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Updated documentation for 16-bit.

1 nigel 53 .TH PCRETEST 1
2     .SH NAME
3     pcretest - a program for testing Perl-compatible regular expressions.
4     .SH SYNOPSIS
5 nigel 75 .rs
6     .sp
7 ph10 612 .B pcretest "[options] [input file [output file]]"
8 nigel 91 .sp
9 nigel 75 \fBpcretest\fP was written as a test program for the PCRE regular expression
10 nigel 53 library itself, but it can also be used for experimenting with regular
11 nigel 63 expressions. This document describes the features of the test program; for
12     details of the regular expressions themselves, see the
13     .\" HREF
14 nigel 75 \fBpcrepattern\fP
15 nigel 63 .\"
16 nigel 75 documentation. For details of the PCRE library function calls and their
17     options, see the
18 nigel 63 .\" HREF
19 nigel 75 \fBpcreapi\fP
20 nigel 63 .\"
21 ph10 866 and
22     .\" HREF
23     \fBpcre16\fP
24     .\"
25 ph10 654 documentation. The input for \fBpcretest\fP is a sequence of regular expression
26     patterns and strings to be matched, as described below. The output shows the
27     result of each match. Options on the command line and the patterns control PCRE
28 ph10 612 options and exactly what is output.
29 nigel 75 .
30     .
31 ph10 866 .SH "PCRE's 8-BIT and 16-BIT LIBRARIES"
32 nigel 63 .rs
33 ph10 866 .sp
34     From release 8.30, two separate PCRE libraries can be built. The original one
35     supports 8-bit character strings, whereas the newer 16-bit library supports
36     character strings encoded in 16-bit units. The \fBpcretest\fP program can be
37     used to test both libraries. However, it is itself still an 8-bit program,
38     reading 8-bit input and writing 8-bit output. When testing the 16-bit library,
39     the patterns and data strings are converted to 16-bit format before being
40     passed to the PCRE library functions. Results are converted to 8-bit for
41     output.
42     .P
43     References to functions and structures of the form \fBpcre[16]_xx\fP below
44     mean "\fBpcre_xx\fP when using the 8-bit library or \fBpcre16_xx\fP when using
45     the 16-bit library".
46     .
47     .
48     .SH "COMMAND LINE OPTIONS"
49     .rs
50 nigel 53 .TP 10
51 ph10 866 \fB-16\fP
52     If both the 8-bit and the 16-bit libraries have been built, this option causes
53     the 16-bit library to be used. If only the 16-bit library has been built, this
54     is the default (so has no effect). If only the 8-bit library has been built,
55     this option causes an error.
56     .TP 10
57 nigel 93 \fB-b\fP
58 ph10 612 Behave as if each pattern has the \fB/B\fP (show byte code) modifier; the
59 ph10 599 internal form is output after compilation.
60 nigel 93 .TP 10
61 nigel 75 \fB-C\fP
62 nigel 63 Output the version number of the PCRE library, and all available information
63 ph10 866 about the optional features that are included, and then exit. All other options
64     are ignored.
65 nigel 63 .TP 10
66 ph10 866 \fB-C\fP \fIoption\fP
67     Output information about a specific build-time option, then exit. This
68     functionality is intended for use in scripts such as \fBRunTest\fP. The
69     following options output the value indicated:
70     .sp
71     linksize the internal link size (2, 3, or 4)
72     newline the default newline setting:
73     CR, LF, CRLF, ANYCRLF, or ANY
74     .sp
75     The following options output 1 for true or zero for false:
76     .sp
77     jit just-in-time support is available
78     pcre16 the 16-bit library was built
79     pcre8 the 8-bit library was built
80     ucp Unicode property support is available
81     utf UTF-8 and/or UTF-16 support is available
82     .TP 10
83 nigel 75 \fB-d\fP
84 ph10 612 Behave as if each pattern has the \fB/D\fP (debug) modifier; the internal
85 nigel 93 form and information about the compiled pattern is output after compilation;
86     \fB-d\fP is equivalent to \fB-b -i\fP.
87 nigel 53 .TP 10
88 nigel 77 \fB-dfa\fP
89     Behave as if each data line contains the \eD escape sequence; this causes the
90 ph10 866 alternative matching function, \fBpcre[16]_dfa_exec()\fP, to be used instead of
91     the standard \fBpcre[16]_exec()\fP function (more detail is given below).
92 nigel 77 .TP 10
93 nigel 93 \fB-help\fP
94     Output a brief summary these options and then exit.
95     .TP 10
96 nigel 75 \fB-i\fP
97 ph10 612 Behave as if each pattern has the \fB/I\fP modifier; information about the
98 nigel 53 compiled pattern is given after compilation.
99     .TP 10
100 ph10 386 \fB-M\fP
101     Behave as if each data line contains the \eM escape sequence; this causes
102 ph10 392 PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
103 ph10 866 calling \fBpcre[16]_exec()\fP repeatedly with different limits.
104 ph10 386 .TP 10
105 nigel 75 \fB-m\fP
106 nigel 53 Output the size of each compiled pattern after it has been compiled. This is
107 ph10 866 equivalent to adding \fB/M\fP to each regular expression. The size is given in
108     bytes for both libraries.
