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Final tidies and documentation updates for 8.44.
1 .TH PCRETEST 1 "10 February 2020" "PCRE 8.44"
2 .SH NAME
3 pcretest - a program for testing Perl-compatible regular expressions.
4 .SH SYNOPSIS
5 .rs
6 .sp
7 .B pcretest "[options] [input file [output file]]"
8 .sp
9 \fBpcretest\fP was written as a test program for the PCRE regular expression
10 library itself, but it can also be used for experimenting with regular
11 expressions. This document describes the features of the test program; for
12 details of the regular expressions themselves, see the
13 .\" HREF
14 \fBpcrepattern\fP
15 .\"
16 documentation. For details of the PCRE library function calls and their
17 options, see the
18 .\" HREF
19 \fBpcreapi\fP
20 .\"
21 ,
22 .\" HREF
23 \fBpcre16\fP
24 and
25 .\" HREF
26 \fBpcre32\fP
27 .\"
28 documentation.
29 .P
30 The input for \fBpcretest\fP is a sequence of regular expression patterns and
31 strings to be matched, as described below. The output shows the result of each
32 match. Options on the command line and the patterns control PCRE options and
33 exactly what is output.
34 .P
35 As PCRE has evolved, it has acquired many different features, and as a result,
36 \fBpcretest\fP now has rather a lot of obscure options for testing every
37 possible feature. Some of these options are specifically designed for use in
38 conjunction with the test script and data files that are distributed as part of
39 PCRE, and are unlikely to be of use otherwise. They are all documented here,
40 but without much justification.
41 .
42 .
43 .SH "INPUT DATA FORMAT"
44 .rs
45 .sp
46 Input to \fBpcretest\fP is processed line by line, either by calling the C
47 library's \fBfgets()\fP function, or via the \fBlibreadline\fP library (see
48 below). In Unix-like environments, \fBfgets()\fP treats any bytes other than
49 newline as data characters. However, in some Windows environments character 26
50 (hex 1A) causes an immediate end of file, and no further data is read. For
51 maximum portability, therefore, it is safest to use only ASCII characters in
52 \fBpcretest\fP input files.
53 .P
54 The input is processed using using C's string functions, so must not
55 contain binary zeroes, even though in Unix-like environments, \fBfgets()\fP
56 treats any bytes other than newline as data characters.
57 .
58 .
59 .SH "PCRE's 8-BIT, 16-BIT AND 32-BIT LIBRARIES"
60 .rs
61 .sp
62 From release 8.30, two separate PCRE libraries can be built. The original one
63 supports 8-bit character strings, whereas the newer 16-bit library supports
64 character strings encoded in 16-bit units. From release 8.32, a third library
65 can be built, supporting character strings encoded in 32-bit units. The
66 \fBpcretest\fP program can be used to test all three libraries. However, it is
67 itself still an 8-bit program, reading 8-bit input and writing 8-bit output.
68 When testing the 16-bit or 32-bit library, the patterns and data strings are
69 converted to 16- or 32-bit format before being passed to the PCRE library
70 functions. Results are converted to 8-bit for output.
71 .P
72 References to functions and structures of the form \fBpcre[16|32]_xx\fP below
73 mean "\fBpcre_xx\fP when using the 8-bit library, \fBpcre16_xx\fP when using
74 the 16-bit library, or \fBpcre32_xx\fP when using the 32-bit library".
75 .
76 .
77 .SH "COMMAND LINE OPTIONS"
78 .rs
79 .TP 10
80 \fB-8\fP
81 If the 8-bit library has been built, this option causes it to be used (this is
82 the default). If the 8-bit library has not been built, this option causes an
83 error.
84 .TP 10
85 \fB-16\fP
86 If the 16-bit library has been built, this option causes it to be used. If only
87 the 16-bit library has been built, this is the default. If the 16-bit library
88 has not been built, this option causes an error.
89 .TP 10
90 \fB-32\fP
91 If the 32-bit library has been built, this option causes it to be used. If only
92 the 32-bit library has been built, this is the default. If the 32-bit library
93 has not been built, this option causes an error.
94 .TP 10
95 \fB-b\fP
96 Behave as if each pattern has the \fB/B\fP (show byte code) modifier; the
97 internal form is output after compilation.
98 .TP 10
99 \fB-C\fP
100 Output the version number of the PCRE library, and all available information
101 about the optional features that are included, and then exit with zero exit
102 code. All other options are ignored.
103 .TP 10
104 \fB-C\fP \fIoption\fP
105 Output information about a specific build-time option, then exit. This
106 functionality is intended for use in scripts such as \fBRunTest\fP. The
107 following options output the value and set the exit code as indicated:
108 .sp
109 ebcdic-nl the code for LF (= NL) in an EBCDIC environment:
110 0x15 or 0x25
111 0 if used in an ASCII environment
112 exit code is always 0
113 linksize the configured internal link size (2, 3, or 4)
114 exit code is set to the link size
115 newline the default newline setting:
116 CR, LF, CRLF, ANYCRLF, or ANY
117 exit code is always 0
118 bsr the default setting for what \eR matches:
119 ANYCRLF or ANY
120 exit code is always 0
121 .sp
122 The following options output 1 for true or 0 for false, and set the exit code
123 to the same value:
124 .sp
125 ebcdic compiled for an EBCDIC environment
126 jit just-in-time support is available
127 pcre16 the 16-bit library was built
128 pcre32 the 32-bit library was built
129 pcre8 the 8-bit library was built
130 ucp Unicode property support is available
131 utf UTF-8 and/or UTF-16 and/or UTF-32 support
132 is available
133 .sp
134 If an unknown option is given, an error message is output; the exit code is 0.
135 .TP 10
136 \fB-d\fP
137 Behave as if each pattern has the \fB/D\fP (debug) modifier; the internal
138 form and information about the compiled pattern is output after compilation;
139 \fB-d\fP is equivalent to \fB-b -i\fP.
140 .TP 10
141 \fB-dfa\fP
142 Behave as if each data line contains the \eD escape sequence; this causes the
143 alternative matching function, \fBpcre[16|32]_dfa_exec()\fP, to be used instead
144 of the standard \fBpcre[16|32]_exec()\fP function (more detail is given below).
145 .TP 10
146 \fB-help\fP
147 Output a brief summary these options and then exit.
148 .TP 10
149 \fB-i\fP
150 Behave as if each pattern has the \fB/I\fP modifier; information about the
151 compiled pattern is given after compilation.
152 .TP 10
153 \fB-M\fP
154 Behave as if each data line contains the \eM escape sequence; this causes
155 PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
156 calling \fBpcre[16|32]_exec()\fP repeatedly with different limits.
