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Tue May 28 09:13:59 2013 UTC (6 years, 2 months ago) by ph10
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Final source file tidies for 8.33 release.
1 .TH PCRETEST 1 "26 April 2013" "PCRE 8.33"
3 pcretest - a program for testing Perl-compatible regular expressions.
5 .rs
6 .sp
7 .B pcretest "[options] [input file [output file]]"
8 .sp
9 \fBpcretest\fP was written as a test program for the PCRE regular expression
10 library itself, but it can also be used for experimenting with regular
11 expressions. This document describes the features of the test program; for
12 details of the regular expressions themselves, see the
13 .\" HREF
14 \fBpcrepattern\fP
15 .\"
16 documentation. For details of the PCRE library function calls and their
17 options, see the
18 .\" HREF
19 \fBpcreapi\fP
20 .\"
21 ,
22 .\" HREF
23 \fBpcre16\fP
24 and
25 .\" HREF
26 \fBpcre32\fP
27 .\"
28 documentation.
29 .P
30 The input for \fBpcretest\fP is a sequence of regular expression patterns and
31 strings to be matched, as described below. The output shows the result of each
32 match. Options on the command line and the patterns control PCRE options and
33 exactly what is output.
34 .P
35 As PCRE has evolved, it has acquired many different features, and as a result,
36 \fBpcretest\fP now has rather a lot of obscure options for testing every
37 possible feature. Some of these options are specifically designed for use in
38 conjunction with the test script and data files that are distributed as part of
39 PCRE, and are unlikely to be of use otherwise. They are all documented here,
40 but without much justification.
41 .
42 .
44 .rs
45 .sp
46 Input to \fBpcretest\fP is processed line by line, either by calling the C
47 library's \fBfgets()\fP function, or via the \fBlibreadline\fP library (see
48 below). In Unix-like environments, \fBfgets()\fP treats any bytes other than
49 newline as data characters. However, in some Windows environments character 26
50 (hex 1A) causes an immediate end of file, and no further data is read. For
51 maximum portability, therefore, it is safest to use only ASCII characters in
52 \fBpcretest\fP input files.
53 .
54 .
56 .rs
57 .sp
58 From release 8.30, two separate PCRE libraries can be built. The original one
59 supports 8-bit character strings, whereas the newer 16-bit library supports
60 character strings encoded in 16-bit units. From release 8.32, a third library
61 can be built, supporting character strings encoded in 32-bit units. The
62 \fBpcretest\fP program can be used to test all three libraries. However, it is
63 itself still an 8-bit program, reading 8-bit input and writing 8-bit output.
64 When testing the 16-bit or 32-bit library, the patterns and data strings are
65 converted to 16- or 32-bit format before being passed to the PCRE library
66 functions. Results are converted to 8-bit for output.
67 .P
68 References to functions and structures of the form \fBpcre[16|32]_xx\fP below
69 mean "\fBpcre_xx\fP when using the 8-bit library, \fBpcre16_xx\fP when using
70 the 16-bit library, or \fBpcre32_xx\fP when using the 32-bit library".
71 .
72 .
74 .rs
75 .TP 10
76 \fB-8\fP
77 If both the 8-bit library has been built, this option causes the 8-bit library
78 to be used (which is the default); if the 8-bit library has not been built,
79 this option causes an error.
80 .TP 10
81 \fB-16\fP
82 If both the 8-bit or the 32-bit, and the 16-bit libraries have been built, this
83 option causes the 16-bit library to be used. If only the 16-bit library has been
84 built, this is the default (so has no effect). If only the 8-bit or the 32-bit
85 library has been built, this option causes an error.
86 .TP 10
87 \fB-32\fP
88 If both the 8-bit or the 16-bit, and the 32-bit libraries have been built, this
89 option causes the 32-bit library to be used. If only the 32-bit library has been
90 built, this is the default (so has no effect). If only the 8-bit or the 16-bit
91 library has been built, this option causes an error.
92 .TP 10
93 \fB-b\fP
94 Behave as if each pattern has the \fB/B\fP (show byte code) modifier; the
95 internal form is output after compilation.
96 .TP 10
97 \fB-C\fP
98 Output the version number of the PCRE library, and all available information
99 about the optional features that are included, and then exit with zero exit
100 code. All other options are ignored.
101 .TP 10
102 \fB-C\fP \fIoption\fP
103 Output information about a specific build-time option, then exit. This
104 functionality is intended for use in scripts such as \fBRunTest\fP. The
105 following options output the value and set the exit code as indicated:
106 .sp
107 ebcdic-nl the code for LF (= NL) in an EBCDIC environment:
108 0x15 or 0x25
109 0 if used in an ASCII environment
110 exit code is always 0
111 linksize the configured internal link size (2, 3, or 4)
112 exit code is set to the link size
113 newline the default newline setting:
115 exit code is always 0
116 .sp
117 The following options output 1 for true or 0 for false, and set the exit code
118 to the same value:
119 .sp
120 ebcdic compiled for an EBCDIC environment
121 jit just-in-time support is available
122 pcre16 the 16-bit library was built
123 pcre32 the 32-bit library was built
124 pcre8 the 8-bit library was built
125 ucp Unicode property support is available
126 utf UTF-8 and/or UTF-16 and/or UTF-32 support
127 is available
128 .sp
129 If an unknown option is given, an error message is output; the exit code is 0.
130 .TP 10
131 \fB-d\fP
132 Behave as if each pattern has the \fB/D\fP (debug) modifier; the internal
133 form and information about the compiled pattern is output after compilation;
134 \fB-d\fP is equivalent to \fB-b -i\fP.
135 .TP 10
136 \fB-dfa\fP
137 Behave as if each data line contains the \eD escape sequence; this causes the
138 alternative matching function, \fBpcre[16|32]_dfa_exec()\fP, to be used instead
139 of the standard \fBpcre[16|32]_exec()\fP function (more detail is given below).