109 nigel 53 .TP 10
110 nigel 75 \fB-o\fP \fIosize\fP
111     Set the number of elements in the output vector that is used when calling
112 ph10 866 \fBpcre[16]_exec()\fP or \fBpcre[16]_dfa_exec()\fP to be \fIosize\fP. The
113     default value is 45, which is enough for 14 capturing subexpressions for
114     \fBpcre[16]_exec()\fP or 22 different matches for \fBpcre[16]_dfa_exec()\fP.
115     The vector size can be changed for individual matching calls by including \eO
116     in the data line (see below).
117 nigel 53 .TP 10
118 nigel 75 \fB-p\fP
119 ph10 612 Behave as if each pattern has the \fB/P\fP modifier; the POSIX wrapper API is
120 nigel 77 used to call PCRE. None of the other options has any effect when \fB-p\fP is
121 ph10 866 set. This option can be used only with the 8-bit library.
122 nigel 53 .TP 10
123 nigel 91 \fB-q\fP
124 nigel 87 Do not output the version number of \fBpcretest\fP at the start of execution.
125     .TP 10
126 nigel 91 \fB-S\fP \fIsize\fP
127 ph10 599 On Unix-like systems, set the size of the run-time stack to \fIsize\fP
128 nigel 91 megabytes.
129     .TP 10
130 ph10 678 \fB-s\fP or \fB-s+\fP
131 ph10 612 Behave as if each pattern has the \fB/S\fP modifier; in other words, force each
132 ph10 678 pattern to be studied. If \fB-s+\fP is used, the PCRE_STUDY_JIT_COMPILE flag is
133 ph10 866 passed to \fBpcre[16]_study()\fP, causing just-in-time optimization to be set
134     up if it is available. If the \fB/I\fP or \fB/D\fP option is present on a
135     pattern (requesting output about the compiled pattern), information about the
136     result of studying is not included when studying is caused only by \fB-s\fP and
137     neither \fB-i\fP nor \fB-d\fP is present on the command line. This behaviour
138     means that the output from tests that are run with and without \fB-s\fP should
139     be identical, except when options that output information about the actual
140     running of a match are set.
141     .sp
142     The \fB-M\fP, \fB-t\fP, and \fB-tm\fP options, which give information about
143     resources used, are likely to produce different output with and without
144     \fB-s\fP. Output may also differ if the \fB/C\fP option is present on an
145     individual pattern. This uses callouts to trace the the matching process, and
146     this may be different between studied and non-studied patterns. If the pattern
147     contains (*MARK) items there may also be differences, for the same reason. The
148     \fB-s\fP command line option can be overridden for specific patterns that
149     should never be studied (see the \fB/S\fP pattern modifier below).
150 ph10 606 .TP 10
151 nigel 75 \fB-t\fP
152 nigel 63 Run each compile, study, and match many times with a timer, and output
153 nigel 75 resulting time per compile or match (in milliseconds). Do not set \fB-m\fP with
154     \fB-t\fP, because you will then get the size output a zillion times, and the
155 nigel 93 timing will be distorted. You can control the number of iterations that are
156     used for timing by following \fB-t\fP with a number (as a separate item on the
157     command line). For example, "-t 1000" would iterate 1000 times. The default is
158     to iterate 500000 times.
159     .TP 10
160     \fB-tm\fP
161     This is like \fB-t\fP except that it times only the matching phase, not the
162     compile or study phases.
163 nigel 75 .
164     .
165 nigel 53 .SH DESCRIPTION
166 nigel 63 .rs
167     .sp
168 nigel 75 If \fBpcretest\fP is given two filename arguments, it reads from the first and
169 nigel 53 writes to the second. If it is given only one filename argument, it reads from
170     that file and writes to stdout. Otherwise, it reads from stdin and writes to
171     stdout, and prompts for each line of input, using "re>" to prompt for regular
172     expressions, and "data>" to prompt for data lines.
173 nigel 75 .P
174 ph10 289 When \fBpcretest\fP is built, a configuration option can specify that it should
175 ph10 287 be linked with the \fBlibreadline\fP library. When this is done, if the input
176     is from a terminal, it is read using the \fBreadline()\fP function. This
177     provides line-editing and history facilities. The output from the \fB-help\fP
178     option states whether or not \fBreadline()\fP will be used.
179     .P
180 nigel 53 The program handles any number of sets of input on a single input file. Each
181     set starts with a regular expression, and continues with any number of data
182 nigel 63 lines to be matched against the pattern.
183 nigel 75 .P
184     Each data line is matched separately and independently. If you want to do
185 nigel 91 multi-line matches, you have to use the \en escape sequence (or \er or \er\en,
186 nigel 93 etc., depending on the newline setting) in a single line of input to encode the
187     newline sequences. There is no limit on the length of data lines; the input
188 nigel 91 buffer is automatically extended if it is too small.
189 nigel 75 .P
190 nigel 63 An empty line signals the end of the data lines, at which point a new regular
191     expression is read. The regular expressions are given enclosed in any
192 nigel 91 non-alphanumeric delimiters other than backslash, for example:
193 nigel 75 .sp
194 nigel 53 /(a|bc)x+yz/
195 nigel 75 .sp
196 nigel 53 White space before the initial delimiter is ignored. A regular expression may
197     be continued over several input lines, in which case the newline characters are
198     included within it. It is possible to include the delimiter within the pattern
199     by escaping it, for example
200 nigel 75 .sp
201     /abc\e/def/
202     .sp
203 nigel 53 If you do so, the escape and the delimiter form part of the pattern, but since
204 nigel 75 delimiters are always non-alphanumeric, this does not affect its interpretation.