157 .TP 10
158 \fB-m\fP
159 Output the size of each compiled pattern after it has been compiled. This is
160 equivalent to adding \fB/M\fP to each regular expression. The size is given in
161 bytes for both libraries.
162 .TP 10
163 \fB-O\fP
164 Behave as if each pattern has the \fB/O\fP modifier, that is disable
165 auto-possessification for all patterns.
166 .TP 10
167 \fB-o\fP \fIosize\fP
168 Set the number of elements in the output vector that is used when calling
169 \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP to be \fIosize\fP. The
170 default value is 45, which is enough for 14 capturing subexpressions for
171 \fBpcre[16|32]_exec()\fP or 22 different matches for
172 \fBpcre[16|32]_dfa_exec()\fP.
173 The vector size can be changed for individual matching calls by including \eO
174 in the data line (see below).
175 .TP 10
176 \fB-p\fP
177 Behave as if each pattern has the \fB/P\fP modifier; the POSIX wrapper API is
178 used to call PCRE. None of the other options has any effect when \fB-p\fP is
179 set. This option can be used only with the 8-bit library.
180 .TP 10
181 \fB-q\fP
182 Do not output the version number of \fBpcretest\fP at the start of execution.
183 .TP 10
184 \fB-S\fP \fIsize\fP
185 On Unix-like systems, set the size of the run-time stack to \fIsize\fP
186 megabytes.
187 .TP 10
188 \fB-s\fP or \fB-s+\fP
189 Behave as if each pattern has the \fB/S\fP modifier; in other words, force each
190 pattern to be studied. If \fB-s+\fP is used, all the JIT compile options are
191 passed to \fBpcre[16|32]_study()\fP, causing just-in-time optimization to be set
192 up if it is available, for both full and partial matching. Specific JIT compile
193 options can be selected by following \fB-s+\fP with a digit in the range 1 to
194 7, which selects the JIT compile modes as follows:
195 .sp
196 1 normal match only
197 2 soft partial match only
198 3 normal match and soft partial match
199 4 hard partial match only
200 6 soft and hard partial match
201 7 all three modes (default)
202 .sp
203 If \fB-s++\fP is used instead of \fB-s+\fP (with or without a following digit),
204 the text "(JIT)" is added to the first output line after a match or no match
205 when JIT-compiled code was actually used.
206 .sp
207 Note that there are pattern options that can override \fB-s\fP, either
208 specifying no studying at all, or suppressing JIT compilation.
209 .sp
210 If the \fB/I\fP or \fB/D\fP option is present on a pattern (requesting output
211 about the compiled pattern), information about the result of studying is not
212 included when studying is caused only by \fB-s\fP and neither \fB-i\fP nor
213 \fB-d\fP is present on the command line. This behaviour means that the output
214 from tests that are run with and without \fB-s\fP should be identical, except
215 when options that output information about the actual running of a match are
216 set.
217 .sp
218 The \fB-M\fP, \fB-t\fP, and \fB-tm\fP options, which give information about
219 resources used, are likely to produce different output with and without
220 \fB-s\fP. Output may also differ if the \fB/C\fP option is present on an
221 individual pattern. This uses callouts to trace the the matching process, and
222 this may be different between studied and non-studied patterns. If the pattern
223 contains (*MARK) items there may also be differences, for the same reason. The
224 \fB-s\fP command line option can be overridden for specific patterns that
225 should never be studied (see the \fB/S\fP pattern modifier below).
226 .TP 10
227 \fB-t\fP
228 Run each compile, study, and match many times with a timer, and output the
229 resulting times per compile, study, or match (in milliseconds). Do not set
230 \fB-m\fP with \fB-t\fP, because you will then get the size output a zillion
231 times, and the timing will be distorted. You can control the number of
232 iterations that are used for timing by following \fB-t\fP with a number (as a
233 separate item on the command line). For example, "-t 1000" iterates 1000 times.
234 The default is to iterate 500000 times.
235 .TP 10
236 \fB-tm\fP
237 This is like \fB-t\fP except that it times only the matching phase, not the
238 compile or study phases.
239 .TP 10
240 \fB-T\fP \fB-TM\fP
241 These behave like \fB-t\fP and \fB-tm\fP, but in addition, at the end of a run,
242 the total times for all compiles, studies, and matches are output.
243 .
244 .
245 .SH DESCRIPTION
246 .rs
247 .sp
248 If \fBpcretest\fP is given two filename arguments, it reads from the first and
249 writes to the second. If it is given only one filename argument, it reads from
250 that file and writes to stdout. Otherwise, it reads from stdin and writes to
251 stdout, and prompts for each line of input, using "re>" to prompt for regular
252 expressions, and "data>" to prompt for data lines.
253 .P
254 When \fBpcretest\fP is built, a configuration option can specify that it should
255 be linked with the \fBlibreadline\fP library. When this is done, if the input
256 is from a terminal, it is read using the \fBreadline()\fP function. This
257 provides line-editing and history facilities. The output from the \fB-help\fP
258 option states whether or not \fBreadline()\fP will be used.
259 .P
260 The program handles any number of sets of input on a single input file. Each
261 set starts with a regular expression, and continues with any number of data
262 lines to be matched against that pattern.
263 .P
264 Each data line is matched separately and independently. If you want to do
265 multi-line matches, you have to use the \en escape sequence (or \er or \er\en,
266 etc., depending on the newline setting) in a single line of input to encode the
267 newline sequences. There is no limit on the length of data lines; the input
268 buffer is automatically extended if it is too small.
269 .P
270 An empty line signals the end of the data lines, at which point a new regular
271 expression is read. The regular expressions are given enclosed in any
272 non-alphanumeric delimiters other than backslash, for example:
273 .sp
274 /(a|bc)x+yz/
275 .sp
276 White space before the initial delimiter is ignored. A regular expression may
277 be continued over several input lines, in which case the newline characters are
278 included within it. It is possible to include the delimiter within the pattern
279 by escaping it, for example
280 .sp
281 /abc\e/def/
282 .sp
283 If you do so, the escape and the delimiter form part of the pattern, but since
284 delimiters are always non-alphanumeric, this does not affect its interpretation.
285 If the terminating delimiter is immediately followed by a backslash, for
286 example,
287 .sp
288 /abc/\e
289 .sp
290 then a backslash is added to the end of the pattern. This is done to provide a
291 way of testing the error condition that arises if a pattern finishes with a
292 backslash, because
293 .sp
294 /abc\e/
295 .sp
296 is interpreted as the first line of a pattern that starts with "abc/", causing
297 pcretest to read the next line as a continuation of the regular expression.
