1PCRE2TEST(1) General Commands Manual PCRE2TEST(1)
2
6 pcre2test - a program for testing Perl-compatible regular expressions.
7
9 pcre2test [options] [input file [output file]]
11 pcre2test is a test program for the PCRE2 regular expression libraries,
13 but it can also be used for experimenting with regular expressions.
14 This document describes the features of the test program; for details
15 of the regular expressions themselves, see the pcre2pattern documenta‐
16 tion. For details of the PCRE2 library function calls and their
17 options, see the pcre2api documentation.
18 The input for pcre2test is a sequence of regular expression patterns
20 and subject strings to be matched. There are also command lines for
21 setting defaults and controlling some special actions. The output shows
22 the result of each match attempt. Modifiers on external or internal
23 command lines, the patterns, and the subject lines specify PCRE2 func‐
24 tion options, control how the subject is processed, and what output is
25 produced.
26 As the original fairly simple PCRE library evolved, it acquired many
28 different features, and as a result, the original pcretest program
29 ended up with a lot of options in a messy, arcane syntax for testing
30 all the features. The move to the new PCRE2 API provided an opportunity
31 to re-implement the test program as pcre2test, with a cleaner modifier
32 syntax. Nevertheless, there are still many obscure modifiers, some of
33 which are specifically designed for use in conjunction with the test
34 script and data files that are distributed as part of PCRE2. All the
35 modifiers are documented here, some without much justification, but
36 many of them are unlikely to be of use except when testing the
37 libraries.
38
40 Different versions of the PCRE2 library can be built to support charac‐
42 ter strings that are encoded in 8-bit, 16-bit, or 32-bit code units.
43 One, two, or all three of these libraries may be simultaneously
44 installed. The pcre2test program can be used to test all the libraries.
45 However, its own input and output are always in 8-bit format. When
46 testing the 16-bit or 32-bit libraries, patterns and subject strings
47 are converted to 16-bit or 32-bit format before being passed to the
48 library functions. Results are converted back to 8-bit code units for
49 output.
50 In the rest of this document, the names of library functions and struc‐
52 tures are given in generic form, for example, pcre_compile(). The
53 actual names used in the libraries have a suffix _8, _16, or _32, as
54 appropriate.
55
57 Input to pcre2test is processed line by line, either by calling the C
59 library's fgets() function, or via the libreadline library. In some
60 Windows environments character 26 (hex 1A) causes an immediate end of
61 file, and no further data is read, so this character should be avoided
62 unless you really want that action.
63 The input is processed using using C's string functions, so must not
65 contain binary zeros, even though in Unix-like environments, fgets()
66 treats any bytes other than newline as data characters. An error is
67 generated if a binary zero is encountered. By default subject lines are
68 processed for backslash escapes, which makes it possible to include any
69 data value in strings that are passed to the library for matching. For
70 patterns, there is a facility for specifying some or all of the 8-bit
71 input characters as hexadecimal pairs, which makes it possible to
72 include binary zeros.
73 Input for the 16-bit and 32-bit libraries
75 When testing the 16-bit or 32-bit libraries, there is a need to be able
77 to generate character code points greater than 255 in the strings that
78 are passed to the library. For subject lines, backslash escapes can be
79 used. In addition, when the utf modifier (see "Setting compilation
80 options" below) is set, the pattern and any following subject lines are
81 interpreted as UTF-8 strings and translated to UTF-16 or UTF-32 as
82 appropriate.
83 For non-UTF testing of wide characters, the utf8_input modifier can be
85 used. This is mutually exclusive with utf, and is allowed only in
86 16-bit or 32-bit mode. It causes the pattern and following subject
87 lines to be treated as UTF-8 according to the original definition (RFC
88 2279), which allows for character values up to 0x7fffffff. Each charac‐
89 ter is placed in one 16-bit or 32-bit code unit (in the 16-bit case,
90 values greater than 0xffff cause an error to occur).
91 UTF-8 (in its original definition) is not capable of encoding values
93 greater than 0x7fffffff, but such values can be handled by the 32-bit
94 library. When testing this library in non-UTF mode with utf8_input set,
95 if any character is preceded by the byte 0xff (which is an invalid byte
96 in UTF-8) 0x80000000 is added to the character's value. This is the
97 only way of passing such code points in a pattern string. For subject
98 strings, using an escape sequence is preferable.
99
101 -8 If the 8-bit library has been built, this option causes it to
103 be used (this is the default). If the 8-bit library has not
104 been built, this option causes an error.
105 -16 If the 16-bit library has been built, this option causes it
107 to be used. If only the 16-bit library has been built, this
108 is the default. If the 16-bit library has not been built,
109 this option causes an error.
110 -32 If the 32-bit library has been built, this option causes it
112 to be used. If only the 32-bit library has been built, this
113 is the default. If the 32-bit library has not been built,
114 this option causes an error.
115 -ac Behave as if each pattern has the auto_callout modifier, that
117 is, insert automatic callouts into every pattern that is com‐
118 piled.
119 -AC As for -ac, but in addition behave as if each subject line
121 has the callout_extra modifier, that is, show additional
122 information from callouts.
123 -b Behave as if each pattern has the fullbincode modifier; the
125 full internal binary form of the pattern is output after com‐
126 pilation.
127 -C Output the version number of the PCRE2 library, and all
129 available information about the optional features that are
130 included, and then exit with zero exit code. All other
131 options are ignored. If both -C and -LM are present, which‐
132 ever is first is recognized.
133 -C option Output information about a specific build-time option, then
135 exit. This functionality is intended for use in scripts such
136 as RunTest. The following options output the value and set
137 the exit code as indicated:
138 ebcdic-nl the code for LF (= NL) in an EBCDIC environment:
140 0x15 or 0x25
141 0 if used in an ASCII environment
142 exit code is always 0
143 linksize the configured internal link size (2, 3, or 4)
144 exit code is set to the link size
145 newline the default newline setting:
146 CR, LF, CRLF, ANYCRLF, ANY, or NUL
147 exit code is always 0
148 bsr the default setting for what \R matches:
149 ANYCRLF or ANY
150 exit code is always 0
151 The following options output 1 for true or 0 for false, and
153 set the exit code to the same value:
154 backslash-C \C is supported (not locked out)
156 ebcdic compiled for an EBCDIC environment
157 jit just-in-time support is available
158 pcre2-16 the 16-bit library was built
159 pcre2-32 the 32-bit library was built
160 pcre2-8 the 8-bit library was built
161 unicode Unicode support is available
162 If an unknown option is given, an error message is output;
164 the exit code is 0.
165 -d Behave as if each pattern has the debug modifier; the inter‐
167 nal form and information about the compiled pattern is output
168 after compilation; -d is equivalent to -b -i.
169 -dfa Behave as if each subject line has the dfa modifier; matching
171 is done using the pcre2_dfa_match() function instead of the
172 default pcre2_match().
173 -error number[,number,...]
175 Call pcre2_get_error_message() for each of the error numbers
176 in the comma-separated list, display the resulting messages
177 on the standard output, then exit with zero exit code. The
178 numbers may be positive or negative. This is a convenience
179 facility for PCRE2 maintainers.
180 -help Output a brief summary these options and then exit.
182 -i Behave as if each pattern has the info modifier; information
184 about the compiled pattern is given after compilation.
185 -jit Behave as if each pattern line has the jit modifier; after
187 successful compilation, each pattern is passed to the just-
188 in-time compiler, if available.
189 -jitfast Behave as if each pattern line has the jitfast modifier;
191 after successful compilation, each pattern is passed to the
192 just-in-time compiler, if available, and each subject line is
193 passed directly to the JIT matcher via its "fast path".
194 -jitverify
196 Behave as if each pattern line has the jitverify modifier;
197 after successful compilation, each pattern is passed to the
198 just-in-time compiler, if available, and the use of JIT for
199 matching is verified.
200 -LM List modifiers: write a list of available pattern and subject
202 modifiers to the standard output, then exit with zero exit
203 code. All other options are ignored. If both -C and -LM are
204 present, whichever is first is recognized.
205 -pattern modifier-list
207 Behave as if each pattern line contains the given modifiers.
208 -q Do not output the version number of pcre2test at the start of
210 execution.
211 -S size On Unix-like systems, set the size of the run-time stack to
213 size mebibytes (units of 1024*1024 bytes).
214 -subject modifier-list
216 Behave as if each subject line contains the given modifiers.
217 -t Run each compile and match many times with a timer, and out‐
219 put the resulting times per compile or match. When JIT is
220 used, separate times are given for the initial compile and
221 the JIT compile. You can control the number of iterations
222 that are used for timing by following -t with a number (as a
223 separate item on the command line). For example, "-t 1000"
224 iterates 1000 times. The default is to iterate 500,000 times.
225 -tm This is like -t except that it times only the matching phase,
227 not the compile phase.
228 -T -TM These behave like -t and -tm, but in addition, at the end of
230 a run, the total times for all compiles and matches are out‐
231 put.
232 -version Output the PCRE2 version number and then exit.
234
236 If pcre2test is given two filename arguments, it reads from the first
238 and writes to the second. If the first name is "-", input is taken from
239 the standard input. If pcre2test is given only one argument, it reads
240 from that file and writes to stdout. Otherwise, it reads from stdin and
241 writes to stdout.
242 When pcre2test is built, a configuration option can specify that it
244 should be linked with the libreadline or libedit library. When this is
245 done, if the input is from a terminal, it is read using the readline()
246 function. This provides line-editing and history facilities. The output
247 from the -help option states whether or not readline() will be used.