205 nigel 53 If the terminating delimiter is immediately followed by a backslash, for
206     example,
207 nigel 75 .sp
208     /abc/\e
209     .sp
210 nigel 53 then a backslash is added to the end of the pattern. This is done to provide a
211     way of testing the error condition that arises if a pattern finishes with a
212     backslash, because
213 nigel 75 .sp
214     /abc\e/
215     .sp
216 nigel 53 is interpreted as the first line of a pattern that starts with "abc/", causing
217     pcretest to read the next line as a continuation of the regular expression.
218 nigel 75 .
219     .
220     .SH "PATTERN MODIFIERS"
221 nigel 63 .rs
222     .sp
223 nigel 75 A pattern may be followed by any number of modifiers, which are mostly single
224     characters. Following Perl usage, these are referred to below as, for example,
225     "the \fB/i\fP modifier", even though the delimiter of the pattern need not
226 ph10 599 always be a slash, and no slash is used when writing modifiers. White space may
227 nigel 75 appear between the final pattern delimiter and the first modifier, and between
228     the modifiers themselves.
229     .P
230     The \fB/i\fP, \fB/m\fP, \fB/s\fP, and \fB/x\fP modifiers set the PCRE_CASELESS,
231     PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
232 ph10 866 \fBpcre[16]_compile()\fP is called. These four modifier letters have the same
233 nigel 75 effect as they do in Perl. For example:
234     .sp
235 nigel 53 /caseless/i
236 nigel 75 .sp
237 ph10 518 The following table shows additional modifiers for setting PCRE compile-time
238     options that do not correspond to anything in Perl:
239 nigel 75 .sp
240 ph10 866 \fB/8\fP PCRE_UTF8 ) when using the 8-bit
241     \fB/?\fP PCRE_NO_UTF8_CHECK ) library
242     .sp
243     \fB/8\fP PCRE_UTF16 ) when using the 16-bit
244     \fB/?\fP PCRE_NO_UTF16_CHECK ) library
245     .sp
246 ph10 231 \fB/A\fP PCRE_ANCHORED
247     \fB/C\fP PCRE_AUTO_CALLOUT
248     \fB/E\fP PCRE_DOLLAR_ENDONLY
249     \fB/f\fP PCRE_FIRSTLINE
250     \fB/J\fP PCRE_DUPNAMES
251     \fB/N\fP PCRE_NO_AUTO_CAPTURE
252     \fB/U\fP PCRE_UNGREEDY
253 ph10 535 \fB/W\fP PCRE_UCP
254 ph10 231 \fB/X\fP PCRE_EXTRA
255 ph10 579 \fB/Y\fP PCRE_NO_START_OPTIMIZE
256 ph10 345 \fB/<JS>\fP PCRE_JAVASCRIPT_COMPAT
257 ph10 231 \fB/<cr>\fP PCRE_NEWLINE_CR
258     \fB/<lf>\fP PCRE_NEWLINE_LF
259     \fB/<crlf>\fP PCRE_NEWLINE_CRLF
260     \fB/<anycrlf>\fP PCRE_NEWLINE_ANYCRLF
261     \fB/<any>\fP PCRE_NEWLINE_ANY
262     \fB/<bsr_anycrlf>\fP PCRE_BSR_ANYCRLF
263     \fB/<bsr_unicode>\fP PCRE_BSR_UNICODE
264 nigel 75 .sp
265 ph10 518 The modifiers that are enclosed in angle brackets are literal strings as shown,
266 ph10 612 including the angle brackets, but the letters within can be in either case.
267     This example sets multiline matching with CRLF as the line ending sequence:
268 nigel 93 .sp
269 ph10 612 /^abc/m<CRLF>
270 nigel 93 .sp
271 ph10 866 As well as turning on the PCRE_UTF8/16 option, the \fB/8\fP modifier causes
272     all non-printing characters in output strings to be printed using the
273     \ex{hh...} notation. Otherwise, those less than 0x100 are output in hex without
274     the curly brackets.
275     .P
276     Full details of the PCRE options are given in the
277 nigel 91 .\" HREF
278     \fBpcreapi\fP
279     .\"
280 ph10 535 documentation.
281 nigel 91 .
282     .
283     .SS "Finding all matches in a string"
284     .rs
285     .sp
286 nigel 53 Searching for all possible matches within each subject string can be requested
287 nigel 75 by the \fB/g\fP or \fB/G\fP modifier. After finding a match, PCRE is called
288 nigel 53 again to search the remainder of the subject string. The difference between
289 nigel 75 \fB/g\fP and \fB/G\fP is that the former uses the \fIstartoffset\fP argument to
290 ph10 866 \fBpcre[16]_exec()\fP to start searching at a new point within the entire
291     string (which is in effect what Perl does), whereas the latter passes over a
292     shortened substring. This makes a difference to the matching process if the
293     pattern begins with a lookbehind assertion (including \eb or \eB).