298 .
299 .
300 .SH "PATTERN MODIFIERS"
301 .rs
302 .sp
303 A pattern may be followed by any number of modifiers, which are mostly single
304 characters, though some of these can be qualified by further characters.
305 Following Perl usage, these are referred to below as, for example, "the
306 \fB/i\fP modifier", even though the delimiter of the pattern need not always be
307 a slash, and no slash is used when writing modifiers. White space may appear
308 between the final pattern delimiter and the first modifier, and between the
309 modifiers themselves. For reference, here is a complete list of modifiers. They
310 fall into several groups that are described in detail in the following
311 sections.
312 .sp
313 \fB/8\fP set UTF mode
314 \fB/9\fP set PCRE_NEVER_UTF (locks out UTF mode)
315 \fB/?\fP disable UTF validity check
316 \fB/+\fP show remainder of subject after match
317 \fB/=\fP show all captures (not just those that are set)
318 .sp
319 \fB/A\fP set PCRE_ANCHORED
320 \fB/B\fP show compiled code
321 \fB/C\fP set PCRE_AUTO_CALLOUT
322 \fB/D\fP same as \fB/B\fP plus \fB/I\fP
323 \fB/E\fP set PCRE_DOLLAR_ENDONLY
324 \fB/F\fP flip byte order in compiled pattern
325 \fB/f\fP set PCRE_FIRSTLINE
326 \fB/G\fP find all matches (shorten string)
327 \fB/g\fP find all matches (use startoffset)
328 \fB/I\fP show information about pattern
329 \fB/i\fP set PCRE_CASELESS
330 \fB/J\fP set PCRE_DUPNAMES
331 \fB/K\fP show backtracking control names
332 \fB/L\fP set locale
333 \fB/M\fP show compiled memory size
334 \fB/m\fP set PCRE_MULTILINE
335 \fB/N\fP set PCRE_NO_AUTO_CAPTURE
336 \fB/O\fP set PCRE_NO_AUTO_POSSESS
337 \fB/P\fP use the POSIX wrapper
338 \fB/Q\fP test external stack check function
339 \fB/S\fP study the pattern after compilation
340 \fB/s\fP set PCRE_DOTALL
341 \fB/T\fP select character tables
342 \fB/U\fP set PCRE_UNGREEDY
343 \fB/W\fP set PCRE_UCP
344 \fB/X\fP set PCRE_EXTRA
345 \fB/x\fP set PCRE_EXTENDED
346 \fB/Y\fP set PCRE_NO_START_OPTIMIZE
347 \fB/Z\fP don't show lengths in \fB/B\fP output
348 .sp
349 \fB/<any>\fP set PCRE_NEWLINE_ANY
350 \fB/<anycrlf>\fP set PCRE_NEWLINE_ANYCRLF
351 \fB/<cr>\fP set PCRE_NEWLINE_CR
352 \fB/<crlf>\fP set PCRE_NEWLINE_CRLF
353 \fB/<lf>\fP set PCRE_NEWLINE_LF
354 \fB/<bsr_anycrlf>\fP set PCRE_BSR_ANYCRLF
355 \fB/<bsr_unicode>\fP set PCRE_BSR_UNICODE
356 \fB/<JS>\fP set PCRE_JAVASCRIPT_COMPAT
357 .sp
358 .
359 .
360 .SS "Perl-compatible modifiers"
361 .rs
362 .sp
363 The \fB/i\fP, \fB/m\fP, \fB/s\fP, and \fB/x\fP modifiers set the PCRE_CASELESS,
364 PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
365 \fBpcre[16|32]_compile()\fP is called. These four modifier letters have the same
366 effect as they do in Perl. For example:
367 .sp
368 /caseless/i
369 .sp
370 .
371 .
372 .SS "Modifiers for other PCRE options"
373 .rs
374 .sp
375 The following table shows additional modifiers for setting PCRE compile-time
376 options that do not correspond to anything in Perl:
377 .sp
378 \fB/8\fP PCRE_UTF8 ) when using the 8-bit
379 \fB/?\fP PCRE_NO_UTF8_CHECK ) library
380 .sp
381 \fB/8\fP PCRE_UTF16 ) when using the 16-bit
382 \fB/?\fP PCRE_NO_UTF16_CHECK ) library
383 .sp
384 \fB/8\fP PCRE_UTF32 ) when using the 32-bit
385 \fB/?\fP PCRE_NO_UTF32_CHECK ) library
386 .sp
387 \fB/9\fP PCRE_NEVER_UTF
388 \fB/A\fP PCRE_ANCHORED
389 \fB/C\fP PCRE_AUTO_CALLOUT
390 \fB/E\fP PCRE_DOLLAR_ENDONLY
391 \fB/f\fP PCRE_FIRSTLINE
392 \fB/J\fP PCRE_DUPNAMES
393 \fB/N\fP PCRE_NO_AUTO_CAPTURE
394 \fB/O\fP PCRE_NO_AUTO_POSSESS
395 \fB/U\fP PCRE_UNGREEDY
396 \fB/W\fP PCRE_UCP
397 \fB/X\fP PCRE_EXTRA
398 \fB/Y\fP PCRE_NO_START_OPTIMIZE
399 \fB/<any>\fP PCRE_NEWLINE_ANY
400 \fB/<anycrlf>\fP PCRE_NEWLINE_ANYCRLF
401 \fB/<cr>\fP PCRE_NEWLINE_CR
402 \fB/<crlf>\fP PCRE_NEWLINE_CRLF
403 \fB/<lf>\fP PCRE_NEWLINE_LF
404 \fB/<bsr_anycrlf>\fP PCRE_BSR_ANYCRLF
405 \fB/<bsr_unicode>\fP PCRE_BSR_UNICODE
406 \fB/<JS>\fP PCRE_JAVASCRIPT_COMPAT
407 .sp
408 The modifiers that are enclosed in angle brackets are literal strings as shown,
409 including the angle brackets, but the letters within can be in either case.
410 This example sets multiline matching with CRLF as the line ending sequence:
411 .sp
412 /^abc/m<CRLF>
413 .sp
414 As well as turning on the PCRE_UTF8/16/32 option, the \fB/8\fP modifier causes
415 all non-printing characters in output strings to be printed using the
416 \ex{hh...} notation. Otherwise, those less than 0x100 are output in hex without
417 the curly brackets.
418 .P
419 Full details of the PCRE options are given in the
420 .\" HREF
421 \fBpcreapi\fP
422 .\"
423 documentation.
424 .
425 .
