1PCRETEST(1) General Commands Manual PCRETEST(1)
2
6 pcretest - a program for testing Perl-compatible regular expressions.
7
9 pcretest [options] [input file [output file]]
11 pcretest was written as a test program for the PCRE regular expression
13 library itself, but it can also be used for experimenting with regular
14 expressions. This document describes the features of the test program;
15 for details of the regular expressions themselves, see the pcrepattern
16 documentation. For details of the PCRE library function calls and their
17 options, see the pcreapi , pcre16 and pcre32 documentation.
18 The input for pcretest is a sequence of regular expression patterns and
20 strings to be matched, as described below. The output shows the result
21 of each match. Options on the command line and the patterns control
22 PCRE options and exactly what is output.
23 As PCRE has evolved, it has acquired many different features, and as a
25 result, pcretest now has rather a lot of obscure options for testing
26 every possible feature. Some of these options are specifically designed
27 for use in conjunction with the test script and data files that are
28 distributed as part of PCRE, and are unlikely to be of use otherwise.
29 They are all documented here, but without much justification.
30
32 From release 8.30, two separate PCRE libraries can be built. The origi‐
34 nal one supports 8-bit character strings, whereas the newer 16-bit
35 library supports character strings encoded in 16-bit units. From
36 release 8.32, a third library can be built, supporting character
37 strings encoded in 32-bit units. The pcretest program can be used to
38 test all three libraries. However, it is itself still an 8-bit program,
39 reading 8-bit input and writing 8-bit output. When testing the 16-bit
40 or 32-bit library, the patterns and data strings are converted to 16-
41 or 32-bit format before being passed to the PCRE library functions.
42 Results are converted to 8-bit for output.
43 References to functions and structures of the form pcre[16|32]_xx below
45 mean "pcre_xx when using the 8-bit library or pcre16_xx when using the
46 16-bit library".
47
49 -8 If both the 8-bit library has been built, this option causes
51 the 8-bit library to be used (which is the default); if the
52 8-bit library has not been built, this option causes an
53 error.
54 -16 If both the 8-bit or the 32-bit, and the 16-bit libraries
56 have been built, this option causes the 16-bit library to be
57 used. If only the 16-bit library has been built, this is the
58 default (so has no effect). If only the 8-bit or the 32-bit
59 library has been built, this option causes an error.
60 -32 If both the 8-bit or the 16-bit, and the 32-bit libraries
62 have been built, this option causes the 32-bit library to be
63 used. If only the 32-bit library has been built, this is the
64 default (so has no effect). If only the 8-bit or the 16-bit
65 library has been built, this option causes an error.
66 -b Behave as if each pattern has the /B (show byte code) modi‐
68 fier; the internal form is output after compilation.
69 -C Output the version number of the PCRE library, and all avail‐
71 able information about the optional features that are
72 included, and then exit. All other options are ignored.
73 -C option Output information about a specific build-time option, then
75 exit. This functionality is intended for use in scripts such
76 as RunTest. The following options output the value indicated:
77 ebcdic-nl the code for LF (= NL) in an EBCDIC environment:
79 0x15 or 0x25
80 0 if used in an ASCII environment
81 linksize the internal link size (2, 3, or 4)
82 newline the default newline setting:
83 CR, LF, CRLF, ANYCRLF, or ANY
84 The following options output 1 for true or zero for false:
86 ebcdic compiled for an EBCDIC environment
88 jit just-in-time support is available
89 pcre16 the 16-bit library was built
90 pcre32 the 32-bit library was built
91 pcre8 the 8-bit library was built
92 ucp Unicode property support is available
93 utf UTF-8 and/or UTF-16 and/or UTF-32 support is
94 available
95 -d Behave as if each pattern has the /D (debug) modifier; the
97 internal form and information about the compiled pattern is
98 output after compilation; -d is equivalent to -b -i.
99 -dfa Behave as if each data line contains the \D escape sequence;
101 this causes the alternative matching function,
102 pcre[16|32]_dfa_exec(), to be used instead of the standard
103 pcre[16|32]_exec() function (more detail is given below).
104 -help Output a brief summary these options and then exit.
106 -i Behave as if each pattern has the /I modifier; information
108 about the compiled pattern is given after compilation.
109 -M Behave as if each data line contains the \M escape sequence;
111 this causes PCRE to discover the minimum MATCH_LIMIT and
112 MATCH_LIMIT_RECURSION settings by calling pcre[16|32]_exec()
113 repeatedly with different limits.
114 -m Output the size of each compiled pattern after it has been
116 compiled. This is equivalent to adding /M to each regular
117 expression. The size is given in bytes for both libraries.
118 -o osize Set the number of elements in the output vector that is used
120 when calling pcre[16|32]_exec() or pcre[16|32]_dfa_exec() to
121 be osize. The default value is 45, which is enough for 14
122 capturing subexpressions for pcre[16|32]_exec() or 22 differ‐
123 ent matches for pcre[16|32]_dfa_exec(). The vector size can
124 be changed for individual matching calls by including \O in
125 the data line (see below).
