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1 nigel 63 <html>
2     <head>
3     <title>pcretest specification</title>
4     </head>
5     <body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB">
6 nigel 75 <h1>pcretest man page</h1>
7     <p>
8     Return to the <a href="index.html">PCRE index page</a>.
9     </p>
10 ph10 111 <p>
11 nigel 75 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 ph10 111 <br>
15 nigel 63 <ul>
16     <li><a name="TOC1" href="#SEC1">SYNOPSIS</a>
17 ph10 654 <li><a name="TOC2" href="#SEC2">COMMAND LINE OPTIONS</a>
18 nigel 63 <li><a name="TOC3" href="#SEC3">DESCRIPTION</a>
19     <li><a name="TOC4" href="#SEC4">PATTERN MODIFIERS</a>
20 nigel 75 <li><a name="TOC5" href="#SEC5">DATA LINES</a>
21 nigel 77 <li><a name="TOC6" href="#SEC6">THE ALTERNATIVE MATCHING FUNCTION</a>
22     <li><a name="TOC7" href="#SEC7">DEFAULT OUTPUT FROM PCRETEST</a>
23     <li><a name="TOC8" href="#SEC8">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a>
24     <li><a name="TOC9" href="#SEC9">RESTARTING AFTER A PARTIAL MATCH</a>
25     <li><a name="TOC10" href="#SEC10">CALLOUTS</a>
26 nigel 93 <li><a name="TOC11" href="#SEC11">NON-PRINTING CHARACTERS</a>
27     <li><a name="TOC12" href="#SEC12">SAVING AND RELOADING COMPILED PATTERNS</a>
28     <li><a name="TOC13" href="#SEC13">SEE ALSO</a>
29     <li><a name="TOC14" href="#SEC14">AUTHOR</a>
30 ph10 99 <li><a name="TOC15" href="#SEC15">REVISION</a>
31 nigel 63 </ul>
32     <br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br>
33     <P>
34 ph10 654 <b>pcretest [options] [input file [output file]]</b>
35 nigel 91 <br>
36     <br>
37 nigel 63 <b>pcretest</b> was written as a test program for the PCRE regular expression
38     library itself, but it can also be used for experimenting with regular
39     expressions. This document describes the features of the test program; for
40     details of the regular expressions themselves, see the
41     <a href="pcrepattern.html"><b>pcrepattern</b></a>
42 nigel 75 documentation. For details of the PCRE library function calls and their
43     options, see the
44 nigel 63 <a href="pcreapi.html"><b>pcreapi</b></a>
45 ph10 654 documentation. The input for <b>pcretest</b> is a sequence of regular expression
46     patterns and strings to be matched, as described below. The output shows the
47     result of each match. Options on the command line and the patterns control PCRE
48     options and exactly what is output.
49 nigel 63 </P>
50 ph10 654 <br><a name="SEC2" href="#TOC1">COMMAND LINE OPTIONS</a><br>
51 nigel 63 <P>
52 nigel 93 <b>-b</b>
53 ph10 654 Behave as if each pattern has the <b>/B</b> (show byte code) modifier; the
54     internal form is output after compilation.
55 nigel 93 </P>
56     <P>
57 nigel 63 <b>-C</b>
58     Output the version number of the PCRE library, and all available information
59     about the optional features that are included, and then exit.
60     </P>
61     <P>
62     <b>-d</b>
63 ph10 654 Behave as if each pattern has the <b>/D</b> (debug) modifier; the internal
64 nigel 93 form and information about the compiled pattern is output after compilation;
65     <b>-d</b> is equivalent to <b>-b -i</b>.
66 nigel 63 </P>
67     <P>
68 nigel 77 <b>-dfa</b>
69     Behave as if each data line contains the \D escape sequence; this causes the
70     alternative matching function, <b>pcre_dfa_exec()</b>, to be used instead of the
71     standard <b>pcre_exec()</b> function (more detail is given below).
72     </P>
73     <P>
74 nigel 93 <b>-help</b>
75     Output a brief summary these options and then exit.
76     </P>
77     <P>
78 nigel 63 <b>-i</b>
79 ph10 654 Behave as if each pattern has the <b>/I</b> modifier; information about the
80 nigel 63 compiled pattern is given after compilation.
81     </P>
82     <P>
83 ph10 392 <b>-M</b>
84     Behave as if each data line contains the \M escape sequence; this causes
85     PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
86     calling <b>pcre_exec()</b> repeatedly with different limits.
87     </P>
88     <P>
89 nigel 63 <b>-m</b>
90     Output the size of each compiled pattern after it has been compiled. This is
91 ph10 654 equivalent to adding <b>/M</b> to each regular expression.
92 nigel 63 </P>
93     <P>
94     <b>-o</b> <i>osize</i>
95 nigel 75 Set the number of elements in the output vector that is used when calling
96 nigel 93 <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b> to be <i>osize</i>. The default value
97     is 45, which is enough for 14 capturing subexpressions for <b>pcre_exec()</b> or
98     22 different matches for <b>pcre_dfa_exec()</b>. The vector size can be
99     changed for individual matching calls by including \O in the data line (see
100     below).
101 nigel 63 </P>
102     <P>
103     <b>-p</b>
104 ph10 654 Behave as if each pattern has the <b>/P</b> modifier; the POSIX wrapper API is
105 nigel 77 used to call PCRE. None of the other options has any effect when <b>-p</b> is
106     set.
107 nigel 63 </P>
108     <P>
109 nigel 91 <b>-q</b>
110 nigel 87 Do not output the version number of <b>pcretest</b> at the start of execution.