426 .SS "Finding all matches in a string"
427 .rs
428 .sp
429 Searching for all possible matches within each subject string can be requested
430 by the \fB/g\fP or \fB/G\fP modifier. After finding a match, PCRE is called
431 again to search the remainder of the subject string. The difference between
432 \fB/g\fP and \fB/G\fP is that the former uses the \fIstartoffset\fP argument to
433 \fBpcre[16|32]_exec()\fP to start searching at a new point within the entire
434 string (which is in effect what Perl does), whereas the latter passes over a
435 shortened substring. This makes a difference to the matching process if the
436 pattern begins with a lookbehind assertion (including \eb or \eB).
437 .P
438 If any call to \fBpcre[16|32]_exec()\fP in a \fB/g\fP or \fB/G\fP sequence matches
439 an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
440 PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
441 same point. If this second match fails, the start offset is advanced, and the
442 normal match is retried. This imitates the way Perl handles such cases when
443 using the \fB/g\fP modifier or the \fBsplit()\fP function. Normally, the start
444 offset is advanced by one character, but if the newline convention recognizes
445 CRLF as a newline, and the current character is CR followed by LF, an advance
446 of two is used.
447 .
448 .
449 .SS "Other modifiers"
450 .rs
451 .sp
452 There are yet more modifiers for controlling the way \fBpcretest\fP
453 operates.
454 .P
455 The \fB/+\fP modifier requests that as well as outputting the substring that
456 matched the entire pattern, \fBpcretest\fP should in addition output the
457 remainder of the subject string. This is useful for tests where the subject
458 contains multiple copies of the same substring. If the \fB+\fP modifier appears
459 twice, the same action is taken for captured substrings. In each case the
460 remainder is output on the following line with a plus character following the
461 capture number. Note that this modifier must not immediately follow the /S
462 modifier because /S+ and /S++ have other meanings.
463 .P
464 The \fB/=\fP modifier requests that the values of all potential captured
465 parentheses be output after a match. By default, only those up to the highest
466 one actually used in the match are output (corresponding to the return code
467 from \fBpcre[16|32]_exec()\fP). Values in the offsets vector corresponding to
468 higher numbers should be set to -1, and these are output as "<unset>". This
469 modifier gives a way of checking that this is happening.
470 .P
471 The \fB/B\fP modifier is a debugging feature. It requests that \fBpcretest\fP
472 output a representation of the compiled code after compilation. Normally this
473 information contains length and offset values; however, if \fB/Z\fP is also
474 present, this data is replaced by spaces. This is a special feature for use in
475 the automatic test scripts; it ensures that the same output is generated for
476 different internal link sizes.
477 .P
478 The \fB/D\fP modifier is a PCRE debugging feature, and is equivalent to
479 \fB/BI\fP, that is, both the \fB/B\fP and the \fB/I\fP modifiers.
480 .P
481 The \fB/F\fP modifier causes \fBpcretest\fP to flip the byte order of the
482 2-byte and 4-byte fields in the compiled pattern. This facility is for testing
483 the feature in PCRE that allows it to execute patterns that were compiled on a
484 host with a different endianness. This feature is not available when the POSIX
485 interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
486 specified. See also the section about saving and reloading compiled patterns
487 below.
488 .P
489 The \fB/I\fP modifier requests that \fBpcretest\fP output information about the
490 compiled pattern (whether it is anchored, has a fixed first character, and
491 so on). It does this by calling \fBpcre[16|32]_fullinfo()\fP after compiling a
492 pattern. If the pattern is studied, the results of that are also output. In
493 this output, the word "char" means a non-UTF character, that is, the value of a
494 single data item (8-bit, 16-bit, or 32-bit, depending on the library that is
495 being tested).
496 .P
497 The \fB/K\fP modifier requests \fBpcretest\fP to show names from backtracking
498 control verbs that are returned from calls to \fBpcre[16|32]_exec()\fP. It causes
499 \fBpcretest\fP to create a \fBpcre[16|32]_extra\fP block if one has not already
500 been created by a call to \fBpcre[16|32]_study()\fP, and to set the
501 PCRE_EXTRA_MARK flag and the \fBmark\fP field within it, every time that
502 \fBpcre[16|32]_exec()\fP is called. If the variable that the \fBmark\fP field
503 points to is non-NULL for a match, non-match, or partial match, \fBpcretest\fP
504 prints the string to which it points. For a match, this is shown on a line by
505 itself, tagged with "MK:". For a non-match it is added to the message.
506 .P
507 The \fB/L\fP modifier must be followed directly by the name of a locale, for
508 example,
509 .sp
510 /pattern/Lfr_FR
511 .sp
512 For this reason, it must be the last modifier. The given locale is set,
513 \fBpcre[16|32]_maketables()\fP is called to build a set of character tables for
514 the locale, and this is then passed to \fBpcre[16|32]_compile()\fP when compiling
515 the regular expression. Without an \fB/L\fP (or \fB/T\fP) modifier, NULL is
516 passed as the tables pointer; that is, \fB/L\fP applies only to the expression
517 on which it appears.
518 .P
519 The \fB/M\fP modifier causes the size in bytes of the memory block used to hold
520 the compiled pattern to be output. This does not include the size of the
521 \fBpcre[16|32]\fP block; it is just the actual compiled data. If the pattern is
522 successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the
523 JIT compiled code is also output.
524 .P
525 The \fB/Q\fP modifier is used to test the use of \fBpcre_stack_guard\fP. It
526 must be followed by '0' or '1', specifying the return code to be given from an
527 external function that is passed to PCRE and used for stack checking during
528 compilation (see the
529 .\" HREF
530 \fBpcreapi\fP
531 .\"
532 documentation for details).
533 .P
534 The \fB/S\fP modifier causes \fBpcre[16|32]_study()\fP to be called after the
535 expression has been compiled, and the results used when the expression is
536 matched. There are a number of qualifying characters that may follow \fB/S\fP.
537 They may appear in any order.
538 .P
539 If \fB/S\fP is followed by an exclamation mark, \fBpcre[16|32]_study()\fP is
540 called with the PCRE_STUDY_EXTRA_NEEDED option, causing it always to return a
541 \fBpcre_extra\fP block, even when studying discovers no useful information.
542 .P
543 If \fB/S\fP is followed by a second S character, it suppresses studying, even
544 if it was requested externally by the \fB-s\fP command line option. This makes
545 it possible to specify that certain patterns are always studied, and others are
546 never studied, independently of \fB-s\fP. This feature is used in the test
547 files in a few cases where the output is different when the pattern is studied.