294 nigel 75 .P
295 ph10 866 If any call to \fBpcre[16]_exec()\fP in a \fB/g\fP or \fB/G\fP sequence matches
296     an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
297 ph10 442 PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
298 ph10 566 same point. If this second match fails, the start offset is advanced, and the
299     normal match is retried. This imitates the way Perl handles such cases when
300 ph10 579 using the \fB/g\fP modifier or the \fBsplit()\fP function. Normally, the start
301     offset is advanced by one character, but if the newline convention recognizes
302     CRLF as a newline, and the current character is CR followed by LF, an advance
303 ph10 566 of two is used.
304 nigel 91 .
305     .
306     .SS "Other modifiers"
307     .rs
308     .sp
309 nigel 75 There are yet more modifiers for controlling the way \fBpcretest\fP
310 nigel 53 operates.
311 nigel 75 .P
312     The \fB/+\fP modifier requests that as well as outputting the substring that
313 ph10 616 matched the entire pattern, \fBpcretest\fP should in addition output the
314     remainder of the subject string. This is useful for tests where the subject
315     contains multiple copies of the same substring. If the \fB+\fP modifier appears
316 ph10 654 twice, the same action is taken for captured substrings. In each case the
317     remainder is output on the following line with a plus character following the
318 ph10 691 capture number. Note that this modifier must not immediately follow the /S
319 ph10 678 modifier because /S+ has another meaning.
320 nigel 75 .P
321 ph10 654 The \fB/=\fP modifier requests that the values of all potential captured
322 ph10 866 parentheses be output after a match. By default, only those up to the highest
323     one actually used in the match are output (corresponding to the return code
324     from \fBpcre[16]_exec()\fP). Values in the offsets vector corresponding to
325     higher numbers should be set to -1, and these are output as "<unset>". This
326     modifier gives a way of checking that this is happening.
327 ph10 626 .P
328 nigel 93 The \fB/B\fP modifier is a debugging feature. It requests that \fBpcretest\fP
329 ph10 866 output a representation of the compiled code after compilation. Normally this
330     information contains length and offset values; however, if \fB/Z\fP is also
331     present, this data is replaced by spaces. This is a special feature for use in
332     the automatic test scripts; it ensures that the same output is generated for
333     different internal link sizes.
334 nigel 93 .P
335     The \fB/D\fP modifier is a PCRE debugging feature, and is equivalent to
336 ph10 148 \fB/BI\fP, that is, both the \fB/B\fP and the \fB/I\fP modifiers.
337 nigel 75 .P
338     The \fB/F\fP modifier causes \fBpcretest\fP to flip the byte order of the
339 ph10 866 2-byte and 4-byte fields in the compiled pattern. This facility is for testing
340     the feature in PCRE that allows it to execute patterns that were compiled on a
341     host with a different endianness. This feature is not available when the POSIX
342     interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
343     specified. See also the section about saving and reloading compiled patterns
344     below.
345 nigel 75 .P
346 ph10 510 The \fB/I\fP modifier requests that \fBpcretest\fP output information about the
347     compiled pattern (whether it is anchored, has a fixed first character, and
348 ph10 866 so on). It does this by calling \fBpcre[16]_fullinfo()\fP after compiling a
349 ph10 510 pattern. If the pattern is studied, the results of that are also output.
350 nigel 75 .P
351 ph10 510 The \fB/K\fP modifier requests \fBpcretest\fP to show names from backtracking
352 ph10 866 control verbs that are returned from calls to \fBpcre[16]_exec()\fP. It causes
353     \fBpcretest\fP to create a \fBpcre[16]_extra\fP block if one has not already
354     been created by a call to \fBpcre[16]_study()\fP, and to set the
355     PCRE_EXTRA_MARK flag and the \fBmark\fP field within it, every time that
356     \fBpcre[16]_exec()\fP is called. If the variable that the \fBmark\fP field
357     points to is non-NULL for a match, non-match, or partial match, \fBpcretest\fP
358     prints the string to which it points. For a match, this is shown on a line by
359     itself, tagged with "MK:". For a non-match it is added to the message.
360 ph10 510 .P
361     The \fB/L\fP modifier must be followed directly by the name of a locale, for
362     example,
363     .sp
364     /pattern/Lfr_FR
365     .sp
366     For this reason, it must be the last modifier. The given locale is set,
367 ph10 866 \fBpcre[16]_maketables()\fP is called to build a set of character tables for
368     the locale, and this is then passed to \fBpcre[16]_compile()\fP when compiling
369     the regular expression. Without an \fB/L\fP (or \fB/T\fP) modifier, NULL is
370     passed as the tables pointer; that is, \fB/L\fP applies only to the expression
371     on which it appears.
372 ph10 510 .P
373 ph10 866 The \fB/M\fP modifier causes the size in bytes of the memory block used to hold
374     the compiled pattern to be output. This does not include the size of the
375     \fBpcre[16]\fP block; it is just the actual compiled data. If the pattern is
376     successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the
377     JIT compiled code is also output.
378 nigel 75 .P
379 ph10 866 If the \fB/S\fP modifier appears once, it causes \fBpcre[16]_study()\fP to be
380 ph10 612 called after the expression has been compiled, and the results used when the
381 ph10 654 expression is matched. If \fB/S\fP appears twice, it suppresses studying, even
382     if it was requested externally by the \fB-s\fP command line option. This makes
383     it possible to specify that certain patterns are always studied, and others are
384     never studied, independently of \fB-s\fP. This feature is used in the test
385 ph10 612 files in a few cases where the output is different when the pattern is studied.
