themselves, see the
42 <a href="pcrepattern.html"><b>pcrepattern</b></a>
43 documentation. For details of the PCRE library function calls and their
44 options, see the
45 <a href="pcreapi.html"><b>pcreapi</b></a>
46 and
47 <a href="pcre16.html"><b>pcre16</b></a>
48 documentation. The input for <b>pcretest</b> is a sequence of regular expression
49 patterns and strings to be matched, as described below. The output shows the
50 result of each match. Options on the command line and the patterns control PCRE
51 options and exactly what is output.
52 </P>
53 <br><a name="SEC2" href="#TOC1">PCRE's 8-BIT and 16-BIT LIBRARIES</a><br>
54 <P>
55 From release 8.30, two separate PCRE libraries can be built. The original one
56 supports 8-bit character strings, whereas the newer 16-bit library supports
57 character strings encoded in 16-bit units. The <b>pcretest</b> program can be
58 used to test both libraries. However, it is itself still an 8-bit program,
59 reading 8-bit input and writing 8-bit output. When testing the 16-bit library,
60 the patterns and data strings are converted to 16-bit format before being
61 passed to the PCRE library functions. Results are converted to 8-bit for
62 output.
63 </P>
64 <P>
65 References to functions and structures of the form <b>pcre[16]_xx</b> below
66 mean "<b>pcre_xx</b> when using the 8-bit library or <b>pcre16_xx</b> when using
67 the 16-bit library".
68 </P>
69 <br><a name="SEC3" href="#TOC1">COMMAND LINE OPTIONS</a><br>
70 <P>
71 <b>-16</b>
72 If both the 8-bit and the 16-bit libraries have been built, this option causes
73 the 16-bit library to be used. If only the 16-bit library has been built, this
74 is the default (so has no effect). If only the 8-bit library has been built,
75 this option causes an error.
76 </P>
77 <P>
78 <b>-b</b>
79 Behave as if each pattern has the <b>/B</b> (show byte code) modifier; the
80 internal form is output after compilation.
81 </P>
82 <P>
83 <b>-C</b>
84 Output the version number of the PCRE library, and all available information
85 about the optional features that are included, and then exit. All other options
86 are ignored.
87 </P>
88 <P>
89 <b>-C</b> <i>option</i>
90 Output information about a specific build-time option, then exit. This
91 functionality is intended for use in scripts such as <b>RunTest</b>. The
92 following options output the value indicated:
93 <pre>
94 linksize the internal link size (2, 3, or 4)
95 newline the default newline setting:
97 </pre>
98 The following options output 1 for true or zero for false:
99 <pre>
100 jit just-in-time support is available
101 pcre16 the 16-bit library was built
102 pcre8 the 8-bit library was built
103 ucp Unicode property support is available
104 utf UTF-8 and/or UTF-16 support is available
105 </PRE>
106 </P>
107 <P>
108 <b>-d</b>
109 Behave as if each pattern has the <b>/D</b> (debug) modifier; the internal
110 form and information about the compiled pattern is output after compilation;
111 <b>-d</b> is equivalent to <b>-b -i</b>.
112 </P>
113 <P>
114 <b>-dfa</b>
115 Behave as if each data line contains the \D escape sequence; this causes the
116 alternative matching function, <b>pcre[16]_dfa_exec()</b>, to be used instead of
117 the standard <b>pcre[16]_exec()</b> function (more detail is given below).
118 </P>
119 <P>
120 <b>-help</b>
121 Output a brief summary these options and then exit.
122 </P>
123 <P>
124 <b>-i</b>
125 Behave as if each pattern has the <b>/I</b> modifier; information about the
126 compiled pattern is given after compilation.
127 </P>
128 <P>
129 <b>-M</b>
130 Behave as if each data line contains the \M escape sequence; this causes
131 PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
132 calling <b>pcre[16]_exec()</b> repeatedly with different limits.
133 </P>
134 <P>
135 <b>-m</b>
136 Output the size of each compiled pattern after it has been compiled. This is
137 equivalent to adding <b>/M</b> to each regular expression. The size is given in
138 bytes for both libraries.
139 </P>
140 <P>
141 <b>-o</b> <i>osize</i>
142 Set the number of elements in the output vector that is used when calling
143 <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> to be <i>osize</i>. The
144 default value is 45, which is enough for 14 capturing subexpressions for
145 <b>pcre[16]_exec()</b> or 22 different matches for <b>pcre[16]_dfa_exec()</b>.
146 The vector size can be changed for individual matching calls by including \O
147 in the data line (see below).
148 </P>
149 <P>
150 <b>-p</b>
151 Behave as if each pattern has the <b>/P</b> modifier; the POSIX wrapper API is
152 used to call PCRE. None of the other options has any effect when <b>-p</b> is
153 set. This option can be used only with the 8-bit library.
154 </P>
155 <P>
156 <b>-q</b>
157 Do not output the version number of <b>pcretest</b> at the start of execution.
158 </P>
159 <P>
160 <b>-S</b> <i>size</i>
161 On Unix-like systems, set the size of the run-time stack to <i>size</i>
162 megabytes.
