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 Input to pcretest is processed line by line, either by calling the C
34 library's fgets() function, or via the libreadline library (see below).
35 In Unix-like environments, fgets() treats any bytes other than newline
36 as data characters. However, in some Windows environments character 26
37 (hex 1A) causes an immediate end of file, and no further data is read.
38 For maximum portability, therefore, it is safest to use only ASCII
39 characters in pcretest input files.
40 The input is processed using using C's string functions, so must not
42 contain binary zeroes, even though in Unix-like environments, fgets()
43 treats any bytes other than newline as data characters.
44
46 From release 8.30, two separate PCRE libraries can be built. The origi‐
48 nal one supports 8-bit character strings, whereas the newer 16-bit
49 library supports character strings encoded in 16-bit units. From
50 release 8.32, a third library can be built, supporting character
51 strings encoded in 32-bit units. The pcretest program can be used to
52 test all three libraries. However, it is itself still an 8-bit program,
53 reading 8-bit input and writing 8-bit output. When testing the 16-bit
54 or 32-bit library, the patterns and data strings are converted to 16-
55 or 32-bit format before being passed to the PCRE library functions.
56 Results are converted to 8-bit for output.
57 References to functions and structures of the form pcre[16|32]_xx below
59 mean "pcre_xx when using the 8-bit library, pcre16_xx when using the
60 16-bit library, or pcre32_xx when using the 32-bit library".
61
63 -8 If both the 8-bit library has been built, this option causes
65 the 8-bit library to be used (which is the default); if the
66 8-bit library has not been built, this option causes an
67 error.
68 -16 If both the 8-bit or the 32-bit, and the 16-bit libraries
70 have been built, this option causes the 16-bit library to be
71 used. If only the 16-bit library has been built, this is the
72 default (so has no effect). If only the 8-bit or the 32-bit
73 library has been built, this option causes an error.
74 -32 If both the 8-bit or the 16-bit, and the 32-bit libraries
76 have been built, this option causes the 32-bit library to be
77 used. If only the 32-bit library has been built, this is the
78 default (so has no effect). If only the 8-bit or the 16-bit
79 library has been built, this option causes an error.
80 -b Behave as if each pattern has the /B (show byte code) modi‐
82 fier; the internal form is output after compilation.
83 -C Output the version number of the PCRE library, and all avail‐
85 able information about the optional features that are
86 included, and then exit with zero exit code. All other
87 options are ignored.
88 -C option Output information about a specific build-time option, then
90 exit. This functionality is intended for use in scripts such
91 as RunTest. The following options output the value and set
92 the exit code as indicated:
93 ebcdic-nl the code for LF (= NL) in an EBCDIC environment:
95 0x15 or 0x25
96 0 if used in an ASCII environment
97 exit code is always 0
98 linksize the configured internal link size (2, 3, or 4)
99 exit code is set to the link size
100 newline the default newline setting:
101 CR, LF, CRLF, ANYCRLF, or ANY
102 exit code is always 0
103 bsr the default setting for what \R matches:
104 ANYCRLF or ANY
105 exit code is always 0
106 The following options output 1 for true or 0 for false, and
108 set the exit code to the same value:
109 ebcdic compiled for an EBCDIC environment
111 jit just-in-time support is available
112 pcre16 the 16-bit library was built
113 pcre32 the 32-bit library was built
114 pcre8 the 8-bit library was built
115 ucp Unicode property support is available
116 utf UTF-8 and/or UTF-16 and/or UTF-32 support
117 is available
118 If an unknown option is given, an error message is output;
120 the exit code is 0.
121 -d Behave as if each pattern has the /D (debug) modifier; the
123 internal form and information about the compiled pattern is
124 output after compilation; -d is equivalent to -b -i.
125 -dfa Behave as if each data line contains the \D escape sequence;
127 this causes the alternative matching function,
128 pcre[16|32]_dfa_exec(), to be used instead of the standard
129 pcre[16|32]_exec() function (more detail is given below).
130 -help Output a brief summary these options and then exit.
132 -i Behave as if each pattern has the /I modifier; information
134 about the compiled pattern is given after compilation.
135 -M Behave as if each data line contains the \M escape sequence;
137 this causes PCRE to discover the minimum MATCH_LIMIT and
138 MATCH_LIMIT_RECURSION settings by calling pcre[16|32]_exec()
139 repeatedly with different limits.
140 -m Output the size of each compiled pattern after it has been
142 compiled. This is equivalent to adding /M to each regular
143 expression. The size is given in bytes for both libraries.
144 -O Behave as if each pattern has the /O modifier, that is dis‐
146 able auto-possessification for all patterns.
147 -o osize Set the number of elements in the output vector that is used
149 when calling pcre[16|32]_exec() or pcre[16|32]_dfa_exec() to
150 be osize. The default value is 45, which is enough for 14
151 capturing subexpressions for pcre[16|32]_exec() or 22 differ‐
152 ent matches for pcre[16|32]_dfa_exec(). The vector size can
153 be changed for individual matching calls by including \O in
154 the data line (see below).
155 -p Behave as if each pattern has the /P modifier; the POSIX
157 wrapper API is used to call PCRE. None of the other options
158 has any effect when -p is set. This option can be used only
159 with the 8-bit library.
160 -q Do not output the version number of pcretest at the start of
162 execution.