111     </P>
112     <P>
113 nigel 91 <b>-S</b> <i>size</i>
114 ph10 654 On Unix-like systems, set the size of the run-time stack to <i>size</i>
115 nigel 91 megabytes.
116     </P>
117     <P>
118 ph10 691 <b>-s</b> or <b>-s+</b>
119 ph10 654 Behave as if each pattern has the <b>/S</b> modifier; in other words, force each
120 ph10 691 pattern to be studied. If <b>-s+</b> is used, the PCRE_STUDY_JIT_COMPILE flag is
121     passed to <b>pcre_study()</b>, causing just-in-time optimization to be set up if
122     it is available. If the <b>/I</b> or <b>/D</b> option is present on a pattern
123     (requesting output about the compiled pattern), information about the result of
124     studying is not included when studying is caused only by <b>-s</b> and neither
125     <b>-i</b> nor <b>-d</b> is present on the command line. This behaviour means that
126     the output from tests that are run with and without <b>-s</b> should be
127     identical, except when options that output information about the actual running
128     of a match are set. The <b>-M</b>, <b>-t</b>, and <b>-tm</b> options, which give
129     information about resources used, are likely to produce different output with
130     and without <b>-s</b>. Output may also differ if the <b>/C</b> option is present
131     on an individual pattern. This uses callouts to trace the the matching process,
132     and this may be different between studied and non-studied patterns. If the
133     pattern contains (*MARK) items there may also be differences, for the same
134     reason. The <b>-s</b> command line option can be overridden for specific
135     patterns that should never be studied (see the <b>/S</b> pattern modifier
136     below).
137 ph10 654 </P>
138     <P>
139 nigel 63 <b>-t</b>
140     Run each compile, study, and match many times with a timer, and output
141 nigel 75 resulting time per compile or match (in milliseconds). Do not set <b>-m</b> with
142     <b>-t</b>, because you will then get the size output a zillion times, and the
143 nigel 93 timing will be distorted. You can control the number of iterations that are
144     used for timing by following <b>-t</b> with a number (as a separate item on the
145     command line). For example, "-t 1000" would iterate 1000 times. The default is
146     to iterate 500000 times.
147 nigel 63 </P>
148 nigel 93 <P>
149     <b>-tm</b>
150     This is like <b>-t</b> except that it times only the matching phase, not the
151     compile or study phases.
152     </P>
153 nigel 63 <br><a name="SEC3" href="#TOC1">DESCRIPTION</a><br>
154     <P>
155     If <b>pcretest</b> is given two filename arguments, it reads from the first and
156     writes to the second. If it is given only one filename argument, it reads from
157     that file and writes to stdout. Otherwise, it reads from stdin and writes to
158     stdout, and prompts for each line of input, using "re&#62;" to prompt for regular
159     expressions, and "data&#62;" to prompt for data lines.
160     </P>
161     <P>
162 ph10 289 When <b>pcretest</b> is built, a configuration option can specify that it should
163     be linked with the <b>libreadline</b> library. When this is done, if the input
164     is from a terminal, it is read using the <b>readline()</b> function. This
165     provides line-editing and history facilities. The output from the <b>-help</b>
166     option states whether or not <b>readline()</b> will be used.
167     </P>
168     <P>
169 nigel 63 The program handles any number of sets of input on a single input file. Each
170     set starts with a regular expression, and continues with any number of data
171     lines to be matched against the pattern.
172     </P>
173     <P>
174 nigel 75 Each data line is matched separately and independently. If you want to do
175 nigel 91 multi-line matches, you have to use the \n escape sequence (or \r or \r\n,
176 nigel 93 etc., depending on the newline setting) in a single line of input to encode the
177     newline sequences. There is no limit on the length of data lines; the input
178 nigel 91 buffer is automatically extended if it is too small.
179 nigel 63 </P>
180     <P>
181     An empty line signals the end of the data lines, at which point a new regular
182     expression is read. The regular expressions are given enclosed in any
183 nigel 91 non-alphanumeric delimiters other than backslash, for example:
184 nigel 63 <pre>
185     /(a|bc)x+yz/
186 nigel 75 </pre>
187 nigel 63 White space before the initial delimiter is ignored. A regular expression may
188     be continued over several input lines, in which case the newline characters are
189     included within it. It is possible to include the delimiter within the pattern
190     by escaping it, for example
191     <pre>
192     /abc\/def/
193 nigel 75 </pre>
194 nigel 63 If you do so, the escape and the delimiter form part of the pattern, but since
195 nigel 75 delimiters are always non-alphanumeric, this does not affect its interpretation.
196 nigel 63 If the terminating delimiter is immediately followed by a backslash, for
197     example,
198     <pre>
199     /abc/\
200 nigel 75 </pre>
201 nigel 63 then a backslash is added to the end of the pattern. This is done to provide a
202     way of testing the error condition that arises if a pattern finishes with a
203     backslash, because
204     <pre>
205     /abc\/
206 nigel 75 </pre>
207 nigel 63 is interpreted as the first line of a pattern that starts with "abc/", causing
208     pcretest to read the next line as a continuation of the regular expression.
209     </P>
210     <br><a name="SEC4" href="#TOC1">PATTERN MODIFIERS</a><br>
211     <P>
212 nigel 75 A pattern may be followed by any number of modifiers, which are mostly single
213     characters. Following Perl usage, these are referred to below as, for example,
214     "the <b>/i</b> modifier", even though the delimiter of the pattern need not
215 ph10 654 always be a slash, and no slash is used when writing modifiers. White space may
216 nigel 75 appear between the final pattern delimiter and the first modifier, and between
217     the modifiers themselves.