140 .TP 10
141 \fB-help\fP
142 Output a brief summary these options and then exit.
143 .TP 10
144 \fB-i\fP
145 Behave as if each pattern has the \fB/I\fP modifier; information about the
146 compiled pattern is given after compilation.
147 .TP 10
148 \fB-M\fP
149 Behave as if each data line contains the \eM escape sequence; this causes
150 PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
151 calling \fBpcre[16|32]_exec()\fP repeatedly with different limits.
152 .TP 10
153 \fB-m\fP
154 Output the size of each compiled pattern after it has been compiled. This is
155 equivalent to adding \fB/M\fP to each regular expression. The size is given in
156 bytes for both libraries.
157 .TP 10
158 \fB-o\fP \fIosize\fP
159 Set the number of elements in the output vector that is used when calling
160 \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP to be \fIosize\fP. The
161 default value is 45, which is enough for 14 capturing subexpressions for
162 \fBpcre[16|32]_exec()\fP or 22 different matches for
163 \fBpcre[16|32]_dfa_exec()\fP.
164 The vector size can be changed for individual matching calls by including \eO
165 in the data line (see below).
166 .TP 10
167 \fB-p\fP
168 Behave as if each pattern has the \fB/P\fP modifier; the POSIX wrapper API is
169 used to call PCRE. None of the other options has any effect when \fB-p\fP is
170 set. This option can be used only with the 8-bit library.
171 .TP 10
172 \fB-q\fP
173 Do not output the version number of \fBpcretest\fP at the start of execution.
174 .TP 10
175 \fB-S\fP \fIsize\fP
176 On Unix-like systems, set the size of the run-time stack to \fIsize\fP
177 megabytes.
178 .TP 10
179 \fB-s\fP or \fB-s+\fP
180 Behave as if each pattern has the \fB/S\fP modifier; in other words, force each
181 pattern to be studied. If \fB-s+\fP is used, all the JIT compile options are
182 passed to \fBpcre[16|32]_study()\fP, causing just-in-time optimization to be set
183 up if it is available, for both full and partial matching. Specific JIT compile
184 options can be selected by following \fB-s+\fP with a digit in the range 1 to
185 7, which selects the JIT compile modes as follows:
186 .sp
187 1 normal match only
188 2 soft partial match only
189 3 normal match and soft partial match
190 4 hard partial match only
191 6 soft and hard partial match
192 7 all three modes (default)
193 .sp
194 If \fB-s++\fP is used instead of \fB-s+\fP (with or without a following digit),
195 the text "(JIT)" is added to the first output line after a match or no match
196 when JIT-compiled code was actually used.
197 .sp
198 Note that there are pattern options that can override \fB-s\fP, either
199 specifying no studying at all, or suppressing JIT compilation.
200 .sp
201 If the \fB/I\fP or \fB/D\fP option is present on a pattern (requesting output
202 about the compiled pattern), information about the result of studying is not
203 included when studying is caused only by \fB-s\fP and neither \fB-i\fP nor
204 \fB-d\fP is present on the command line. This behaviour means that the output
205 from tests that are run with and without \fB-s\fP should be identical, except
206 when options that output information about the actual running of a match are
207 set.
208 .sp
209 The \fB-M\fP, \fB-t\fP, and \fB-tm\fP options, which give information about
210 resources used, are likely to produce different output with and without
211 \fB-s\fP. Output may also differ if the \fB/C\fP option is present on an
212 individual pattern. This uses callouts to trace the the matching process, and
213 this may be different between studied and non-studied patterns. If the pattern
214 contains (*MARK) items there may also be differences, for the same reason. The
215 \fB-s\fP command line option can be overridden for specific patterns that
216 should never be studied (see the \fB/S\fP pattern modifier below).
217 .TP 10
218 \fB-t\fP
219 Run each compile, study, and match many times with a timer, and output
220 resulting time per compile or match (in milliseconds). Do not set \fB-m\fP with
221 \fB-t\fP, because you will then get the size output a zillion times, and the
222 timing will be distorted. You can control the number of iterations that are
223 used for timing by following \fB-t\fP with a number (as a separate item on the
224 command line). For example, "-t 1000" would iterate 1000 times. The default is
225 to iterate 500000 times.
226 .TP 10
227 \fB-tm\fP
228 This is like \fB-t\fP except that it times only the matching phase, not the
229 compile or study phases.
230 .
231 .
233 .rs
234 .sp
235 If \fBpcretest\fP is given two filename arguments, it reads from the first and
236 writes to the second. If it is given only one filename argument, it reads from
237 that file and writes to stdout. Otherwise, it reads from stdin and writes to
238 stdout, and prompts for each line of input, using "re>" to prompt for regular
239 expressions, and "data>" to prompt for data lines.
240 .P
241 When \fBpcretest\fP is built, a configuration option can specify that it should
242 be linked with the \fBlibreadline\fP library. When this is done, if the input
243 is from a terminal, it is read using the \fBreadline()\fP function. This
244 provides line-editing and history facilities. The output from the \fB-help\fP
245 option states whether or not \fBreadline()\fP will be used.
246 .P
247 The program handles any number of sets of input on a single input file. Each
248 set starts with a regular expression, and continues with any number of data
249 lines to be matched against the pattern.
250 .P
251 Each data line is matched separately and independently. If you want to do
252 multi-line matches, you have to use the \en escape sequence (or \er or \er\en,
253 etc., depending on the newline setting) in a single line of input to encode the
254 newline sequences. There is no limit on the length of data lines; the input
255 buffer is automatically extended if it is too small.
256 .P
257 An empty line signals the end of the data lines, at which point a new regular
258 expression is read. The regular expressions are given enclosed in any
259 non-alphanumeric delimiters other than backslash, for example:
260 .sp
261 /(a|bc)x+yz/
262 .sp
263 White space before the initial delimiter is ignored. A regular expression may
264 be continued over several input lines, in which case the newline characters are
265 included within it. It is possible to include the delimiter within the pattern
266 by escaping it, for example
267 .sp
268 /abc\e/def/
269 .sp
270 If you do so, the escape and the delimiter form part of the pattern, but since
271 delimiters are always non-alphanumeric, this does not affect its interpretation.