163 -S size On Unix-like systems, set the size of the run-time stack to
165 size megabytes.
166 -s or -s+ Behave as if each pattern has the /S modifier; in other
168 words, force each pattern to be studied. If -s+ is used, all
169 the JIT compile options are passed to pcre[16|32]_study(),
170 causing just-in-time optimization to be set up if it is
171 available, for both full and partial matching. Specific JIT
172 compile options can be selected by following -s+ with a digit
173 in the range 1 to 7, which selects the JIT compile modes as
174 follows:
175 1 normal match only
177 2 soft partial match only
178 3 normal match and soft partial match
179 4 hard partial match only
180 6 soft and hard partial match
181 7 all three modes (default)
182 If -s++ is used instead of -s+ (with or without a following
184 digit), the text "(JIT)" is added to the first output line
185 after a match or no match when JIT-compiled code was actually
186 used.
187 Note that there are pattern options that can override -s,
189 either specifying no studying at all, or suppressing JIT com‐
190 pilation.
191 If the /I or /D option is present on a pattern (requesting
193 output about the compiled pattern), information about the
194 result of studying is not included when studying is caused
195 only by -s and neither -i nor -d is present on the command
196 line. This behaviour means that the output from tests that
197 are run with and without -s should be identical, except when
198 options that output information about the actual running of a
199 match are set.
200 The -M, -t, and -tm options, which give information about
202 resources used, are likely to produce different output with
203 and without -s. Output may also differ if the /C option is
204 present on an individual pattern. This uses callouts to trace
205 the the matching process, and this may be different between
206 studied and non-studied patterns. If the pattern contains
207 (*MARK) items there may also be differences, for the same
208 reason. The -s command line option can be overridden for spe‐
209 cific patterns that should never be studied (see the /S pat‐
210 tern modifier below).
211 -t Run each compile, study, and match many times with a timer,
213 and output the resulting times per compile, study, or match
214 (in milliseconds). Do not set -m with -t, because you will
215 then get the size output a zillion times, and the timing will
216 be distorted. You can control the number of iterations that
217 are used for timing by following -t with a number (as a sepa‐
218 rate item on the command line). For example, "-t 1000" iter‐
219 ates 1000 times. The default is to iterate 500000 times.
220 -tm This is like -t except that it times only the matching phase,
222 not the compile or study phases.
223 -T -TM These behave like -t and -tm, but in addition, at the end of
225 a run, the total times for all compiles, studies, and matches
226 are output.
227
229 If pcretest is given two filename arguments, it reads from the first
231 and writes to the second. If it is given only one filename argument, it
232 reads from that file and writes to stdout. Otherwise, it reads from
233 stdin and writes to stdout, and prompts for each line of input, using
234 "re>" to prompt for regular expressions, and "data>" to prompt for data
235 lines.
236 When pcretest is built, a configuration option can specify that it
238 should be linked with the libreadline library. When this is done, if
239 the input is from a terminal, it is read using the readline() function.
240 This provides line-editing and history facilities. The output from the
241 -help option states whether or not readline() will be used.
242 The program handles any number of sets of input on a single input file.
244 Each set starts with a regular expression, and continues with any num‐
245 ber of data lines to be matched against that pattern.
246 Each data line is matched separately and independently. If you want to
248 do multi-line matches, you have to use the \n escape sequence (or \r or
249 \r\n, etc., depending on the newline setting) in a single line of input
250 to encode the newline sequences. There is no limit on the length of
251 data lines; the input buffer is automatically extended if it is too
252 small.
253 An empty line signals the end of the data lines, at which point a new
255 regular expression is read. The regular expressions are given enclosed
256 in any non-alphanumeric delimiters other than backslash, for example:
257 /(a|bc)x+yz/
259 White space before the initial delimiter is ignored. A regular expres‐
261 sion may be continued over several input lines, in which case the new‐
262 line characters are included within it. It is possible to include the
263 delimiter within the pattern by escaping it, for example
264 /abc\/def/
266 If you do so, the escape and the delimiter form part of the pattern,
268 but since delimiters are always non-alphanumeric, this does not affect
269 its interpretation. If the terminating delimiter is immediately fol‐
270 lowed by a backslash, for example,
271 /abc/\
273 then a backslash is added to the end of the pattern. This is done to
275 provide a way of testing the error condition that arises if a pattern
276 finishes with a backslash, because
277 /abc\/
279 is interpreted as the first line of a pattern that starts with "abc/",
281 causing pcretest to read the next line as a continuation of the regular
282 expression.
283
285 A pattern may be followed by any number of modifiers, which are mostly
287 single characters, though some of these can be qualified by further
288 characters. Following Perl usage, these are referred to below as, for
289 example, "the /i modifier", even though the delimiter of the pattern
290 need not always be a slash, and no slash is used when writing modi‐
291 fiers. White space may appear between the final pattern delimiter and
292 the first modifier, and between the modifiers themselves. For refer‐
293 ence, here is a complete list of modifiers. They fall into several
294 groups that are described in detail in the following sections.