218 nigel 63 </P>
219     <P>
220 nigel 75 The <b>/i</b>, <b>/m</b>, <b>/s</b>, and <b>/x</b> modifiers set the PCRE_CASELESS,
221     PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
222     <b>pcre_compile()</b> is called. These four modifier letters have the same
223     effect as they do in Perl. For example:
224 nigel 63 <pre>
225     /caseless/i
226 nigel 75 </pre>
227 ph10 535 The following table shows additional modifiers for setting PCRE compile-time
228     options that do not correspond to anything in Perl:
229 nigel 75 <pre>
230 ph10 518 <b>/8</b> PCRE_UTF8
231 ph10 535 <b>/?</b> PCRE_NO_UTF8_CHECK
232 ph10 231 <b>/A</b> PCRE_ANCHORED
233     <b>/C</b> PCRE_AUTO_CALLOUT
234     <b>/E</b> PCRE_DOLLAR_ENDONLY
235     <b>/f</b> PCRE_FIRSTLINE
236     <b>/J</b> PCRE_DUPNAMES
237     <b>/N</b> PCRE_NO_AUTO_CAPTURE
238     <b>/U</b> PCRE_UNGREEDY
239 ph10 535 <b>/W</b> PCRE_UCP
240 ph10 231 <b>/X</b> PCRE_EXTRA
241 ph10 579 <b>/Y</b> PCRE_NO_START_OPTIMIZE
242 ph10 345 <b>/&#60;JS&#62;</b> PCRE_JAVASCRIPT_COMPAT
243 ph10 231 <b>/&#60;cr&#62;</b> PCRE_NEWLINE_CR
244     <b>/&#60;lf&#62;</b> PCRE_NEWLINE_LF
245     <b>/&#60;crlf&#62;</b> PCRE_NEWLINE_CRLF
246     <b>/&#60;anycrlf&#62;</b> PCRE_NEWLINE_ANYCRLF
247     <b>/&#60;any&#62;</b> PCRE_NEWLINE_ANY
248     <b>/&#60;bsr_anycrlf&#62;</b> PCRE_BSR_ANYCRLF
249     <b>/&#60;bsr_unicode&#62;</b> PCRE_BSR_UNICODE
250 nigel 75 </pre>
251 ph10 518 The modifiers that are enclosed in angle brackets are literal strings as shown,
252 ph10 654 including the angle brackets, but the letters within can be in either case.
253     This example sets multiline matching with CRLF as the line ending sequence:
254 nigel 93 <pre>
255 ph10 654 /^abc/m&#60;CRLF&#62;
256 nigel 93 </pre>
257 ph10 518 As well as turning on the PCRE_UTF8 option, the <b>/8</b> modifier also causes
258     any non-printing characters in output strings to be printed using the
259     \x{hh...} notation if they are valid UTF-8 sequences. Full details of the PCRE
260     options are given in the
261 nigel 91 <a href="pcreapi.html"><b>pcreapi</b></a>
262 ph10 535 documentation.
263 nigel 91 </P>
264     <br><b>
265     Finding all matches in a string
266     </b><br>
267     <P>
268 nigel 63 Searching for all possible matches within each subject string can be requested
269     by the <b>/g</b> or <b>/G</b> modifier. After finding a match, PCRE is called
270     again to search the remainder of the subject string. The difference between
271     <b>/g</b> and <b>/G</b> is that the former uses the <i>startoffset</i> argument to
272     <b>pcre_exec()</b> to start searching at a new point within the entire string
273     (which is in effect what Perl does), whereas the latter passes over a shortened
274     substring. This makes a difference to the matching process if the pattern
275     begins with a lookbehind assertion (including \b or \B).
276     </P>
277     <P>
278     If any call to <b>pcre_exec()</b> in a <b>/g</b> or <b>/G</b> sequence matches an
279 ph10 453 empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
280     PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
281 ph10 567 same point. If this second match fails, the start offset is advanced, and the
282     normal match is retried. This imitates the way Perl handles such cases when
283 ph10 579 using the <b>/g</b> modifier or the <b>split()</b> function. Normally, the start
284     offset is advanced by one character, but if the newline convention recognizes
285     CRLF as a newline, and the current character is CR followed by LF, an advance
286 ph10 567 of two is used.
287 nigel 63 </P>
288 nigel 91 <br><b>
289     Other modifiers
290     </b><br>
291 nigel 63 <P>
292 nigel 75 There are yet more modifiers for controlling the way <b>pcretest</b>
293 nigel 63 operates.
294     </P>
295     <P>
296     The <b>/+</b> modifier requests that as well as outputting the substring that
297 ph10 654 matched the entire pattern, <b>pcretest</b> should in addition output the
298     remainder of the subject string. This is useful for tests where the subject
299     contains multiple copies of the same substring. If the <b>+</b> modifier appears
300     twice, the same action is taken for captured substrings. In each case the
301     remainder is output on the following line with a plus character following the
302 ph10 691 capture number. Note that this modifier must not immediately follow the /S
303     modifier because /S+ has another meaning.
304 nigel 63 </P>
305     <P>
306 ph10 654 The <b>/=</b> modifier requests that the values of all potential captured
307     parentheses be output after a match by <b>pcre_exec()</b>. By default, only
308     those up to the highest one actually used in the match are output
309     (corresponding to the return code from <b>pcre_exec()</b>). Values in the
310     offsets vector corresponding to higher numbers should be set to -1, and these
311     are output as "&#60;unset&#62;". This modifier gives a way of checking that this is
312     happening.