126 -p Behave as if each pattern has the /P modifier; the POSIX
128 wrapper API is used to call PCRE. None of the other options
129 has any effect when -p is set. This option can be used only
130 with the 8-bit library.
131 -q Do not output the version number of pcretest at the start of
133 execution.
134 -S size On Unix-like systems, set the size of the run-time stack to
136 size megabytes.
137 -s or -s+ Behave as if each pattern has the /S modifier; in other
139 words, force each pattern to be studied. If -s+ is used, all
140 the JIT compile options are passed to pcre[16|32]_study(),
141 causing just-in-time optimization to be set up if it is
142 available, for both full and partial matching. Specific JIT
143 compile options can be selected by following -s+ with a digit
144 in the range 1 to 7, which selects the JIT compile modes as
145 follows:
146 1 normal match only
148 2 soft partial match only
149 3 normal match and soft partial match
150 4 hard partial match only
151 6 soft and hard partial match
152 7 all three modes (default)
153 If -s++ is used instead of -s+ (with or without a following
155 digit), the text "(JIT)" is added to the first output line
156 after a match or no match when JIT-compiled code was actually
157 used.
158 Note that there are pattern options that can override -s,
160 either specifying no studying at all, or suppressing JIT com‐
161 pilation.
162 If the /I or /D option is present on a pattern (requesting
164 output about the compiled pattern), information about the
165 result of studying is not included when studying is caused
166 only by -s and neither -i nor -d is present on the command
167 line. This behaviour means that the output from tests that
168 are run with and without -s should be identical, except when
169 options that output information about the actual running of a
170 match are set.
171 The -M, -t, and -tm options, which give information about
173 resources used, are likely to produce different output with
174 and without -s. Output may also differ if the /C option is
175 present on an individual pattern. This uses callouts to trace
176 the the matching process, and this may be different between
177 studied and non-studied patterns. If the pattern contains
178 (*MARK) items there may also be differences, for the same
179 reason. The -s command line option can be overridden for spe‐
180 cific patterns that should never be studied (see the /S pat‐
181 tern modifier below).
182 -t Run each compile, study, and match many times with a timer,
184 and output resulting time per compile or match (in millisec‐
185 onds). Do not set -m with -t, because you will then get the
186 size output a zillion times, and the timing will be dis‐
187 torted. You can control the number of iterations that are
188 used for timing by following -t with a number (as a separate
189 item on the command line). For example, "-t 1000" would iter‐
190 ate 1000 times. The default is to iterate 500000 times.
191 -tm This is like -t except that it times only the matching phase,
193 not the compile or study phases.
194
196 If pcretest is given two filename arguments, it reads from the first
198 and writes to the second. If it is given only one filename argument, it
199 reads from that file and writes to stdout. Otherwise, it reads from
200 stdin and writes to stdout, and prompts for each line of input, using
201 "re>" to prompt for regular expressions, and "data>" to prompt for data
202 lines.
203 When pcretest is built, a configuration option can specify that it
205 should be linked with the libreadline library. When this is done, if
206 the input is from a terminal, it is read using the readline() function.
207 This provides line-editing and history facilities. The output from the
208 -help option states whether or not readline() will be used.
209 The program handles any number of sets of input on a single input file.
211 Each set starts with a regular expression, and continues with any num‐
212 ber of data lines to be matched against the pattern.
213 Each data line is matched separately and independently. If you want to
215 do multi-line matches, you have to use the \n escape sequence (or \r or
216 \r\n, etc., depending on the newline setting) in a single line of input
217 to encode the newline sequences. There is no limit on the length of
218 data lines; the input buffer is automatically extended if it is too
219 small.
220 An empty line signals the end of the data lines, at which point a new
222 regular expression is read. The regular expressions are given enclosed
223 in any non-alphanumeric delimiters other than backslash, for example:
224 /(a|bc)x+yz/
226 White space before the initial delimiter is ignored. A regular expres‐
228 sion may be continued over several input lines, in which case the new‐
229 line characters are included within it. It is possible to include the
230 delimiter within the pattern by escaping it, for example
231 /abc\/def/
233 If you do so, the escape and the delimiter form part of the pattern,
235 but since delimiters are always non-alphanumeric, this does not affect
236 its interpretation. If the terminating delimiter is immediately fol‐
237 lowed by a backslash, for example,
238 /abc/\
240 then a backslash is added to the end of the pattern. This is done to
242 provide a way of testing the error condition that arises if a pattern
243 finishes with a backslash, because
244 /abc\/
246 is interpreted as the first line of a pattern that starts with "abc/",
248 causing pcretest to read the next line as a continuation of the regular
249 expression.
250
252 A pattern may be followed by any number of modifiers, which are mostly
254 single characters, though some of these can be qualified by further
255 characters. Following Perl usage, these are referred to below as, for
256 example, "the /i modifier", even though the delimiter of the pattern
257 need not always be a slash, and no slash is used when writing modi‐
258 fiers. White space may appear between the final pattern delimiter and
259 the first modifier, and between the modifiers themselves. For refer‐
260 ence, here is a complete list of modifiers. They fall into several
261 groups that are described in detail in the following sections.