386 ph10 541 .P
387 ph10 691 If the \fB/S\fP modifier is immediately followed by a + character, the call to
388 ph10 866 \fBpcre[16]_study()\fP is made with the PCRE_STUDY_JIT_COMPILE option,
389     requesting just-in-time optimization support if it is available. Note that
390     there is also a \fB/+\fP modifier; it must not be given immediately after
391     \fB/S\fP because this will be misinterpreted. If JIT studying is successful, it
392     will automatically be used when \fBpcre[16]_exec()\fP is run, except when
393     incompatible run-time options are specified. These include the partial matching
394     options; a complete list is given in the
395 ph10 678 .\" HREF
396     \fBpcrejit\fP
397     .\"
398 ph10 691 documentation. See also the \fB\eJ\fP escape sequence below for a way of
399 ph10 678 setting the size of the JIT stack.
400     .P
401 ph10 545 The \fB/T\fP modifier must be followed by a single digit. It causes a specific
402 ph10 866 set of built-in character tables to be passed to \fBpcre[16]_compile()\fP. It
403     is used in the standard PCRE tests to check behaviour with different character
404 ph10 541 tables. The digit specifies the tables as follows:
405     .sp
406 ph10 545 0 the default ASCII tables, as distributed in
407 ph10 541 pcre_chartables.c.dist
408     1 a set of tables defining ISO 8859 characters
409     .sp
410 ph10 545 In table 1, some characters whose codes are greater than 128 are identified as
411 ph10 541 letters, digits, spaces, etc.
412 nigel 75 .
413     .
414 ph10 518 .SS "Using the POSIX wrapper API"
415     .rs
416     .sp
417     The \fB/P\fP modifier causes \fBpcretest\fP to call PCRE via the POSIX wrapper
418 ph10 866 API rather than its native API. This supports only the 8-bit library. When
419     \fB/P\fP is set, the following modifiers set options for the \fBregcomp()\fP
420     function:
421 ph10 518 .sp
422     /i REG_ICASE
423     /m REG_NEWLINE
424     /N REG_NOSUB
425     /s REG_DOTALL )
426 ph10 535 /U REG_UNGREEDY ) These options are not part of
427 ph10 518 /W REG_UCP ) the POSIX standard
428     /8 REG_UTF8 )
429     .sp
430     The \fB/+\fP modifier works as described above. All other modifiers are
431     ignored.
432     .
433     .
434 nigel 75 .SH "DATA LINES"
435 nigel 63 .rs
436     .sp
437 ph10 866 Before each data line is passed to \fBpcre[16]_exec()\fP, leading and trailing
438 ph10 599 white space is removed, and it is then scanned for \e escapes. Some of these
439     are pretty esoteric features, intended for checking out some of the more
440 nigel 63 complicated features of PCRE. If you are just testing "ordinary" regular
441     expressions, you probably don't need any of these. The following escapes are
442 nigel 53 recognized:
443 nigel 75 .sp
444 nigel 93 \ea alarm (BEL, \ex07)
445     \eb backspace (\ex08)
446     \ee escape (\ex27)
447 ph10 599 \ef form feed (\ex0c)
448 nigel 93 \en newline (\ex0a)
449 nigel 91 .\" JOIN
450     \eqdd set the PCRE_MATCH_LIMIT limit to dd
451     (any number of digits)
452 nigel 93 \er carriage return (\ex0d)
453     \et tab (\ex09)
454     \ev vertical tab (\ex0b)
455 ph10 866 \ennn octal character (up to 3 octal digits); always
456     a byte unless > 255 in UTF-8 or 16-bit mode
457 ph10 570 \exhh hexadecimal byte (up to 2 hex digits)
458 ph10 866 \ex{hh...} hexadecimal character (any number of hex digits)
459 nigel 75 .\" JOIN
460 ph10 866 \eA pass the PCRE_ANCHORED option to \fBpcre[16]_exec()\fP
461     or \fBpcre[16]_dfa_exec()\fP
462 nigel 91 .\" JOIN
463 ph10 866 \eB pass the PCRE_NOTBOL option to \fBpcre[16]_exec()\fP
464     or \fBpcre[16]_dfa_exec()\fP
465 nigel 91 .\" JOIN
466 ph10 866 \eCdd call pcre[16]_copy_substring() for substring dd
467 nigel 75 after a successful match (number less than 32)
468     .\" JOIN
469 ph10 866 \eCname call pcre[16]_copy_named_substring() for substring
470 nigel 63 "name" after a successful match (name termin-
471     ated by next non alphanumeric character)
472 nigel 75 .\" JOIN
473     \eC+ show the current captured substrings at callout
474 nigel 63 time
475 nigel 75 \eC- do not supply a callout function
476     .\" JOIN
477     \eC!n return 1 instead of 0 when callout number n is
478 nigel 63 reached
479 nigel 75 .\" JOIN
480     \eC!n!m return 1 instead of 0 when callout number n is
481 nigel 63 reached for the nth time
482 nigel 75 .\" JOIN
483     \eC*n pass the number n (may be negative) as callout