295 /8 set UTF mode
297 /9 set PCRE_NEVER_UTF (locks out UTF mode)
298 /? disable UTF validity check
299 /+ show remainder of subject after match
300 /= show all captures (not just those that are set)
301 /A set PCRE_ANCHORED
303 /B show compiled code
304 /C set PCRE_AUTO_CALLOUT
305 /D same as /B plus /I
306 /E set PCRE_DOLLAR_ENDONLY
307 /F flip byte order in compiled pattern
308 /f set PCRE_FIRSTLINE
309 /G find all matches (shorten string)
310 /g find all matches (use startoffset)
311 /I show information about pattern
312 /i set PCRE_CASELESS
313 /J set PCRE_DUPNAMES
314 /K show backtracking control names
315 /L set locale
316 /M show compiled memory size
317 /m set PCRE_MULTILINE
318 /N set PCRE_NO_AUTO_CAPTURE
319 /O set PCRE_NO_AUTO_POSSESS
320 /P use the POSIX wrapper
321 /Q test external stack check function
322 /S study the pattern after compilation
323 /s set PCRE_DOTALL
324 /T select character tables
325 /U set PCRE_UNGREEDY
326 /W set PCRE_UCP
327 /X set PCRE_EXTRA
328 /x set PCRE_EXTENDED
329 /Y set PCRE_NO_START_OPTIMIZE
330 /Z don't show lengths in /B output
331 /<any> set PCRE_NEWLINE_ANY
333 /<anycrlf> set PCRE_NEWLINE_ANYCRLF
334 /<cr> set PCRE_NEWLINE_CR
335 /<crlf> set PCRE_NEWLINE_CRLF
336 /<lf> set PCRE_NEWLINE_LF
337 /<bsr_anycrlf> set PCRE_BSR_ANYCRLF
338 /<bsr_unicode> set PCRE_BSR_UNICODE
339 /<JS> set PCRE_JAVASCRIPT_COMPAT
340 Perl-compatible modifiers
343 The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,
345 PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
346 pcre[16|32]_compile() is called. These four modifier letters have the
347 same effect as they do in Perl. For example:
348 /caseless/i
350 Modifiers for other PCRE options
353 The following table shows additional modifiers for setting PCRE com‐
355 pile-time options that do not correspond to anything in Perl:
356 /8 PCRE_UTF8 ) when using the 8-bit
358 /? PCRE_NO_UTF8_CHECK ) library
359 /8 PCRE_UTF16 ) when using the 16-bit
361 /? PCRE_NO_UTF16_CHECK ) library
362 /8 PCRE_UTF32 ) when using the 32-bit
364 /? PCRE_NO_UTF32_CHECK ) library
365 /9 PCRE_NEVER_UTF
367 /A PCRE_ANCHORED
368 /C PCRE_AUTO_CALLOUT
369 /E PCRE_DOLLAR_ENDONLY
370 /f PCRE_FIRSTLINE
371 /J PCRE_DUPNAMES
372 /N PCRE_NO_AUTO_CAPTURE
373 /O PCRE_NO_AUTO_POSSESS
374 /U PCRE_UNGREEDY
375 /W PCRE_UCP
376 /X PCRE_EXTRA
377 /Y PCRE_NO_START_OPTIMIZE
378 /<any> PCRE_NEWLINE_ANY
379 /<anycrlf> PCRE_NEWLINE_ANYCRLF
380 /<cr> PCRE_NEWLINE_CR
381 /<crlf> PCRE_NEWLINE_CRLF
382 /<lf> PCRE_NEWLINE_LF
383 /<bsr_anycrlf> PCRE_BSR_ANYCRLF
384 /<bsr_unicode> PCRE_BSR_UNICODE
385 /<JS> PCRE_JAVASCRIPT_COMPAT
386 The modifiers that are enclosed in angle brackets are literal strings
388 as shown, including the angle brackets, but the letters within can be
389 in either case. This example sets multiline matching with CRLF as the
390 line ending sequence:
391 /^abc/m<CRLF>
393 As well as turning on the PCRE_UTF8/16/32 option, the /8 modifier
395 causes all non-printing characters in output strings to be printed
396 using the \x{hh...} notation. Otherwise, those less than 0x100 are out‐
397 put in hex without the curly brackets.
398 Full details of the PCRE options are given in the pcreapi documenta‐
400 tion.
401 Finding all matches in a string
403 Searching for all possible matches within each subject string can be
405 requested by the /g or /G modifier. After finding a match, PCRE is
406 called again to search the remainder of the subject string. The differ‐
407 ence between /g and /G is that the former uses the startoffset argument
408 to pcre[16|32]_exec() to start searching at a new point within the
409 entire string (which is in effect what Perl does), whereas the latter
410 passes over a shortened substring. This makes a difference to the
411 matching process if the pattern begins with a lookbehind assertion
412 (including \b or \B).
413 If any call to pcre[16|32]_exec() in a /g or /G sequence matches an
415 empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
416 PCRE_ANCHORED flags set in order to search for another, non-empty,
417 match at the same point. If this second match fails, the start offset
418 is advanced, and the normal match is retried. This imitates the way
419 Perl handles such cases when using the /g modifier or the split() func‐
420 tion. Normally, the start offset is advanced by one character, but if
421 the newline convention recognizes CRLF as a newline, and the current
422 character is CR followed by LF, an advance of two is used.
423 Other modifiers
425 There are yet more modifiers for controlling the way pcretest operates.
427 The /+ modifier requests that as well as outputting the substring that
429 matched the entire pattern, pcretest should in addition output the
430 remainder of the subject string. This is useful for tests where the
431 subject contains multiple copies of the same substring. If the + modi‐
432 fier appears twice, the same action is taken for captured substrings.