262 /8 set UTF mode
264 /? disable UTF validity check
265 /+ show remainder of subject after match
266 /= show all captures (not just those that are set)
267 /A set PCRE_ANCHORED
269 /B show compiled code
270 /C set PCRE_AUTO_CALLOUT
271 /D same as /B plus /I
272 /E set PCRE_DOLLAR_ENDONLY
273 /F flip byte order in compiled pattern
274 /f set PCRE_FIRSTLINE
275 /G find all matches (shorten string)
276 /g find all matches (use startoffset)
277 /I show information about pattern
278 /i set PCRE_CASELESS
279 /J set PCRE_DUPNAMES
280 /K show backtracking control names
281 /L set locale
282 /M show compiled memory size
283 /m set PCRE_MULTILINE
284 /N set PCRE_NO_AUTO_CAPTURE
285 /P use the POSIX wrapper
286 /S study the pattern after compilation
287 /s set PCRE_DOTALL
288 /T select character tables
289 /U set PCRE_UNGREEDY
290 /W set PCRE_UCP
291 /X set PCRE_EXTRA
292 /x set PCRE_EXTENDED
293 /Y set PCRE_NO_START_OPTIMIZE
294 /Z don't show lengths in /B output
295 /<any> set PCRE_NEWLINE_ANY
297 /<anycrlf> set PCRE_NEWLINE_ANYCRLF
298 /<cr> set PCRE_NEWLINE_CR
299 /<crlf> set PCRE_NEWLINE_CRLF
300 /<lf> set PCRE_NEWLINE_LF
301 /<bsr_anycrlf> set PCRE_BSR_ANYCRLF
302 /<bsr_unicode> set PCRE_BSR_UNICODE
303 /<JS> set PCRE_JAVASCRIPT_COMPAT
304 Perl-compatible modifiers
307 The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,
309 PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
310 pcre[16|32]_compile() is called. These four modifier letters have the
311 same effect as they do in Perl. For example:
312 /caseless/i
314 Modifiers for other PCRE options
317 The following table shows additional modifiers for setting PCRE com‐
319 pile-time options that do not correspond to anything in Perl:
320 /8 PCRE_UTF8 ) when using the 8-bit
322 /? PCRE_NO_UTF8_CHECK ) library
323 /8 PCRE_UTF16 ) when using the 16-bit
325 /? PCRE_NO_UTF16_CHECK ) library
326 /8 PCRE_UTF32 ) when using the 32-bit
328 /? PCRE_NO_UTF32_CHECK ) library
329 /A PCRE_ANCHORED
331 /C PCRE_AUTO_CALLOUT
332 /E PCRE_DOLLAR_ENDONLY
333 /f PCRE_FIRSTLINE
334 /J PCRE_DUPNAMES
335 /N PCRE_NO_AUTO_CAPTURE
336 /U PCRE_UNGREEDY
337 /W PCRE_UCP
338 /X PCRE_EXTRA
339 /Y PCRE_NO_START_OPTIMIZE
340 /<any> PCRE_NEWLINE_ANY
341 /<anycrlf> PCRE_NEWLINE_ANYCRLF
342 /<cr> PCRE_NEWLINE_CR
343 /<crlf> PCRE_NEWLINE_CRLF
344 /<lf> PCRE_NEWLINE_LF
345 /<bsr_anycrlf> PCRE_BSR_ANYCRLF
346 /<bsr_unicode> PCRE_BSR_UNICODE
347 /<JS> PCRE_JAVASCRIPT_COMPAT
348 The modifiers that are enclosed in angle brackets are literal strings
350 as shown, including the angle brackets, but the letters within can be
351 in either case. This example sets multiline matching with CRLF as the
352 line ending sequence:
353 /^abc/m<CRLF>
355 As well as turning on the PCRE_UTF8/16/32 option, the /8 modifier
357 causes all non-printing characters in output strings to be printed
358 using the \x{hh...} notation. Otherwise, those less than 0x100 are out‐
359 put in hex without the curly brackets.
360 Full details of the PCRE options are given in the pcreapi documenta‐
362 tion.
363 Finding all matches in a string
365 Searching for all possible matches within each subject string can be
367 requested by the /g or /G modifier. After finding a match, PCRE is
368 called again to search the remainder of the subject string. The differ‐
369 ence between /g and /G is that the former uses the startoffset argument
370 to pcre[16|32]_exec() to start searching at a new point within the
371 entire string (which is in effect what Perl does), whereas the latter
372 passes over a shortened substring. This makes a difference to the
373 matching process if the pattern begins with a lookbehind assertion
374 (including \b or \B).
375 If any call to pcre[16|32]_exec() in a /g or /G sequence matches an
377 empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
378 PCRE_ANCHORED flags set in order to search for another, non-empty,
379 match at the same point. If this second match fails, the start offset
380 is advanced, and the normal match is retried. This imitates the way
381 Perl handles such cases when using the /g modifier or the split() func‐
382 tion. Normally, the start offset is advanced by one character, but if
383 the newline convention recognizes CRLF as a newline, and the current
384 character is CR followed by LF, an advance of two is used.