484     data; this is used as the callout return value
485 ph10 866 \eD use the \fBpcre[16]_dfa_exec()\fP match function
486     \eF only shortest match for \fBpcre[16]_dfa_exec()\fP
487 nigel 75 .\" JOIN
488 ph10 866 \eGdd call pcre[16]_get_substring() for substring dd
489 nigel 75 after a successful match (number less than 32)
490     .\" JOIN
491 ph10 866 \eGname call pcre[16]_get_named_substring() for substring
492 nigel 63 "name" after a successful match (name termin-
493     ated by next non-alphanumeric character)
494 nigel 75 .\" JOIN
495 ph10 678 \eJdd set up a JIT stack of dd kilobytes maximum (any
496 ph10 691 number of digits)
497 ph10 678 .\" JOIN
498 ph10 866 \eL call pcre[16]_get_substringlist() after a
499 nigel 63 successful match
500 nigel 91 .\" JOIN
501 nigel 87 \eM discover the minimum MATCH_LIMIT and
502     MATCH_LIMIT_RECURSION settings
503 nigel 91 .\" JOIN
504 ph10 866 \eN pass the PCRE_NOTEMPTY option to \fBpcre[16]_exec()\fP
505     or \fBpcre[16]_dfa_exec()\fP; if used twice, pass the
506 ph10 461 PCRE_NOTEMPTY_ATSTART option
507 nigel 75 .\" JOIN
508     \eOdd set the size of the output vector passed to
509 ph10 866 \fBpcre[16]_exec()\fP to dd (any number of digits)
510 nigel 77 .\" JOIN
511 ph10 866 \eP pass the PCRE_PARTIAL_SOFT option to \fBpcre[16]_exec()\fP
512     or \fBpcre[16]_dfa_exec()\fP; if used twice, pass the
513 ph10 461 PCRE_PARTIAL_HARD option
514 nigel 91 .\" JOIN
515     \eQdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd
516     (any number of digits)
517 ph10 866 \eR pass the PCRE_DFA_RESTART option to \fBpcre[16]_dfa_exec()\fP
518 nigel 75 \eS output details of memory get/free calls during matching
519 nigel 91 .\" JOIN
520 ph10 866 \eY pass the PCRE_NO_START_OPTIMIZE option to \fBpcre[16]_exec()\fP
521     or \fBpcre[16]_dfa_exec()\fP
522 ph10 455 .\" JOIN
523 ph10 866 \eZ pass the PCRE_NOTEOL option to \fBpcre[16]_exec()\fP
524     or \fBpcre[16]_dfa_exec()\fP
525 nigel 75 .\" JOIN
526 ph10 866 \e? pass the PCRE_NO_UTF[8|16]_CHECK option to
527     \fBpcre[16]_exec()\fP or \fBpcre[16]_dfa_exec()\fP
528 nigel 91 .\" JOIN
529 ph10 567 \e>dd start the match at offset dd (optional "-"; then
530 ph10 579 any number of digits); this sets the \fIstartoffset\fP
531 ph10 866 argument for \fBpcre[16]_exec()\fP or \fBpcre[16]_dfa_exec()\fP
532 nigel 91 .\" JOIN
533 ph10 866 \e<cr> pass the PCRE_NEWLINE_CR option to \fBpcre[16]_exec()\fP
534     or \fBpcre[16]_dfa_exec()\fP
535 nigel 91 .\" JOIN
536 ph10 866 \e<lf> pass the PCRE_NEWLINE_LF option to \fBpcre[16]_exec()\fP
537     or \fBpcre[16]_dfa_exec()\fP
538 nigel 91 .\" JOIN
539 ph10 866 \e<crlf> pass the PCRE_NEWLINE_CRLF option to \fBpcre[16]_exec()\fP
540     or \fBpcre[16]_dfa_exec()\fP
541 nigel 93 .\" JOIN
542 ph10 866 \e<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to \fBpcre[16]_exec()\fP
543     or \fBpcre[16]_dfa_exec()\fP
544 ph10 149 .\" JOIN
545 ph10 866 \e<any> pass the PCRE_NEWLINE_ANY option to \fBpcre[16]_exec()\fP
546     or \fBpcre[16]_dfa_exec()\fP
547 nigel 75 .sp
548 ph10 866 The use of \ex{hh...} is not dependent on the use of the \fB/8\fP modifier on
549     the pattern. It is recognized always. There may be any number of hexadecimal
550     digits inside the braces; invalid values provoke error messages.
551 ph10 570 .P
552 ph10 866 Note that \exhh specifies one byte in UTF-8 mode; this makes it possible to
553     construct invalid UTF-8 sequences for testing purposes. On the other hand,
554     \ex{hh} is interpreted as a UTF-8 character in UTF-8 mode, generating more than
555     one byte if the value is greater than 127. When testing the 8-bit library not
556     in UTF-8 mode, \ex{hh} generates one byte for values less than 256, and causes
557     an error for greater values.
558     .P
559     In UTF-16 mode, all 4-digit \ex{hhhh} values are accepted. This makes it
560     possible to construct invalid UTF-16 sequences for testing purposes.
561     .P
562 nigel 93 The escapes that specify line ending sequences are literal strings, exactly as
563     shown. No more than one newline setting should be present in any data line.
564 nigel 75 .P
565 nigel 93 A backslash followed by anything else just escapes the anything else. If
566     the very last character is a backslash, it is ignored. This gives a way of
567     passing an empty line as data, since a real empty line terminates the data
568     input.