163 </P>
164 <P>
165 <b>-s</b> or <b>-s+</b>
166 Behave as if each pattern has the <b>/S</b> modifier; in other words, force each
167 pattern to be studied. If <b>-s+</b> is used, the PCRE_STUDY_JIT_COMPILE flag is
168 passed to <b>pcre[16]_study()</b>, causing just-in-time optimization to be set
169 up if it is available. If the <b>/I</b> or <b>/D</b> option is present on a
170 pattern (requesting output about the compiled pattern), information about the
171 result of studying is not included when studying is caused only by <b>-s</b> and
172 neither <b>-i</b> nor <b>-d</b> is present on the command line. This behaviour
173 means that the output from tests that are run with and without <b>-s</b> should
174 be identical, except when options that output information about the actual
175 running of a match are set.
176 <br>
177 <br>
178 The <b>-M</b>, <b>-t</b>, and <b>-tm</b> options, which give information about
179 resources used, are likely to produce different output with and without
180 <b>-s</b>. Output may also differ if the <b>/C</b> option is present on an
181 individual pattern. This uses callouts to trace the the matching process, and
182 this may be different between studied and non-studied patterns. If the pattern
183 contains (*MARK) items there may also be differences, for the same reason. The
184 <b>-s</b> command line option can be overridden for specific patterns that
185 should never be studied (see the <b>/S</b> pattern modifier below).
186 </P>
187 <P>
188 <b>-t</b>
189 Run each compile, study, and match many times with a timer, and output
190 resulting time per compile or match (in milliseconds). Do not set <b>-m</b> with
191 <b>-t</b>, because you will then get the size output a zillion times, and the
192 timing will be distorted. You can control the number of iterations that are
193 used for timing by following <b>-t</b> with a number (as a separate item on the
194 command line). For example, "-t 1000" would iterate 1000 times. The default is
195 to iterate 500000 times.
196 </P>
197 <P>
198 <b>-tm</b>
199 This is like <b>-t</b> except that it times only the matching phase, not the
200 compile or study phases.
201 </P>
202 <br><a name="SEC4" href="#TOC1">DESCRIPTION</a><br>
203 <P>
204 If <b>pcretest</b> is given two filename arguments, it reads from the first and
205 writes to the second. If it is given only one filename argument, it reads from
206 that file and writes to stdout. Otherwise, it reads from stdin and writes to
207 stdout, and prompts for each line of input, using "re&#62;" to prompt for regular
208 expressions, and "data&#62;" to prompt for data lines.
209 </P>
210 <P>
211 When <b>pcretest</b> is built, a configuration option can specify that it should
212 be linked with the <b>libreadline</b> library. When this is done, if the input
213 is from a terminal, it is read using the <b>readline()</b> function. This
214 provides line-editing and history facilities. The output from the <b>-help</b>
215 option states whether or not <b>readline()</b> will be used.
216 </P>
217 <P>
218 The program handles any number of sets of input on a single input file. Each
219 set starts with a regular expression, and continues with any number of data
220 lines to be matched against the pattern.
221 </P>
222 <P>
223 Each data line is matched separately and independently. If you want to do
224 multi-line matches, you have to use the \n escape sequence (or \r or \r\n,
225 etc., depending on the newline setting) in a single line of input to encode the
226 newline sequences. There is no limit on the length of data lines; the input
227 buffer is automatically extended if it is too small.
228 </P>
229 <P>
230 An empty line signals the end of the data lines, at which point a new regular
231 expression is read. The regular expressions are given enclosed in any
232 non-alphanumeric delimiters other than backslash, for example:
233 <pre>
234 /(a|bc)x+yz/
235 </pre>
236 White space before the initial delimiter is ignored. A regular expression may
237 be continued over several input lines, in which case the newline characters are
238 included within it. It is possible to include the delimiter within the pattern
239 by escaping it, for example
240 <pre>
241 /abc\/def/
242 </pre>
243 If you do so, the escape and the delimiter form part of the pattern, but since
244 delimiters are always non-alphanumeric, this does not affect its interpretation.
245 If the terminating delimiter is immediately followed by a backslash, for
246 example,
247 <pre>
248 /abc/\
249 </pre>
250 then a backslash is added to the end of the pattern. This is done to provide a
251 way of testing the error condition that arises if a pattern finishes with a
252 backslash, because
253 <pre>
254 /abc\/
255 </pre>
256 is interpreted as the first line of a pattern that starts with "abc/", causing
257 pcretest to read the next line as a continuation of the regular expression.
258 </P>
259 <br><a name="SEC5" href="#TOC1">PATTERN MODIFIERS</a><br>
260 <P>
261 A pattern may be followed by any number of modifiers, which are mostly single
262 characters. Following Perl usage, these are referred to below as, for example,
263 "the <b>/i</b> modifier", even though the delimiter of the pattern need not
264 always be a slash, and no slash is used when writing modifiers. White space may
265 appear between the final pattern delimiter and the first modifier, and between
266 the modifiers themselves.