385 Other modifiers
387 There are yet more modifiers for controlling the way pcretest operates.
389 The /+ modifier requests that as well as outputting the substring that
391 matched the entire pattern, pcretest should in addition output the
392 remainder of the subject string. This is useful for tests where the
393 subject contains multiple copies of the same substring. If the + modi‐
394 fier appears twice, the same action is taken for captured substrings.
395 In each case the remainder is output on the following line with a plus
396 character following the capture number. Note that this modifier must
397 not immediately follow the /S modifier because /S+ and /S++ have other
398 meanings.
399 The /= modifier requests that the values of all potential captured
401 parentheses be output after a match. By default, only those up to the
402 highest one actually used in the match are output (corresponding to the
403 return code from pcre[16|32]_exec()). Values in the offsets vector cor‐
404 responding to higher numbers should be set to -1, and these are output
405 as "<unset>". This modifier gives a way of checking that this is hap‐
406 pening.
407 The /B modifier is a debugging feature. It requests that pcretest out‐
409 put a representation of the compiled code after compilation. Normally
410 this information contains length and offset values; however, if /Z is
411 also present, this data is replaced by spaces. This is a special fea‐
412 ture for use in the automatic test scripts; it ensures that the same
413 output is generated for different internal link sizes.
414 The /D modifier is a PCRE debugging feature, and is equivalent to /BI,
416 that is, both the /B and the /I modifiers.
417 The /F modifier causes pcretest to flip the byte order of the 2-byte
419 and 4-byte fields in the compiled pattern. This facility is for testing
420 the feature in PCRE that allows it to execute patterns that were com‐
421 piled on a host with a different endianness. This feature is not avail‐
422 able when the POSIX interface to PCRE is being used, that is, when the
423 /P pattern modifier is specified. See also the section about saving and
424 reloading compiled patterns below.
425 The /I modifier requests that pcretest output information about the
427 compiled pattern (whether it is anchored, has a fixed first character,
428 and so on). It does this by calling pcre[16|32]_fullinfo() after com‐
429 piling a pattern. If the pattern is studied, the results of that are
430 also output.
431 The /K modifier requests pcretest to show names from backtracking con‐
433 trol verbs that are returned from calls to pcre[16|32]_exec(). It
434 causes pcretest to create a pcre[16|32]_extra block if one has not
435 already been created by a call to pcre[16|32]_study(), and to set the
436 PCRE_EXTRA_MARK flag and the mark field within it, every time that
437 pcre[16|32]_exec() is called. If the variable that the mark field
438 points to is non-NULL for a match, non-match, or partial match,
439 pcretest prints the string to which it points. For a match, this is
440 shown on a line by itself, tagged with "MK:". For a non-match it is
441 added to the message.
442 The /L modifier must be followed directly by the name of a locale, for
444 example,
445 /pattern/Lfr_FR
447 For this reason, it must be the last modifier. The given locale is set,
449 pcre[16|32]_maketables() is called to build a set of character tables
450 for the locale, and this is then passed to pcre[16|32]_compile() when
451 compiling the regular expression. Without an /L (or /T) modifier, NULL
452 is passed as the tables pointer; that is, /L applies only to the
453 expression on which it appears.
454 The /M modifier causes the size in bytes of the memory block used to
456 hold the compiled pattern to be output. This does not include the size
457 of the pcre[16|32] block; it is just the actual compiled data. If the
458 pattern is successfully studied with the PCRE_STUDY_JIT_COMPILE option,
459 the size of the JIT compiled code is also output.
460 The /S modifier causes pcre[16|32]_study() to be called after the
462 expression has been compiled, and the results used when the expression
463 is matched. There are a number of qualifying characters that may follow
464 /S. They may appear in any order.
465 If S is followed by an exclamation mark, pcre[16|32]_study() is called
467 with the PCRE_STUDY_EXTRA_NEEDED option, causing it always to return a
468 pcre_extra block, even when studying discovers no useful information.
469 If /S is followed by a second S character, it suppresses studying, even
471 if it was requested externally by the -s command line option. This
472 makes it possible to specify that certain patterns are always studied,
473 and others are never studied, independently of -s. This feature is used
474 in the test files in a few cases where the output is different when the
475 pattern is studied.
476 If the /S modifier is followed by a + character, the call to
478 pcre[16|32]_study() is made with all the JIT study options, requesting
479 just-in-time optimization support if it is available, for both normal
480 and partial matching. If you want to restrict the JIT compiling modes,
481 you can follow /S+ with a digit in the range 1 to 7:
482 1 normal match only
484 2 soft partial match only
485 3 normal match and soft partial match
486 4 hard partial match only
487 6 soft and hard partial match
488 7 all three modes (default)
489 If /S++ is used instead of /S+ (with or without a following digit), the
491 text "(JIT)" is added to the first output line after a match or no
492 match when JIT-compiled code was actually used.