248 The program handles any number of tests, each of which consists of a
250 set of input lines. Each set starts with a regular expression pattern,
251 followed by any number of subject lines to be matched against that pat‐
252 tern. In between sets of test data, command lines that begin with # may
253 appear. This file format, with some restrictions, can also be processed
254 by the perltest.sh script that is distributed with PCRE2 as a means of
255 checking that the behaviour of PCRE2 and Perl is the same. For a speci‐
256 fication of perltest.sh, see the comments near its beginning.
257 When the input is a terminal, pcre2test prompts for each line of input,
259 using "re>" to prompt for regular expression patterns, and "data>" to
260 prompt for subject lines. Command lines starting with # can be entered
261 only in response to the "re>" prompt.
262 Each subject line is matched separately and independently. If you want
264 to do multi-line matches, you have to use the \n escape sequence (or \r
265 or \r\n, etc., depending on the newline setting) in a single line of
266 input to encode the newline sequences. There is no limit on the length
267 of subject lines; the input buffer is automatically extended if it is
268 too small. There are replication features that makes it possible to
269 generate long repetitive pattern or subject lines without having to
270 supply them explicitly.
271 An empty line or the end of the file signals the end of the subject
273 lines for a test, at which point a new pattern or command line is
274 expected if there is still input to be read.
275
277 In between sets of test data, a line that begins with # is interpreted
279 as a command line. If the first character is followed by white space or
280 an exclamation mark, the line is treated as a comment, and ignored.
281 Otherwise, the following commands are recognized:
282 #forbid_utf
284 Subsequent patterns automatically have the PCRE2_NEVER_UTF and
286 PCRE2_NEVER_UCP options set, which locks out the use of the PCRE2_UTF
287 and PCRE2_UCP options and the use of (*UTF) and (*UCP) at the start of
288 patterns. This command also forces an error if a subsequent pattern
289 contains any occurrences of \P, \p, or \X, which are still supported
290 when PCRE2_UTF is not set, but which require Unicode property support
291 to be included in the library.
292 This is a trigger guard that is used in test files to ensure that UTF
294 or Unicode property tests are not accidentally added to files that are
295 used when Unicode support is not included in the library. Setting
296 PCRE2_NEVER_UTF and PCRE2_NEVER_UCP as a default can also be obtained
297 by the use of #pattern; the difference is that #forbid_utf cannot be
298 unset, and the automatic options are not displayed in pattern informa‐
299 tion, to avoid cluttering up test output.
300 #load <filename>
302 This command is used to load a set of precompiled patterns from a file,
304 as described in the section entitled "Saving and restoring compiled
305 patterns" below.
306 #newline_default [<newline-list>]
308 When PCRE2 is built, a default newline convention can be specified.
310 This determines which characters and/or character pairs are recognized
311 as indicating a newline in a pattern or subject string. The default can
312 be overridden when a pattern is compiled. The standard test files con‐
313 tain tests of various newline conventions, but the majority of the
314 tests expect a single linefeed to be recognized as a newline by
315 default. Without special action the tests would fail when PCRE2 is com‐
316 piled with either CR or CRLF as the default newline.
317 The #newline_default command specifies a list of newline types that are
319 acceptable as the default. The types must be one of CR, LF, CRLF, ANY‐
320 CRLF, ANY, or NUL (in upper or lower case), for example:
321 #newline_default LF Any anyCRLF
323 If the default newline is in the list, this command has no effect. Oth‐
325 erwise, except when testing the POSIX API, a newline modifier that
326 specifies the first newline convention in the list (LF in the above
327 example) is added to any pattern that does not already have a newline
328 modifier. If the newline list is empty, the feature is turned off. This
329 command is present in a number of the standard test input files.
330 When the POSIX API is being tested there is no way to override the
332 default newline convention, though it is possible to set the newline
333 convention from within the pattern. A warning is given if the posix or
334 posix_nosub modifier is used when #newline_default would set a default
335 for the non-POSIX API.
336 #pattern <modifier-list>
338 This command sets a default modifier list that applies to all subse‐
340 quent patterns. Modifiers on a pattern can change these settings.
341 #perltest
343 The appearance of this line causes all subsequent modifier settings to
345 be checked for compatibility with the perltest.sh script, which is used
346 to confirm that Perl gives the same results as PCRE2. Also, apart from
347 comment lines, #pattern commands, and #subject commands that set or
348 unset "mark", no command lines are permitted, because they and many of
349 the modifiers are specific to pcre2test, and should not be used in test
350 files that are also processed by perltest.sh. The #perltest command
351 helps detect tests that are accidentally put in the wrong file.
352 #pop [<modifiers>]
354 #popcopy [<modifiers>]
355 These commands are used to manipulate the stack of compiled patterns,
357 as described in the section entitled "Saving and restoring compiled
358 patterns" below.
359 #save <filename>
361 This command is used to save a set of compiled patterns to a file, as
363 described in the section entitled "Saving and restoring compiled pat‐
364 terns" below.
365 #subject <modifier-list>
367 This command sets a default modifier list that applies to all subse‐
369 quent subject lines. Modifiers on a subject line can change these set‐
370 tings.
371
373 Modifier lists are used with both pattern and subject lines. Items in a
375 list are separated by commas followed by optional white space. Trailing
376 whitespace in a modifier list is ignored. Some modifiers may be given
377 for both patterns and subject lines, whereas others are valid only for
378 one or the other. Each modifier has a long name, for example
379 "anchored", and some of them must be followed by an equals sign and a
380 value, for example, "offset=12". Values cannot contain comma charac‐
381 ters, but may contain spaces. Modifiers that do not take values may be
382 preceded by a minus sign to turn off a previous setting.
383 A few of the more common modifiers can also be specified as single let‐
385 ters, for example "i" for "caseless". In documentation, following the
386 Perl convention, these are written with a slash ("the /i modifier") for
387 clarity. Abbreviated modifiers must all be concatenated in the first
388 item of a modifier list. If the first item is not recognized as a long
389 modifier name, it is interpreted as a sequence of these abbreviations.
390 For example:
391 /abc/ig,newline=cr,jit=3
393 This is a pattern line whose modifier list starts with two one-letter
395 modifiers (/i and /g). The lower-case abbreviated modifiers are the
396 same as used in Perl.
397
399 A pattern line must start with one of the following characters (common
401 symbols, excluding pattern meta-characters):
402 / ! " ' ` - = _ : ; , % & @ ~
404 This is interpreted as the pattern's delimiter. A regular expression
406 may be continued over several input lines, in which case the newline
407 characters are included within it. It is possible to include the delim‐
408 iter within the pattern by escaping it with a backslash, for example
409 /abc\/def/
411 If you do this, the escape and the delimiter form part of the pattern,
413 but since the delimiters are all non-alphanumeric, this does not affect
414 its interpretation. If the terminating delimiter is immediately fol‐
415 lowed by a backslash, for example,
416 /abc/\
418 then a backslash is added to the end of the pattern. This is done to
420 provide a way of testing the error condition that arises if a pattern
421 finishes with a backslash, because
422 /abc\/
424 is interpreted as the first line of a pattern that starts with "abc/",
426 causing pcre2test to read the next line as a continuation of the regu‐
427 lar expression.
428 A pattern can be followed by a modifier list (details below).
430
432 Before each subject line is passed to pcre2_match() or
434 pcre2_dfa_match(), leading and trailing white space is removed, and the
435 line is scanned for backslash escapes, unless the subject_literal modi‐
436 fier was set for the pattern. The following provide a means of encoding
437 non-printing characters in a visible way:
438 \a alarm (BEL, \x07)
440 \b backspace (\x08)
441 \e escape (\x27)
442 \f form feed (\x0c)
443 \n newline (\x0a)
444 \r carriage return (\x0d)
445 \t tab (\x09)
446 \v vertical tab (\x0b)
447 \nnn octal character (up to 3 octal digits); always
448 a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode
449 \o{dd...} octal character (any number of octal digits}
450 \xhh hexadecimal byte (up to 2 hex digits)
451 \x{hh...} hexadecimal character (any number of hex digits)
452 The use of \x{hh...} is not dependent on the use of the utf modifier on
454 the pattern. It is recognized always. There may be any number of hexa‐
455 decimal digits inside the braces; invalid values provoke error mes‐
456 sages.
457 Note that \xhh specifies one byte rather than one character in UTF-8
459 mode; this makes it possible to construct invalid UTF-8 sequences for
460 testing purposes. On the other hand, \x{hh} is interpreted as a UTF-8
461 character in UTF-8 mode, generating more than one byte if the value is
462 greater than 127. When testing the 8-bit library not in UTF-8 mode,
463 \x{hh} generates one byte for values less than 256, and causes an error
464 for greater values.
465 In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it
467 possible to construct invalid UTF-16 sequences for testing purposes.
468 In UTF-32 mode, all 4- to 8-digit \x{...} values are accepted. This
470 makes it possible to construct invalid UTF-32 sequences for testing
471 purposes.
472 There is a special backslash sequence that specifies replication of one
474 or more characters:
475 \[<characters>]{<count>}
477 This makes it possible to test long strings without having to provide
479 them as part of the file. For example:
480 \[abc]{4}
482 is converted to "abcabcabcabc". This feature does not support nesting.
484 To include a closing square bracket in the characters, code it as \x5D.
485 A backslash followed by an equals sign marks the end of the subject
487 string and the start of a modifier list. For example:
488 abc\=notbol,notempty
490 If the subject string is empty and \= is followed by whitespace, the
492 line is treated as a comment line, and is not used for matching. For
493 example:
494 \= This is a comment.
496 abc\= This is an invalid modifier list.
497 A backslash followed by any other non-alphanumeric character just
499 escapes that character. A backslash followed by anything else causes an
500 error. However, if the very last character in the line is a backslash
501 (and there is no modifier list), it is ignored. This gives a way of
502 passing an empty line as data, since a real empty line terminates the
503 data input.