267 </P>
268 <P>
269 The <b>/i</b>, <b>/m</b>, <b>/s</b>, and <b>/x</b> modifiers set the PCRE_CASELESS,
270 PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
271 <b>pcre[16]_compile()</b> is called. These four modifier letters have the same
272 effect as they do in Perl. For example:
273 <pre>
274 /caseless/i
275 </pre>
276 The following table shows additional modifiers for setting PCRE compile-time
277 options that do not correspond to anything in Perl:
278 <pre>
279 <b>/8</b> PCRE_UTF8 ) when using the 8-bit
280 <b>/?</b> PCRE_NO_UTF8_CHECK ) library
282 <b>/8</b> PCRE_UTF16 ) when using the 16-bit
283 <b>/?</b> PCRE_NO_UTF16_CHECK ) library
285 <b>/A</b> PCRE_ANCHORED
288 <b>/f</b> PCRE_FIRSTLINE
289 <b>/J</b> PCRE_DUPNAMES
291 <b>/U</b> PCRE_UNGREEDY
292 <b>/W</b> PCRE_UCP
293 <b>/X</b> PCRE_EXTRA
295 <b>/&#60;JS&#62;</b> PCRE_JAVASCRIPT_COMPAT
296 <b>/&#60;cr&#62;</b> PCRE_NEWLINE_CR
297 <b>/&#60;lf&#62;</b> PCRE_NEWLINE_LF
298 <b>/&#60;crlf&#62;</b> PCRE_NEWLINE_CRLF
299 <b>/&#60;anycrlf&#62;</b> PCRE_NEWLINE_ANYCRLF
300 <b>/&#60;any&#62;</b> PCRE_NEWLINE_ANY
301 <b>/&#60;bsr_anycrlf&#62;</b> PCRE_BSR_ANYCRLF
302 <b>/&#60;bsr_unicode&#62;</b> PCRE_BSR_UNICODE
303 </pre>
304 The modifiers that are enclosed in angle brackets are literal strings as shown,
305 including the angle brackets, but the letters within can be in either case.
306 This example sets multiline matching with CRLF as the line ending sequence:
307 <pre>
308 /^abc/m&#60;CRLF&#62;
309 </pre>
310 As well as turning on the PCRE_UTF8/16 option, the <b>/8</b> modifier causes
311 all non-printing characters in output strings to be printed using the
312 \x{hh...} notation. Otherwise, those less than 0x100 are output in hex without
313 the curly brackets.
314 </P>
315 <P>
316 Full details of the PCRE options are given in the
317 <a href="pcreapi.html"><b>pcreapi</b></a>
318 documentation.
319 </P>
320 <br><b>
321 Finding all matches in a string
322 </b><br>
323 <P>
324 Searching for all possible matches within each subject string can be requested
325 by the <b>/g</b> or <b>/G</b> modifier. After finding a match, PCRE is called
326 again to search the remainder of the subject string. The difference between
327 <b>/g</b> and <b>/G</b> is that the former uses the <i>startoffset</i> argument to
328 <b>pcre[16]_exec()</b> to start searching at a new point within the entire
329 string (which is in effect what Perl does), whereas the latter passes over a
330 shortened substring. This makes a difference to the matching process if the
331 pattern begins with a lookbehind assertion (including \b or \B).
332 </P>
333 <P>
334 If any call to <b>pcre[16]_exec()</b> in a <b>/g</b> or <b>/G</b> sequence matches
335 an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
336 PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
337 same point. If this second match fails, the start offset is advanced, and the
338 normal match is retried. This imitates the way Perl handles such cases when
339 using the <b>/g</b> modifier or the <b>split()</b> function. Normally, the start
340 offset is advanced by one character, but if the newline convention recognizes
341 CRLF as a newline, and the current character is CR followed by LF, an advance
342 of two is used.
343 </P>
344 <br><b>
345 Other modifiers
346 </b><br>
347 <P>
348 There are yet more modifiers for controlling the way <b>pcretest</b>
349 operates.
350 </P>
351 <P>
352 The <b>/+</b> modifier requests that as well as outputting the substring that
353 matched the entire pattern, <b>pcretest</b> should in addition output the
354 remainder of the subject string. This is useful for tests where the subject
355 contains multiple copies of the same substring. If the <b>+</b> modifier appears
356 twice, the same action is taken for captured substrings. In each case the
357 remainder is output on the following line with a plus character following the
358 capture number. Note that this modifier must not immediately follow the /S
359 modifier because /S+ has another meaning.
360 </P>
361 <P>
362 The <b>/=</b> modifier requests that the values of all potential captured
363 parentheses be output after a match. By default, only those up to the highest
364 one actually used in the match are output (corresponding to the return code
365 from <b>pcre[16]_exec()</b>). Values in the offsets vector corresponding to
366 higher numbers should be set to -1, and these are output as "&#60;unset&#62;". This
367 modifier gives a way of checking that this is happening.
368 </P>
369 <P>
370 The <b>/B</b> modifier is a debugging feature. It requests that <b>pcretest</b>
371 output a representation of the compiled code after compilation. Normally this
372 information contains length and offset values; however, if <b>/Z</b> is also
373 present, this data is replaced by spaces. This is a special feature for use in
374 the automatic test scripts; it ensures that the same output is generated for
375 different internal link sizes.