493 Note that there is also an independent /+ modifier; it must not be
495 given immediately after /S or /S+ because this will be misinterpreted.
496 If JIT studying is successful, the compiled JIT code will automatically
498 be used when pcre[16|32]_exec() is run, except when incompatible run-
499 time options are specified. For more details, see the pcrejit documen‐
500 tation. See also the \J escape sequence below for a way of setting the
501 size of the JIT stack.
502 Finally, if /S is followed by a minus character, JIT compilation is
504 suppressed, even if it was requested externally by the -s command line
505 option. This makes it possible to specify that JIT is never to be used
506 for certain patterns.
507 The /T modifier must be followed by a single digit. It causes a spe‐
509 cific set of built-in character tables to be passed to pcre[16|32]_com‐
510 pile(). It is used in the standard PCRE tests to check behaviour with
511 different character tables. The digit specifies the tables as follows:
512 0 the default ASCII tables, as distributed in
514 pcre_chartables.c.dist
515 1 a set of tables defining ISO 8859 characters
516 In table 1, some characters whose codes are greater than 128 are iden‐
518 tified as letters, digits, spaces, etc.
519 Using the POSIX wrapper API
521 The /P modifier causes pcretest to call PCRE via the POSIX wrapper API
523 rather than its native API. This supports only the 8-bit library. When
524 /P is set, the following modifiers set options for the regcomp() func‐
525 tion:
526 /i REG_ICASE
528 /m REG_NEWLINE
529 /N REG_NOSUB
530 /s REG_DOTALL )
531 /U REG_UNGREEDY ) These options are not part of
532 /W REG_UCP ) the POSIX standard
533 /8 REG_UTF8 )
534 The /+ modifier works as described above. All other modifiers are
536 ignored.
537
539 Before each data line is passed to pcre[16|32]_exec(), leading and
541 trailing white space is removed, and it is then scanned for \ escapes.
542 Some of these are pretty esoteric features, intended for checking out
543 some of the more complicated features of PCRE. If you are just testing
544 "ordinary" regular expressions, you probably don't need any of these.
545 The following escapes are recognized:
546 \a alarm (BEL, \x07)
548 \b backspace (\x08)
549 \e escape (\x27)
550 \f form feed (\x0c)
551 \n newline (\x0a)
552 \qdd set the PCRE_MATCH_LIMIT limit to dd
553 (any number of digits)
554 \r carriage return (\x0d)
555 \t tab (\x09)
556 \v vertical tab (\x0b)
557 \nnn octal character (up to 3 octal digits); always
558 a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode
559 \xhh hexadecimal byte (up to 2 hex digits)
560 \x{hh...} hexadecimal character (any number of hex digits)
561 \A pass the PCRE_ANCHORED option to pcre[16|32]_exec()
562 or pcre[16|32]_dfa_exec()
563 \B pass the PCRE_NOTBOL option to pcre[16|32]_exec()
564 or pcre[16|32]_dfa_exec()
565 \Cdd call pcre[16|32]_copy_substring() for substring dd
566 after a successful match (number less than 32)
567 \Cname call pcre[16|32]_copy_named_substring() for substring
568 "name" after a successful match (name terminated
569 by next non alphanumeric character)
570 \C+ show the current captured substrings at callout
571 time
572 \C- do not supply a callout function
573 \C!n return 1 instead of 0 when callout number n is
574 reached
575 \C!n!m return 1 instead of 0 when callout number n is
576 reached for the nth time
577 \C*n pass the number n (may be negative) as callout
578 data; this is used as the callout return value
579 \D use the pcre[16|32]_dfa_exec() match function
580 \F only shortest match for pcre[16|32]_dfa_exec()
581 \Gdd call pcre[16|32]_get_substring() for substring dd
582 after a successful match (number less than 32)
583 \Gname call pcre[16|32]_get_named_substring() for substring
584 "name" after a successful match (name terminated
585 by next non-alphanumeric character)
586 \Jdd set up a JIT stack of dd kilobytes maximum (any
587 number of digits)
588 \L call pcre[16|32]_get_substringlist() after a
589 successful match
590 \M discover the minimum MATCH_LIMIT and
591 MATCH_LIMIT_RECURSION settings
592 \N pass the PCRE_NOTEMPTY option to pcre[16|32]_exec()
593 or pcre[16|32]_dfa_exec(); if used twice, pass the
594 PCRE_NOTEMPTY_ATSTART option
595 \Odd set the size of the output vector passed to
596 pcre[16|32]_exec() to dd (any number of digits)
597 \P pass the PCRE_PARTIAL_SOFT option to pcre[16|32]_exec()
598 or pcre[16|32]_dfa_exec(); if used twice, pass the
599 PCRE_PARTIAL_HARD option
600 \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd
601 (any number of digits)
602 \R pass the PCRE_DFA_RESTART option to pcre[16|32]_dfa_exec()
603 \S output details of memory get/free calls during matching
604 \Y pass the PCRE_NO_START_OPTIMIZE option to
605 pcre[16|32]_exec()
606 or pcre[16|32]_dfa_exec()
607 \Z pass the PCRE_NOTEOL option to pcre[16|32]_exec()