504 If the subject_literal modifier is set for a pattern, all subject lines
506 that follow are treated as literals, with no special treatment of back‐
507 slashes. No replication is possible, and any subject modifiers must be
508 set as defaults by a #subject command.
509
511 There are several types of modifier that can appear in pattern lines.
513 Except where noted below, they may also be used in #pattern commands. A
514 pattern's modifier list can add to or override default modifiers that
515 were set by a previous #pattern command.
516 Setting compilation options
518 The following modifiers set options for pcre2_compile(). Most of them
520 set bits in the options argument of that function, but those whose
521 names start with PCRE2_EXTRA are additional options that are set in the
522 compile context. For the main options, there are some single-letter
523 abbreviations that are the same as Perl options. There is special han‐
524 dling for /x: if a second x is present, PCRE2_EXTENDED is converted
525 into PCRE2_EXTENDED_MORE as in Perl. A third appearance adds
526 PCRE2_EXTENDED as well, though this makes no difference to the way
527 pcre2_compile() behaves. See pcre2api for a description of the effects
528 of these options.
529 allow_empty_class set PCRE2_ALLOW_EMPTY_CLASS
531 allow_surrogate_escapes set PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES
532 alt_bsux set PCRE2_ALT_BSUX
533 alt_circumflex set PCRE2_ALT_CIRCUMFLEX
534 alt_verbnames set PCRE2_ALT_VERBNAMES
535 anchored set PCRE2_ANCHORED
536 auto_callout set PCRE2_AUTO_CALLOUT
537 bad_escape_is_literal set PCRE2_EXTRA_BAD_ESCAPE_IS_LITERAL
538 /i caseless set PCRE2_CASELESS
539 dollar_endonly set PCRE2_DOLLAR_ENDONLY
540 /s dotall set PCRE2_DOTALL
541 dupnames set PCRE2_DUPNAMES
542 endanchored set PCRE2_ENDANCHORED
543 escaped_cr_is_lf set PCRE2_EXTRA_ESCAPED_CR_IS_LF
544 /x extended set PCRE2_EXTENDED
545 /xx extended_more set PCRE2_EXTENDED_MORE
546 extra_alt_bsux set PCRE2_EXTRA_ALT_BSUX
547 firstline set PCRE2_FIRSTLINE
548 literal set PCRE2_LITERAL
549 match_line set PCRE2_EXTRA_MATCH_LINE
550 match_invalid_utf set PCRE2_MATCH_INVALID_UTF
551 match_unset_backref set PCRE2_MATCH_UNSET_BACKREF
552 match_word set PCRE2_EXTRA_MATCH_WORD
553 /m multiline set PCRE2_MULTILINE
554 never_backslash_c set PCRE2_NEVER_BACKSLASH_C
555 never_ucp set PCRE2_NEVER_UCP
556 never_utf set PCRE2_NEVER_UTF
557 /n no_auto_capture set PCRE2_NO_AUTO_CAPTURE
558 no_auto_possess set PCRE2_NO_AUTO_POSSESS
559 no_dotstar_anchor set PCRE2_NO_DOTSTAR_ANCHOR
560 no_start_optimize set PCRE2_NO_START_OPTIMIZE
561 no_utf_check set PCRE2_NO_UTF_CHECK
562 ucp set PCRE2_UCP
563 ungreedy set PCRE2_UNGREEDY
564 use_offset_limit set PCRE2_USE_OFFSET_LIMIT
565 utf set PCRE2_UTF
566 As well as turning on the PCRE2_UTF option, the utf modifier causes all
568 non-printing characters in output strings to be printed using the
569 \x{hh...} notation. Otherwise, those less than 0x100 are output in hex
570 without the curly brackets. Setting utf in 16-bit or 32-bit mode also
571 causes pattern and subject strings to be translated to UTF-16 or
572 UTF-32, respectively, before being passed to library functions.
573 Setting compilation controls
575 The following modifiers affect the compilation process or request
577 information about the pattern. There are single-letter abbreviations
578 for some that are heavily used in the test files.
579 bsr=[anycrlf|unicode] specify \R handling
581 /B bincode show binary code without lengths
582 callout_info show callout information
583 convert=<options> request foreign pattern conversion
584 convert_glob_escape=c set glob escape character
585 convert_glob_separator=c set glob separator character
586 convert_length set convert buffer length
587 debug same as info,fullbincode
588 framesize show matching frame size
589 fullbincode show binary code with lengths
590 /I info show info about compiled pattern
591 hex unquoted characters are hexadecimal
592 jit[=<number>] use JIT
593 jitfast use JIT fast path
594 jitverify verify JIT use
595 locale=<name> use this locale
596 max_pattern_length=<n> set the maximum pattern length
597 memory show memory used
598 newline=<type> set newline type
599 null_context compile with a NULL context
600 parens_nest_limit=<n> set maximum parentheses depth
601 posix use the POSIX API
602 posix_nosub use the POSIX API with REG_NOSUB
603 push push compiled pattern onto the stack
604 pushcopy push a copy onto the stack
605 stackguard=<number> test the stackguard feature
606 subject_literal treat all subject lines as literal
607 tables=[0|1|2] select internal tables
608 use_length do not zero-terminate the pattern
609 utf8_input treat input as UTF-8
610 The effects of these modifiers are described in the following sections.
612 Newline and \R handling
614 The bsr modifier specifies what \R in a pattern should match. If it is
616 set to "anycrlf", \R matches CR, LF, or CRLF only. If it is set to
617 "unicode", \R matches any Unicode newline sequence. The default can be
618 specified when PCRE2 is built; if it is not, the default is set to Uni‐
619 code.
620 The newline modifier specifies which characters are to be interpreted
622 as newlines, both in the pattern and in subject lines. The type must be
623 one of CR, LF, CRLF, ANYCRLF, ANY, or NUL (in upper or lower case).
624 Information about a pattern
626 The debug modifier is a shorthand for info,fullbincode, requesting all
628 available information.
629 The bincode modifier causes a representation of the compiled code to be
631 output after compilation. This information does not contain length and
632 offset values, which ensures that the same output is generated for dif‐
633 ferent internal link sizes and different code unit widths. By using
634 bincode, the same regression tests can be used in different environ‐
635 ments.
636 The fullbincode modifier, by contrast, does include length and offset
638 values. This is used in a few special tests that run only for specific
639 code unit widths and link sizes, and is also useful for one-off tests.
640 The info modifier requests information about the compiled pattern
642 (whether it is anchored, has a fixed first character, and so on). The
643 information is obtained from the pcre2_pattern_info() function. Here
644 are some typical examples:
645 re> /(?i)(^a|^b)/m,info
647 Capture group count = 1
648 Compile options: multiline
649 Overall options: caseless multiline
650 First code unit at start or follows newline
651 Subject length lower bound = 1
652 re> /(?i)abc/info
654 Capture group count = 0
655 Compile options: <none>
656 Overall options: caseless
657 First code unit = 'a' (caseless)
658 Last code unit = 'c' (caseless)
659 Subject length lower bound = 3
660 "Compile options" are those specified by modifiers; "overall options"
662 have added options that are taken or deduced from the pattern. If both
663 sets of options are the same, just a single "options" line is output;
664 if there are no options, the line is omitted. "First code unit" is
665 where any match must start; if there is more than one they are listed
666 as "starting code units". "Last code unit" is the last literal code
667 unit that must be present in any match. This is not necessarily the
668 last character. These lines are omitted if no starting or ending code
669 units are recorded. The subject length line is omitted when
670 no_start_optimize is set because the minimum length is not calculated
671 when it can never be used.
672 The framesize modifier shows the size, in bytes, of the storage frames
674 used by pcre2_match() for handling backtracking. The size depends on
675 the number of capturing parentheses in the pattern.
676 The callout_info modifier requests information about all the callouts
678 in the pattern. A list of them is output at the end of any other infor‐
679 mation that is requested. For each callout, either its number or string
680 is given, followed by the item that follows it in the pattern.
681 Passing a NULL context
683 Normally, pcre2test passes a context block to pcre2_compile(). If the
685 null_context modifier is set, however, NULL is passed. This is for
686 testing that pcre2_compile() behaves correctly in this case (it uses
687 default values).
688 Specifying pattern characters in hexadecimal
690 The hex modifier specifies that the characters of the pattern, except
692 for substrings enclosed in single or double quotes, are to be inter‐
693 preted as pairs of hexadecimal digits. This feature is provided as a
694 way of creating patterns that contain binary zeros and other non-print‐
695 ing characters. White space is permitted between pairs of digits. For
696 example, this pattern contains three characters:
697 /ab 32 59/hex
699 Parts of such a pattern are taken literally if quoted. This pattern
701 contains nine characters, only two of which are specified in hexadeci‐
702 mal:
703 /ab "literal" 32/hex
705 Either single or double quotes may be used. There is no way of includ‐
707 ing the delimiter within a substring. The hex and expand modifiers are
708 mutually exclusive.
709 Specifying the pattern's length
711 By default, patterns are passed to the compiling functions as zero-ter‐
713 minated strings but can be passed by length instead of being zero-ter‐
714 minated. The use_length modifier causes this to happen. Using a length
715 happens automatically (whether or not use_length is set) when hex is
716 set, because patterns specified in hexadecimal may contain binary
717 zeros.
718 If hex or use_length is used with the POSIX wrapper API (see "Using the
720 POSIX wrapper API" below), the REG_PEND extension is used to pass the
721 pattern's length.