376 </P>
377 <P>
378 The <b>/D</b> modifier is a PCRE debugging feature, and is equivalent to
379 <b>/BI</b>, that is, both the <b>/B</b> and the <b>/I</b> modifiers.
380 </P>
381 <P>
382 The <b>/F</b> modifier causes <b>pcretest</b> to flip the byte order of the
383 2-byte and 4-byte fields in the compiled pattern. This facility is for testing
384 the feature in PCRE that allows it to execute patterns that were compiled on a
385 host with a different endianness. This feature is not available when the POSIX
386 interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is
387 specified. See also the section about saving and reloading compiled patterns
388 below.
389 </P>
390 <P>
391 The <b>/I</b> modifier requests that <b>pcretest</b> output information about the
392 compiled pattern (whether it is anchored, has a fixed first character, and
393 so on). It does this by calling <b>pcre[16]_fullinfo()</b> after compiling a
394 pattern. If the pattern is studied, the results of that are also output.
395 </P>
396 <P>
397 The <b>/K</b> modifier requests <b>pcretest</b> to show names from backtracking
398 control verbs that are returned from calls to <b>pcre[16]_exec()</b>. It causes
399 <b>pcretest</b> to create a <b>pcre[16]_extra</b> block if one has not already
400 been created by a call to <b>pcre[16]_study()</b>, and to set the
401 PCRE_EXTRA_MARK flag and the <b>mark</b> field within it, every time that
402 <b>pcre[16]_exec()</b> is called. If the variable that the <b>mark</b> field
403 points to is non-NULL for a match, non-match, or partial match, <b>pcretest</b>
404 prints the string to which it points. For a match, this is shown on a line by
405 itself, tagged with "MK:". For a non-match it is added to the message.
406 </P>
407 <P>
408 The <b>/L</b> modifier must be followed directly by the name of a locale, for
409 example,
410 <pre>
411 /pattern/Lfr_FR
412 </pre>
413 For this reason, it must be the last modifier. The given locale is set,
414 <b>pcre[16]_maketables()</b> is called to build a set of character tables for
415 the locale, and this is then passed to <b>pcre[16]_compile()</b> when compiling
416 the regular expression. Without an <b>/L</b> (or <b>/T</b>) modifier, NULL is
417 passed as the tables pointer; that is, <b>/L</b> applies only to the expression
418 on which it appears.
419 </P>
420 <P>
421 The <b>/M</b> modifier causes the size in bytes of the memory block used to hold
422 the compiled pattern to be output. This does not include the size of the
423 <b>pcre[16]</b> block; it is just the actual compiled data. If the pattern is
424 successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the
425 JIT compiled code is also output.
426 </P>
427 <P>
428 If the <b>/S</b> modifier appears once, it causes <b>pcre[16]_study()</b> to be
429 called after the expression has been compiled, and the results used when the
430 expression is matched. If <b>/S</b> appears twice, it suppresses studying, even
431 if it was requested externally by the <b>-s</b> command line option. This makes
432 it possible to specify that certain patterns are always studied, and others are
433 never studied, independently of <b>-s</b>. This feature is used in the test
434 files in a few cases where the output is different when the pattern is studied.
435 </P>
436 <P>
437 If the <b>/S</b> modifier is immediately followed by a + character, the call to
438 <b>pcre[16]_study()</b> is made with the PCRE_STUDY_JIT_COMPILE option,
439 requesting just-in-time optimization support if it is available. Note that
440 there is also a <b>/+</b> modifier; it must not be given immediately after
441 <b>/S</b> because this will be misinterpreted. If JIT studying is successful, it
442 will automatically be used when <b>pcre[16]_exec()</b> is run, except when
443 incompatible run-time options are specified. These include the partial matching
444 options; a complete list is given in the
445 <a href="pcrejit.html"><b>pcrejit</b></a>
446 documentation. See also the <b>\J</b> escape sequence below for a way of
447 setting the size of the JIT stack.
448 </P>
449 <P>
450 The <b>/T</b> modifier must be followed by a single digit. It causes a specific
451 set of built-in character tables to be passed to <b>pcre[16]_compile()</b>. It
452 is used in the standard PCRE tests to check behaviour with different character
453 tables. The digit specifies the tables as follows:
454 <pre>
455 0 the default ASCII tables, as distributed in
456 pcre_chartables.c.dist
457 1 a set of tables defining ISO 8859 characters
458 </pre>
459 In table 1, some characters whose codes are greater than 128 are identified as
460 letters, digits, spaces, etc.
461 </P>
462 <br><b>
463 Using the POSIX wrapper API
464 </b><br>
465 <P>
466 The <b>/P</b> modifier causes <b>pcretest</b> to call PCRE via the POSIX wrapper
467 API rather than its native API. This supports only the 8-bit library. When
468 <b>/P</b> is set, the following modifiers set options for the <b>regcomp()</b>
469 function:
470 <pre>
471 /i REG_ICASE
474 /s REG_DOTALL )
475 /U REG_UNGREEDY ) These options are not part of
476 /W REG_UCP ) the POSIX standard
477 /8 REG_UTF8 )
478 </pre>
479 The <b>/+</b> modifier works as described above. All other modifiers are
480 ignored.