313     </P>
314     <P>
315 nigel 93 The <b>/B</b> modifier is a debugging feature. It requests that <b>pcretest</b>
316 ph10 123 output a representation of the compiled byte code after compilation. Normally
317     this information contains length and offset values; however, if <b>/Z</b> is
318     also present, this data is replaced by spaces. This is a special feature for
319     use in the automatic test scripts; it ensures that the same output is generated
320     for different internal link sizes.
321 nigel 93 </P>
322     <P>
323     The <b>/D</b> modifier is a PCRE debugging feature, and is equivalent to
324 ph10 148 <b>/BI</b>, that is, both the <b>/B</b> and the <b>/I</b> modifiers.
325 nigel 63 </P>
326     <P>
327 nigel 75 The <b>/F</b> modifier causes <b>pcretest</b> to flip the byte order of the
328     fields in the compiled pattern that contain 2-byte and 4-byte numbers. This
329     facility is for testing the feature in PCRE that allows it to execute patterns
330     that were compiled on a host with a different endianness. This feature is not
331     available when the POSIX interface to PCRE is being used, that is, when the
332     <b>/P</b> pattern modifier is specified. See also the section about saving and
333     reloading compiled patterns below.
334     </P>
335     <P>
336 ph10 512 The <b>/I</b> modifier requests that <b>pcretest</b> output information about the
337     compiled pattern (whether it is anchored, has a fixed first character, and
338     so on). It does this by calling <b>pcre_fullinfo()</b> after compiling a
339     pattern. If the pattern is studied, the results of that are also output.
340 nigel 63 </P>
341     <P>
342 ph10 512 The <b>/K</b> modifier requests <b>pcretest</b> to show names from backtracking
343     control verbs that are returned from calls to <b>pcre_exec()</b>. It causes
344     <b>pcretest</b> to create a <b>pcre_extra</b> block if one has not already been
345     created by a call to <b>pcre_study()</b>, and to set the PCRE_EXTRA_MARK flag
346     and the <b>mark</b> field within it, every time that <b>pcre_exec()</b> is
347     called. If the variable that the <b>mark</b> field points to is non-NULL for a
348     match, non-match, or partial match, <b>pcretest</b> prints the string to which
349     it points. For a match, this is shown on a line by itself, tagged with "MK:".
350     For a non-match it is added to the message.
351     </P>
352     <P>
353     The <b>/L</b> modifier must be followed directly by the name of a locale, for
354     example,
355     <pre>
356     /pattern/Lfr_FR
357     </pre>
358     For this reason, it must be the last modifier. The given locale is set,
359     <b>pcre_maketables()</b> is called to build a set of character tables for the
360     locale, and this is then passed to <b>pcre_compile()</b> when compiling the
361 ph10 545 regular expression. Without an <b>/L</b> (or <b>/T</b>) modifier, NULL is passed
362     as the tables pointer; that is, <b>/L</b> applies only to the expression on
363     which it appears.
364 ph10 512 </P>
365     <P>
366 nigel 63 The <b>/M</b> modifier causes the size of memory block used to hold the compiled
367     pattern to be output.
368     </P>
369     <P>
370 ph10 654 If the <b>/S</b> modifier appears once, it causes <b>pcre_study()</b> to be
371     called after the expression has been compiled, and the results used when the
372     expression is matched. If <b>/S</b> appears twice, it suppresses studying, even
373     if it was requested externally by the <b>-s</b> command line option. This makes
374     it possible to specify that certain patterns are always studied, and others are
375     never studied, independently of <b>-s</b>. This feature is used in the test
376     files in a few cases where the output is different when the pattern is studied.
377 nigel 63 </P>
378 ph10 545 <P>
379 ph10 691 If the <b>/S</b> modifier is immediately followed by a + character, the call to
380     <b>pcre_study()</b> is made with the PCRE_STUDY_JIT_COMPILE option, requesting
381     just-in-time optimization support if it is available. Note that there is also a
382     <b>/+</b> modifier; it must not be given immediately after <b>/S</b> because this
383     will be misinterpreted. If JIT studying is successful, it will automatically be
384     used when <b>pcre_exec()</b> is run, except when incompatible run-time options
385     are specified. These include the partial matching options; a complete list is
386     given in the
387     <a href="pcrejit.html"><b>pcrejit</b></a>
388     documentation. See also the <b>\J</b> escape sequence below for a way of
389     setting the size of the JIT stack.
390     </P>
391     <P>
392 ph10 545 The <b>/T</b> modifier must be followed by a single digit. It causes a specific
393     set of built-in character tables to be passed to <b>pcre_compile()</b>. It is
394     used in the standard PCRE tests to check behaviour with different character
395     tables. The digit specifies the tables as follows:
396     <pre>
397     0 the default ASCII tables, as distributed in
398     pcre_chartables.c.dist
399     1 a set of tables defining ISO 8859 characters
400     </pre>
401     In table 1, some characters whose codes are greater than 128 are identified as
402     letters, digits, spaces, etc.
403     </P>
404 ph10 535 <br><b>
405     Using the POSIX wrapper API
406     </b><br>
407     <P>
408     The <b>/P</b> modifier causes <b>pcretest</b> to call PCRE via the POSIX wrapper
409     API rather than its native API. When <b>/P</b> is set, the following modifiers
410     set options for the <b>regcomp()</b> function:
411     <pre>
412     /i REG_ICASE
413     /m REG_NEWLINE
414     /N REG_NOSUB
415     /s REG_DOTALL )
416     /U REG_UNGREEDY ) These options are not part of
417     /W REG_UCP ) the POSIX standard
418     /8 REG_UTF8 )
419     </pre>
420     The <b>/+</b> modifier works as described above. All other modifiers are
421     ignored.