433 In each case the remainder is output on the following line with a plus
434 character following the capture number. Note that this modifier must
435 not immediately follow the /S modifier because /S+ and /S++ have other
436 meanings.
437 The /= modifier requests that the values of all potential captured
439 parentheses be output after a match. By default, only those up to the
440 highest one actually used in the match are output (corresponding to the
441 return code from pcre[16|32]_exec()). Values in the offsets vector cor‐
442 responding to higher numbers should be set to -1, and these are output
443 as "<unset>". This modifier gives a way of checking that this is hap‐
444 pening.
445 The /B modifier is a debugging feature. It requests that pcretest out‐
447 put a representation of the compiled code after compilation. Normally
448 this information contains length and offset values; however, if /Z is
449 also present, this data is replaced by spaces. This is a special fea‐
450 ture for use in the automatic test scripts; it ensures that the same
451 output is generated for different internal link sizes.
452 The /D modifier is a PCRE debugging feature, and is equivalent to /BI,
454 that is, both the /B and the /I modifiers.
455 The /F modifier causes pcretest to flip the byte order of the 2-byte
457 and 4-byte fields in the compiled pattern. This facility is for testing
458 the feature in PCRE that allows it to execute patterns that were com‐
459 piled on a host with a different endianness. This feature is not avail‐
460 able when the POSIX interface to PCRE is being used, that is, when the
461 /P pattern modifier is specified. See also the section about saving and
462 reloading compiled patterns below.
463 The /I modifier requests that pcretest output information about the
465 compiled pattern (whether it is anchored, has a fixed first character,
466 and so on). It does this by calling pcre[16|32]_fullinfo() after com‐
467 piling a pattern. If the pattern is studied, the results of that are
468 also output. In this output, the word "char" means a non-UTF character,
469 that is, the value of a single data item (8-bit, 16-bit, or 32-bit,
470 depending on the library that is being tested).
471 The /K modifier requests pcretest to show names from backtracking con‐
473 trol verbs that are returned from calls to pcre[16|32]_exec(). It
474 causes pcretest to create a pcre[16|32]_extra block if one has not
475 already been created by a call to pcre[16|32]_study(), and to set the
476 PCRE_EXTRA_MARK flag and the mark field within it, every time that
477 pcre[16|32]_exec() is called. If the variable that the mark field
478 points to is non-NULL for a match, non-match, or partial match,
479 pcretest prints the string to which it points. For a match, this is
480 shown on a line by itself, tagged with "MK:". For a non-match it is
481 added to the message.
482 The /L modifier must be followed directly by the name of a locale, for
484 example,
485 /pattern/Lfr_FR
487 For this reason, it must be the last modifier. The given locale is set,
489 pcre[16|32]_maketables() is called to build a set of character tables
490 for the locale, and this is then passed to pcre[16|32]_compile() when
491 compiling the regular expression. Without an /L (or /T) modifier, NULL
492 is passed as the tables pointer; that is, /L applies only to the
493 expression on which it appears.
494 The /M modifier causes the size in bytes of the memory block used to
496 hold the compiled pattern to be output. This does not include the size
497 of the pcre[16|32] block; it is just the actual compiled data. If the
498 pattern is successfully studied with the PCRE_STUDY_JIT_COMPILE option,
499 the size of the JIT compiled code is also output.
500 The /Q modifier is used to test the use of pcre_stack_guard. It must be
502 followed by '0' or '1', specifying the return code to be given from an
503 external function that is passed to PCRE and used for stack checking
504 during compilation (see the pcreapi documentation for details).
505 The /S modifier causes pcre[16|32]_study() to be called after the
507 expression has been compiled, and the results used when the expression
508 is matched. There are a number of qualifying characters that may follow
509 /S. They may appear in any order.
510 If /S is followed by an exclamation mark, pcre[16|32]_study() is called
512 with the PCRE_STUDY_EXTRA_NEEDED option, causing it always to return a
513 pcre_extra block, even when studying discovers no useful information.
514 If /S is followed by a second S character, it suppresses studying, even
516 if it was requested externally by the -s command line option. This
517 makes it possible to specify that certain patterns are always studied,
518 and others are never studied, independently of -s. This feature is used
519 in the test files in a few cases where the output is different when the
520 pattern is studied.
521 If the /S modifier is followed by a + character, the call to
523 pcre[16|32]_study() is made with all the JIT study options, requesting
524 just-in-time optimization support if it is available, for both normal
525 and partial matching. If you want to restrict the JIT compiling modes,
526 you can follow /S+ with a digit in the range 1 to 7:
527 1 normal match only
529 2 soft partial match only
530 3 normal match and soft partial match
531 4 hard partial match only
532 6 soft and hard partial match
533 7 all three modes (default)
534 If /S++ is used instead of /S+ (with or without a following digit), the
536 text "(JIT)" is added to the first output line after a match or no
537 match when JIT-compiled code was actually used.
538 Note that there is also an independent /+ modifier; it must not be
540 given immediately after /S or /S+ because this will be misinterpreted.
541 If JIT studying is successful, the compiled JIT code will automatically
543 be used when pcre[16|32]_exec() is run, except when incompatible run-
544 time options are specified. For more details, see the pcrejit documen‐
545 tation. See also the \J escape sequence below for a way of setting the
546 size of the JIT stack.