481 </P>
482 <br><a name="SEC6" href="#TOC1">DATA LINES</a><br>
483 <P>
484 Before each data line is passed to <b>pcre[16]_exec()</b>, leading and trailing
485 white space is removed, and it is then scanned for \ escapes. Some of these
486 are pretty esoteric features, intended for checking out some of the more
487 complicated features of PCRE. If you are just testing "ordinary" regular
488 expressions, you probably don't need any of these. The following escapes are
489 recognized:
490 <pre>
491 \a alarm (BEL, \x07)
492 \b backspace (\x08)
493 \e escape (\x27)
494 \f form feed (\x0c)
495 \n newline (\x0a)
496 \qdd set the PCRE_MATCH_LIMIT limit to dd (any number of digits)
497 \r carriage return (\x0d)
498 \t tab (\x09)
499 \v vertical tab (\x0b)
500 \nnn octal character (up to 3 octal digits); always
501 a byte unless &#62; 255 in UTF-8 or 16-bit mode
502 \xhh hexadecimal byte (up to 2 hex digits)
503 \x{hh...} hexadecimal character (any number of hex digits)
504 \A pass the PCRE_ANCHORED option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>
505 \B pass the PCRE_NOTBOL option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>
506 \Cdd call pcre[16]_copy_substring() for substring dd after a successful match (number less than 32)
507 \Cname call pcre[16]_copy_named_substring() for substring "name" after a successful match (name termin-
508 ated by next non alphanumeric character)
509 \C+ show the current captured substrings at callout time
510 \C- do not supply a callout function
511 \C!n return 1 instead of 0 when callout number n is reached
512 \C!n!m return 1 instead of 0 when callout number n is reached for the nth time
513 \C*n pass the number n (may be negative) as callout data; this is used as the callout return value
514 \D use the <b>pcre[16]_dfa_exec()</b> match function
515 \F only shortest match for <b>pcre[16]_dfa_exec()</b>
516 \Gdd call pcre[16]_get_substring() for substring dd after a successful match (number less than 32)
517 \Gname call pcre[16]_get_named_substring() for substring "name" after a successful match (name termin-
518 ated by next non-alphanumeric character)
519 \Jdd set up a JIT stack of dd kilobytes maximum (any number of digits)
520 \L call pcre[16]_get_substringlist() after a successful match
521 \M discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings
522 \N pass the PCRE_NOTEMPTY option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>; if used twice, pass the
524 \Odd set the size of the output vector passed to <b>pcre[16]_exec()</b> to dd (any number of digits)
525 \P pass the PCRE_PARTIAL_SOFT option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>; if used twice, pass the
527 \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd (any number of digits)
528 \R pass the PCRE_DFA_RESTART option to <b>pcre[16]_dfa_exec()</b>
529 \S output details of memory get/free calls during matching
530 \Y pass the PCRE_NO_START_OPTIMIZE option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>
531 \Z pass the PCRE_NOTEOL option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>
532 \? pass the PCRE_NO_UTF[8|16]_CHECK option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>
533 \&#62;dd start the match at offset dd (optional "-"; then any number of digits); this sets the <i>startoffset</i>
534 argument for <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>
535 \&#60;cr&#62; pass the PCRE_NEWLINE_CR option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>
536 \&#60;lf&#62; pass the PCRE_NEWLINE_LF option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>
537 \&#60;crlf&#62; pass the PCRE_NEWLINE_CRLF option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>
538 \&#60;anycrlf&#62; pass the PCRE_NEWLINE_ANYCRLF option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>
539 \&#60;any&#62; pass the PCRE_NEWLINE_ANY option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>
540 </pre>
541 The use of \x{hh...} is not dependent on the use of the <b>/8</b> modifier on
542 the pattern. It is recognized always. There may be any number of hexadecimal
543 digits inside the braces; invalid values provoke error messages.
544 </P>
545 <P>
546 Note that \xhh specifies one byte in UTF-8 mode; this makes it possible to
547 construct invalid UTF-8 sequences for testing purposes. On the other hand,
548 \x{hh} is interpreted as a UTF-8 character in UTF-8 mode, generating more than
549 one byte if the value is greater than 127. When testing the 8-bit library not
550 in UTF-8 mode, \x{hh} generates one byte for values less than 256, and causes
551 an error for greater values.
552 </P>
553 <P>
554 In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it
555 possible to construct invalid UTF-16 sequences for testing purposes.
556 </P>
557 <P>
558 The escapes that specify line ending sequences are literal strings, exactly as
559 shown. No more than one newline setting should be present in any data line.
560 </P>
561 <P>
562 A backslash followed by anything else just escapes the anything else. If
563 the very last character is a backslash, it is ignored. This gives a way of
564 passing an empty line as data, since a real empty line terminates the data
565 input.
566 </P>
567 <P>
568 The <b>\J</b> escape provides a way of setting the maximum stack size that is
569 used by the just-in-time optimization code. It is ignored if JIT optimization
570 is not being used. Providing a stack that is larger than the default 32K is
571 necessary only for very complicated patterns.