722 Specifying wide characters in 16-bit and 32-bit modes
724 In 16-bit and 32-bit modes, all input is automatically treated as UTF-8
726 and translated to UTF-16 or UTF-32 when the utf modifier is set. For
727 testing the 16-bit and 32-bit libraries in non-UTF mode, the utf8_input
728 modifier can be used. It is mutually exclusive with utf. Input lines
729 are interpreted as UTF-8 as a means of specifying wide characters. More
730 details are given in "Input encoding" above.
731 Generating long repetitive patterns
733 Some tests use long patterns that are very repetitive. Instead of cre‐
735 ating a very long input line for such a pattern, you can use a special
736 repetition feature, similar to the one described for subject lines
737 above. If the expand modifier is present on a pattern, parts of the
738 pattern that have the form
739 \[<characters>]{<count>}
741 are expanded before the pattern is passed to pcre2_compile(). For exam‐
743 ple, \[AB]{6000} is expanded to "ABAB..." 6000 times. This construction
744 cannot be nested. An initial "\[" sequence is recognized only if "]{"
745 followed by decimal digits and "}" is found later in the pattern. If
746 not, the characters remain in the pattern unaltered. The expand and hex
747 modifiers are mutually exclusive.
748 If part of an expanded pattern looks like an expansion, but is really
750 part of the actual pattern, unwanted expansion can be avoided by giving
751 two values in the quantifier. For example, \[AB]{6000,6000} is not rec‐
752 ognized as an expansion item.
753 If the info modifier is set on an expanded pattern, the result of the
755 expansion is included in the information that is output.
756 JIT compilation
758 Just-in-time (JIT) compiling is a heavyweight optimization that can
760 greatly speed up pattern matching. See the pcre2jit documentation for
761 details. JIT compiling happens, optionally, after a pattern has been
762 successfully compiled into an internal form. The JIT compiler converts
763 this to optimized machine code. It needs to know whether the match-time
764 options PCRE2_PARTIAL_HARD and PCRE2_PARTIAL_SOFT are going to be used,
765 because different code is generated for the different cases. See the
766 partial modifier in "Subject Modifiers" below for details of how these
767 options are specified for each match attempt.
768 JIT compilation is requested by the jit pattern modifier, which may
770 optionally be followed by an equals sign and a number in the range 0 to
771 7. The three bits that make up the number specify which of the three
772 JIT operating modes are to be compiled:
773 1 compile JIT code for non-partial matching
775 2 compile JIT code for soft partial matching
776 4 compile JIT code for hard partial matching
777 The possible values for the jit modifier are therefore:
779 0 disable JIT
781 1 normal matching only
782 2 soft partial matching only
783 3 normal and soft partial matching
784 4 hard partial matching only
785 6 soft and hard partial matching only
786 7 all three modes
787 If no number is given, 7 is assumed. The phrase "partial matching"
789 means a call to pcre2_match() with either the PCRE2_PARTIAL_SOFT or the
790 PCRE2_PARTIAL_HARD option set. Note that such a call may return a com‐
791 plete match; the options enable the possibility of a partial match, but
792 do not require it. Note also that if you request JIT compilation only
793 for partial matching (for example, jit=2) but do not set the partial
794 modifier on a subject line, that match will not use JIT code because
795 none was compiled for non-partial matching.
796 If JIT compilation is successful, the compiled JIT code will automati‐
798 cally be used when an appropriate type of match is run, except when
799 incompatible run-time options are specified. For more details, see the
800 pcre2jit documentation. See also the jitstack modifier below for a way
801 of setting the size of the JIT stack.
802 If the jitfast modifier is specified, matching is done using the JIT
804 "fast path" interface, pcre2_jit_match(), which skips some of the san‐
805 ity checks that are done by pcre2_match(), and of course does not work
806 when JIT is not supported. If jitfast is specified without jit, jit=7
807 is assumed.
808 If the jitverify modifier is specified, information about the compiled
810 pattern shows whether JIT compilation was or was not successful. If
811 jitverify is specified without jit, jit=7 is assumed. If JIT compila‐
812 tion is successful when jitverify is set, the text "(JIT)" is added to
813 the first output line after a match or non match when JIT-compiled code
814 was actually used in the match.
815 Setting a locale
817 The locale modifier must specify the name of a locale, for example:
819 /pattern/locale=fr_FR
821 The given locale is set, pcre2_maketables() is called to build a set of
823 character tables for the locale, and this is then passed to pcre2_com‐
824 pile() when compiling the regular expression. The same tables are used
825 when matching the following subject lines. The locale modifier applies
826 only to the pattern on which it appears, but can be given in a #pattern
827 command if a default is needed. Setting a locale and alternate charac‐
828 ter tables are mutually exclusive.
829 Showing pattern memory
831 The memory modifier causes the size in bytes of the memory used to hold
833 the compiled pattern to be output. This does not include the size of
834 the pcre2_code block; it is just the actual compiled data. If the pat‐
835 tern is subsequently passed to the JIT compiler, the size of the JIT
836 compiled code is also output. Here is an example:
837 re> /a(b)c/jit,memory
839 Memory allocation (code space): 21
840 Memory allocation (JIT code): 1910
841 Limiting nested parentheses
844 The parens_nest_limit modifier sets a limit on the depth of nested
846 parentheses in a pattern. Breaching the limit causes a compilation
847 error. The default for the library is set when PCRE2 is built, but
848 pcre2test sets its own default of 220, which is required for running
849 the standard test suite.
850 Limiting the pattern length
852 The max_pattern_length modifier sets a limit, in code units, to the
854 length of pattern that pcre2_compile() will accept. Breaching the limit
855 causes a compilation error. The default is the largest number a
856 PCRE2_SIZE variable can hold (essentially unlimited).
857 Using the POSIX wrapper API
859 The posix and posix_nosub modifiers cause pcre2test to call PCRE2 via
861 the POSIX wrapper API rather than its native API. When posix_nosub is
862 used, the POSIX option REG_NOSUB is passed to regcomp(). The POSIX
863 wrapper supports only the 8-bit library. Note that it does not imply
864 POSIX matching semantics; for more detail see the pcre2posix documenta‐
865 tion. The following pattern modifiers set options for the regcomp()
866 function:
867 caseless REG_ICASE
869 multiline REG_NEWLINE
870 dotall REG_DOTALL )
871 ungreedy REG_UNGREEDY ) These options are not part of
872 ucp REG_UCP ) the POSIX standard
873 utf REG_UTF8 )
874 The regerror_buffsize modifier specifies a size for the error buffer
876 that is passed to regerror() in the event of a compilation error. For
877 example:
878 /abc/posix,regerror_buffsize=20
880 This provides a means of testing the behaviour of regerror() when the
882 buffer is too small for the error message. If this modifier has not
883 been set, a large buffer is used.
884 The aftertext and allaftertext subject modifiers work as described
886 below. All other modifiers are either ignored, with a warning message,
887 or cause an error.
888 The pattern is passed to regcomp() as a zero-terminated string by
890 default, but if the use_length or hex modifiers are set, the REG_PEND
891 extension is used to pass it by length.
892 Testing the stack guard feature
894 The stackguard modifier is used to test the use of pcre2_set_com‐
896 pile_recursion_guard(), a function that is provided to enable stack
897 availability to be checked during compilation (see the pcre2api docu‐
898 mentation for details). If the number specified by the modifier is
899 greater than zero, pcre2_set_compile_recursion_guard() is called to set
900 up callback from pcre2_compile() to a local function. The argument it
901 receives is the current nesting parenthesis depth; if this is greater
902 than the value given by the modifier, non-zero is returned, causing the
903 compilation to be aborted.
904 Using alternative character tables
906 The value specified for the tables modifier must be one of the digits
908 0, 1, or 2. It causes a specific set of built-in character tables to be
909 passed to pcre2_compile(). This is used in the PCRE2 tests to check be‐
910 haviour with different character tables. The digit specifies the tables
911 as follows:
912 0 do not pass any special character tables
914 1 the default ASCII tables, as distributed in
915 pcre2_chartables.c.dist
916 2 a set of tables defining ISO 8859 characters
917 In table 2, some characters whose codes are greater than 128 are iden‐
919 tified as letters, digits, spaces, etc. Setting alternate character
920 tables and a locale are mutually exclusive.
921 Setting certain match controls
923 The following modifiers are really subject modifiers, and are described
925 under "Subject Modifiers" below. However, they may be included in a
926 pattern's modifier list, in which case they are applied to every sub‐
927 ject line that is processed with that pattern. These modifiers do not
928 affect the compilation process.
929 aftertext show text after match
931 allaftertext show text after captures
932 allcaptures show all captures
933 allvector show the entire ovector
934 allusedtext show all consulted text
935 altglobal alternative global matching
936 /g global global matching
937 jitstack=<n> set size of JIT stack
938 mark show mark values
939 replace=<string> specify a replacement string
940 startchar show starting character when relevant
941 substitute_callout use substitution callouts
942 substitute_extended use PCRE2_SUBSTITUTE_EXTENDED
943 substitute_skip=<n> skip substitution number n
944 substitute_overflow_length use PCRE2_SUBSTITUTE_OVERFLOW_LENGTH
945 substitute_stop=<n> skip substitution number n and greater
946 substitute_unknown_unset use PCRE2_SUBSTITUTE_UNKNOWN_UNSET
947 substitute_unset_empty use PCRE2_SUBSTITUTE_UNSET_EMPTY
948 These modifiers may not appear in a #pattern command. If you want them
950 as defaults, set them in a #subject command.
951 Specifying literal subject lines
953 If the subject_literal modifier is present on a pattern, all the sub‐
955 ject lines that it matches are taken as literal strings, with no inter‐
956 pretation of backslashes. It is not possible to set subject modifiers
957 on such lines, but any that are set as defaults by a #subject command
958 are recognized.