547 Finally, if /S is followed by a minus character, JIT compilation is
549 suppressed, even if it was requested externally by the -s command line
550 option. This makes it possible to specify that JIT is never to be used
551 for certain patterns.
552 The /T modifier must be followed by a single digit. It causes a spe‐
554 cific set of built-in character tables to be passed to pcre[16|32]_com‐
555 pile(). It is used in the standard PCRE tests to check behaviour with
556 different character tables. The digit specifies the tables as follows:
557 0 the default ASCII tables, as distributed in
559 pcre_chartables.c.dist
560 1 a set of tables defining ISO 8859 characters
561 In table 1, some characters whose codes are greater than 128 are iden‐
563 tified as letters, digits, spaces, etc.
564 Using the POSIX wrapper API
566 The /P modifier causes pcretest to call PCRE via the POSIX wrapper API
568 rather than its native API. This supports only the 8-bit library. When
569 /P is set, the following modifiers set options for the regcomp() func‐
570 tion:
571 /i REG_ICASE
573 /m REG_NEWLINE
574 /N REG_NOSUB
575 /s REG_DOTALL )
576 /U REG_UNGREEDY ) These options are not part of
577 /W REG_UCP ) the POSIX standard
578 /8 REG_UTF8 )
579 The /+ modifier works as described above. All other modifiers are
581 ignored.
582 Locking out certain modifiers
584 PCRE can be compiled with or without support for certain features such
586 as UTF-8/16/32 or Unicode properties. Accordingly, the standard tests
587 are split up into a number of different files that are selected for
588 running depending on which features are available. When updating the
589 tests, it is all too easy to put a new test into the wrong file by mis‐
590 take; for example, to put a test that requires UTF support into a file
591 that is used when it is not available. To help detect such mistakes as
592 early as possible, there is a facility for locking out specific modi‐
593 fiers. If an input line for pcretest starts with the string "< forbid "
594 the following sequence of characters is taken as a list of forbidden
595 modifiers. For example, in the test files that must not use UTF or Uni‐
596 code property support, this line appears:
597 < forbid 8W
599 This locks out the /8 and /W modifiers. An immediate error is given if
601 they are subsequently encountered. If the character string contains <
602 but not >, all the multi-character modifiers that begin with < are
603 locked out. Otherwise, such modifiers must be explicitly listed, for
604 example:
605 < forbid <JS><cr>
607 There must be a single space between < and "forbid" for this feature to
609 be recognised. If there is not, the line is interpreted either as a
610 request to re-load a pre-compiled pattern (see "SAVING AND RELOADING
611 COMPILED PATTERNS" below) or, if there is a another < character, as a
612 pattern that uses < as its delimiter.
613
615 Before each data line is passed to pcre[16|32]_exec(), leading and
617 trailing white space is removed, and it is then scanned for \ escapes.
618 Some of these are pretty esoteric features, intended for checking out
619 some of the more complicated features of PCRE. If you are just testing
620 "ordinary" regular expressions, you probably don't need any of these.
621 The following escapes are recognized:
622 \a alarm (BEL, \x07)
624 \b backspace (\x08)
625 \e escape (\x27)
626 \f form feed (\x0c)
627 \n newline (\x0a)
628 \qdd set the PCRE_MATCH_LIMIT limit to dd
629 (any number of digits)
630 \r carriage return (\x0d)
631 \t tab (\x09)
632 \v vertical tab (\x0b)
633 \nnn octal character (up to 3 octal digits); always
634 a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode
635 \o{dd...} octal character (any number of octal digits}
636 \xhh hexadecimal byte (up to 2 hex digits)
637 \x{hh...} hexadecimal character (any number of hex digits)
638 \A pass the PCRE_ANCHORED option to pcre[16|32]_exec()
639 or pcre[16|32]_dfa_exec()
640 \B pass the PCRE_NOTBOL option to pcre[16|32]_exec()
641 or pcre[16|32]_dfa_exec()
642 \Cdd call pcre[16|32]_copy_substring() for substring dd
643 after a successful match (number less than 32)
644 \Cname call pcre[16|32]_copy_named_substring() for substring
645 "name" after a successful match (name terminated
646 by next non alphanumeric character)
647 \C+ show the current captured substrings at callout
648 time
649 \C- do not supply a callout function
650 \C!n return 1 instead of 0 when callout number n is
651 reached
652 \C!n!m return 1 instead of 0 when callout number n is
653 reached for the nth time
654 \C*n pass the number n (may be negative) as callout
655 data; this is used as the callout return value
656 \D use the pcre[16|32]_dfa_exec() match function
657 \F only shortest match for pcre[16|32]_dfa_exec()
658 \Gdd call pcre[16|32]_get_substring() for substring dd
659 after a successful match (number less than 32)
660 \Gname call pcre[16|32]_get_named_substring() for substring
661 "name" after a successful match (name terminated
662 by next non-alphanumeric character)
663 \Jdd set up a JIT stack of dd kilobytes maximum (any
664 number of digits)
665 \L call pcre[16|32]_get_substringlist() after a
666 successful match
667 \M discover the minimum MATCH_LIMIT and
668 MATCH_LIMIT_RECURSION settings
669 \N pass the PCRE_NOTEMPTY option to pcre[16|32]_exec()