272 If the terminating delimiter is immediately followed by a backslash, for
273 example,
274 .sp
275 /abc/\e
276 .sp
277 then a backslash is added to the end of the pattern. This is done to provide a
278 way of testing the error condition that arises if a pattern finishes with a
279 backslash, because
280 .sp
281 /abc\e/
282 .sp
283 is interpreted as the first line of a pattern that starts with "abc/", causing
284 pcretest to read the next line as a continuation of the regular expression.
285 .
286 .
288 .rs
289 .sp
290 A pattern may be followed by any number of modifiers, which are mostly single
291 characters, though some of these can be qualified by further characters.
292 Following Perl usage, these are referred to below as, for example, "the
293 \fB/i\fP modifier", even though the delimiter of the pattern need not always be
294 a slash, and no slash is used when writing modifiers. White space may appear
295 between the final pattern delimiter and the first modifier, and between the
296 modifiers themselves. For reference, here is a complete list of modifiers. They
297 fall into several groups that are described in detail in the following
298 sections.
299 .sp
300 \fB/8\fP set UTF mode
301 \fB/9\fP set PCRE_NEVER_UTF (locks out UTF mode)
302 \fB/?\fP disable UTF validity check
303 \fB/+\fP show remainder of subject after match
304 \fB/=\fP show all captures (not just those that are set)
305 .sp
306 \fB/A\fP set PCRE_ANCHORED
307 \fB/B\fP show compiled code
309 \fB/D\fP same as \fB/B\fP plus \fB/I\fP
311 \fB/F\fP flip byte order in compiled pattern
312 \fB/f\fP set PCRE_FIRSTLINE
313 \fB/G\fP find all matches (shorten string)
314 \fB/g\fP find all matches (use startoffset)
315 \fB/I\fP show information about pattern
316 \fB/i\fP set PCRE_CASELESS
317 \fB/J\fP set PCRE_DUPNAMES
318 \fB/K\fP show backtracking control names
319 \fB/L\fP set locale
320 \fB/M\fP show compiled memory size
321 \fB/m\fP set PCRE_MULTILINE
323 \fB/P\fP use the POSIX wrapper
324 \fB/S\fP study the pattern after compilation
325 \fB/s\fP set PCRE_DOTALL
326 \fB/T\fP select character tables
327 \fB/U\fP set PCRE_UNGREEDY
328 \fB/W\fP set PCRE_UCP
329 \fB/X\fP set PCRE_EXTRA
330 \fB/x\fP set PCRE_EXTENDED
332 \fB/Z\fP don't show lengths in \fB/B\fP output
333 .sp
334 \fB/<any>\fP set PCRE_NEWLINE_ANY
335 \fB/<anycrlf>\fP set PCRE_NEWLINE_ANYCRLF
336 \fB/<cr>\fP set PCRE_NEWLINE_CR
337 \fB/<crlf>\fP set PCRE_NEWLINE_CRLF
338 \fB/<lf>\fP set PCRE_NEWLINE_LF
339 \fB/<bsr_anycrlf>\fP set PCRE_BSR_ANYCRLF
340 \fB/<bsr_unicode>\fP set PCRE_BSR_UNICODE
342 .sp
343 .
344 .
345 .SS "Perl-compatible modifiers"
346 .rs
347 .sp
348 The \fB/i\fP, \fB/m\fP, \fB/s\fP, and \fB/x\fP modifiers set the PCRE_CASELESS,
349 PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
350 \fBpcre[16|32]_compile()\fP is called. These four modifier letters have the same
351 effect as they do in Perl. For example:
352 .sp
353 /caseless/i
354 .sp
355 .
356 .
357 .SS "Modifiers for other PCRE options"
358 .rs
359 .sp
360 The following table shows additional modifiers for setting PCRE compile-time
361 options that do not correspond to anything in Perl:
362 .sp
363 \fB/8\fP PCRE_UTF8 ) when using the 8-bit
364 \fB/?\fP PCRE_NO_UTF8_CHECK ) library
365 .sp
366 \fB/8\fP PCRE_UTF16 ) when using the 16-bit
367 \fB/?\fP PCRE_NO_UTF16_CHECK ) library
368 .sp
369 \fB/8\fP PCRE_UTF32 ) when using the 32-bit
370 \fB/?\fP PCRE_NO_UTF32_CHECK ) library
371 .sp
380 \fB/W\fP PCRE_UCP
383 \fB/<any>\fP PCRE_NEWLINE_ANY
384 \fB/<anycrlf>\fP PCRE_NEWLINE_ANYCRLF
385 \fB/<cr>\fP PCRE_NEWLINE_CR
386 \fB/<crlf>\fP PCRE_NEWLINE_CRLF
387 \fB/<lf>\fP PCRE_NEWLINE_LF
388 \fB/<bsr_anycrlf>\fP PCRE_BSR_ANYCRLF
389 \fB/<bsr_unicode>\fP PCRE_BSR_UNICODE
391 .sp
392 The modifiers that are enclosed in angle brackets are literal strings as shown,
393 including the angle brackets, but the letters within can be in either case.
394 This example sets multiline matching with CRLF as the line ending sequence:
395 .sp
396 /^abc/m<CRLF>
397 .sp
398 As well as turning on the PCRE_UTF8/16/32 option, the \fB/8\fP modifier causes
399 all non-printing characters in output strings to be printed using the
400 \ex{hh...} notation. Otherwise, those less than 0x100 are output in hex without
401 the curly brackets.
402 .P
403 Full details of the PCRE options are given in the
404 .\" HREF
405 \fBpcreapi\fP
406 .\"
407 documentation.
408 .
409 .