959 Saving a compiled pattern
961 When a pattern with the push modifier is successfully compiled, it is
963 pushed onto a stack of compiled patterns, and pcre2test expects the
964 next line to contain a new pattern (or a command) instead of a subject
965 line. This facility is used when saving compiled patterns to a file, as
966 described in the section entitled "Saving and restoring compiled pat‐
967 terns" below. If pushcopy is used instead of push, a copy of the com‐
968 piled pattern is stacked, leaving the original as current, ready to
969 match the following input lines. This provides a way of testing the
970 pcre2_code_copy() function. The push and pushcopy modifiers are
971 incompatible with compilation modifiers such as global that act at
972 match time. Any that are specified are ignored (for the stacked copy),
973 with a warning message, except for replace, which causes an error. Note
974 that jitverify, which is allowed, does not carry through to any subse‐
975 quent matching that uses a stacked pattern.
976 Testing foreign pattern conversion
978 The experimental foreign pattern conversion functions in PCRE2 can be
980 tested by setting the convert modifier. Its argument is a colon-sepa‐
981 rated list of options, which set the equivalent option for the
982 pcre2_pattern_convert() function:
983 glob PCRE2_CONVERT_GLOB
985 glob_no_starstar PCRE2_CONVERT_GLOB_NO_STARSTAR
986 glob_no_wild_separator PCRE2_CONVERT_GLOB_NO_WILD_SEPARATOR
987 posix_basic PCRE2_CONVERT_POSIX_BASIC
988 posix_extended PCRE2_CONVERT_POSIX_EXTENDED
989 unset Unset all options
990 The "unset" value is useful for turning off a default that has been set
992 by a #pattern command. When one of these options is set, the input pat‐
993 tern is passed to pcre2_pattern_convert(). If the conversion is suc‐
994 cessful, the result is reflected in the output and then passed to
995 pcre2_compile(). The normal utf and no_utf_check options, if set, cause
996 the PCRE2_CONVERT_UTF and PCRE2_CONVERT_NO_UTF_CHECK options to be
997 passed to pcre2_pattern_convert().
998 By default, the conversion function is allowed to allocate a buffer for
1000 its output. However, if the convert_length modifier is set to a value
1001 greater than zero, pcre2test passes a buffer of the given length. This
1002 makes it possible to test the length check.
1003 The convert_glob_escape and convert_glob_separator modifiers can be
1005 used to specify the escape and separator characters for glob process‐
1006 ing, overriding the defaults, which are operating-system dependent.
1007
1009 The modifiers that can appear in subject lines and the #subject command
1011 are of two types.
1012 Setting match options
1014 The following modifiers set options for pcre2_match() or
1016 pcre2_dfa_match(). See pcreapi for a description of their effects.
1017 anchored set PCRE2_ANCHORED
1019 endanchored set PCRE2_ENDANCHORED
1020 dfa_restart set PCRE2_DFA_RESTART
1021 dfa_shortest set PCRE2_DFA_SHORTEST
1022 no_jit set PCRE2_NO_JIT
1023 no_utf_check set PCRE2_NO_UTF_CHECK
1024 notbol set PCRE2_NOTBOL
1025 notempty set PCRE2_NOTEMPTY
1026 notempty_atstart set PCRE2_NOTEMPTY_ATSTART
1027 noteol set PCRE2_NOTEOL
1028 partial_hard (or ph) set PCRE2_PARTIAL_HARD
1029 partial_soft (or ps) set PCRE2_PARTIAL_SOFT
1030 The partial matching modifiers are provided with abbreviations because
1032 they appear frequently in tests.
1033 If the posix or posix_nosub modifier was present on the pattern, caus‐
1035 ing the POSIX wrapper API to be used, the only option-setting modifiers
1036 that have any effect are notbol, notempty, and noteol, causing REG_NOT‐
1037 BOL, REG_NOTEMPTY, and REG_NOTEOL, respectively, to be passed to
1038 regexec(). The other modifiers are ignored, with a warning message.
1039 There is one additional modifier that can be used with the POSIX wrap‐
1041 per. It is ignored (with a warning) if used for non-POSIX matching.
1042 posix_startend=<n>[:<m>]
1044 This causes the subject string to be passed to regexec() using the
1046 REG_STARTEND option, which uses offsets to specify which part of the
1047 string is searched. If only one number is given, the end offset is
1048 passed as the end of the subject string. For more detail of REG_STAR‐
1049 TEND, see the pcre2posix documentation. If the subject string contains
1050 binary zeros (coded as escapes such as \x{00} because pcre2test does
1051 not support actual binary zeros in its input), you must use posix_star‐
1052 tend to specify its length.
1053 Setting match controls
1055 The following modifiers affect the matching process or request addi‐
1057 tional information. Some of them may also be specified on a pattern
1058 line (see above), in which case they apply to every subject line that
1059 is matched against that pattern.
1060 aftertext show text after match
1062 allaftertext show text after captures
1063 allcaptures show all captures
1064 allvector show the entire ovector
1065 allusedtext show all consulted text (non-JIT only)
1066 altglobal alternative global matching
1067 callout_capture show captures at callout time
1068 callout_data=<n> set a value to pass via callouts
1069 callout_error=<n>[:<m>] control callout error
1070 callout_extra show extra callout information
1071 callout_fail=<n>[:<m>] control callout failure
1072 callout_no_where do not show position of a callout
1073 callout_none do not supply a callout function
1074 copy=<number or name> copy captured substring
1075 depth_limit=<n> set a depth limit
1076 dfa use pcre2_dfa_match()
1077 find_limits find match and depth limits
1078 get=<number or name> extract captured substring
1079 getall extract all captured substrings
1080 /g global global matching
1081 heap_limit=<n> set a limit on heap memory (Kbytes)
1082 jitstack=<n> set size of JIT stack
1083 mark show mark values
1084 match_limit=<n> set a match limit
1085 memory show heap memory usage
1086 null_context match with a NULL context
1087 offset=<n> set starting offset
1088 offset_limit=<n> set offset limit
1089 ovector=<n> set size of output vector
1090 recursion_limit=<n> obsolete synonym for depth_limit
1091 replace=<string> specify a replacement string
1092 startchar show startchar when relevant
1093 startoffset=<n> same as offset=<n>
1094 substitute_callout use substitution callouts
1095 substitute_extedded use PCRE2_SUBSTITUTE_EXTENDED
1096 substitute_skip=<n> skip substitution number n
1097 substitute_overflow_length use PCRE2_SUBSTITUTE_OVERFLOW_LENGTH
1098 substitute_stop=<n> skip substitution number n and greater
1099 substitute_unknown_unset use PCRE2_SUBSTITUTE_UNKNOWN_UNSET
1100 substitute_unset_empty use PCRE2_SUBSTITUTE_UNSET_EMPTY
1101 zero_terminate pass the subject as zero-terminated
1102 The effects of these modifiers are described in the following sections.
1104 When matching via the POSIX wrapper API, the aftertext, allaftertext,
1105 and ovector subject modifiers work as described below. All other modi‐
1106 fiers are either ignored, with a warning message, or cause an error.
1107 Showing more text
1109 The aftertext modifier requests that as well as outputting the part of
1111 the subject string that matched the entire pattern, pcre2test should in
1112 addition output the remainder of the subject string. This is useful for
1113 tests where the subject contains multiple copies of the same substring.
1114 The allaftertext modifier requests the same action for captured sub‐
1115 strings as well as the main matched substring. In each case the remain‐
1116 der is output on the following line with a plus character following the
1117 capture number.
1118 The allusedtext modifier requests that all the text that was consulted
1120 during a successful pattern match by the interpreter should be shown,
1121 for both full and partial matches. This feature is not supported for
1122 JIT matching, and if requested with JIT it is ignored (with a warning
1123 message). Setting this modifier affects the output if there is a look‐
1124 behind at the start of a match, or, for a complete match, a lookahead
1125 at the end, or if \K is used in the pattern. Characters that precede or
1126 follow the start and end of the actual match are indicated in the out‐
1127 put by '<' or '>' characters underneath them. Here is an example:
1128 re> /(?<=pqr)abc(?=xyz)/
1130 data> 123pqrabcxyz456\=allusedtext
1131 0: pqrabcxyz
1132 <<< >>>
1133 data> 123pqrabcxy\=ph,allusedtext
1134 Partial match: pqrabcxy
1135 <<<
1136 The first, complete match shows that the matched string is "abc", with
1138 the preceding and following strings "pqr" and "xyz" having been con‐
1139 sulted during the match (when processing the assertions). The partial
1140 match can indicate only the preceding string.
1141 The startchar modifier requests that the starting character for the
1143 match be indicated, if it is different to the start of the matched
1144 string. The only time when this occurs is when \K has been processed as
1145 part of the match. In this situation, the output for the matched string
1146 is displayed from the starting character instead of from the match
1147 point, with circumflex characters under the earlier characters. For
1148 example:
1149 re> /abc\Kxyz/
1151 data> abcxyz\=startchar
1152 0: abcxyz
1153 ^^^
1154 Unlike allusedtext, the startchar modifier can be used with JIT. How‐
1156 ever, these two modifiers are mutually exclusive.
1157 Showing the value of all capture groups
1159 The allcaptures modifier requests that the values of all potential cap‐
1161 tured parentheses be output after a match. By default, only those up to
1162 the highest one actually used in the match are output (corresponding to
1163 the return code from pcre2_match()). Groups that did not take part in
1164 the match are output as "<unset>". This modifier is not relevant for
1165 DFA matching (which does no capturing) and does not apply when replace
1166 is specified; it is ignored, with a warning message, if present.