572 </P>
573 <P>
574 If \M is present, <b>pcretest</b> calls <b>pcre[16]_exec()</b> several times,
575 with different values in the <i>match_limit</i> and <i>match_limit_recursion</i>
576 fields of the <b>pcre[16]_extra</b> data structure, until it finds the minimum
577 numbers for each parameter that allow <b>pcre[16]_exec()</b> to complete without
578 error. Because this is testing a specific feature of the normal interpretive
579 <b>pcre[16]_exec()</b> execution, the use of any JIT optimization that might
580 have been set up by the <b>/S+</b> qualifier of <b>-s+</b> option is disabled.
581 </P>
582 <P>
583 The <i>match_limit</i> number is a measure of the amount of backtracking
584 that takes place, and checking it out can be instructive. For most simple
585 matches, the number is quite small, but for patterns with very large numbers of
586 matching possibilities, it can become large very quickly with increasing length
587 of subject string. The <i>match_limit_recursion</i> number is a measure of how
588 much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
589 needed to complete the match attempt.
590 </P>
591 <P>
592 When \O is used, the value specified may be higher or lower than the size set
593 by the <b>-O</b> command line option (or defaulted to 45); \O applies only to
594 the call of <b>pcre[16]_exec()</b> for the line in which it appears.
595 </P>
596 <P>
597 If the <b>/P</b> modifier was present on the pattern, causing the POSIX wrapper
598 API to be used, the only option-setting sequences that have any effect are \B,
599 \N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
600 to be passed to <b>regexec()</b>.
601 </P>
602 <br><a name="SEC7" href="#TOC1">THE ALTERNATIVE MATCHING FUNCTION</a><br>
603 <P>
604 By default, <b>pcretest</b> uses the standard PCRE matching function,
605 <b>pcre[16]_exec()</b> to match each data line. PCRE also supports an
606 alternative matching function, <b>pcre[16]_dfa_test()</b>, which operates in a
607 different way, and has some restrictions. The differences between the two
608 functions are described in the
609 <a href="pcrematching.html"><b>pcrematching</b></a>
610 documentation.
611 </P>
612 <P>
613 If a data line contains the \D escape sequence, or if the command line
614 contains the <b>-dfa</b> option, the alternative matching function is used.
615 This function finds all possible matches at a given point. If, however, the \F
616 escape sequence is present in the data line, it stops after the first match is
617 found. This is always the shortest possible match.
618 </P>
619 <br><a name="SEC8" href="#TOC1">DEFAULT OUTPUT FROM PCRETEST</a><br>
620 <P>
621 This section describes the output when the normal matching function,
622 <b>pcre[16]_exec()</b>, is being used.
623 </P>
624 <P>
625 When a match succeeds, <b>pcretest</b> outputs the list of captured substrings
626 that <b>pcre[16]_exec()</b> returns, starting with number 0 for the string that
627 matched the whole pattern. Otherwise, it outputs "No match" when the return is
628 PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
629 substring when <b>pcre[16]_exec()</b> returns PCRE_ERROR_PARTIAL. (Note that
630 this is the entire substring that was inspected during the partial match; it
631 may include characters before the actual match start if a lookbehind assertion,
632 \K, \b, or \B was involved.) For any other return, <b>pcretest</b> outputs
633 the PCRE negative error number and a short descriptive phrase. If the error is
634 a failed UTF string check, the offset of the start of the failing character and
635 the reason code are also output, provided that the size of the output vector is
636 at least two. Here is an example of an interactive <b>pcretest</b> run.
637 <pre>
638 $ pcretest
639 PCRE version 8.13 2011-04-30
641 re&#62; /^abc(\d+)/
642 data&#62; abc123
643 0: abc123
644 1: 123
645 data&#62; xyz
646 No match
647 </pre>
648 Unset capturing substrings that are not followed by one that is set are not
649 returned by <b>pcre[16]_exec()</b>, and are not shown by <b>pcretest</b>. In the
650 following example, there are two capturing substrings, but when the first data
651 line is matched, the second, unset substring is not shown. An "internal" unset
652 substring is shown as "&#60;unset&#62;", as for the second data line.
653 <pre>
654 re&#62; /(a)|(b)/
655 data&#62; a
656 0: a
657 1: a
658 data&#62; b
659 0: b
660 1: &#60;unset&#62;
661 2: b
662 </pre>
663 If the strings contain any non-printing characters, they are output as \xhh
664 escapes if the value is less than 256 and UTF mode is not set. Otherwise they
665 are output as \x{hh...} escapes. See below for the definition of non-printing
666 characters. If the pattern has the <b>/+</b> modifier, the output for substring
667 0 is followed by the the rest of the subject string, identified by "0+" like
668 this:
669 <pre>
670 re&#62; /cat/+
671 data&#62; cataract
672 0: cat
673 0+ aract
674 </pre>
675 If the pattern has the <b>/g</b> or <b>/G</b> modifier, the results of successive
676 matching attempts are output in sequence, like this:
677 <pre>
678 re&#62; /\Bi(\w\w)/g
679 data&#62; Mississippi
680 0: iss
681 1: ss
682 0: iss
683 1: ss
684 0: ipp
685 1: pp
686 </pre>
687 "No match" is output only if the first match attempt fails. Here is an example
688 of a failure message (the offset 4 that is specified by \&#62;4 is past the end of
689 the subject string):
690 <pre>
691 re&#62; /xyz/
692 data&#62; xyz\&#62;4
693 Error -24 (bad offset value)
694 </PRE>
695 </P>
696 <P>
697 If any of the sequences <b>\C</b>, <b>\G</b>, or <b>\L</b> are present in a
698 data line that is successfully matched, the substrings extracted by the
699 convenience functions are output with C, G, or L after the string number
700 instead of a colon. This is in addition to the normal full list. The string
701 length (that is, the return from the extraction function) is given in
702 parentheses after each string for <b>\C</b> and <b>\G</b>.