569     .P
570 ph10 678 The \fB\eJ\fP escape provides a way of setting the maximum stack size that is
571 ph10 691 used by the just-in-time optimization code. It is ignored if JIT optimization
572     is not being used. Providing a stack that is larger than the default 32K is
573 ph10 678 necessary only for very complicated patterns.
574     .P
575 ph10 866 If \eM is present, \fBpcretest\fP calls \fBpcre[16]_exec()\fP several times,
576     with different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP
577     fields of the \fBpcre[16]_extra\fP data structure, until it finds the minimum
578     numbers for each parameter that allow \fBpcre[16]_exec()\fP to complete without
579 ph10 691 error. Because this is testing a specific feature of the normal interpretive
580 ph10 866 \fBpcre[16]_exec()\fP execution, the use of any JIT optimization that might
581     have been set up by the \fB/S+\fP qualifier of \fB-s+\fP option is disabled.
582 nigel 75 .P
583 ph10 678 The \fImatch_limit\fP number is a measure of the amount of backtracking
584     that takes place, and checking it out can be instructive. For most simple
585     matches, the number is quite small, but for patterns with very large numbers of
586     matching possibilities, it can become large very quickly with increasing length
587     of subject string. The \fImatch_limit_recursion\fP number is a measure of how
588     much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
589     needed to complete the match attempt.
590     .P
591 nigel 75 When \eO is used, the value specified may be higher or lower than the size set
592     by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to
593 ph10 866 the call of \fBpcre[16]_exec()\fP for the line in which it appears.
594 nigel 75 .P
595     If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper
596 ph10 518 API to be used, the only option-setting sequences that have any effect are \eB,
597     \eN, and \eZ, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
598     to be passed to \fBregexec()\fP.
599 nigel 75 .
600     .
601 nigel 77 .SH "THE ALTERNATIVE MATCHING FUNCTION"
602 nigel 63 .rs
603     .sp
604 nigel 77 By default, \fBpcretest\fP uses the standard PCRE matching function,
605 ph10 866 \fBpcre[16]_exec()\fP to match each data line. PCRE also supports an
606     alternative matching function, \fBpcre[16]_dfa_test()\fP, which operates in a
607 nigel 77 different way, and has some restrictions. The differences between the two
608     functions are described in the
609     .\" HREF
610     \fBpcrematching\fP
611     .\"
612     documentation.
613     .P
614     If a data line contains the \eD escape sequence, or if the command line
615 ph10 866 contains the \fB-dfa\fP option, the alternative matching function is used.
616 nigel 77 This function finds all possible matches at a given point. If, however, the \eF
617     escape sequence is present in the data line, it stops after the first match is
618     found. This is always the shortest possible match.
619     .
620     .
621     .SH "DEFAULT OUTPUT FROM PCRETEST"
622     .rs
623     .sp
624     This section describes the output when the normal matching function,
625 ph10 866 \fBpcre[16]_exec()\fP, is being used.
626 nigel 77 .P
627 ph10 598 When a match succeeds, \fBpcretest\fP outputs the list of captured substrings
628 ph10 866 that \fBpcre[16]_exec()\fP returns, starting with number 0 for the string that
629 ph10 598 matched the whole pattern. Otherwise, it outputs "No match" when the return is
630 ph10 435 PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
631 ph10 866 substring when \fBpcre[16]_exec()\fP returns PCRE_ERROR_PARTIAL. (Note that
632     this is the entire substring that was inspected during the partial match; it
633     may include characters before the actual match start if a lookbehind assertion,
634 ph10 598 \eK, \eb, or \eB was involved.) For any other return, \fBpcretest\fP outputs
635     the PCRE negative error number and a short descriptive phrase. If the error is
636 ph10 866 a failed UTF string check, the offset of the start of the failing character and
637     the reason code are also output, provided that the size of the output vector is
638     at least two. Here is an example of an interactive \fBpcretest\fP run.
639 nigel 75 .sp
640 nigel 53 $ pcretest
641 ph10 598 PCRE version 8.13 2011-04-30
642 nigel 75 .sp
643     re> /^abc(\ed+)/
644 nigel 53 data> abc123
645     0: abc123
646     1: 123
647     data> xyz
648     No match
649 nigel 75 .sp
650 ph10 598 Unset capturing substrings that are not followed by one that is set are not
651 ph10 866 returned by \fBpcre[16]_exec()\fP, and are not shown by \fBpcretest\fP. In the
652 ph10 598 following example, there are two capturing substrings, but when the first data
653     line is matched, the second, unset substring is not shown. An "internal" unset
654     substring is shown as "<unset>", as for the second data line.