1167 Showing the entire ovector, for all outcomes
1169 The allvector modifier requests that the entire ovector be shown, what‐
1171 ever the outcome of the match. Compare allcaptures, which shows only up
1172 to the maximum number of capture groups for the pattern, and then only
1173 for a successful complete non-DFA match. This modifier, which acts
1174 after any match result, and also for DFA matching, provides a means of
1175 checking that there are no unexpected modifications to ovector fields.
1176 Before each match attempt, the ovector is filled with a special value,
1177 and if this is found in both elements of a capturing pair,
1178 "<unchanged>" is output. After a successful match, this applies to all
1179 groups after the maximum capture group for the pattern. In other cases
1180 it applies to the entire ovector. After a partial match, the first two
1181 elements are the only ones that should be set. After a DFA match, the
1182 amount of ovector that is used depends on the number of matches that
1183 were found.
1184 Testing pattern callouts
1186 A callout function is supplied when pcre2test calls the library match‐
1188 ing functions, unless callout_none is specified. Its behaviour can be
1189 controlled by various modifiers listed above whose names begin with
1190 callout_. Details are given in the section entitled "Callouts" below.
1191 Testing callouts from pcre2_substitute() is decribed separately in
1192 "Testing the substitution function" below.
1193 Finding all matches in a string
1195 Searching for all possible matches within a subject can be requested by
1197 the global or altglobal modifier. After finding a match, the matching
1198 function is called again to search the remainder of the subject. The
1199 difference between global and altglobal is that the former uses the
1200 start_offset argument to pcre2_match() or pcre2_dfa_match() to start
1201 searching at a new point within the entire string (which is what Perl
1202 does), whereas the latter passes over a shortened subject. This makes a
1203 difference to the matching process if the pattern begins with a lookbe‐
1204 hind assertion (including \b or \B).
1205 If an empty string is matched, the next match is done with the
1207 PCRE2_NOTEMPTY_ATSTART and PCRE2_ANCHORED flags set, in order to search
1208 for another, non-empty, match at the same point in the subject. If this
1209 match fails, the start offset is advanced, and the normal match is
1210 retried. This imitates the way Perl handles such cases when using the
1211 /g modifier or the split() function. Normally, the start offset is
1212 advanced by one character, but if the newline convention recognizes
1213 CRLF as a newline, and the current character is CR followed by LF, an
1214 advance of two characters occurs.
1215 Testing substring extraction functions
1217 The copy and get modifiers can be used to test the pcre2_sub‐
1219 string_copy_xxx() and pcre2_substring_get_xxx() functions. They can be
1220 given more than once, and each can specify a capture group name or num‐
1221 ber, for example:
1222 abcd\=copy=1,copy=3,get=G1
1224 If the #subject command is used to set default copy and/or get lists,
1226 these can be unset by specifying a negative number to cancel all num‐
1227 bered groups and an empty name to cancel all named groups.
1228 The getall modifier tests pcre2_substring_list_get(), which extracts
1230 all captured substrings.
1231 If the subject line is successfully matched, the substrings extracted
1233 by the convenience functions are output with C, G, or L after the
1234 string number instead of a colon. This is in addition to the normal
1235 full list. The string length (that is, the return from the extraction
1236 function) is given in parentheses after each substring, followed by the
1237 name when the extraction was by name.
1238 Testing the substitution function
1240 If the replace modifier is set, the pcre2_substitute() function is
1242 called instead of one of the matching functions. Note that replacement
1243 strings cannot contain commas, because a comma signifies the end of a
1244 modifier. This is not thought to be an issue in a test program.
1245 Unlike subject strings, pcre2test does not process replacement strings
1247 for escape sequences. In UTF mode, a replacement string is checked to
1248 see if it is a valid UTF-8 string. If so, it is correctly converted to
1249 a UTF string of the appropriate code unit width. If it is not a valid
1250 UTF-8 string, the individual code units are copied directly. This pro‐
1251 vides a means of passing an invalid UTF-8 string for testing purposes.
1252 The following modifiers set options (in additional to the normal match
1254 options) for pcre2_substitute():
1255 global PCRE2_SUBSTITUTE_GLOBAL
1257 substitute_extended PCRE2_SUBSTITUTE_EXTENDED
1258 substitute_overflow_length PCRE2_SUBSTITUTE_OVERFLOW_LENGTH
1259 substitute_unknown_unset PCRE2_SUBSTITUTE_UNKNOWN_UNSET
1260 substitute_unset_empty PCRE2_SUBSTITUTE_UNSET_EMPTY
1261 After a successful substitution, the modified string is output, pre‐
1264 ceded by the number of replacements. This may be zero if there were no
1265 matches. Here is a simple example of a substitution test:
1266 /abc/replace=xxx
1268 =abc=abc=
1269 1: =xxx=abc=
1270 =abc=abc=\=global
1271 2: =xxx=xxx=
1272 Subject and replacement strings should be kept relatively short (fewer
1274 than 256 characters) for substitution tests, as fixed-size buffers are
1275 used. To make it easy to test for buffer overflow, if the replacement
1276 string starts with a number in square brackets, that number is passed
1277 to pcre2_substitute() as the size of the output buffer, with the
1278 replacement string starting at the next character. Here is an example
1279 that tests the edge case:
1280 /abc/
1282 123abc123\=replace=[10]XYZ
1283 1: 123XYZ123
1284 123abc123\=replace=[9]XYZ
1285 Failed: error -47: no more memory
1286 The default action of pcre2_substitute() is to return
1288 PCRE2_ERROR_NOMEMORY when the output buffer is too small. However, if
1289 the PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set (by using the sub‐
1290 stitute_overflow_length modifier), pcre2_substitute() continues to go
1291 through the motions of matching and substituting (but not doing any
1292 callouts), in order to compute the size of buffer that is required.
1293 When this happens, pcre2test shows the required buffer length (which
1294 includes space for the trailing zero) as part of the error message. For
1295 example:
1296 /abc/substitute_overflow_length
1298 123abc123\=replace=[9]XYZ
1299 Failed: error -47: no more memory: 10 code units are needed
1300 A replacement string is ignored with POSIX and DFA matching. Specifying
1302 partial matching provokes an error return ("bad option value") from
1303 pcre2_substitute().
1304 Testing substitute callouts
1306 If the substitute_callout modifier is set, a substitution callout func‐
1308 tion is set up. The null_context modifier must not be set, because the
1309 address of the callout function is passed in a match context. When the
1310 callout function is called (after each substitution), details of the
1311 the input and output strings are output. For example:
1312 /abc/g,replace=<$0>,substitute_callout
1314 abcdefabcpqr
1315 1(1) Old 0 3 "abc" New 0 5 "<abc>"
1316 2(1) Old 6 9 "abc" New 8 13 "<abc>"
1317 2: <abc>def<abc>pqr
1318 The first number on each callout line is the count of matches. The
1320 parenthesized number is the number of pairs that are set in the ovector
1321 (that is, one more than the number of capturing groups that were set).
1322 Then are listed the offsets of the old substring, its contents, and the
1323 same for the replacement.
1324 By default, the substitution callout function returns zero, which
1326 accepts the replacement and causes matching to continue if /g was used.
1327 Two further modifiers can be used to test other return values. If sub‐
1328 stitute_skip is set to a value greater than zero the callout function
1329 returns +1 for the match of that number, and similarly substitute_stop
1330 returns -1. These cause the replacement to be rejected, and -1 causes
1331 no further matching to take place. If either of them are set, substi‐
1332 tute_callout is assumed. For example:
1333 /abc/g,replace=<$0>,substitute_skip=1
1335 abcdefabcpqr
1336 1(1) Old 0 3 "abc" New 0 5 "<abc> SKIPPED"
1337 2(1) Old 6 9 "abc" New 6 11 "<abc>"
1338 2: abcdef<abc>pqr
1339 abcdefabcpqr\=substitute_stop=1
1340 1(1) Old 0 3 "abc" New 0 5 "<abc> STOPPED"
1341 1: abcdefabcpqr
1342 If both are set for the same number, stop takes precedence. Only a sin‐
1344 gle skip or stop is supported, which is sufficient for testing that the
1345 feature works.
1346 Setting the JIT stack size
1348 The jitstack modifier provides a way of setting the maximum stack size
1350 that is used by the just-in-time optimization code. It is ignored if
1351 JIT optimization is not being used. The value is a number of kibibytes
1352 (units of 1024 bytes). Setting zero reverts to the default of 32KiB.
1353 Providing a stack that is larger than the default is necessary only for
1354 very complicated patterns. If jitstack is set non-zero on a subject
1355 line it overrides any value that was set on the pattern.
1356 Setting heap, match, and depth limits
1358 The heap_limit, match_limit, and depth_limit modifiers set the appro‐
1360 priate limits in the match context. These values are ignored when the
1361 find_limits modifier is specified.
1362 Finding minimum limits
1364 If the find_limits modifier is present on a subject line, pcre2test
1366 calls the relevant matching function several times, setting different
1367 values in the match context via pcre2_set_heap_limit(),
1368 pcre2_set_match_limit(), or pcre2_set_depth_limit() until it finds the
1369 minimum values for each parameter that allows the match to complete
1370 without error. If JIT is being used, only the match limit is relevant.
1371 When using this modifier, the pattern should not contain any limit set‐
1373 tings such as (*LIMIT_MATCH=...) within it. If such a setting is
1374 present and is lower than the minimum matching value, the minimum value
1375 cannot be found because pcre2_set_match_limit() etc. are only able to
1376 reduce the value of an in-pattern limit; they cannot increase it.