422     </P>
423 nigel 75 <br><a name="SEC5" href="#TOC1">DATA LINES</a><br>
424 nigel 63 <P>
425     Before each data line is passed to <b>pcre_exec()</b>, leading and trailing
426 ph10 654 white space is removed, and it is then scanned for \ escapes. Some of these
427     are pretty esoteric features, intended for checking out some of the more
428 nigel 63 complicated features of PCRE. If you are just testing "ordinary" regular
429     expressions, you probably don't need any of these. The following escapes are
430     recognized:
431     <pre>
432 nigel 93 \a alarm (BEL, \x07)
433     \b backspace (\x08)
434     \e escape (\x27)
435 ph10 654 \f form feed (\x0c)
436 nigel 93 \n newline (\x0a)
437 nigel 91 \qdd set the PCRE_MATCH_LIMIT limit to dd (any number of digits)
438 nigel 93 \r carriage return (\x0d)
439     \t tab (\x09)
440     \v vertical tab (\x0b)
441 nigel 63 \nnn octal character (up to 3 octal digits)
442 ph10 579 always a byte unless &#62; 255 in UTF-8 mode
443 ph10 572 \xhh hexadecimal byte (up to 2 hex digits)
444 nigel 75 \x{hh...} hexadecimal character, any number of digits in UTF-8 mode
445 nigel 91 \A pass the PCRE_ANCHORED option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
446     \B pass the PCRE_NOTBOL option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
447 nigel 75 \Cdd call pcre_copy_substring() for substring dd after a successful match (number less than 32)
448     \Cname call pcre_copy_named_substring() for substring "name" after a successful match (name termin-
449 nigel 63 ated by next non alphanumeric character)
450 nigel 75 \C+ show the current captured substrings at callout time
451 nigel 63 \C- do not supply a callout function
452 nigel 75 \C!n return 1 instead of 0 when callout number n is reached
453     \C!n!m return 1 instead of 0 when callout number n is reached for the nth time
454     \C*n pass the number n (may be negative) as callout data; this is used as the callout return value
455 nigel 77 \D use the <b>pcre_dfa_exec()</b> match function
456     \F only shortest match for <b>pcre_dfa_exec()</b>
457 nigel 75 \Gdd call pcre_get_substring() for substring dd after a successful match (number less than 32)
458     \Gname call pcre_get_named_substring() for substring "name" after a successful match (name termin-
459 nigel 63 ated by next non-alphanumeric character)
460 ph10 691 \Jdd set up a JIT stack of dd kilobytes maximum (any number of digits)
461 nigel 75 \L call pcre_get_substringlist() after a successful match
462 nigel 91 \M discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings
463 ph10 453 \N pass the PCRE_NOTEMPTY option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>; if used twice, pass the
464 ph10 461 PCRE_NOTEMPTY_ATSTART option
465 nigel 75 \Odd set the size of the output vector passed to <b>pcre_exec()</b> to dd (any number of digits)
466 ph10 429 \P pass the PCRE_PARTIAL_SOFT option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>; if used twice, pass the
467 ph10 461 PCRE_PARTIAL_HARD option
468 nigel 91 \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd (any number of digits)
469 nigel 77 \R pass the PCRE_DFA_RESTART option to <b>pcre_dfa_exec()</b>
470 nigel 73 \S output details of memory get/free calls during matching
471 ph10 461 \Y pass the PCRE_NO_START_OPTIMIZE option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
472 nigel 91 \Z pass the PCRE_NOTEOL option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
473     \? pass the PCRE_NO_UTF8_CHECK option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
474 ph10 579 \&#62;dd start the match at offset dd (optional "-"; then any number of digits); this sets the <i>startoffset</i>
475 ph10 567 argument for <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
476 nigel 91 \&#60;cr&#62; pass the PCRE_NEWLINE_CR option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
477     \&#60;lf&#62; pass the PCRE_NEWLINE_LF option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
478     \&#60;crlf&#62; pass the PCRE_NEWLINE_CRLF option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
479 ph10 150 \&#60;anycrlf&#62; pass the PCRE_NEWLINE_ANYCRLF option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
480 nigel 93 \&#60;any&#62; pass the PCRE_NEWLINE_ANY option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
481 nigel 75 </pre>
482 ph10 579 Note that \xhh always specifies one byte, even in UTF-8 mode; this makes it
483     possible to construct invalid UTF-8 sequences for testing purposes. On the
484 ph10 572 other hand, \x{hh} is interpreted as a UTF-8 character in UTF-8 mode,
485 ph10 579 generating more than one byte if the value is greater than 127. When not in
486     UTF-8 mode, it generates one byte for values less than 256, and causes an error
487 ph10 572 for greater values.
488     </P>
489     <P>
490 nigel 93 The escapes that specify line ending sequences are literal strings, exactly as
491     shown. No more than one newline setting should be present in any data line.
492 nigel 63 </P>
493     <P>
494 nigel 93 A backslash followed by anything else just escapes the anything else. If
495     the very last character is a backslash, it is ignored. This gives a way of
496     passing an empty line as data, since a real empty line terminates the data
497     input.
498     </P>
499     <P>
500 ph10 691 The <b>\J</b> escape provides a way of setting the maximum stack size that is
501     used by the just-in-time optimization code. It is ignored if JIT optimization
502     is not being used. Providing a stack that is larger than the default 32K is
503     necessary only for very complicated patterns.