608 or pcre[16|32]_dfa_exec()
609 \? pass the PCRE_NO_UTF[8|16|32]_CHECK option to
610 pcre[16|32]_exec() or pcre[16|32]_dfa_exec()
611 \>dd start the match at offset dd (optional "-"; then
612 any number of digits); this sets the startoffset
613 argument for pcre[16|32]_exec() or
614 pcre[16|32]_dfa_exec()
615 \<cr> pass the PCRE_NEWLINE_CR option to pcre[16|32]_exec()
616 or pcre[16|32]_dfa_exec()
617 \<lf> pass the PCRE_NEWLINE_LF option to pcre[16|32]_exec()
618 or pcre[16|32]_dfa_exec()
619 \<crlf> pass the PCRE_NEWLINE_CRLF option to pcre[16|32]_exec()
620 or pcre[16|32]_dfa_exec()
621 \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to pcre[16|32]_exec()
622 or pcre[16|32]_dfa_exec()
623 \<any> pass the PCRE_NEWLINE_ANY option to pcre[16|32]_exec()
624 or pcre[16|32]_dfa_exec()
625 The use of \x{hh...} is not dependent on the use of the /8 modifier on
627 the pattern. It is recognized always. There may be any number of hexa‐
628 decimal digits inside the braces; invalid values provoke error mes‐
629 sages.
630 Note that \xhh specifies one byte rather than one character in UTF-8
632 mode; this makes it possible to construct invalid UTF-8 sequences for
633 testing purposes. On the other hand, \x{hh} is interpreted as a UTF-8
634 character in UTF-8 mode, generating more than one byte if the value is
635 greater than 127. When testing the 8-bit library not in UTF-8 mode,
636 \x{hh} generates one byte for values less than 256, and causes an error
637 for greater values.
638 In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it
640 possible to construct invalid UTF-16 sequences for testing purposes.
641 In UTF-32 mode, all 4- to 8-digit \x{...} values are accepted. This
643 makes it possible to construct invalid UTF-32 sequences for testing
644 purposes.
645 The escapes that specify line ending sequences are literal strings,
647 exactly as shown. No more than one newline setting should be present in
648 any data line.
649 A backslash followed by anything else just escapes the anything else.
651 If the very last character is a backslash, it is ignored. This gives a
652 way of passing an empty line as data, since a real empty line termi‐
653 nates the data input.
654 The \J escape provides a way of setting the maximum stack size that is
656 used by the just-in-time optimization code. It is ignored if JIT opti‐
657 mization is not being used. Providing a stack that is larger than the
658 default 32K is necessary only for very complicated patterns.
659 If \M is present, pcretest calls pcre[16|32]_exec() several times, with
661 different values in the match_limit and match_limit_recursion fields of
662 the pcre[16|32]_extra data structure, until it finds the minimum num‐
663 bers for each parameter that allow pcre[16|32]_exec() to complete with‐
664 out error. Because this is testing a specific feature of the normal
665 interpretive pcre[16|32]_exec() execution, the use of any JIT optimiza‐
666 tion that might have been set up by the /S+ qualifier of -s+ option is
667 disabled.
668 The match_limit number is a measure of the amount of backtracking that
670 takes place, and checking it out can be instructive. For most simple
671 matches, the number is quite small, but for patterns with very large
672 numbers of matching possibilities, it can become large very quickly
673 with increasing length of subject string. The match_limit_recursion
674 number is a measure of how much stack (or, if PCRE is compiled with
675 NO_RECURSE, how much heap) memory is needed to complete the match
676 attempt.
677 When \O is used, the value specified may be higher or lower than the
679 size set by the -O command line option (or defaulted to 45); \O applies
680 only to the call of pcre[16|32]_exec() for the line in which it
681 appears.
682 If the /P modifier was present on the pattern, causing the POSIX wrap‐
684 per API to be used, the only option-setting sequences that have any
685 effect are \B, \N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and
686 REG_NOTEOL, respectively, to be passed to regexec().
687
689 By default, pcretest uses the standard PCRE matching function,
691 pcre[16|32]_exec() to match each data line. PCRE also supports an
692 alternative matching function, pcre[16|32]_dfa_test(), which operates
693 in a different way, and has some restrictions. The differences between
694 the two functions are described in the pcrematching documentation.
695 If a data line contains the \D escape sequence, or if the command line
697 contains the -dfa option, the alternative matching function is used.
698 This function finds all possible matches at a given point. If, however,
699 the \F escape sequence is present in the data line, it stops after the
700 first match is found. This is always the shortest possible match.
701
703 This section describes the output when the normal matching function,
705 pcre[16|32]_exec(), is being used.