703 </P>
704 <P>
705 Note that whereas patterns can be continued over several lines (a plain "&#62;"
706 prompt is used for continuations), data lines may not. However newlines can be
707 included in data by means of the \n escape (or \r, \r\n, etc., depending on
708 the newline sequence setting).
709 </P>
711 <P>
712 When the alternative matching function, <b>pcre[16]_dfa_exec()</b>, is used (by
713 means of the \D escape sequence or the <b>-dfa</b> command line option), the
714 output consists of a list of all the matches that start at the first point in
715 the subject where there is at least one match. For example:
716 <pre>
717 re&#62; /(tang|tangerine|tan)/
718 data&#62; yellow tangerine\D
719 0: tangerine
720 1: tang
721 2: tan
722 </pre>
723 (Using the normal matching function on this data finds only "tang".) The
724 longest matching string is always given first (and numbered zero). After a
725 PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
726 partially matching substring. (Note that this is the entire substring that was
727 inspected during the partial match; it may include characters before the actual
728 match start if a lookbehind assertion, \K, \b, or \B was involved.)
729 </P>
730 <P>
731 If <b>/g</b> is present on the pattern, the search for further matches resumes
732 at the end of the longest match. For example:
733 <pre>
734 re&#62; /(tang|tangerine|tan)/g
735 data&#62; yellow tangerine and tangy sultana\D
736 0: tangerine
737 1: tang
738 2: tan
739 0: tang
740 1: tan
741 0: tan
742 </pre>
743 Since the matching function does not support substring capture, the escape
744 sequences that are concerned with captured substrings are not relevant.
745 </P>
746 <br><a name="SEC10" href="#TOC1">RESTARTING AFTER A PARTIAL MATCH</a><br>
747 <P>
748 When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
749 indicating that the subject partially matched the pattern, you can restart the
750 match with additional subject data by means of the \R escape sequence. For
751 example:
752 <pre>
753 re&#62; /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
754 data&#62; 23ja\P\D
755 Partial match: 23ja
756 data&#62; n05\R\D
757 0: n05
758 </pre>
759 For further information about partial matching, see the
760 <a href="pcrepartial.html"><b>pcrepartial</b></a>
761 documentation.
762 </P>
763 <br><a name="SEC11" href="#TOC1">CALLOUTS</a><br>
764 <P>
765 If the pattern contains any callout requests, <b>pcretest</b>'s callout function
766 is called during matching. This works with both matching functions. By default,
767 the called function displays the callout number, the start and current
768 positions in the text at the callout time, and the next pattern item to be
769 tested. For example:
770 <pre>
771 ---&#62;pqrabcdef
772 0 ^ ^ \d
773 </pre>
774 This output indicates that callout number 0 occurred for a match attempt
775 starting at the fourth character of the subject string, when the pointer was at
776 the seventh character of the data, and when the next pattern item was \d. Just
777 one circumflex is output if the start and current positions are the same.
778 </P>
779 <P>
780 Callouts numbered 255 are assumed to be automatic callouts, inserted as a
781 result of the <b>/C</b> pattern modifier. In this case, instead of showing the
782 callout number, the offset in the pattern, preceded by a plus, is output. For
783 example:
784 <pre>
785 re&#62; /\d?[A-E]\*/C
786 data&#62; E*
787 ---&#62;E*
788 +0 ^ \d?
789 +3 ^ [A-E]
790 +8 ^^ \*
791 +10 ^ ^
792 0: E*
793 </pre>
794 If a pattern contains (*MARK) items, an additional line is output whenever
795 a change of latest mark is passed to the callout function. For example:
796 <pre>
797 re&#62; /a(*MARK:X)bc/C
798 data&#62; abc
799 ---&#62;abc
800 +0 ^ a
801 +1 ^^ (*MARK:X)
802 +10 ^^ b
803 Latest Mark: X
804 +11 ^ ^ c
805 +12 ^ ^
806 0: abc
807 </pre>
808 The mark changes between matching "a" and "b", but stays the same for the rest
809 of the match, so nothing more is output. If, as a result of backtracking, the
810 mark reverts to being unset, the text "&#60;unset&#62;" is output.
811 </P>
812 <P>
813 The callout function in <b>pcretest</b> returns zero (carry on matching) by
814 default, but you can use a \C item in a data line (as described above) to
815 change this and other parameters of the callout.
816 </P>
817 <P>
818 Inserting callouts can be helpful when using <b>pcretest</b> to check
819 complicated regular expressions. For further information about callouts, see
820 the
821 <a href="pcrecallout.html"><b>pcrecallout</b></a>
822 documentation.