504     </P>
505     <P>
506 nigel 63 If \M is present, <b>pcretest</b> calls <b>pcre_exec()</b> several times, with
507 nigel 87 different values in the <i>match_limit</i> and <i>match_limit_recursion</i>
508     fields of the <b>pcre_extra</b> data structure, until it finds the minimum
509 ph10 691 numbers for each parameter that allow <b>pcre_exec()</b> to complete without
510     error. Because this is testing a specific feature of the normal interpretive
511     <b>pcre_exec()</b> execution, the use of any JIT optimization that might have
512     been set up by the <b>/S+</b> qualifier of <b>-s+</b> option is disabled.
513 nigel 63 </P>
514     <P>
515 ph10 691 The <i>match_limit</i> number is a measure of the amount of backtracking
516     that takes place, and checking it out can be instructive. For most simple
517     matches, the number is quite small, but for patterns with very large numbers of
518     matching possibilities, it can become large very quickly with increasing length
519     of subject string. The <i>match_limit_recursion</i> number is a measure of how
520     much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
521     needed to complete the match attempt.
522     </P>
523     <P>
524 nigel 75 When \O is used, the value specified may be higher or lower than the size set
525     by the <b>-O</b> command line option (or defaulted to 45); \O applies only to
526     the call of <b>pcre_exec()</b> for the line in which it appears.
527 nigel 63 </P>
528     <P>
529 nigel 75 If the <b>/P</b> modifier was present on the pattern, causing the POSIX wrapper
530 ph10 535 API to be used, the only option-setting sequences that have any effect are \B,
531     \N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
532     to be passed to <b>regexec()</b>.
533 nigel 63 </P>
534     <P>
535     The use of \x{hh...} to represent UTF-8 characters is not dependent on the use
536     of the <b>/8</b> modifier on the pattern. It is recognized always. There may be
537     any number of hexadecimal digits inside the braces. The result is from one to
538 ph10 211 six bytes, encoded according to the original UTF-8 rules of RFC 2279. This
539     allows for values in the range 0 to 0x7FFFFFFF. Note that not all of those are
540     valid Unicode code points, or indeed valid UTF-8 characters according to the
541     later rules in RFC 3629.
542 nigel 63 </P>
543 nigel 77 <br><a name="SEC6" href="#TOC1">THE ALTERNATIVE MATCHING FUNCTION</a><br>
544 nigel 63 <P>
545 nigel 77 By default, <b>pcretest</b> uses the standard PCRE matching function,
546     <b>pcre_exec()</b> to match each data line. From release 6.0, PCRE supports an
547     alternative matching function, <b>pcre_dfa_test()</b>, which operates in a
548     different way, and has some restrictions. The differences between the two
549     functions are described in the
550     <a href="pcrematching.html"><b>pcrematching</b></a>
551     documentation.
552     </P>
553     <P>
554     If a data line contains the \D escape sequence, or if the command line
555     contains the <b>-dfa</b> option, the alternative matching function is called.
556     This function finds all possible matches at a given point. If, however, the \F
557     escape sequence is present in the data line, it stops after the first match is
558     found. This is always the shortest possible match.
559     </P>
560     <br><a name="SEC7" href="#TOC1">DEFAULT OUTPUT FROM PCRETEST</a><br>
561     <P>
562     This section describes the output when the normal matching function,
563     <b>pcre_exec()</b>, is being used.
564     </P>
565     <P>
566 ph10 654 When a match succeeds, <b>pcretest</b> outputs the list of captured substrings
567     that <b>pcre_exec()</b> returns, starting with number 0 for the string that
568     matched the whole pattern. Otherwise, it outputs "No match" when the return is
569 ph10 453 PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
570 ph10 567 substring when <b>pcre_exec()</b> returns PCRE_ERROR_PARTIAL. (Note that this is
571     the entire substring that was inspected during the partial match; it may
572     include characters before the actual match start if a lookbehind assertion,
573 ph10 654 \K, \b, or \B was involved.) For any other return, <b>pcretest</b> outputs
574     the PCRE negative error number and a short descriptive phrase. If the error is
575     a failed UTF-8 string check, the byte offset of the start of the failing
576     character and the reason code are also output, provided that the size of the
577     output vector is at least two. Here is an example of an interactive
578     <b>pcretest</b> run.
579 nigel 63 <pre>
580     $ pcretest
581 ph10 654 PCRE version 8.13 2011-04-30
582 nigel 75
583 nigel 63 re&#62; /^abc(\d+)/
584     data&#62; abc123
585     0: abc123
586     1: 123
587     data&#62; xyz
588     No match
589 nigel 75 </pre>
590 ph10 654 Unset capturing substrings that are not followed by one that is set are not
591     returned by <b>pcre_exec()</b>, and are not shown by <b>pcretest</b>. In the
592     following example, there are two capturing substrings, but when the first data
593     line is matched, the second, unset substring is not shown. An "internal" unset
594     substring is shown as "&#60;unset&#62;", as for the second data line.