1377 For non-DFA matching, the minimum depth_limit number is a measure of
1379 how much nested backtracking happens (that is, how deeply the pattern's
1380 tree is searched). In the case of DFA matching, depth_limit controls
1381 the depth of recursive calls of the internal function that is used for
1382 handling pattern recursion, lookaround assertions, and atomic groups.
1383 For non-DFA matching, the match_limit number is a measure of the amount
1385 of backtracking that takes place, and learning the minimum value can be
1386 instructive. For most simple matches, the number is quite small, but
1387 for patterns with very large numbers of matching possibilities, it can
1388 become large very quickly with increasing length of subject string. In
1389 the case of DFA matching, match_limit controls the total number of
1390 calls, both recursive and non-recursive, to the internal matching func‐
1391 tion, thus controlling the overall amount of computing resource that is
1392 used.
1393 For both kinds of matching, the heap_limit number, which is in
1395 kibibytes (units of 1024 bytes), limits the amount of heap memory used
1396 for matching. A value of zero disables the use of any heap memory; many
1397 simple pattern matches can be done without using the heap, so zero is
1398 not an unreasonable setting.
1399 Showing MARK names
1401 The mark modifier causes the names from backtracking control verbs that
1404 are returned from calls to pcre2_match() to be displayed. If a mark is
1405 returned for a match, non-match, or partial match, pcre2test shows it.
1406 For a match, it is on a line by itself, tagged with "MK:". Otherwise,
1407 it is added to the non-match message.
1408 Showing memory usage
1410 The memory modifier causes pcre2test to log the sizes of all heap mem‐
1412 ory allocation and freeing calls that occur during a call to
1413 pcre2_match() or pcre2_dfa_match(). These occur only when a match
1414 requires a bigger vector than the default for remembering backtracking
1415 points (pcre2_match()) or for internal workspace (pcre2_dfa_match()).
1416 In many cases there will be no heap memory used and therefore no addi‐
1417 tional output. No heap memory is allocated during matching with JIT, so
1418 in that case the memory modifier never has any effect. For this modi‐
1419 fier to work, the null_context modifier must not be set on both the
1420 pattern and the subject, though it can be set on one or the other.
1421 Setting a starting offset
1423 The offset modifier sets an offset in the subject string at which
1425 matching starts. Its value is a number of code units, not characters.
1426 Setting an offset limit
1428 The offset_limit modifier sets a limit for unanchored matches. If a
1430 match cannot be found starting at or before this offset in the subject,
1431 a "no match" return is given. The data value is a number of code units,
1432 not characters. When this modifier is used, the use_offset_limit modi‐
1433 fier must have been set for the pattern; if not, an error is generated.
1434 Setting the size of the output vector
1436 The ovector modifier applies only to the subject line in which it
1438 appears, though of course it can also be used to set a default in a
1439 #subject command. It specifies the number of pairs of offsets that are
1440 available for storing matching information. The default is 15.
1441 A value of zero is useful when testing the POSIX API because it causes
1443 regexec() to be called with a NULL capture vector. When not testing the
1444 POSIX API, a value of zero is used to cause pcre2_match_data_cre‐
1445 ate_from_pattern() to be called, in order to create a match block of
1446 exactly the right size for the pattern. (It is not possible to create a
1447 match block with a zero-length ovector; there is always at least one
1448 pair of offsets.)
1449 Passing the subject as zero-terminated
1451 By default, the subject string is passed to a native API matching func‐
1453 tion with its correct length. In order to test the facility for passing
1454 a zero-terminated string, the zero_terminate modifier is provided. It
1455 causes the length to be passed as PCRE2_ZERO_TERMINATED. When matching
1456 via the POSIX interface, this modifier is ignored, with a warning.
1457 When testing pcre2_substitute(), this modifier also has the effect of
1459 passing the replacement string as zero-terminated.
1460 Passing a NULL context
1462 Normally, pcre2test passes a context block to pcre2_match(),
1464 pcre2_dfa_match(), pcre2_jit_match() or pcre2_substitute(). If the
1465 null_context modifier is set, however, NULL is passed. This is for
1466 testing that the matching and substitution functions behave correctly
1467 in this case (they use default values). This modifier cannot be used
1468 with the find_limits or substitute_callout modifiers.
1469
1471 By default, pcre2test uses the standard PCRE2 matching function,
1473 pcre2_match() to match each subject line. PCRE2 also supports an alter‐
1474 native matching function, pcre2_dfa_match(), which operates in a dif‐
1475 ferent way, and has some restrictions. The differences between the two
1476 functions are described in the pcre2matching documentation.
1477 If the dfa modifier is set, the alternative matching function is used.
1479 This function finds all possible matches at a given point in the sub‐
1480 ject. If, however, the dfa_shortest modifier is set, processing stops
1481 after the first match is found. This is always the shortest possible
1482 match.
1483
1485 This section describes the output when the normal matching function,
1487 pcre2_match(), is being used.
1488 When a match succeeds, pcre2test outputs the list of captured sub‐
1490 strings, starting with number 0 for the string that matched the whole
1491 pattern. Otherwise, it outputs "No match" when the return is
1492 PCRE2_ERROR_NOMATCH, or "Partial match:" followed by the partially
1493 matching substring when the return is PCRE2_ERROR_PARTIAL. (Note that
1494 this is the entire substring that was inspected during the partial
1495 match; it may include characters before the actual match start if a
1496 lookbehind assertion, \K, \b, or \B was involved.)
1497 For any other return, pcre2test outputs the PCRE2 negative error number
1499 and a short descriptive phrase. If the error is a failed UTF string
1500 check, the code unit offset of the start of the failing character is
1501 also output. Here is an example of an interactive pcre2test run.
1502 $ pcre2test
1504 PCRE2 version 10.22 2016-07-29
1505 re> /^abc(\d+)/
1507 data> abc123
1508 0: abc123
1509 1: 123
1510 data> xyz
1511 No match
1512 Unset capturing substrings that are not followed by one that is set are
1514 not shown by pcre2test unless the allcaptures modifier is specified. In
1515 the following example, there are two capturing substrings, but when the
1516 first data line is matched, the second, unset substring is not shown.
1517 An "internal" unset substring is shown as "<unset>", as for the second
1518 data line.
1519 re> /(a)|(b)/
1521 data> a
1522 0: a
1523 1: a
1524 data> b
1525 0: b
1526 1: <unset>
1527 2: b
1528 If the strings contain any non-printing characters, they are output as
1530 \xhh escapes if the value is less than 256 and UTF mode is not set.
1531 Otherwise they are output as \x{hh...} escapes. See below for the defi‐
1532 nition of non-printing characters. If the aftertext modifier is set,
1533 the output for substring 0 is followed by the the rest of the subject
1534 string, identified by "0+" like this:
1535 re> /cat/aftertext
1537 data> cataract
1538 0: cat
1539 0+ aract
1540 If global matching is requested, the results of successive matching
1542 attempts are output in sequence, like this:
1543 re> /\Bi(\w\w)/g
1545 data> Mississippi
1546 0: iss
1547 1: ss
1548 0: iss
1549 1: ss
1550 0: ipp
1551 1: pp
1552 "No match" is output only if the first match attempt fails. Here is an
1554 example of a failure message (the offset 4 that is specified by the
1555 offset modifier is past the end of the subject string):
1556 re> /xyz/
1558 data> xyz\=offset=4
1559 Error -24 (bad offset value)
1560 Note that whereas patterns can be continued over several lines (a plain
1562 ">" prompt is used for continuations), subject lines may not. However
1563 newlines can be included in a subject by means of the \n escape (or \r,
1564 \r\n, etc., depending on the newline sequence setting).
1565
1567 When the alternative matching function, pcre2_dfa_match(), is used, the
1569 output consists of a list of all the matches that start at the first
1570 point in the subject where there is at least one match. For example:
1571 re> /(tang|tangerine|tan)/
1573 data> yellow tangerine\=dfa
1574 0: tangerine
1575 1: tang
1576 2: tan
1577 Using the normal matching function on this data finds only "tang". The
1579 longest matching string is always given first (and numbered zero).
1580 After a PCRE2_ERROR_PARTIAL return, the output is "Partial match:",
1581 followed by the partially matching substring. Note that this is the
1582 entire substring that was inspected during the partial match; it may
1583 include characters before the actual match start if a lookbehind asser‐
1584 tion, \b, or \B was involved. (\K is not supported for DFA matching.)
1585 If global matching is requested, the search for further matches resumes
1587 at the end of the longest match. For example:
1588 re> /(tang|tangerine|tan)/g
1590 data> yellow tangerine and tangy sultana\=dfa
1591 0: tangerine
1592 1: tang
1593 2: tan
1594 0: tang
1595 1: tan
1596 0: tan
1597 The alternative matching function does not support substring capture,
1599 so the modifiers that are concerned with captured substrings are not
1600 relevant.
1601
1603 When the alternative matching function has given the PCRE2_ERROR_PAR‐
1605 TIAL return, indicating that the subject partially matched the pattern,
1606 you can restart the match with additional subject data by means of the
1607 dfa_restart modifier. For example:
1608 re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
1610 data> 23ja\=ps,dfa
1611 Partial match: 23ja
1612 data> n05\=dfa,dfa_restart
1613 0: n05
1614 For further information about partial matching, see the pcre2partial
1616 documentation.
1617
1619 If the pattern contains any callout requests, pcre2test's callout func‐
1621 tion is called during matching unless callout_none is specified. This
1622 works with both matching functions, and with JIT, though there are some
1623 differences in behaviour. The output for callouts with numerical argu‐
1624 ments and those with string arguments is slightly different.