410 .SS "Finding all matches in a string"
411 .rs
412 .sp
413 Searching for all possible matches within each subject string can be requested
414 by the \fB/g\fP or \fB/G\fP modifier. After finding a match, PCRE is called
415 again to search the remainder of the subject string. The difference between
416 \fB/g\fP and \fB/G\fP is that the former uses the \fIstartoffset\fP argument to
417 \fBpcre[16|32]_exec()\fP to start searching at a new point within the entire
418 string (which is in effect what Perl does), whereas the latter passes over a
419 shortened substring. This makes a difference to the matching process if the
420 pattern begins with a lookbehind assertion (including \eb or \eB).
421 .P
422 If any call to \fBpcre[16|32]_exec()\fP in a \fB/g\fP or \fB/G\fP sequence matches
423 an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
424 PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
425 same point. If this second match fails, the start offset is advanced, and the
426 normal match is retried. This imitates the way Perl handles such cases when
427 using the \fB/g\fP modifier or the \fBsplit()\fP function. Normally, the start
428 offset is advanced by one character, but if the newline convention recognizes
429 CRLF as a newline, and the current character is CR followed by LF, an advance
430 of two is used.
431 .
432 .
433 .SS "Other modifiers"
434 .rs
435 .sp
436 There are yet more modifiers for controlling the way \fBpcretest\fP
437 operates.
438 .P
439 The \fB/+\fP modifier requests that as well as outputting the substring that
440 matched the entire pattern, \fBpcretest\fP should in addition output the
441 remainder of the subject string. This is useful for tests where the subject
442 contains multiple copies of the same substring. If the \fB+\fP modifier appears
443 twice, the same action is taken for captured substrings. In each case the
444 remainder is output on the following line with a plus character following the
445 capture number. Note that this modifier must not immediately follow the /S
446 modifier because /S+ and /S++ have other meanings.
447 .P
448 The \fB/=\fP modifier requests that the values of all potential captured
449 parentheses be output after a match. By default, only those up to the highest
450 one actually used in the match are output (corresponding to the return code
451 from \fBpcre[16|32]_exec()\fP). Values in the offsets vector corresponding to
452 higher numbers should be set to -1, and these are output as "<unset>". This
453 modifier gives a way of checking that this is happening.
454 .P
455 The \fB/B\fP modifier is a debugging feature. It requests that \fBpcretest\fP
456 output a representation of the compiled code after compilation. Normally this
457 information contains length and offset values; however, if \fB/Z\fP is also
458 present, this data is replaced by spaces. This is a special feature for use in
459 the automatic test scripts; it ensures that the same output is generated for
460 different internal link sizes.
461 .P
462 The \fB/D\fP modifier is a PCRE debugging feature, and is equivalent to
463 \fB/BI\fP, that is, both the \fB/B\fP and the \fB/I\fP modifiers.
464 .P
465 The \fB/F\fP modifier causes \fBpcretest\fP to flip the byte order of the
466 2-byte and 4-byte fields in the compiled pattern. This facility is for testing
467 the feature in PCRE that allows it to execute patterns that were compiled on a
468 host with a different endianness. This feature is not available when the POSIX
469 interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
470 specified. See also the section about saving and reloading compiled patterns
471 below.
472 .P
473 The \fB/I\fP modifier requests that \fBpcretest\fP output information about the
474 compiled pattern (whether it is anchored, has a fixed first character, and
475 so on). It does this by calling \fBpcre[16|32]_fullinfo()\fP after compiling a
476 pattern. If the pattern is studied, the results of that are also output.
477 .P
478 The \fB/K\fP modifier requests \fBpcretest\fP to show names from backtracking
479 control verbs that are returned from calls to \fBpcre[16|32]_exec()\fP. It causes
480 \fBpcretest\fP to create a \fBpcre[16|32]_extra\fP block if one has not already
481 been created by a call to \fBpcre[16|32]_study()\fP, and to set the
482 PCRE_EXTRA_MARK flag and the \fBmark\fP field within it, every time that
483 \fBpcre[16|32]_exec()\fP is called. If the variable that the \fBmark\fP field
484 points to is non-NULL for a match, non-match, or partial match, \fBpcretest\fP
485 prints the string to which it points. For a match, this is shown on a line by
486 itself, tagged with "MK:". For a non-match it is added to the message.
487 .P
488 The \fB/L\fP modifier must be followed directly by the name of a locale, for
489 example,
490 .sp
491 /pattern/Lfr_FR
492 .sp
493 For this reason, it must be the last modifier. The given locale is set,
494 \fBpcre[16|32]_maketables()\fP is called to build a set of character tables for
495 the locale, and this is then passed to \fBpcre[16|32]_compile()\fP when compiling
496 the regular expression. Without an \fB/L\fP (or \fB/T\fP) modifier, NULL is
497 passed as the tables pointer; that is, \fB/L\fP applies only to the expression
498 on which it appears.
499 .P
500 The \fB/M\fP modifier causes the size in bytes of the memory block used to hold
501 the compiled pattern to be output. This does not include the size of the
502 \fBpcre[16|32]\fP block; it is just the actual compiled data. If the pattern is
503 successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the
504 JIT compiled code is also output.
505 .P
506 The \fB/S\fP modifier causes \fBpcre[16|32]_study()\fP to be called after the
507 expression has been compiled, and the results used when the expression is
508 matched. There are a number of qualifying characters that may follow \fB/S\fP.
509 They may appear in any order.
510 .P
511 If \fBS\fP is followed by an exclamation mark, \fBpcre[16|32]_study()\fP is called
512 with the PCRE_STUDY_EXTRA_NEEDED option, causing it always to return a
513 \fBpcre_extra\fP block, even when studying discovers no useful information.
514 .P
515 If \fB/S\fP is followed by a second S character, it suppresses studying, even
516 if it was requested externally by the \fB-s\fP command line option. This makes
517 it possible to specify that certain patterns are always studied, and others are
518 never studied, independently of \fB-s\fP. This feature is used in the test
519 files in a few cases where the output is different when the pattern is studied.