706 When a match succeeds, pcretest outputs the list of captured substrings
708 that pcre[16|32]_exec() returns, starting with number 0 for the string
709 that matched the whole pattern. Otherwise, it outputs "No match" when
710 the return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the
711 partially matching substring when pcre[16|32]_exec() returns
712 PCRE_ERROR_PARTIAL. (Note that this is the entire substring that was
713 inspected during the partial match; it may include characters before
714 the actual match start if a lookbehind assertion, \K, \b, or \B was
715 involved.) For any other return, pcretest outputs the PCRE negative
716 error number and a short descriptive phrase. If the error is a failed
717 UTF string check, the offset of the start of the failing character and
718 the reason code are also output, provided that the size of the output
719 vector is at least two. Here is an example of an interactive pcretest
720 run.
721 $ pcretest
723 PCRE version 8.13 2011-04-30
724 re> /^abc(\d+)/
726 data> abc123
727 0: abc123
728 1: 123
729 data> xyz
730 No match
731 Unset capturing substrings that are not followed by one that is set are
733 not returned by pcre[16|32]_exec(), and are not shown by pcretest. In
734 the following example, there are two capturing substrings, but when the
735 first data line is matched, the second, unset substring is not shown.
736 An "internal" unset substring is shown as "<unset>", as for the second
737 data line.
738 re> /(a)|(b)/
740 data> a
741 0: a
742 1: a
743 data> b
744 0: b
745 1: <unset>
746 2: b
747 If the strings contain any non-printing characters, they are output as
749 \xhh escapes if the value is less than 256 and UTF mode is not set.
750 Otherwise they are output as \x{hh...} escapes. See below for the defi‐
751 nition of non-printing characters. If the pattern has the /+ modifier,
752 the output for substring 0 is followed by the the rest of the subject
753 string, identified by "0+" like this:
754 re> /cat/+
756 data> cataract
757 0: cat
758 0+ aract
759 If the pattern has the /g or /G modifier, the results of successive
761 matching attempts are output in sequence, like this:
762 re> /\Bi(\w\w)/g
764 data> Mississippi
765 0: iss
766 1: ss
767 0: iss
768 1: ss
769 0: ipp
770 1: pp
771 "No match" is output only if the first match attempt fails. Here is an
773 example of a failure message (the offset 4 that is specified by \>4 is
774 past the end of the subject string):
775 re> /xyz/
777 data> xyz\>4
778 Error -24 (bad offset value)
779 If any of the sequences \C, \G, or \L are present in a data line that
781 is successfully matched, the substrings extracted by the convenience
782 functions are output with C, G, or L after the string number instead of
783 a colon. This is in addition to the normal full list. The string length
784 (that is, the return from the extraction function) is given in paren‐
785 theses after each string for \C and \G.
786 Note that whereas patterns can be continued over several lines (a plain
788 ">" prompt is used for continuations), data lines may not. However new‐
789 lines can be included in data by means of the \n escape (or \r, \r\n,
790 etc., depending on the newline sequence setting).
791
793 When the alternative matching function, pcre[16|32]_dfa_exec(), is used
795 (by means of the \D escape sequence or the -dfa command line option),
796 the output consists of a list of all the matches that start at the
797 first point in the subject where there is at least one match. For exam‐
798 ple:
799 re> /(tang|tangerine|tan)/
801 data> yellow tangerine\D
802 0: tangerine
803 1: tang
804 2: tan
805 (Using the normal matching function on this data finds only "tang".)
807 The longest matching string is always given first (and numbered zero).
808 After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol‐
809 lowed by the partially matching substring. (Note that this is the
810 entire substring that was inspected during the partial match; it may
811 include characters before the actual match start if a lookbehind asser‐
812 tion, \K, \b, or \B was involved.)
813 If /g is present on the pattern, the search for further matches resumes
815 at the end of the longest match. For example:
816 re> /(tang|tangerine|tan)/g
818 data> yellow tangerine and tangy sultana\D
819 0: tangerine
820 1: tang
821 2: tan
822 0: tang
823 1: tan
824 0: tan
825 Since the matching function does not support substring capture, the
827 escape sequences that are concerned with captured substrings are not
828 relevant.
829
831 When the alternative matching function has given the PCRE_ERROR_PARTIAL
833 return, indicating that the subject partially matched the pattern, you
834 can restart the match with additional subject data by means of the \R
835 escape sequence. For example:
836 re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
838 data> 23ja\P\D
839 Partial match: 23ja
840 data> n05\R\D
841 0: n05
842 For further information about partial matching, see the pcrepartial
844 documentation.
845
847 If the pattern contains any callout requests, pcretest's callout func‐
849 tion is called during matching. This works with both matching func‐
850 tions. By default, the called function displays the callout number, the
851 start and current positions in the text at the callout time, and the
852 next pattern item to be tested. For example:
853 --->pqrabcdef
855 0 ^ ^ \d
856 This output indicates that callout number 0 occurred for a match
858 attempt starting at the fourth character of the subject string, when
859 the pointer was at the seventh character of the data, and when the next
860 pattern item was \d. Just one circumflex is output if the start and
861 current positions are the same.