823 </P>
824 <br><a name="SEC12" href="#TOC1">NON-PRINTING CHARACTERS</a><br>
825 <P>
826 When <b>pcretest</b> is outputting text in the compiled version of a pattern,
827 bytes other than 32-126 are always treated as non-printing characters are are
828 therefore shown as hex escapes.
829 </P>
830 <P>
831 When <b>pcretest</b> is outputting text that is a matched part of a subject
832 string, it behaves in the same way, unless a different locale has been set for
833 the pattern (using the <b>/L</b> modifier). In this case, the <b>isprint()</b>
834 function to distinguish printing and non-printing characters.
835 </P>
836 <br><a name="SEC13" href="#TOC1">SAVING AND RELOADING COMPILED PATTERNS</a><br>
837 <P>
838 The facilities described in this section are not available when the POSIX
839 interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is
840 specified.
841 </P>
842 <P>
843 When the POSIX interface is not in use, you can cause <b>pcretest</b> to write a
844 compiled pattern to a file, by following the modifiers with &#62; and a file name.
845 For example:
846 <pre>
847 /pattern/im &#62;/some/file
848 </pre>
849 See the
850 <a href="pcreprecompile.html"><b>pcreprecompile</b></a>
851 documentation for a discussion about saving and re-using compiled patterns.
852 Note that if the pattern was successfully studied with JIT optimization, the
853 JIT data cannot be saved.
854 </P>
855 <P>
856 The data that is written is binary. The first eight bytes are the length of the
857 compiled pattern data followed by the length of the optional study data, each
858 written as four bytes in big-endian order (most significant byte first). If
859 there is no study data (either the pattern was not studied, or studying did not
860 return any data), the second length is zero. The lengths are followed by an
861 exact copy of the compiled pattern. If there is additional study data, this
862 (excluding any JIT data) follows immediately after the compiled pattern. After
863 writing the file, <b>pcretest</b> expects to read a new pattern.
864 </P>
865 <P>
866 A saved pattern can be reloaded into <b>pcretest</b> by specifying &#60; and a file
867 name instead of a pattern. The name of the file must not contain a &#60; character,
868 as otherwise <b>pcretest</b> will interpret the line as a pattern delimited by &#60;
869 characters.
870 For example:
871 <pre>
872 re&#62; &#60;/some/file
873 Compiled pattern loaded from /some/file
874 No study data
875 </pre>
876 If the pattern was previously studied with the JIT optimization, the JIT
877 information cannot be saved and restored, and so is lost. When the pattern has
878 been loaded, <b>pcretest</b> proceeds to read data lines in the usual way.
879 </P>
880 <P>
881 You can copy a file written by <b>pcretest</b> to a different host and reload it
882 there, even if the new host has opposite endianness to the one on which the
883 pattern was compiled. For example, you can compile on an i86 machine and run on
884 a SPARC machine. When a pattern is reloaded on a host with different
885 endianness, the confirmation message is changed to:
886 <pre>
887 Compiled pattern (byte-inverted) loaded from /some/file
888 </pre>
889 The test suite contains some saved pre-compiled patterns with different
890 endianness. These are reloaded using "&#60;!" instead of just "&#60;". This suppresses
891 the "(byte-inverted)" text so that the output is the same on all hosts. It also
892 forces debugging output once the pattern has been reloaded.
893 </P>
894 <P>
895 File names for saving and reloading can be absolute or relative, but note that
896 the shell facility of expanding a file name that starts with a tilde (~) is not
897 available.
898 </P>
899 <P>
900 The ability to save and reload files in <b>pcretest</b> is intended for testing
901 and experimentation. It is not intended for production use because only a
902 single pattern can be written to a file. Furthermore, there is no facility for
903 supplying custom character tables for use with a reloaded pattern. If the
904 original pattern was compiled with custom tables, an attempt to match a subject
905 string using a reloaded pattern is likely to cause <b>pcretest</b> to crash.
906 Finally, if you attempt to load a file that is not in the correct format, the
907 result is undefined.
908 </P>
909 <br><a name="SEC14" href="#TOC1">SEE ALSO</a><br>
910 <P>
911 <b>pcre</b>(3), <b>pcre16</b>(3), <b>pcreapi</b>(3), <b>pcrecallout</b>(3),
912 <b>pcrejit</b>, <b>pcrematching</b>(3), <b>pcrepartial</b>(d),
913 <b>pcrepattern</b>(3), <b>pcreprecompile</b>(3).
914 </P>
915 <br><a name="SEC15" href="#TOC1">AUTHOR</a><br>
916 <P>
917 Philip Hazel
918 <br>
919 University Computing Service
920 <br>
921 Cambridge CB2 3QH, England.
922 <br>
923 </P>
924 <br><a name="SEC16" href="#TOC1">REVISION</a><br>
925 <P>
926 Last updated: 13 January 2012
927 <br>
928 Copyright &copy; 1997-2012 University of Cambridge.
929 <br>
930 <p>
931 Return to the <a href="index.html">PCRE index page</a>.
932 </p>


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