520 .P
521 If the \fB/S\fP modifier is followed by a + character, the call to
522 \fBpcre[16|32]_study()\fP is made with all the JIT study options, requesting
523 just-in-time optimization support if it is available, for both normal and
524 partial matching. If you want to restrict the JIT compiling modes, you can
525 follow \fB/S+\fP with a digit in the range 1 to 7:
526 .sp
527 1 normal match only
528 2 soft partial match only
529 3 normal match and soft partial match
530 4 hard partial match only
531 6 soft and hard partial match
532 7 all three modes (default)
533 .sp
534 If \fB/S++\fP is used instead of \fB/S+\fP (with or without a following digit),
535 the text "(JIT)" is added to the first output line after a match or no match
536 when JIT-compiled code was actually used.
537 .P
538 Note that there is also an independent \fB/+\fP modifier; it must not be given
539 immediately after \fB/S\fP or \fB/S+\fP because this will be misinterpreted.
540 .P
541 If JIT studying is successful, the compiled JIT code will automatically be used
542 when \fBpcre[16|32]_exec()\fP is run, except when incompatible run-time options
543 are specified. For more details, see the
544 .\" HREF
545 \fBpcrejit\fP
546 .\"
547 documentation. See also the \fB\eJ\fP escape sequence below for a way of
548 setting the size of the JIT stack.
549 .P
550 Finally, if \fB/S\fP is followed by a minus character, JIT compilation is
551 suppressed, even if it was requested externally by the \fB-s\fP command line
552 option. This makes it possible to specify that JIT is never to be used for
553 certain patterns.
554 .P
555 The \fB/T\fP modifier must be followed by a single digit. It causes a specific
556 set of built-in character tables to be passed to \fBpcre[16|32]_compile()\fP. It
557 is used in the standard PCRE tests to check behaviour with different character
558 tables. The digit specifies the tables as follows:
559 .sp
560 0 the default ASCII tables, as distributed in
561 pcre_chartables.c.dist
562 1 a set of tables defining ISO 8859 characters
563 .sp
564 In table 1, some characters whose codes are greater than 128 are identified as
565 letters, digits, spaces, etc.
566 .
567 .
568 .SS "Using the POSIX wrapper API"
569 .rs
570 .sp
571 The \fB/P\fP modifier causes \fBpcretest\fP to call PCRE via the POSIX wrapper
572 API rather than its native API. This supports only the 8-bit library. When
573 \fB/P\fP is set, the following modifiers set options for the \fBregcomp()\fP
574 function:
575 .sp
576 /i REG_ICASE
579 /s REG_DOTALL )
580 /U REG_UNGREEDY ) These options are not part of
581 /W REG_UCP ) the POSIX standard
582 /8 REG_UTF8 )
583 .sp
584 The \fB/+\fP modifier works as described above. All other modifiers are
585 ignored.
586 .
587 .
589 .rs
590 .sp
591 Before each data line is passed to \fBpcre[16|32]_exec()\fP, leading and trailing
592 white space is removed, and it is then scanned for \e escapes. Some of these
593 are pretty esoteric features, intended for checking out some of the more
594 complicated features of PCRE. If you are just testing "ordinary" regular
595 expressions, you probably don't need any of these. The following escapes are
596 recognized:
597 .sp
598 \ea alarm (BEL, \ex07)
599 \eb backspace (\ex08)
600 \ee escape (\ex27)
601 \ef form feed (\ex0c)
602 \en newline (\ex0a)
603 .\" JOIN
604 \eqdd set the PCRE_MATCH_LIMIT limit to dd
605 (any number of digits)
606 \er carriage return (\ex0d)
607 \et tab (\ex09)
608 \ev vertical tab (\ex0b)
609 \ennn octal character (up to 3 octal digits); always
610 a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode
611 \exhh hexadecimal byte (up to 2 hex digits)
612 \ex{hh...} hexadecimal character (any number of hex digits)
613 .\" JOIN
614 \eA pass the PCRE_ANCHORED option to \fBpcre[16|32]_exec()\fP
615 or \fBpcre[16|32]_dfa_exec()\fP
616 .\" JOIN
617 \eB pass the PCRE_NOTBOL option to \fBpcre[16|32]_exec()\fP
618 or \fBpcre[16|32]_dfa_exec()\fP
619 .\" JOIN
620 \eCdd call pcre[16|32]_copy_substring() for substring dd
621 after a successful match (number less than 32)
622 .\" JOIN
623 \eCname call pcre[16|32]_copy_named_substring() for substring
624 "name" after a successful match (name termin-
625 ated by next non alphanumeric character)
626 .\" JOIN
627 \eC+ show the current captured substrings at callout
628 time
629 \eC- do not supply a callout function
630 .\" JOIN
631 \eC!n return 1 instead of 0 when callout number n is
632 reached
633 .\" JOIN
634 \eC!n!m return 1 instead of 0 when callout number n is
635 reached for the nth time
636 .\" JOIN
637 \eC*n pass the number n (may be negative) as callout
638 data; this is used as the callout return value
639 \eD use the \fBpcre[16|32]_dfa_exec()\fP match function
640 \eF only shortest match for \fBpcre[16|32]_dfa_exec()\fP
641 .\" JOIN
642 \eGdd call pcre[16|32]_get_substring() for substring dd
643 after a successful match (number less than 32)
644 .\" JOIN
645 \eGname call pcre[16|32]_get_named_substring() for substring
646 "name" after a successful match (name termin-
647 ated by next non-alphanumeric character)
648 .\" JOIN
649 \eJdd set up a JIT stack of dd kilobytes maximum (any
650 number of digits)
651 .\" JOIN
652 \eL call pcre[16|32]_get_substringlist() after a
653 successful match
654 .\" JOIN
655 \eM discover the minimum MATCH_LIMIT and
657 .\" JOIN
658 \eN pass the PCRE_NOTEMPTY option to \fBpcre[16|32]_exec()\fP
659 or \fBpcre[16|32]_dfa_exec()\fP; if used twice, pass the
661 .\" JOIN
662 \eOdd set the size of the output vector passed to
663 \fBpcre[16|32]_exec()\fP to dd (any number of digits)
664 .\" JOIN
665 \eP pass the PCRE_PARTIAL_SOFT option to \fBpcre[16|32]_exec()\fP
666 or \fBpcre[16|32]_dfa_exec()\fP; if used twice, pass the