548 .P
549 If the \fB/S\fP modifier is followed by a + character, the call to
550 \fBpcre[16|32]_study()\fP is made with all the JIT study options, requesting
551 just-in-time optimization support if it is available, for both normal and
552 partial matching. If you want to restrict the JIT compiling modes, you can
553 follow \fB/S+\fP with a digit in the range 1 to 7:
554 .sp
555 1 normal match only
556 2 soft partial match only
557 3 normal match and soft partial match
558 4 hard partial match only
559 6 soft and hard partial match
560 7 all three modes (default)
561 .sp
562 If \fB/S++\fP is used instead of \fB/S+\fP (with or without a following digit),
563 the text "(JIT)" is added to the first output line after a match or no match
564 when JIT-compiled code was actually used.
565 .P
566 Note that there is also an independent \fB/+\fP modifier; it must not be given
567 immediately after \fB/S\fP or \fB/S+\fP because this will be misinterpreted.
568 .P
569 If JIT studying is successful, the compiled JIT code will automatically be used
570 when \fBpcre[16|32]_exec()\fP is run, except when incompatible run-time options
571 are specified. For more details, see the
572 .\" HREF
573 \fBpcrejit\fP
574 .\"
575 documentation. See also the \fB\eJ\fP escape sequence below for a way of
576 setting the size of the JIT stack.
577 .P
578 Finally, if \fB/S\fP is followed by a minus character, JIT compilation is
579 suppressed, even if it was requested externally by the \fB-s\fP command line
580 option. This makes it possible to specify that JIT is never to be used for
581 certain patterns.
582 .P
583 The \fB/T\fP modifier must be followed by a single digit. It causes a specific
584 set of built-in character tables to be passed to \fBpcre[16|32]_compile()\fP. It
585 is used in the standard PCRE tests to check behaviour with different character
586 tables. The digit specifies the tables as follows:
587 .sp
588 0 the default ASCII tables, as distributed in
589 pcre_chartables.c.dist
590 1 a set of tables defining ISO 8859 characters
591 .sp
592 In table 1, some characters whose codes are greater than 128 are identified as
593 letters, digits, spaces, etc.
594 .
595 .
596 .SS "Using the POSIX wrapper API"
597 .rs
598 .sp
599 The \fB/P\fP modifier causes \fBpcretest\fP to call PCRE via the POSIX wrapper
600 API rather than its native API. This supports only the 8-bit library. When
601 \fB/P\fP is set, the following modifiers set options for the \fBregcomp()\fP
602 function:
603 .sp
604 /i REG_ICASE
605 /m REG_NEWLINE
606 /N REG_NOSUB
607 /s REG_DOTALL )
608 /U REG_UNGREEDY ) These options are not part of
609 /W REG_UCP ) the POSIX standard
610 /8 REG_UTF8 )
611 .sp
612 The \fB/+\fP modifier works as described above. All other modifiers are
613 ignored.
614 .
615 .
616 .SS "Locking out certain modifiers"
617 .rs
618 .sp
619 PCRE can be compiled with or without support for certain features such as
620 UTF-8/16/32 or Unicode properties. Accordingly, the standard tests are split up
621 into a number of different files that are selected for running depending on
622 which features are available. When updating the tests, it is all too easy to
623 put a new test into the wrong file by mistake; for example, to put a test that
624 requires UTF support into a file that is used when it is not available. To help
625 detect such mistakes as early as possible, there is a facility for locking out
626 specific modifiers. If an input line for \fBpcretest\fP starts with the string
627 "< forbid " the following sequence of characters is taken as a list of
628 forbidden modifiers. For example, in the test files that must not use UTF or
629 Unicode property support, this line appears:
630 .sp
631 < forbid 8W
632 .sp
633 This locks out the /8 and /W modifiers. An immediate error is given if they are
634 subsequently encountered. If the character string contains < but not >, all the
635 multi-character modifiers that begin with < are locked out. Otherwise, such
636 modifiers must be explicitly listed, for example:
637 .sp
638 < forbid <JS><cr>
639 .sp
640 There must be a single space between < and "forbid" for this feature to be
641 recognised. If there is not, the line is interpreted either as a request to
642 re-load a pre-compiled pattern (see "SAVING AND RELOADING COMPILED PATTERNS"
643 below) or, if there is a another < character, as a pattern that uses < as its
644 delimiter.
645 .
646 .
647 .SH "DATA LINES"
648 .rs
649 .sp
650 Before each data line is passed to \fBpcre[16|32]_exec()\fP, leading and trailing
651 white space is removed, and it is then scanned for \e escapes. Some of these
652 are pretty esoteric features, intended for checking out some of the more
653 complicated features of PCRE. If you are just testing "ordinary" regular
654 expressions, you probably don't need any of these. The following escapes are
655 recognized:
656 .sp
657 \ea alarm (BEL, \ex07)
658 \eb backspace (\ex08)
659 \ee escape (\ex27)
660 \ef form feed (\ex0c)
661 \en newline (\ex0a)
662 .\" JOIN
663 \eqdd set the PCRE_MATCH_LIMIT limit to dd
664 (any number of digits)
665 \er carriage return (\ex0d)
666 \et tab (\ex09)
667 \ev vertical tab (\ex0b)
668 \ennn octal character (up to 3 octal digits); always
669 a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode
670 \eo{dd...} octal character (any number of octal digits}
671 \exhh hexadecimal byte (up to 2 hex digits)
672 \ex{hh...} hexadecimal character (any number of hex digits)
673 .\" JOIN
674 \eA pass the PCRE_ANCHORED option to \fBpcre[16|32]_exec()\fP
675 or \fBpcre[16|32]_dfa_exec()\fP
676 .\" JOIN
677 \eB pass the PCRE_NOTBOL option to \fBpcre[16|32]_exec()\fP
678 or \fBpcre[16|32]_dfa_exec()\fP
679 .\" JOIN
680 \eCdd call pcre[16|32]_copy_substring() for substring dd
681 after a successful match (number less than 32)
682 .\" JOIN
683 \eCname call pcre[16|32]_copy_named_substring() for substring
684 "name" after a successful match (name termin-
685 ated by next non alphanumeric character)
686 .\" JOIN
687 \eC+ show the current captured substrings at callout
688 time
689 \eC- do not supply a callout function
690 .\" JOIN
691 \eC!n return 1 instead of 0 when callout number n is
692 reached
693 .\" JOIN
694 \eC!n!m return 1 instead of 0 when callout number n is
695 reached for the nth time
696 .\" JOIN
697 \eC*n pass the number n (may be negative) as callout
698 data; this is used as the callout return value