1625 Callouts with numerical arguments
1627 By default, the callout function displays the callout number, the start
1629 and current positions in the subject text at the callout time, and the
1630 next pattern item to be tested. For example:
1631 --->pqrabcdef
1633 0 ^ ^ \d
1634 This output indicates that callout number 0 occurred for a match
1636 attempt starting at the fourth character of the subject string, when
1637 the pointer was at the seventh character, and when the next pattern
1638 item was \d. Just one circumflex is output if the start and current
1639 positions are the same, or if the current position precedes the start
1640 position, which can happen if the callout is in a lookbehind assertion.
1641 Callouts numbered 255 are assumed to be automatic callouts, inserted as
1643 a result of the auto_callout pattern modifier. In this case, instead of
1644 showing the callout number, the offset in the pattern, preceded by a
1645 plus, is output. For example:
1646 re> /\d?[A-E]\*/auto_callout
1648 data> E*
1649 --->E*
1650 +0 ^ \d?
1651 +3 ^ [A-E]
1652 +8 ^^ \*
1653 +10 ^ ^
1654 0: E*
1655 If a pattern contains (*MARK) items, an additional line is output when‐
1657 ever a change of latest mark is passed to the callout function. For
1658 example:
1659 re> /a(*MARK:X)bc/auto_callout
1661 data> abc
1662 --->abc
1663 +0 ^ a
1664 +1 ^^ (*MARK:X)
1665 +10 ^^ b
1666 Latest Mark: X
1667 +11 ^ ^ c
1668 +12 ^ ^
1669 0: abc
1670 The mark changes between matching "a" and "b", but stays the same for
1672 the rest of the match, so nothing more is output. If, as a result of
1673 backtracking, the mark reverts to being unset, the text "<unset>" is
1674 output.
1675 Callouts with string arguments
1677 The output for a callout with a string argument is similar, except that
1679 instead of outputting a callout number before the position indicators,
1680 the callout string and its offset in the pattern string are output
1681 before the reflection of the subject string, and the subject string is
1682 reflected for each callout. For example:
1683 re> /^ab(?C'first')cd(?C"second")ef/
1685 data> abcdefg
1686 Callout (7): 'first'
1687 --->abcdefg
1688 ^ ^ c
1689 Callout (20): "second"
1690 --->abcdefg
1691 ^ ^ e
1692 0: abcdef
1693 Callout modifiers
1696 The callout function in pcre2test returns zero (carry on matching) by
1698 default, but you can use a callout_fail modifier in a subject line to
1699 change this and other parameters of the callout (see below).
1700 If the callout_capture modifier is set, the current captured groups are
1702 output when a callout occurs. This is useful only for non-DFA matching,
1703 as pcre2_dfa_match() does not support capturing, so no captures are
1704 ever shown.
1705 The normal callout output, showing the callout number or pattern offset
1707 (as described above) is suppressed if the callout_no_where modifier is
1708 set.
1709 When using the interpretive matching function pcre2_match() without
1711 JIT, setting the callout_extra modifier causes additional output from
1712 pcre2test's callout function to be generated. For the first callout in
1713 a match attempt at a new starting position in the subject, "New match
1714 attempt" is output. If there has been a backtrack since the last call‐
1715 out (or start of matching if this is the first callout), "Backtrack" is
1716 output, followed by "No other matching paths" if the backtrack ended
1717 the previous match attempt. For example:
1718 re> /(a+)b/auto_callout,no_start_optimize,no_auto_possess
1720 data> aac\=callout_extra
1721 New match attempt
1722 --->aac
1723 +0 ^ (
1724 +1 ^ a+
1725 +3 ^ ^ )
1726 +4 ^ ^ b
1727 Backtrack
1728 --->aac
1729 +3 ^^ )
1730 +4 ^^ b
1731 Backtrack
1732 No other matching paths
1733 New match attempt
1734 --->aac
1735 +0 ^ (
1736 +1 ^ a+
1737 +3 ^^ )
1738 +4 ^^ b
1739 Backtrack
1740 No other matching paths
1741 New match attempt
1742 --->aac
1743 +0 ^ (
1744 +1 ^ a+
1745 Backtrack
1746 No other matching paths
1747 New match attempt
1748 --->aac
1749 +0 ^ (
1750 +1 ^ a+
1751 No match
1752 Notice that various optimizations must be turned off if you want all
1754 possible matching paths to be scanned. If no_start_optimize is not
1755 used, there is an immediate "no match", without any callouts, because
1756 the starting optimization fails to find "b" in the subject, which it
1757 knows must be present for any match. If no_auto_possess is not used,
1758 the "a+" item is turned into "a++", which reduces the number of back‐
1759 tracks.
1760 The callout_extra modifier has no effect if used with the DFA matching
1762 function, or with JIT.
1763 Return values from callouts
1765 The default return from the callout function is zero, which allows
1767 matching to continue. The callout_fail modifier can be given one or two
1768 numbers. If there is only one number, 1 is returned instead of 0 (caus‐
1769 ing matching to backtrack) when a callout of that number is reached. If
1770 two numbers (<n>:<m>) are given, 1 is returned when callout <n> is
1771 reached and there have been at least <m> callouts. The callout_error
1772 modifier is similar, except that PCRE2_ERROR_CALLOUT is returned, caus‐
1773 ing the entire matching process to be aborted. If both these modifiers
1774 are set for the same callout number, callout_error takes precedence.
1775 Note that callouts with string arguments are always given the number
1776 zero.
1777 The callout_data modifier can be given an unsigned or a negative num‐
1779 ber. This is set as the "user data" that is passed to the matching
1780 function, and passed back when the callout function is invoked. Any
1781 value other than zero is used as a return from pcre2test's callout
1782 function.
1783 Inserting callouts can be helpful when using pcre2test to check compli‐
1785 cated regular expressions. For further information about callouts, see
1786 the pcre2callout documentation.
1787
1789 When pcre2test is outputting text in the compiled version of a pattern,
1791 bytes other than 32-126 are always treated as non-printing characters
1792 and are therefore shown as hex escapes.
1793 When pcre2test is outputting text that is a matched part of a subject
1795 string, it behaves in the same way, unless a different locale has been
1796 set for the pattern (using the locale modifier). In this case, the
1797 isprint() function is used to distinguish printing and non-printing
1798 characters.
1799
1801 It is possible to save compiled patterns on disc or elsewhere, and
1803 reload them later, subject to a number of restrictions. JIT data cannot
1804 be saved. The host on which the patterns are reloaded must be running
1805 the same version of PCRE2, with the same code unit width, and must also
1806 have the same endianness, pointer width and PCRE2_SIZE type. Before
1807 compiled patterns can be saved they must be serialized, that is, con‐
1808 verted to a stream of bytes. A single byte stream may contain any num‐
1809 ber of compiled patterns, but they must all use the same character
1810 tables. A single copy of the tables is included in the byte stream (its
1811 size is 1088 bytes).
1812 The functions whose names begin with pcre2_serialize_ are used for
1814 serializing and de-serializing. They are described in the pcre2serial‐
1815 ize documentation. In this section we describe the features of
1816 pcre2test that can be used to test these functions.
1817 Note that "serialization" in PCRE2 does not convert compiled patterns
1819 to an abstract format like Java or .NET. It just makes a reloadable
1820 byte code stream. Hence the restrictions on reloading mentioned above.
1821 In pcre2test, when a pattern with push modifier is successfully com‐
1823 piled, it is pushed onto a stack of compiled patterns, and pcre2test
1824 expects the next line to contain a new pattern (or command) instead of
1825 a subject line. By contrast, the pushcopy modifier causes a copy of the
1826 compiled pattern to be stacked, leaving the original available for
1827 immediate matching. By using push and/or pushcopy, a number of patterns
1828 can be compiled and retained. These modifiers are incompatible with
1829 posix, and control modifiers that act at match time are ignored (with a
1830 message) for the stacked patterns. The jitverify modifier applies only
1831 at compile time.
1832 The command
1834 #save <filename>
1836 causes all the stacked patterns to be serialized and the result written
1838 to the named file. Afterwards, all the stacked patterns are freed. The
1839 command
1840 #load <filename>
1842 reads the data in the file, and then arranges for it to be de-serial‐
1844 ized, with the resulting compiled patterns added to the pattern stack.
1845 The pattern on the top of the stack can be retrieved by the #pop com‐
1846 mand, which must be followed by lines of subjects that are to be
1847 matched with the pattern, terminated as usual by an empty line or end
1848 of file. This command may be followed by a modifier list containing
1849 only control modifiers that act after a pattern has been compiled. In
1850 particular, hex, posix, posix_nosub, push, and pushcopy are not
1851 allowed, nor are any option-setting modifiers. The JIT modifiers are,
1852 however permitted. Here is an example that saves and reloads two pat‐
1853 terns.
1854 /abc/push
1856 /xyz/push
1857 #save tempfile
1858 #load tempfile
1859 #pop info
1860 xyz
1861 #pop jit,bincode
1863 abc
1864 If jitverify is used with #pop, it does not automatically imply jit,
1866 which is different behaviour from when it is used on a pattern.
1867 The #popcopy command is analagous to the pushcopy modifier in that it
1869 makes current a copy of the topmost stack pattern, leaving the original
1870 still on the stack.
1871
1873 pcre2(3), pcre2api(3), pcre2callout(3), pcre2jit, pcre2matching(3),
1875 pcre2partial(d), pcre2pattern(3), pcre2serialize(3).
1876
1878 Philip Hazel
1880 University Computing Service
1881 Cambridge, England.
1882
1884 Last updated: 30 July 2019
1886 Copyright (c) 1997-2019 University of Cambridge.
1887PCRE 10.34 30 July 2019 PCRE2TEST(1)