670 or pcre[16|32]_dfa_exec(); if used twice, pass the
671 PCRE_NOTEMPTY_ATSTART option
672 \Odd set the size of the output vector passed to
673 pcre[16|32]_exec() to dd (any number of digits)
674 \P pass the PCRE_PARTIAL_SOFT option to pcre[16|32]_exec()
675 or pcre[16|32]_dfa_exec(); if used twice, pass the
676 PCRE_PARTIAL_HARD option
677 \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd
678 (any number of digits)
679 \R pass the PCRE_DFA_RESTART option to pcre[16|32]_dfa_exec()
680 \S output details of memory get/free calls during matching
681 \Y pass the PCRE_NO_START_OPTIMIZE option to
682 pcre[16|32]_exec()
683 or pcre[16|32]_dfa_exec()
684 \Z pass the PCRE_NOTEOL option to pcre[16|32]_exec()
685 or pcre[16|32]_dfa_exec()
686 \? pass the PCRE_NO_UTF[8|16|32]_CHECK option to
687 pcre[16|32]_exec() or pcre[16|32]_dfa_exec()
688 \>dd start the match at offset dd (optional "-"; then
689 any number of digits); this sets the startoffset
690 argument for pcre[16|32]_exec() or
691 pcre[16|32]_dfa_exec()
692 \<cr> pass the PCRE_NEWLINE_CR option to pcre[16|32]_exec()
693 or pcre[16|32]_dfa_exec()
694 \<lf> pass the PCRE_NEWLINE_LF option to pcre[16|32]_exec()
695 or pcre[16|32]_dfa_exec()
696 \<crlf> pass the PCRE_NEWLINE_CRLF option to pcre[16|32]_exec()
697 or pcre[16|32]_dfa_exec()
698 \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to pcre[16|32]_exec()
699 or pcre[16|32]_dfa_exec()
700 \<any> pass the PCRE_NEWLINE_ANY option to pcre[16|32]_exec()
701 or pcre[16|32]_dfa_exec()
702 The use of \x{hh...} is not dependent on the use of the /8 modifier on
704 the pattern. It is recognized always. There may be any number of hexa‐
705 decimal digits inside the braces; invalid values provoke error mes‐
706 sages.
707 Note that \xhh specifies one byte rather than one character in UTF-8
709 mode; this makes it possible to construct invalid UTF-8 sequences for
710 testing purposes. On the other hand, \x{hh} is interpreted as a UTF-8
711 character in UTF-8 mode, generating more than one byte if the value is
712 greater than 127. When testing the 8-bit library not in UTF-8 mode,
713 \x{hh} generates one byte for values less than 256, and causes an error
714 for greater values.
715 In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it
717 possible to construct invalid UTF-16 sequences for testing purposes.
718 In UTF-32 mode, all 4- to 8-digit \x{...} values are accepted. This
720 makes it possible to construct invalid UTF-32 sequences for testing
721 purposes.
722 The escapes that specify line ending sequences are literal strings,
724 exactly as shown. No more than one newline setting should be present in
725 any data line.
726 A backslash followed by anything else just escapes the anything else.
728 If the very last character is a backslash, it is ignored. This gives a
729 way of passing an empty line as data, since a real empty line termi‐
730 nates the data input.
731 The \J escape provides a way of setting the maximum stack size that is
733 used by the just-in-time optimization code. It is ignored if JIT opti‐
734 mization is not being used. Providing a stack that is larger than the
735 default 32K is necessary only for very complicated patterns.
736 If \M is present, pcretest calls pcre[16|32]_exec() several times, with
738 different values in the match_limit and match_limit_recursion fields of
739 the pcre[16|32]_extra data structure, until it finds the minimum num‐
740 bers for each parameter that allow pcre[16|32]_exec() to complete with‐
741 out error. Because this is testing a specific feature of the normal
742 interpretive pcre[16|32]_exec() execution, the use of any JIT optimiza‐
743 tion that might have been set up by the /S+ qualifier of -s+ option is
744 disabled.
745 The match_limit number is a measure of the amount of backtracking that
747 takes place, and checking it out can be instructive. For most simple
748 matches, the number is quite small, but for patterns with very large
749 numbers of matching possibilities, it can become large very quickly
750 with increasing length of subject string. The match_limit_recursion
751 number is a measure of how much stack (or, if PCRE is compiled with
752 NO_RECURSE, how much heap) memory is needed to complete the match
753 attempt.
754 When \O is used, the value specified may be higher or lower than the
756 size set by the -O command line option (or defaulted to 45); \O applies
757 only to the call of pcre[16|32]_exec() for the line in which it
758 appears.
759 If the /P modifier was present on the pattern, causing the POSIX wrap‐
761 per API to be used, the only option-setting sequences that have any
762 effect are \B, \N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and
763 REG_NOTEOL, respectively, to be passed to regexec().
764
766 By default, pcretest uses the standard PCRE matching function,
768 pcre[16|32]_exec() to match each data line. PCRE also supports an
769 alternative matching function, pcre[16|32]_dfa_test(), which operates
770 in a different way, and has some restrictions. The differences between
771 the two functions are described in the pcrematching documentation.
772 If a data line contains the \D escape sequence, or if the command line
774 contains the -dfa option, the alternative matching function is used.