699 \eD use the \fBpcre[16|32]_dfa_exec()\fP match function
700 \eF only shortest match for \fBpcre[16|32]_dfa_exec()\fP
701 .\" JOIN
702 \eGdd call pcre[16|32]_get_substring() for substring dd
703 after a successful match (number less than 32)
704 .\" JOIN
705 \eGname call pcre[16|32]_get_named_substring() for substring
706 "name" after a successful match (name termin-
707 ated by next non-alphanumeric character)
708 .\" JOIN
709 \eJdd set up a JIT stack of dd kilobytes maximum (any
710 number of digits)
711 .\" JOIN
712 \eL call pcre[16|32]_get_substringlist() after a
713 successful match
714 .\" JOIN
715 \eM discover the minimum MATCH_LIMIT and
716 MATCH_LIMIT_RECURSION settings
717 .\" JOIN
718 \eN pass the PCRE_NOTEMPTY option to \fBpcre[16|32]_exec()\fP
719 or \fBpcre[16|32]_dfa_exec()\fP; if used twice, pass the
720 PCRE_NOTEMPTY_ATSTART option
721 .\" JOIN
722 \eOdd set the size of the output vector passed to
723 \fBpcre[16|32]_exec()\fP to dd (any number of digits)
724 .\" JOIN
725 \eP pass the PCRE_PARTIAL_SOFT option to \fBpcre[16|32]_exec()\fP
726 or \fBpcre[16|32]_dfa_exec()\fP; if used twice, pass the
727 PCRE_PARTIAL_HARD option
728 .\" JOIN
729 \eQdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd
730 (any number of digits)
731 \eR pass the PCRE_DFA_RESTART option to \fBpcre[16|32]_dfa_exec()\fP
732 \eS output details of memory get/free calls during matching
733 .\" JOIN
734 \eY pass the PCRE_NO_START_OPTIMIZE option to \fBpcre[16|32]_exec()\fP
735 or \fBpcre[16|32]_dfa_exec()\fP
736 .\" JOIN
737 \eZ pass the PCRE_NOTEOL option to \fBpcre[16|32]_exec()\fP
738 or \fBpcre[16|32]_dfa_exec()\fP
739 .\" JOIN
740 \e? pass the PCRE_NO_UTF[8|16|32]_CHECK option to
741 \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP
742 .\" JOIN
743 \e>dd start the match at offset dd (optional "-"; then
744 any number of digits); this sets the \fIstartoffset\fP
745 argument for \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP
746 .\" JOIN
747 \e<cr> pass the PCRE_NEWLINE_CR option to \fBpcre[16|32]_exec()\fP
748 or \fBpcre[16|32]_dfa_exec()\fP
749 .\" JOIN
750 \e<lf> pass the PCRE_NEWLINE_LF option to \fBpcre[16|32]_exec()\fP
751 or \fBpcre[16|32]_dfa_exec()\fP
752 .\" JOIN
753 \e<crlf> pass the PCRE_NEWLINE_CRLF option to \fBpcre[16|32]_exec()\fP
754 or \fBpcre[16|32]_dfa_exec()\fP
755 .\" JOIN
756 \e<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to \fBpcre[16|32]_exec()\fP
757 or \fBpcre[16|32]_dfa_exec()\fP
758 .\" JOIN
759 \e<any> pass the PCRE_NEWLINE_ANY option to \fBpcre[16|32]_exec()\fP
760 or \fBpcre[16|32]_dfa_exec()\fP
761 .sp
762 The use of \ex{hh...} is not dependent on the use of the \fB/8\fP modifier on
763 the pattern. It is recognized always. There may be any number of hexadecimal
764 digits inside the braces; invalid values provoke error messages.
765 .P
766 Note that \exhh specifies one byte rather than one character in UTF-8 mode;
767 this makes it possible to construct invalid UTF-8 sequences for testing
768 purposes. On the other hand, \ex{hh} is interpreted as a UTF-8 character in
769 UTF-8 mode, generating more than one byte if the value is greater than 127.
770 When testing the 8-bit library not in UTF-8 mode, \ex{hh} generates one byte
771 for values less than 256, and causes an error for greater values.
772 .P
773 In UTF-16 mode, all 4-digit \ex{hhhh} values are accepted. This makes it
774 possible to construct invalid UTF-16 sequences for testing purposes.
775 .P
776 In UTF-32 mode, all 4- to 8-digit \ex{...} values are accepted. This makes it
777 possible to construct invalid UTF-32 sequences for testing purposes.
778 .P
779 The escapes that specify line ending sequences are literal strings, exactly as
780 shown. No more than one newline setting should be present in any data line.
781 .P
782 A backslash followed by anything else just escapes the anything else. If
783 the very last character is a backslash, it is ignored. This gives a way of
784 passing an empty line as data, since a real empty line terminates the data
785 input.
786 .P
787 The \fB\eJ\fP escape provides a way of setting the maximum stack size that is
788 used by the just-in-time optimization code. It is ignored if JIT optimization
789 is not being used. Providing a stack that is larger than the default 32K is
790 necessary only for very complicated patterns.
791 .P
792 If \eM is present, \fBpcretest\fP calls \fBpcre[16|32]_exec()\fP several times,
793 with different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP
794 fields of the \fBpcre[16|32]_extra\fP data structure, until it finds the minimum
795 numbers for each parameter that allow \fBpcre[16|32]_exec()\fP to complete without
796 error. Because this is testing a specific feature of the normal interpretive
797 \fBpcre[16|32]_exec()\fP execution, the use of any JIT optimization that might
798 have been set up by the \fB/S+\fP qualifier of \fB-s+\fP option is disabled.
799 .P
800 The \fImatch_limit\fP number is a measure of the amount of backtracking
801 that takes place, and checking it out can be instructive. For most simple
802 matches, the number is quite small, but for patterns with very large numbers of
803 matching possibilities, it can become large very quickly with increasing length
804 of subject string. The \fImatch_limit_recursion\fP number is a measure of how
805 much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
806 needed to complete the match attempt.
807 .P
808 When \eO is used, the value specified may be higher or lower than the size set
809 by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to
810 the call of \fBpcre[16|32]_exec()\fP for the line in which it appears.
811 .P
812 If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper
813 API to be used, the only option-setting sequences that have any effect are \eB,
814 \eN, and \eZ, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
815 to be passed to \fBregexec()\fP.
816 .
817 .
818 .SH "THE ALTERNATIVE MATCHING FUNCTION"
819 .rs
820 .sp
821 By default, \fBpcretest\fP uses the standard PCRE matching function,
822 \fBpcre[16|32]_exec()\fP to match each data line. PCRE also supports an
823 alternative matching function, \fBpcre[16|32]_dfa_test()\fP, which operates in a
824 different way, and has some restrictions. The differences between the two
825 functions are described in the
826 .\" HREF
827 \fBpcrematching\fP
828 .\"
829 documentation.