668 .\" JOIN
669 \eQdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd
670 (any number of digits)
671 \eR pass the PCRE_DFA_RESTART option to \fBpcre[16|32]_dfa_exec()\fP
672 \eS output details of memory get/free calls during matching
673 .\" JOIN
674 \eY pass the PCRE_NO_START_OPTIMIZE option to \fBpcre[16|32]_exec()\fP
675 or \fBpcre[16|32]_dfa_exec()\fP
676 .\" JOIN
677 \eZ pass the PCRE_NOTEOL option to \fBpcre[16|32]_exec()\fP
678 or \fBpcre[16|32]_dfa_exec()\fP
679 .\" JOIN
680 \e? pass the PCRE_NO_UTF[8|16|32]_CHECK option to
681 \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP
682 .\" JOIN
683 \e>dd start the match at offset dd (optional "-"; then
684 any number of digits); this sets the \fIstartoffset\fP
685 argument for \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP
686 .\" JOIN
687 \e<cr> pass the PCRE_NEWLINE_CR option to \fBpcre[16|32]_exec()\fP
688 or \fBpcre[16|32]_dfa_exec()\fP
689 .\" JOIN
690 \e<lf> pass the PCRE_NEWLINE_LF option to \fBpcre[16|32]_exec()\fP
691 or \fBpcre[16|32]_dfa_exec()\fP
692 .\" JOIN
693 \e<crlf> pass the PCRE_NEWLINE_CRLF option to \fBpcre[16|32]_exec()\fP
694 or \fBpcre[16|32]_dfa_exec()\fP
695 .\" JOIN
696 \e<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to \fBpcre[16|32]_exec()\fP
697 or \fBpcre[16|32]_dfa_exec()\fP
698 .\" JOIN
699 \e<any> pass the PCRE_NEWLINE_ANY option to \fBpcre[16|32]_exec()\fP
700 or \fBpcre[16|32]_dfa_exec()\fP
701 .sp
702 The use of \ex{hh...} is not dependent on the use of the \fB/8\fP modifier on
703 the pattern. It is recognized always. There may be any number of hexadecimal
704 digits inside the braces; invalid values provoke error messages.
705 .P
706 Note that \exhh specifies one byte rather than one character in UTF-8 mode;
707 this makes it possible to construct invalid UTF-8 sequences for testing
708 purposes. On the other hand, \ex{hh} is interpreted as a UTF-8 character in
709 UTF-8 mode, generating more than one byte if the value is greater than 127.
710 When testing the 8-bit library not in UTF-8 mode, \ex{hh} generates one byte
711 for values less than 256, and causes an error for greater values.
712 .P
713 In UTF-16 mode, all 4-digit \ex{hhhh} values are accepted. This makes it
714 possible to construct invalid UTF-16 sequences for testing purposes.
715 .P
716 In UTF-32 mode, all 4- to 8-digit \ex{...} values are accepted. This makes it
717 possible to construct invalid UTF-32 sequences for testing purposes.
718 .P
719 The escapes that specify line ending sequences are literal strings, exactly as
720 shown. No more than one newline setting should be present in any data line.
721 .P
722 A backslash followed by anything else just escapes the anything else. If
723 the very last character is a backslash, it is ignored. This gives a way of
724 passing an empty line as data, since a real empty line terminates the data
725 input.
726 .P
727 The \fB\eJ\fP escape provides a way of setting the maximum stack size that is
728 used by the just-in-time optimization code. It is ignored if JIT optimization
729 is not being used. Providing a stack that is larger than the default 32K is
730 necessary only for very complicated patterns.
731 .P
732 If \eM is present, \fBpcretest\fP calls \fBpcre[16|32]_exec()\fP several times,
733 with different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP
734 fields of the \fBpcre[16|32]_extra\fP data structure, until it finds the minimum
735 numbers for each parameter that allow \fBpcre[16|32]_exec()\fP to complete without
736 error. Because this is testing a specific feature of the normal interpretive
737 \fBpcre[16|32]_exec()\fP execution, the use of any JIT optimization that might
738 have been set up by the \fB/S+\fP qualifier of \fB-s+\fP option is disabled.
739 .P
740 The \fImatch_limit\fP number is a measure of the amount of backtracking
741 that takes place, and checking it out can be instructive. For most simple
742 matches, the number is quite small, but for patterns with very large numbers of
743 matching possibilities, it can become large very quickly with increasing length
744 of subject string. The \fImatch_limit_recursion\fP number is a measure of how
745 much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
746 needed to complete the match attempt.
747 .P
748 When \eO is used, the value specified may be higher or lower than the size set
749 by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to
750 the call of \fBpcre[16|32]_exec()\fP for the line in which it appears.
751 .P
752 If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper
753 API to be used, the only option-setting sequences that have any effect are \eB,
754 \eN, and \eZ, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
755 to be passed to \fBregexec()\fP.
756 .
757 .
759 .rs
760 .sp
761 By default, \fBpcretest\fP uses the standard PCRE matching function,
762 \fBpcre[16|32]_exec()\fP to match each data line. PCRE also supports an
763 alternative matching function, \fBpcre[16|32]_dfa_test()\fP, which operates in a
764 different way, and has some restrictions. The differences between the two
765 functions are described in the
766 .\" HREF
767 \fBpcrematching\fP
768 .\"
769 documentation.
770 .P
771 If a data line contains the \eD escape sequence, or if the command line
772 contains the \fB-dfa\fP option, the alternative matching function is used.
773 This function finds all possible matches at a given point. If, however, the \eF
774 escape sequence is present in the data line, it stops after the first match is
775 found. This is always the shortest possible match.
776 .
777 .
779 .rs
780 .sp
781 This section describes the output when the normal matching function,
782 \fBpcre[16|32]_exec()\fP, is being used.