775 This function finds all possible matches at a given point. If, however,
776 the \F escape sequence is present in the data line, it stops after the
777 first match is found. This is always the shortest possible match.
778
780 This section describes the output when the normal matching function,
782 pcre[16|32]_exec(), is being used.
783 When a match succeeds, pcretest outputs the list of captured substrings
785 that pcre[16|32]_exec() returns, starting with number 0 for the string
786 that matched the whole pattern. Otherwise, it outputs "No match" when
787 the return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the
788 partially matching substring when pcre[16|32]_exec() returns
789 PCRE_ERROR_PARTIAL. (Note that this is the entire substring that was
790 inspected during the partial match; it may include characters before
791 the actual match start if a lookbehind assertion, \K, \b, or \B was
792 involved.) For any other return, pcretest outputs the PCRE negative
793 error number and a short descriptive phrase. If the error is a failed
794 UTF string check, the offset of the start of the failing character and
795 the reason code are also output, provided that the size of the output
796 vector is at least two. Here is an example of an interactive pcretest
797 run.
798 $ pcretest
800 PCRE version 8.13 2011-04-30
801 re> /^abc(\d+)/
803 data> abc123
804 0: abc123
805 1: 123
806 data> xyz
807 No match
808 Unset capturing substrings that are not followed by one that is set are
810 not returned by pcre[16|32]_exec(), and are not shown by pcretest. In
811 the following example, there are two capturing substrings, but when the
812 first data line is matched, the second, unset substring is not shown.
813 An "internal" unset substring is shown as "<unset>", as for the second
814 data line.
815 re> /(a)|(b)/
817 data> a
818 0: a
819 1: a
820 data> b
821 0: b
822 1: <unset>
823 2: b
824 If the strings contain any non-printing characters, they are output as
826 \xhh escapes if the value is less than 256 and UTF mode is not set.
827 Otherwise they are output as \x{hh...} escapes. See below for the defi‐
828 nition of non-printing characters. If the pattern has the /+ modifier,
829 the output for substring 0 is followed by the the rest of the subject
830 string, identified by "0+" like this:
831 re> /cat/+
833 data> cataract
834 0: cat
835 0+ aract
836 If the pattern has the /g or /G modifier, the results of successive
838 matching attempts are output in sequence, like this:
839 re> /\Bi(\w\w)/g
841 data> Mississippi
842 0: iss
843 1: ss
844 0: iss
845 1: ss
846 0: ipp
847 1: pp
848 "No match" is output only if the first match attempt fails. Here is an
850 example of a failure message (the offset 4 that is specified by \>4 is
851 past the end of the subject string):
852 re> /xyz/
854 data> xyz\>4
855 Error -24 (bad offset value)
856 If any of the sequences \C, \G, or \L are present in a data line that
858 is successfully matched, the substrings extracted by the convenience
859 functions are output with C, G, or L after the string number instead of
860 a colon. This is in addition to the normal full list. The string length
861 (that is, the return from the extraction function) is given in paren‐
862 theses after each string for \C and \G.
863 Note that whereas patterns can be continued over several lines (a plain
865 ">" prompt is used for continuations), data lines may not. However new‐
866 lines can be included in data by means of the \n escape (or \r, \r\n,
867 etc., depending on the newline sequence setting).
868
870 When the alternative matching function, pcre[16|32]_dfa_exec(), is used
872 (by means of the \D escape sequence or the -dfa command line option),
873 the output consists of a list of all the matches that start at the
874 first point in the subject where there is at least one match. For exam‐
875 ple:
876 re> /(tang|tangerine|tan)/
878 data> yellow tangerine\D
879 0: tangerine
880 1: tang
881 2: tan
882 (Using the normal matching function on this data finds only "tang".)
884 The longest matching string is always given first (and numbered zero).
885 After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol‐
886 lowed by the partially matching substring. (Note that this is the
887 entire substring that was inspected during the partial match; it may
888 include characters before the actual match start if a lookbehind asser‐
889 tion, \K, \b, or \B was involved.)
890 If /g is present on the pattern, the search for further matches resumes
892 at the end of the longest match. For example:
893 re> /(tang|tangerine|tan)/g
895 data> yellow tangerine and tangy sultana\D
896 0: tangerine
897 1: tang
898 2: tan
899 0: tang
900 1: tan
901 0: tan
902 Since the matching function does not support substring capture, the
904 escape sequences that are concerned with captured substrings are not
905 relevant.
906
908 When the alternative matching function has given the PCRE_ERROR_PARTIAL
910 return, indicating that the subject partially matched the pattern, you
911 can restart the match with additional subject data by means of the \R
912 escape sequence. For example:
913 re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
915 data> 23ja\P\D
916 Partial match: 23ja
917 data> n05\R\D
918 0: n05
919 For further information about partial matching, see the pcrepartial
921 documentation.
922
924 If the pattern contains any callout requests, pcretest's callout func‐
926 tion is called during matching. This works with both matching func‐
927 tions. By default, the called function displays the callout number, the
928 start and current positions in the text at the callout time, and the
929 next pattern item to be tested. For example:
930 --->pqrabcdef
932 0 ^ ^ \d
933 This output indicates that callout number 0 occurred for a match
935 attempt starting at the fourth character of the subject string, when
936 the pointer was at the seventh character of the data, and when the next
937 pattern item was \d. Just one circumflex is output if the start and
938 current positions are the same.