595 ph10 286 <pre>
596     re&#62; /(a)|(b)/
597     data&#62; a
598     0: a
599     1: a
600     data&#62; b
601     0: b
602     1: &#60;unset&#62;
603     2: b
604     </pre>
605 nigel 63 If the strings contain any non-printing characters, they are output as \0x
606     escapes, or as \x{...} escapes if the <b>/8</b> modifier was present on the
607 nigel 93 pattern. See below for the definition of non-printing characters. If the
608     pattern has the <b>/+</b> modifier, the output for substring 0 is followed by
609     the the rest of the subject string, identified by "0+" like this:
610 nigel 63 <pre>
611     re&#62; /cat/+
612     data&#62; cataract
613     0: cat
614     0+ aract
615 nigel 75 </pre>
616 nigel 63 If the pattern has the <b>/g</b> or <b>/G</b> modifier, the results of successive
617     matching attempts are output in sequence, like this:
618     <pre>
619     re&#62; /\Bi(\w\w)/g
620     data&#62; Mississippi
621     0: iss
622     1: ss
623     0: iss
624     1: ss
625     0: ipp
626     1: pp
627 nigel 75 </pre>
628 ph10 654 "No match" is output only if the first match attempt fails. Here is an example
629     of a failure message (the offset 4 that is specified by \&#62;4 is past the end of
630     the subject string):
631     <pre>
632     re&#62; /xyz/
633     data&#62; xyz\&#62;4
634     Error -24 (bad offset value)
635     </PRE>
636 nigel 63 </P>
637     <P>
638     If any of the sequences <b>\C</b>, <b>\G</b>, or <b>\L</b> are present in a
639     data line that is successfully matched, the substrings extracted by the
640     convenience functions are output with C, G, or L after the string number
641     instead of a colon. This is in addition to the normal full list. The string
642     length (that is, the return from the extraction function) is given in
643     parentheses after each string for <b>\C</b> and <b>\G</b>.
644     </P>
645     <P>
646 nigel 93 Note that whereas patterns can be continued over several lines (a plain "&#62;"
647 nigel 63 prompt is used for continuations), data lines may not. However newlines can be
648 nigel 93 included in data by means of the \n escape (or \r, \r\n, etc., depending on
649     the newline sequence setting).
650 nigel 63 </P>
651 nigel 77 <br><a name="SEC8" href="#TOC1">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a><br>
652 nigel 63 <P>
653 nigel 77 When the alternative matching function, <b>pcre_dfa_exec()</b>, is used (by
654     means of the \D escape sequence or the <b>-dfa</b> command line option), the
655     output consists of a list of all the matches that start at the first point in
656     the subject where there is at least one match. For example:
657     <pre>
658     re&#62; /(tang|tangerine|tan)/
659     data&#62; yellow tangerine\D
660     0: tangerine
661     1: tang
662     2: tan
663     </pre>
664     (Using the normal matching function on this data finds only "tang".) The
665 ph10 429 longest matching string is always given first (and numbered zero). After a
666 ph10 461 PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
667 ph10 567 partially matching substring. (Note that this is the entire substring that was
668     inspected during the partial match; it may include characters before the actual
669     match start if a lookbehind assertion, \K, \b, or \B was involved.)
670 nigel 77 </P>
671     <P>
672 nigel 93 If <b>/g</b> is present on the pattern, the search for further matches resumes
673 nigel 77 at the end of the longest match. For example:
674     <pre>
675     re&#62; /(tang|tangerine|tan)/g
676     data&#62; yellow tangerine and tangy sultana\D
677     0: tangerine
678     1: tang
679     2: tan
680     0: tang
681     1: tan
682     0: tan
683     </pre>
684     Since the matching function does not support substring capture, the escape
685     sequences that are concerned with captured substrings are not relevant.
686     </P>
687     <br><a name="SEC9" href="#TOC1">RESTARTING AFTER A PARTIAL MATCH</a><br>
688     <P>
689     When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
690     indicating that the subject partially matched the pattern, you can restart the
691     match with additional subject data by means of the \R escape sequence. For
692     example:
693     <pre>
694     re&#62; /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
695     data&#62; 23ja\P\D
696     Partial match: 23ja
697     data&#62; n05\R\D
698     0: n05
699     </pre>
700     For further information about partial matching, see the
701     <a href="pcrepartial.html"><b>pcrepartial</b></a>
702     documentation.
703     </P>
704     <br><a name="SEC10" href="#TOC1">CALLOUTS</a><br>
705     <P>
706 nigel 75 If the pattern contains any callout requests, <b>pcretest</b>'s callout function
707 nigel 77 is called during matching. This works with both matching functions. By default,
708     the called function displays the callout number, the start and current
709     positions in the text at the callout time, and the next pattern item to be
710     tested. For example, the output
711 nigel 75 <pre>
712     ---&#62;pqrabcdef
713     0 ^ ^ \d
714     </pre>
715     indicates that callout number 0 occurred for a match attempt starting at the
716     fourth character of the subject string, when the pointer was at the seventh
717     character of the data, and when the next pattern item was \d. Just one
718     circumflex is output if the start and current positions are the same.
719     </P>
720     <P>
721     Callouts numbered 255 are assumed to be automatic callouts, inserted as a
722     result of the <b>/C</b> pattern modifier. In this case, instead of showing the
723     callout number, the offset in the pattern, preceded by a plus, is output. For
724     example:
725     <pre>
726     re&#62; /\d?[A-E]\*/C
727     data&#62; E*
728     ---&#62;E*
729     +0 ^ \d?
730     +3 ^ [A-E]
731     +8 ^^ \*
732     +10 ^ ^
733     0: E*
734     </pre>
735 ph10 654 If a pattern contains (*MARK) items, an additional line is output whenever
736     a change of latest mark is passed to the callout function. For example:
737     <pre>
738     re&#62; /a(*MARK:X)bc/C
739     data&#62; abc
740     ---&#62;abc
741     +0 ^ a
742     +1 ^^ (*MARK:X)
743     +10 ^^ b
744     Latest Mark: X
745     +11 ^ ^ c
746     +12 ^ ^
747     0: abc
748     </pre>
749     The mark changes between matching "a" and "b", but stays the same for the rest
750     of the match, so nothing more is output. If, as a result of backtracking, the
751     mark reverts to being unset, the text "&#60;unset&#62;" is output.