783 .P
784 When a match succeeds, \fBpcretest\fP outputs the list of captured substrings
785 that \fBpcre[16|32]_exec()\fP returns, starting with number 0 for the string that
786 matched the whole pattern. Otherwise, it outputs "No match" when the return is
787 PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
788 substring when \fBpcre[16|32]_exec()\fP returns PCRE_ERROR_PARTIAL. (Note that
789 this is the entire substring that was inspected during the partial match; it
790 may include characters before the actual match start if a lookbehind assertion,
791 \eK, \eb, or \eB was involved.) For any other return, \fBpcretest\fP outputs
792 the PCRE negative error number and a short descriptive phrase. If the error is
793 a failed UTF string check, the offset of the start of the failing character and
794 the reason code are also output, provided that the size of the output vector is
795 at least two. Here is an example of an interactive \fBpcretest\fP run.
796 .sp
797 $ pcretest
798 PCRE version 8.13 2011-04-30
799 .sp
800 re> /^abc(\ed+)/
801 data> abc123
802 0: abc123
803 1: 123
804 data> xyz
805 No match
806 .sp
807 Unset capturing substrings that are not followed by one that is set are not
808 returned by \fBpcre[16|32]_exec()\fP, and are not shown by \fBpcretest\fP. In the
809 following example, there are two capturing substrings, but when the first data
810 line is matched, the second, unset substring is not shown. An "internal" unset
811 substring is shown as "<unset>", as for the second data line.
812 .sp
813 re> /(a)|(b)/
814 data> a
815 0: a
816 1: a
817 data> b
818 0: b
819 1: <unset>
820 2: b
821 .sp
822 If the strings contain any non-printing characters, they are output as \exhh
823 escapes if the value is less than 256 and UTF mode is not set. Otherwise they
824 are output as \ex{hh...} escapes. See below for the definition of non-printing
825 characters. If the pattern has the \fB/+\fP modifier, the output for substring
826 0 is followed by the the rest of the subject string, identified by "0+" like
827 this:
828 .sp
829 re> /cat/+
830 data> cataract
831 0: cat
832 0+ aract
833 .sp
834 If the pattern has the \fB/g\fP or \fB/G\fP modifier, the results of successive
835 matching attempts are output in sequence, like this:
836 .sp
837 re> /\eBi(\ew\ew)/g
838 data> Mississippi
839 0: iss
840 1: ss
841 0: iss
842 1: ss
843 0: ipp
844 1: pp
845 .sp
846 "No match" is output only if the first match attempt fails. Here is an example
847 of a failure message (the offset 4 that is specified by \e>4 is past the end of
848 the subject string):
849 .sp
850 re> /xyz/
851 data> xyz\e>4
852 Error -24 (bad offset value)
853 .P
854 If any of the sequences \fB\eC\fP, \fB\eG\fP, or \fB\eL\fP are present in a
855 data line that is successfully matched, the substrings extracted by the
856 convenience functions are output with C, G, or L after the string number
857 instead of a colon. This is in addition to the normal full list. The string
858 length (that is, the return from the extraction function) is given in
859 parentheses after each string for \fB\eC\fP and \fB\eG\fP.
860 .P
861 Note that whereas patterns can be continued over several lines (a plain ">"
862 prompt is used for continuations), data lines may not. However newlines can be
863 included in data by means of the \en escape (or \er, \er\en, etc., depending on
864 the newline sequence setting).
865 .
866 .
867 .
869 .rs
870 .sp
871 When the alternative matching function, \fBpcre[16|32]_dfa_exec()\fP, is used (by
872 means of the \eD escape sequence or the \fB-dfa\fP command line option), the
873 output consists of a list of all the matches that start at the first point in
874 the subject where there is at least one match. For example:
875 .sp
876 re> /(tang|tangerine|tan)/
877 data> yellow tangerine\eD
878 0: tangerine
879 1: tang
880 2: tan
881 .sp
882 (Using the normal matching function on this data finds only "tang".) The
883 longest matching string is always given first (and numbered zero). After a
884 PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
885 partially matching substring. (Note that this is the entire substring that was
886 inspected during the partial match; it may include characters before the actual
887 match start if a lookbehind assertion, \eK, \eb, or \eB was involved.)
888 .P
889 If \fB/g\fP is present on the pattern, the search for further matches resumes
890 at the end of the longest match. For example:
891 .sp
892 re> /(tang|tangerine|tan)/g
893 data> yellow tangerine and tangy sultana\eD
894 0: tangerine
895 1: tang
896 2: tan
897 0: tang
898 1: tan
899 0: tan
900 .sp
901 Since the matching function does not support substring capture, the escape
902 sequences that are concerned with captured substrings are not relevant.
903 .
904 .
906 .rs
907 .sp
908 When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
909 indicating that the subject partially matched the pattern, you can restart the
910 match with additional subject data by means of the \eR escape sequence. For
911 example:
912 .sp
913 re> /^\ed?\ed(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\ed\ed$/
914 data> 23ja\eP\eD
915 Partial match: 23ja
916 data> n05\eR\eD
917 0: n05
918 .sp
919 For further information about partial matching, see the
920 .\" HREF
921 \fBpcrepartial\fP
922 .\"
923 documentation.
924 .
925 .
927 .rs
928 .sp
929 If the pattern contains any callout requests, \fBpcretest\fP's callout function
930 is called during matching. This works with both matching functions. By default,
931 the called function displays the callout number, the start and current
932 positions in the text at the callout time, and the next pattern item to be
933 tested. For example:
934 .sp
935 --->pqrabcdef
936 0 ^ ^ \ed
937 .sp
938 This output indicates that callout number 0 occurred for a match attempt
939 starting at the fourth character of the subject string, when the pointer was at
940 the seventh character of the data, and when the next pattern item was \ed. Just
941 one circumflex is output if the start and current positions are the same.
942 .P
943 Callouts numbered 255 are assumed to be automatic callouts, inserted as a
944 result of the \fB/C\fP pattern modifier. In this case, instead of showing the
945 callout number, the offset in the pattern, preceded by a plus, is output. For
946 example:
947 .sp
948 re> /\ed?[A-E]\e*/C
949 data> E*
950 --->E*
951 +0 ^ \ed?