862 Callouts numbered 255 are assumed to be automatic callouts, inserted as
864 a result of the /C pattern modifier. In this case, instead of showing
865 the callout number, the offset in the pattern, preceded by a plus, is
866 output. For example:
867 re> /\d?[A-E]\*/C
869 data> E*
870 --->E*
871 +0 ^ \d?
872 +3 ^ [A-E]
873 +8 ^^ \*
874 +10 ^ ^
875 0: E*
876 If a pattern contains (*MARK) items, an additional line is output when‐
878 ever a change of latest mark is passed to the callout function. For
879 example:
880 re> /a(*MARK:X)bc/C
882 data> abc
883 --->abc
884 +0 ^ a
885 +1 ^^ (*MARK:X)
886 +10 ^^ b
887 Latest Mark: X
888 +11 ^ ^ c
889 +12 ^ ^
890 0: abc
891 The mark changes between matching "a" and "b", but stays the same for
893 the rest of the match, so nothing more is output. If, as a result of
894 backtracking, the mark reverts to being unset, the text "<unset>" is
895 output.
896 The callout function in pcretest returns zero (carry on matching) by
898 default, but you can use a \C item in a data line (as described above)
899 to change this and other parameters of the callout.
900 Inserting callouts can be helpful when using pcretest to check compli‐
902 cated regular expressions. For further information about callouts, see
903 the pcrecallout documentation.
904
906 When pcretest is outputting text in the compiled version of a pattern,
908 bytes other than 32-126 are always treated as non-printing characters
909 are are therefore shown as hex escapes.
910 When pcretest is outputting text that is a matched part of a subject
912 string, it behaves in the same way, unless a different locale has been
913 set for the pattern (using the /L modifier). In this case, the
914 isprint() function to distinguish printing and non-printing characters.
915
917 The facilities described in this section are not available when the
919 POSIX interface to PCRE is being used, that is, when the /P pattern
920 modifier is specified.
921 When the POSIX interface is not in use, you can cause pcretest to write
923 a compiled pattern to a file, by following the modifiers with > and a
924 file name. For example:
925 /pattern/im >/some/file
927 See the pcreprecompile documentation for a discussion about saving and
929 re-using compiled patterns. Note that if the pattern was successfully
930 studied with JIT optimization, the JIT data cannot be saved.
931 The data that is written is binary. The first eight bytes are the
933 length of the compiled pattern data followed by the length of the
934 optional study data, each written as four bytes in big-endian order
935 (most significant byte first). If there is no study data (either the
936 pattern was not studied, or studying did not return any data), the sec‐
937 ond length is zero. The lengths are followed by an exact copy of the
938 compiled pattern. If there is additional study data, this (excluding
939 any JIT data) follows immediately after the compiled pattern. After
940 writing the file, pcretest expects to read a new pattern.
941 A saved pattern can be reloaded into pcretest by specifying < and a
943 file name instead of a pattern. The name of the file must not contain a
944 < character, as otherwise pcretest will interpret the line as a pattern
945 delimited by < characters. For example:
946 re> </some/file
948 Compiled pattern loaded from /some/file
949 No study data
950 If the pattern was previously studied with the JIT optimization, the
952 JIT information cannot be saved and restored, and so is lost. When the
953 pattern has been loaded, pcretest proceeds to read data lines in the
954 usual way.
955 You can copy a file written by pcretest to a different host and reload
957 it there, even if the new host has opposite endianness to the one on
958 which the pattern was compiled. For example, you can compile on an i86
959 machine and run on a SPARC machine. When a pattern is reloaded on a
960 host with different endianness, the confirmation message is changed to:
961 Compiled pattern (byte-inverted) loaded from /some/file
963 The test suite contains some saved pre-compiled patterns with different
965 endianness. These are reloaded using "<!" instead of just "<". This
966 suppresses the "(byte-inverted)" text so that the output is the same on
967 all hosts. It also forces debugging output once the pattern has been
968 reloaded.
969 File names for saving and reloading can be absolute or relative, but
971 note that the shell facility of expanding a file name that starts with
972 a tilde (~) is not available.
973 The ability to save and reload files in pcretest is intended for test‐
975 ing and experimentation. It is not intended for production use because
976 only a single pattern can be written to a file. Furthermore, there is
977 no facility for supplying custom character tables for use with a
978 reloaded pattern. If the original pattern was compiled with custom
979 tables, an attempt to match a subject string using a reloaded pattern
980 is likely to cause pcretest to crash. Finally, if you attempt to load
981 a file that is not in the correct format, the result is undefined.
982
984 pcre(3), pcre16(3), pcre32(3), pcreapi(3), pcrecallout(3), pcrejit,
986 pcrematching(3), pcrepartial(d), pcrepattern(3), pcreprecompile(3).
987
989 Philip Hazel
991 University Computing Service
992 Cambridge CB2 3QH, England.
993
995 Last updated: 10 September 2012
997 Copyright (c) 1997-2012 University of Cambridge.
998PCRE 8.32 10 September 2012 PCRETEST(1)