752     </P>
753     <P>
754 nigel 75 The callout function in <b>pcretest</b> returns zero (carry on matching) by
755 nigel 77 default, but you can use a \C item in a data line (as described above) to
756 ph10 654 change this and other parameters of the callout.
757 nigel 75 </P>
758     <P>
759     Inserting callouts can be helpful when using <b>pcretest</b> to check
760     complicated regular expressions. For further information about callouts, see
761     the
762     <a href="pcrecallout.html"><b>pcrecallout</b></a>
763     documentation.
764     </P>
765 nigel 93 <br><a name="SEC11" href="#TOC1">NON-PRINTING CHARACTERS</a><br>
766 nigel 75 <P>
767 nigel 93 When <b>pcretest</b> is outputting text in the compiled version of a pattern,
768     bytes other than 32-126 are always treated as non-printing characters are are
769     therefore shown as hex escapes.
770     </P>
771     <P>
772     When <b>pcretest</b> is outputting text that is a matched part of a subject
773     string, it behaves in the same way, unless a different locale has been set for
774     the pattern (using the <b>/L</b> modifier). In this case, the <b>isprint()</b>
775     function to distinguish printing and non-printing characters.
776     </P>
777     <br><a name="SEC12" href="#TOC1">SAVING AND RELOADING COMPILED PATTERNS</a><br>
778     <P>
779 nigel 75 The facilities described in this section are not available when the POSIX
780 ph10 654 interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is
781 nigel 75 specified.
782     </P>
783     <P>
784     When the POSIX interface is not in use, you can cause <b>pcretest</b> to write a
785     compiled pattern to a file, by following the modifiers with &#62; and a file name.
786     For example:
787     <pre>
788     /pattern/im &#62;/some/file
789     </pre>
790     See the
791     <a href="pcreprecompile.html"><b>pcreprecompile</b></a>
792     documentation for a discussion about saving and re-using compiled patterns.
793 ph10 691 Note that if the pattern was successfully studied with JIT optimization, the
794     JIT data cannot be saved.
795 nigel 75 </P>
796     <P>
797     The data that is written is binary. The first eight bytes are the length of the
798     compiled pattern data followed by the length of the optional study data, each
799     written as four bytes in big-endian order (most significant byte first). If
800     there is no study data (either the pattern was not studied, or studying did not
801     return any data), the second length is zero. The lengths are followed by an
802     exact copy of the compiled pattern. If there is additional study data, this
803 ph10 691 (excluding any JIT data) follows immediately after the compiled pattern. After
804     writing the file, <b>pcretest</b> expects to read a new pattern.
805 nigel 75 </P>
806     <P>
807 ph10 654 A saved pattern can be reloaded into <b>pcretest</b> by specifying &#60; and a file
808 nigel 75 name instead of a pattern. The name of the file must not contain a &#60; character,
809     as otherwise <b>pcretest</b> will interpret the line as a pattern delimited by &#60;
810     characters.
811     For example:
812     <pre>
813     re&#62; &#60;/some/file
814 ph10 654 Compiled pattern loaded from /some/file
815 nigel 75 No study data
816     </pre>
817 ph10 691 If the pattern was previously studied with the JIT optimization, the JIT
818     information cannot be saved and restored, and so is lost. When the pattern has
819     been loaded, <b>pcretest</b> proceeds to read data lines in the usual way.
820 nigel 75 </P>
821     <P>
822     You can copy a file written by <b>pcretest</b> to a different host and reload it
823     there, even if the new host has opposite endianness to the one on which the
824     pattern was compiled. For example, you can compile on an i86 machine and run on
825     a SPARC machine.
826     </P>
827     <P>
828     File names for saving and reloading can be absolute or relative, but note that
829     the shell facility of expanding a file name that starts with a tilde (~) is not
830     available.
831     </P>
832     <P>
833     The ability to save and reload files in <b>pcretest</b> is intended for testing
834     and experimentation. It is not intended for production use because only a
835     single pattern can be written to a file. Furthermore, there is no facility for
836     supplying custom character tables for use with a reloaded pattern. If the
837     original pattern was compiled with custom tables, an attempt to match a subject
838     string using a reloaded pattern is likely to cause <b>pcretest</b> to crash.
839     Finally, if you attempt to load a file that is not in the correct format, the
840     result is undefined.
841     </P>
842 nigel 93 <br><a name="SEC13" href="#TOC1">SEE ALSO</a><br>
843 nigel 75 <P>
844 ph10 691 <b>pcre</b>(3), <b>pcreapi</b>(3), <b>pcrecallout</b>(3), <b>pcrejit</b>,
845     <b>pcrematching</b>(3), <b>pcrepartial</b>(d), <b>pcrepattern</b>(3),
846     <b>pcreprecompile</b>(3).
847 nigel 93 </P>
848     <br><a name="SEC14" href="#TOC1">AUTHOR</a><br>
849     <P>
850 nigel 77 Philip Hazel
851 nigel 63 <br>
852 ph10 99 University Computing Service
853 nigel 63 <br>
854 nigel 93 Cambridge CB2 3QH, England.
855 ph10 99 <br>
856 nigel 63 </P>
857 ph10 99 <br><a name="SEC15" href="#TOC1">REVISION</a><br>
858 nigel 63 <P>
859 ph10 691 Last updated: 26 August 2011
860 nigel 63 <br>
861 ph10 654 Copyright &copy; 1997-2011 University of Cambridge.
862 ph10 99 <br>
863 nigel 75 <p>
864     Return to the <a href="index.html">PCRE index page</a>.
865     </p>

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