830 .P
831 If a data line contains the \eD escape sequence, or if the command line
832 contains the \fB-dfa\fP option, the alternative matching function is used.
833 This function finds all possible matches at a given point. If, however, the \eF
834 escape sequence is present in the data line, it stops after the first match is
835 found. This is always the shortest possible match.
836 .
837 .
838 .SH "DEFAULT OUTPUT FROM PCRETEST"
839 .rs
840 .sp
841 This section describes the output when the normal matching function,
842 \fBpcre[16|32]_exec()\fP, is being used.
843 .P
844 When a match succeeds, \fBpcretest\fP outputs the list of captured substrings
845 that \fBpcre[16|32]_exec()\fP returns, starting with number 0 for the string that
846 matched the whole pattern. Otherwise, it outputs "No match" when the return is
847 PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
848 substring when \fBpcre[16|32]_exec()\fP returns PCRE_ERROR_PARTIAL. (Note that
849 this is the entire substring that was inspected during the partial match; it
850 may include characters before the actual match start if a lookbehind assertion,
851 \eK, \eb, or \eB was involved.) For any other return, \fBpcretest\fP outputs
852 the PCRE negative error number and a short descriptive phrase. If the error is
853 a failed UTF string check, the offset of the start of the failing character and
854 the reason code are also output, provided that the size of the output vector is
855 at least two. Here is an example of an interactive \fBpcretest\fP run.
856 .sp
857 $ pcretest
858 PCRE version 8.13 2011-04-30
859 .sp
860 re> /^abc(\ed+)/
861 data> abc123
862 0: abc123
863 1: 123
864 data> xyz
865 No match
866 .sp
867 Unset capturing substrings that are not followed by one that is set are not
868 returned by \fBpcre[16|32]_exec()\fP, and are not shown by \fBpcretest\fP. In the
869 following example, there are two capturing substrings, but when the first data
870 line is matched, the second, unset substring is not shown. An "internal" unset
871 substring is shown as "<unset>", as for the second data line.
872 .sp
873 re> /(a)|(b)/
874 data> a
875 0: a
876 1: a
877 data> b
878 0: b
879 1: <unset>
880 2: b
881 .sp
882 If the strings contain any non-printing characters, they are output as \exhh
883 escapes if the value is less than 256 and UTF mode is not set. Otherwise they
884 are output as \ex{hh...} escapes. See below for the definition of non-printing
885 characters. If the pattern has the \fB/+\fP modifier, the output for substring
886 0 is followed by the the rest of the subject string, identified by "0+" like
887 this:
888 .sp
889 re> /cat/+
890 data> cataract
891 0: cat
892 0+ aract
893 .sp
894 If the pattern has the \fB/g\fP or \fB/G\fP modifier, the results of successive
895 matching attempts are output in sequence, like this:
896 .sp
897 re> /\eBi(\ew\ew)/g
898 data> Mississippi
899 0: iss
900 1: ss
901 0: iss
902 1: ss
903 0: ipp
904 1: pp
905 .sp
906 "No match" is output only if the first match attempt fails. Here is an example
907 of a failure message (the offset 4 that is specified by \e>4 is past the end of
908 the subject string):
909 .sp
910 re> /xyz/
911 data> xyz\e>4
912 Error -24 (bad offset value)
913 .P
914 If any of the sequences \fB\eC\fP, \fB\eG\fP, or \fB\eL\fP are present in a
915 data line that is successfully matched, the substrings extracted by the
916 convenience functions are output with C, G, or L after the string number
917 instead of a colon. This is in addition to the normal full list. The string
918 length (that is, the return from the extraction function) is given in
919 parentheses after each string for \fB\eC\fP and \fB\eG\fP.
920 .P
921 Note that whereas patterns can be continued over several lines (a plain ">"
922 prompt is used for continuations), data lines may not. However newlines can be
923 included in data by means of the \en escape (or \er, \er\en, etc., depending on
924 the newline sequence setting).
925 .
926 .
927 .
928 .SH "OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION"
929 .rs
930 .sp
931 When the alternative matching function, \fBpcre[16|32]_dfa_exec()\fP, is used (by
932 means of the \eD escape sequence or the \fB-dfa\fP command line option), the
933 output consists of a list of all the matches that start at the first point in
934 the subject where there is at least one match. For example:
935 .sp
936 re> /(tang|tangerine|tan)/
937 data> yellow tangerine\eD
938 0: tangerine
939 1: tang
940 2: tan
941 .sp
942 (Using the normal matching function on this data finds only "tang".) The
943 longest matching string is always given first (and numbered zero). After a
944 PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
945 partially matching substring. (Note that this is the entire substring that was
946 inspected during the partial match; it may include characters before the actual
947 match start if a lookbehind assertion, \eK, \eb, or \eB was involved.)
948 .P
949 If \fB/g\fP is present on the pattern, the search for further matches resumes
950 at the end of the longest match. For example:
951 .sp
952 re> /(tang|tangerine|tan)/g
953 data> yellow tangerine and tangy sultana\eD
954 0: tangerine
955 1: tang
956 2: tan
957 0: tang
958 1: tan
959 0: tan
960 .sp
961 Since the matching function does not support substring capture, the escape
962 sequences that are concerned with captured substrings are not relevant.
963 .
964 .
965 .SH "RESTARTING AFTER A PARTIAL MATCH"
966 .rs
967 .sp
968 When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
969 indicating that the subject partially matched the pattern, you can restart the
970 match with additional subject data by means of the \eR escape sequence. For
971 example:
972 .sp
973 re> /^\ed?\ed(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\ed\ed$/
974 data> 23ja\eP\eD
975 Partial match: 23ja
976 data> n05\eR\eD
977 0: n05
978 .sp
979 For further information about partial matching, see the
980 .\" HREF
981 \fBpcrepartial\fP
982 .\"
983 documentation.
984 .
985 .
986 .SH CALLOUTS
987 .rs
988 .sp
989 If the pattern contains any callout requests, \fBpcretest\fP's callout function
990 is called during matching. This works with both matching functions. By default,
991 the called function displays the callout number, the start and current
992 positions in the text at the callout time, and the next pattern item to be
993 tested. For example:
994 .sp
995 --->pqrabcdef
996 0 ^ ^ \ed
997 .sp
998 This output indicates that callout number 0 occurred for a match attempt
999 starting at the fourth character of the subject string, when the pointer was at
1000 the seventh character of the data, and when the next pattern item was \ed. Just
1001 one circumflex is output if the start and current positions are the same.