939 Callouts numbered 255 are assumed to be automatic callouts, inserted as
941 a result of the /C pattern modifier. In this case, instead of showing
942 the callout number, the offset in the pattern, preceded by a plus, is
943 output. For example:
944 re> /\d?[A-E]\*/C
946 data> E*
947 --->E*
948 +0 ^ \d?
949 +3 ^ [A-E]
950 +8 ^^ \*
951 +10 ^ ^
952 0: E*
953 If a pattern contains (*MARK) items, an additional line is output when‐
955 ever a change of latest mark is passed to the callout function. For
956 example:
957 re> /a(*MARK:X)bc/C
959 data> abc
960 --->abc
961 +0 ^ a
962 +1 ^^ (*MARK:X)
963 +10 ^^ b
964 Latest Mark: X
965 +11 ^ ^ c
966 +12 ^ ^
967 0: abc
968 The mark changes between matching "a" and "b", but stays the same for
970 the rest of the match, so nothing more is output. If, as a result of
971 backtracking, the mark reverts to being unset, the text "<unset>" is
972 output.
973 The callout function in pcretest returns zero (carry on matching) by
975 default, but you can use a \C item in a data line (as described above)
976 to change this and other parameters of the callout.
977 Inserting callouts can be helpful when using pcretest to check compli‐
979 cated regular expressions. For further information about callouts, see
980 the pcrecallout documentation.
981
983 When pcretest is outputting text in the compiled version of a pattern,
985 bytes other than 32-126 are always treated as non-printing characters
986 are are therefore shown as hex escapes.
987 When pcretest is outputting text that is a matched part of a subject
989 string, it behaves in the same way, unless a different locale has been
990 set for the pattern (using the /L modifier). In this case, the
991 isprint() function to distinguish printing and non-printing characters.
992
994 The facilities described in this section are not available when the
996 POSIX interface to PCRE is being used, that is, when the /P pattern
997 modifier is specified.
998 When the POSIX interface is not in use, you can cause pcretest to write
1000 a compiled pattern to a file, by following the modifiers with > and a
1001 file name. For example:
1002 /pattern/im >/some/file
1004 See the pcreprecompile documentation for a discussion about saving and
1006 re-using compiled patterns. Note that if the pattern was successfully
1007 studied with JIT optimization, the JIT data cannot be saved.
1008 The data that is written is binary. The first eight bytes are the
1010 length of the compiled pattern data followed by the length of the
1011 optional study data, each written as four bytes in big-endian order
1012 (most significant byte first). If there is no study data (either the
1013 pattern was not studied, or studying did not return any data), the sec‐
1014 ond length is zero. The lengths are followed by an exact copy of the
1015 compiled pattern. If there is additional study data, this (excluding
1016 any JIT data) follows immediately after the compiled pattern. After
1017 writing the file, pcretest expects to read a new pattern.
1018 A saved pattern can be reloaded into pcretest by specifying < and a
1020 file name instead of a pattern. There must be no space between < and
1021 the file name, which must not contain a < character, as otherwise
1022 pcretest will interpret the line as a pattern delimited by < charac‐
1023 ters. For example:
1024 re> </some/file
1026 Compiled pattern loaded from /some/file
1027 No study data
1028 If the pattern was previously studied with the JIT optimization, the
1030 JIT information cannot be saved and restored, and so is lost. When the
1031 pattern has been loaded, pcretest proceeds to read data lines in the
1032 usual way.
1033 You can copy a file written by pcretest to a different host and reload
1035 it there, even if the new host has opposite endianness to the one on
1036 which the pattern was compiled. For example, you can compile on an i86
1037 machine and run on a SPARC machine. When a pattern is reloaded on a
1038 host with different endianness, the confirmation message is changed to:
1039 Compiled pattern (byte-inverted) loaded from /some/file
1041 The test suite contains some saved pre-compiled patterns with different
1043 endianness. These are reloaded using "<!" instead of just "<". This
1044 suppresses the "(byte-inverted)" text so that the output is the same on
1045 all hosts. It also forces debugging output once the pattern has been
1046 reloaded.
1047 File names for saving and reloading can be absolute or relative, but
1049 note that the shell facility of expanding a file name that starts with
1050 a tilde (~) is not available.
1051 The ability to save and reload files in pcretest is intended for test‐
1053 ing and experimentation. It is not intended for production use because
1054 only a single pattern can be written to a file. Furthermore, there is
1055 no facility for supplying custom character tables for use with a
1056 reloaded pattern. If the original pattern was compiled with custom
1057 tables, an attempt to match a subject string using a reloaded pattern
1058 is likely to cause pcretest to crash. Finally, if you attempt to load
1059 a file that is not in the correct format, the result is undefined.
1060
1062 pcre(3), pcre16(3), pcre32(3), pcreapi(3), pcrecallout(3), pcrejit,
1064 pcrematching(3), pcrepartial(d), pcrepattern(3), pcreprecompile(3).
1065
1067 Philip Hazel
1069 University Computing Service
1070 Cambridge CB2 3QH, England.
1071
1073 Last updated: 23 February 2017
1075 Copyright (c) 1997-2017 University of Cambridge.
1076PCRE 8.41 23 February 2017 PCRETEST(1)