952 +3 ^ [A-E]
953 +8 ^^ \e*
954 +10 ^ ^
955 0: E*
956 .sp
957 If a pattern contains (*MARK) items, an additional line is output whenever
958 a change of latest mark is passed to the callout function. For example:
959 .sp
960 re> /a(*MARK:X)bc/C
961 data> abc
962 --->abc
963 +0 ^ a
964 +1 ^^ (*MARK:X)
965 +10 ^^ b
966 Latest Mark: X
967 +11 ^ ^ c
968 +12 ^ ^
969 0: abc
970 .sp
971 The mark changes between matching "a" and "b", but stays the same for the rest
972 of the match, so nothing more is output. If, as a result of backtracking, the
973 mark reverts to being unset, the text "<unset>" is output.
974 .P
975 The callout function in \fBpcretest\fP returns zero (carry on matching) by
976 default, but you can use a \eC item in a data line (as described above) to
977 change this and other parameters of the callout.
978 .P
979 Inserting callouts can be helpful when using \fBpcretest\fP to check
980 complicated regular expressions. For further information about callouts, see
981 the
982 .\" HREF
983 \fBpcrecallout\fP
984 .\"
985 documentation.
986 .
987 .
988 .
990 .rs
991 .sp
992 When \fBpcretest\fP is outputting text in the compiled version of a pattern,
993 bytes other than 32-126 are always treated as non-printing characters are are
994 therefore shown as hex escapes.
995 .P
996 When \fBpcretest\fP is outputting text that is a matched part of a subject
997 string, it behaves in the same way, unless a different locale has been set for
998 the pattern (using the \fB/L\fP modifier). In this case, the \fBisprint()\fP
999 function to distinguish printing and non-printing characters.
1000 .
1001 .
1002 .
1004 .rs
1005 .sp
1006 The facilities described in this section are not available when the POSIX
1007 interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
1008 specified.
1009 .P
1010 When the POSIX interface is not in use, you can cause \fBpcretest\fP to write a
1011 compiled pattern to a file, by following the modifiers with > and a file name.
1012 For example:
1013 .sp
1014 /pattern/im >/some/file
1015 .sp
1016 See the
1017 .\" HREF
1018 \fBpcreprecompile\fP
1019 .\"
1020 documentation for a discussion about saving and re-using compiled patterns.
1021 Note that if the pattern was successfully studied with JIT optimization, the
1022 JIT data cannot be saved.
1023 .P
1024 The data that is written is binary. The first eight bytes are the length of the
1025 compiled pattern data followed by the length of the optional study data, each
1026 written as four bytes in big-endian order (most significant byte first). If
1027 there is no study data (either the pattern was not studied, or studying did not
1028 return any data), the second length is zero. The lengths are followed by an
1029 exact copy of the compiled pattern. If there is additional study data, this
1030 (excluding any JIT data) follows immediately after the compiled pattern. After
1031 writing the file, \fBpcretest\fP expects to read a new pattern.
1032 .P
1033 A saved pattern can be reloaded into \fBpcretest\fP by specifying < and a file
1034 name instead of a pattern. The name of the file must not contain a < character,
1035 as otherwise \fBpcretest\fP will interpret the line as a pattern delimited by <
1036 characters.
1037 For example:
1038 .sp
1039 re> </some/file
1040 Compiled pattern loaded from /some/file
1041 No study data
1042 .sp
1043 If the pattern was previously studied with the JIT optimization, the JIT
1044 information cannot be saved and restored, and so is lost. When the pattern has
1045 been loaded, \fBpcretest\fP proceeds to read data lines in the usual way.
1046 .P
1047 You can copy a file written by \fBpcretest\fP to a different host and reload it
1048 there, even if the new host has opposite endianness to the one on which the
1049 pattern was compiled. For example, you can compile on an i86 machine and run on
1050 a SPARC machine. When a pattern is reloaded on a host with different
1051 endianness, the confirmation message is changed to:
1052 .sp
1053 Compiled pattern (byte-inverted) loaded from /some/file
1054 .sp
1055 The test suite contains some saved pre-compiled patterns with different
1056 endianness. These are reloaded using "<!" instead of just "<". This suppresses
1057 the "(byte-inverted)" text so that the output is the same on all hosts. It also
1058 forces debugging output once the pattern has been reloaded.
1059 .P
1060 File names for saving and reloading can be absolute or relative, but note that
1061 the shell facility of expanding a file name that starts with a tilde (~) is not
1062 available.
1063 .P
1064 The ability to save and reload files in \fBpcretest\fP is intended for testing
1065 and experimentation. It is not intended for production use because only a
1066 single pattern can be written to a file. Furthermore, there is no facility for
1067 supplying custom character tables for use with a reloaded pattern. If the
1068 original pattern was compiled with custom tables, an attempt to match a subject
1069 string using a reloaded pattern is likely to cause \fBpcretest\fP to crash.
1070 Finally, if you attempt to load a file that is not in the correct format, the
1071 result is undefined.
1072 .
1073 .
1074 .SH "SEE ALSO"
1075 .rs
1076 .sp
1077 \fBpcre\fP(3), \fBpcre16\fP(3), \fBpcre32\fP(3), \fBpcreapi\fP(3),
1078 \fBpcrecallout\fP(3),
1079 \fBpcrejit\fP, \fBpcrematching\fP(3), \fBpcrepartial\fP(d),
1080 \fBpcrepattern\fP(3), \fBpcreprecompile\fP(3).
1081 .
1082 .
1084 .rs
1085 .sp
1086 .nf
1087 Philip Hazel
1088 University Computing Service
1089 Cambridge CB2 3QH, England.
1090 .fi
1091 .
1092 .
1094 .rs
1095 .sp
1096 .nf
1097 Last updated: 26 April 2013
1098 Copyright (c) 1997-2013 University of Cambridge.
1099 .fi


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