1002 .P
1003 Callouts numbered 255 are assumed to be automatic callouts, inserted as a
1004 result of the \fB/C\fP pattern modifier. In this case, instead of showing the
1005 callout number, the offset in the pattern, preceded by a plus, is output. For
1006 example:
1007 .sp
1008 re> /\ed?[A-E]\e*/C
1009 data> E*
1010 --->E*
1011 +0 ^ \ed?
1012 +3 ^ [A-E]
1013 +8 ^^ \e*
1014 +10 ^ ^
1015 0: E*
1016 .sp
1017 If a pattern contains (*MARK) items, an additional line is output whenever
1018 a change of latest mark is passed to the callout function. For example:
1019 .sp
1020 re> /a(*MARK:X)bc/C
1021 data> abc
1022 --->abc
1023 +0 ^ a
1024 +1 ^^ (*MARK:X)
1025 +10 ^^ b
1026 Latest Mark: X
1027 +11 ^ ^ c
1028 +12 ^ ^
1029 0: abc
1030 .sp
1031 The mark changes between matching "a" and "b", but stays the same for the rest
1032 of the match, so nothing more is output. If, as a result of backtracking, the
1033 mark reverts to being unset, the text "<unset>" is output.
1034 .P
1035 The callout function in \fBpcretest\fP returns zero (carry on matching) by
1036 default, but you can use a \eC item in a data line (as described above) to
1037 change this and other parameters of the callout.
1038 .P
1039 Inserting callouts can be helpful when using \fBpcretest\fP to check
1040 complicated regular expressions. For further information about callouts, see
1041 the
1042 .\" HREF
1043 \fBpcrecallout\fP
1044 .\"
1045 documentation.
1046 .
1047 .
1048 .
1049 .SH "NON-PRINTING CHARACTERS"
1050 .rs
1051 .sp
1052 When \fBpcretest\fP is outputting text in the compiled version of a pattern,
1053 bytes other than 32-126 are always treated as non-printing characters are are
1054 therefore shown as hex escapes.
1055 .P
1056 When \fBpcretest\fP is outputting text that is a matched part of a subject
1057 string, it behaves in the same way, unless a different locale has been set for
1058 the pattern (using the \fB/L\fP modifier). In this case, the \fBisprint()\fP
1059 function to distinguish printing and non-printing characters.
1060 .
1061 .
1062 .
1063 .SH "SAVING AND RELOADING COMPILED PATTERNS"
1064 .rs
1065 .sp
1066 The facilities described in this section are not available when the POSIX
1067 interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
1068 specified.
1069 .P
1070 When the POSIX interface is not in use, you can cause \fBpcretest\fP to write a
1071 compiled pattern to a file, by following the modifiers with > and a file name.
1072 For example:
1073 .sp
1074 /pattern/im >/some/file
1075 .sp
1076 See the
1077 .\" HREF
1078 \fBpcreprecompile\fP
1079 .\"
1080 documentation for a discussion about saving and re-using compiled patterns.
1081 Note that if the pattern was successfully studied with JIT optimization, the
1082 JIT data cannot be saved.
1083 .P
1084 The data that is written is binary. The first eight bytes are the length of the
1085 compiled pattern data followed by the length of the optional study data, each
1086 written as four bytes in big-endian order (most significant byte first). If
1087 there is no study data (either the pattern was not studied, or studying did not
1088 return any data), the second length is zero. The lengths are followed by an
1089 exact copy of the compiled pattern. If there is additional study data, this
1090 (excluding any JIT data) follows immediately after the compiled pattern. After
1091 writing the file, \fBpcretest\fP expects to read a new pattern.
1092 .P
1093 A saved pattern can be reloaded into \fBpcretest\fP by specifying < and a file
1094 name instead of a pattern. There must be no space between < and the file name,
1095 which must not contain a < character, as otherwise \fBpcretest\fP will
1096 interpret the line as a pattern delimited by < characters. For example:
1097 .sp
1098 re> </some/file
1099 Compiled pattern loaded from /some/file
1100 No study data
1101 .sp
1102 If the pattern was previously studied with the JIT optimization, the JIT
1103 information cannot be saved and restored, and so is lost. When the pattern has
1104 been loaded, \fBpcretest\fP proceeds to read data lines in the usual way.
1105 .P
1106 You can copy a file written by \fBpcretest\fP to a different host and reload it
1107 there, even if the new host has opposite endianness to the one on which the
1108 pattern was compiled. For example, you can compile on an i86 machine and run on
1109 a SPARC machine. When a pattern is reloaded on a host with different
1110 endianness, the confirmation message is changed to:
1111 .sp
1112 Compiled pattern (byte-inverted) loaded from /some/file
1113 .sp
1114 The test suite contains some saved pre-compiled patterns with different
1115 endianness. These are reloaded using "<!" instead of just "<". This suppresses
1116 the "(byte-inverted)" text so that the output is the same on all hosts. It also
1117 forces debugging output once the pattern has been reloaded.
1118 .P
1119 File names for saving and reloading can be absolute or relative, but note that
1120 the shell facility of expanding a file name that starts with a tilde (~) is not
1121 available.
1122 .P
1123 The ability to save and reload files in \fBpcretest\fP is intended for testing
1124 and experimentation. It is not intended for production use because only a
1125 single pattern can be written to a file. Furthermore, there is no facility for
1126 supplying custom character tables for use with a reloaded pattern. If the
1127 original pattern was compiled with custom tables, an attempt to match a subject
1128 string using a reloaded pattern is likely to cause \fBpcretest\fP to crash.
1129 Finally, if you attempt to load a file that is not in the correct format, the
1130 result is undefined.
1131 .
1132 .
1133 .SH "SEE ALSO"
1134 .rs
1135 .sp
1136 \fBpcre\fP(3), \fBpcre16\fP(3), \fBpcre32\fP(3), \fBpcreapi\fP(3),
1137 \fBpcrecallout\fP(3),
1138 \fBpcrejit\fP, \fBpcrematching\fP(3), \fBpcrepartial\fP(d),
1139 \fBpcrepattern\fP(3), \fBpcreprecompile\fP(3).
1140 .
1141 .
1142 .SH AUTHOR
1143 .rs
1144 .sp
1145 .nf
1146 Philip Hazel
1147 University Computing Service
1148 Cambridge CB2 3QH, England.
1149 .fi
1150 .
1151 .
1152 .SH REVISION
1153 .rs
1154 .sp
1155 .nf
1156 Last updated: 10 February 2020
1157 Copyright (c) 1997-2020 University of Cambridge.
1158 .fi

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