655 ph10 273 .sp
656     re> /(a)|(b)/
657     data> a
658     0: a
659     1: a
660     data> b
661     0: b
662     1: <unset>
663 ph10 286 2: b
664 ph10 273 .sp
665 ph10 866 If the strings contain any non-printing characters, they are output as \exhh
666     escapes if the value is less than 256 and UTF mode is not set. Otherwise they
667     are output as \ex{hh...} escapes. See below for the definition of non-printing
668     characters. If the pattern has the \fB/+\fP modifier, the output for substring
669     0 is followed by the the rest of the subject string, identified by "0+" like
670     this:
671 nigel 75 .sp
672 nigel 53 re> /cat/+
673     data> cataract
674     0: cat
675     0+ aract
676 nigel 75 .sp
677     If the pattern has the \fB/g\fP or \fB/G\fP modifier, the results of successive
678 nigel 53 matching attempts are output in sequence, like this:
679 nigel 75 .sp
680     re> /\eBi(\ew\ew)/g
681 nigel 53 data> Mississippi
682     0: iss
683     1: ss
684     0: iss
685     1: ss
686     0: ipp
687     1: pp
688 nigel 75 .sp
689 ph10 654 "No match" is output only if the first match attempt fails. Here is an example
690     of a failure message (the offset 4 that is specified by \e>4 is past the end of
691 ph10 598 the subject string):
692     .sp
693     re> /xyz/
694 ph10 654 data> xyz\e>4
695     Error -24 (bad offset value)
696 nigel 75 .P
697     If any of the sequences \fB\eC\fP, \fB\eG\fP, or \fB\eL\fP are present in a
698 nigel 53 data line that is successfully matched, the substrings extracted by the
699     convenience functions are output with C, G, or L after the string number
700     instead of a colon. This is in addition to the normal full list. The string
701     length (that is, the return from the extraction function) is given in
702 nigel 75 parentheses after each string for \fB\eC\fP and \fB\eG\fP.
703     .P
704 nigel 93 Note that whereas patterns can be continued over several lines (a plain ">"
705 nigel 53 prompt is used for continuations), data lines may not. However newlines can be
706 nigel 93 included in data by means of the \en escape (or \er, \er\en, etc., depending on
707     the newline sequence setting).
708 nigel 75 .
709     .
710 nigel 93 .
711 nigel 77 .SH "OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION"
712     .rs
713     .sp
714 ph10 866 When the alternative matching function, \fBpcre[16]_dfa_exec()\fP, is used (by
715 nigel 77 means of the \eD escape sequence or the \fB-dfa\fP command line option), the
716     output consists of a list of all the matches that start at the first point in
717     the subject where there is at least one match. For example:
718     .sp
719     re> /(tang|tangerine|tan)/
720     data> yellow tangerine\eD
721     0: tangerine
722     1: tang
723     2: tan
724     .sp
725     (Using the normal matching function on this data finds only "tang".) The
726 ph10 428 longest matching string is always given first (and numbered zero). After a
727 ph10 461 PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
728 ph10 553 partially matching substring. (Note that this is the entire substring that was
729     inspected during the partial match; it may include characters before the actual
730     match start if a lookbehind assertion, \eK, \eb, or \eB was involved.)
731 nigel 77 .P
732 nigel 93 If \fB/g\fP is present on the pattern, the search for further matches resumes
733 nigel 77 at the end of the longest match. For example:
734     .sp
735     re> /(tang|tangerine|tan)/g
736     data> yellow tangerine and tangy sultana\eD
737     0: tangerine
738     1: tang
739     2: tan
740     0: tang
741     1: tan
742     0: tan
743     .sp
744     Since the matching function does not support substring capture, the escape
745     sequences that are concerned with captured substrings are not relevant.
746     .
747     .
748     .SH "RESTARTING AFTER A PARTIAL MATCH"
749     .rs
750     .sp
751     When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
752     indicating that the subject partially matched the pattern, you can restart the
753     match with additional subject data by means of the \eR escape sequence. For
754     example:
755     .sp
756 ph10 155 re> /^\ed?\ed(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\ed\ed$/
757 nigel 77 data> 23ja\eP\eD
758     Partial match: 23ja
759     data> n05\eR\eD
760     0: n05
761     .sp
762     For further information about partial matching, see the
763     .\" HREF
764     \fBpcrepartial\fP
765     .\"
766     documentation.
767     .
768     .
769 nigel 75 .SH CALLOUTS
770     .rs
771     .sp
772     If the pattern contains any callout requests, \fBpcretest\fP's callout function
773 nigel 77 is called during matching. This works with both matching functions. By default,
774     the called function displays the callout number, the start and current
775     positions in the text at the callout time, and the next pattern item to be
776 ph10 866 tested. For example:
777 nigel 75 .sp
778     --->pqrabcdef
779     0 ^ ^ \ed
780     .sp
781 ph10 866 This output indicates that callout number 0 occurred for a match attempt
782     starting at the fourth character of the subject string, when the pointer was at
783     the seventh character of the data, and when the next pattern item was \ed. Just
784     one circumflex is output if the start and current positions are the same.
785 nigel 75 .P
786     Callouts numbered 255 are assumed to be automatic callouts, inserted as a
787     result of the \fB/C\fP pattern modifier. In this case, instead of showing the
788     callout number, the offset in the pattern, preceded by a plus, is output. For
789     example:
790     .sp
791     re> /\ed?[A-E]\e*/C
792     data> E*
793     --->E*
794     +0 ^ \ed?
795     +3 ^ [A-E]
796     +8 ^^ \e*
797     +10 ^ ^
798     0: E*
799     .sp
800 ph10 647 If a pattern contains (*MARK) items, an additional line is output whenever
801     a change of latest mark is passed to the callout function. For example:
802     .sp
803     re> /a(*MARK:X)bc/C
804     data> abc
805     --->abc
806     +0 ^ a
807     +1 ^^ (*MARK:X)
808     +10 ^^ b
809     Latest Mark: X
810     +11 ^ ^ c
811 ph10 654 +12 ^ ^
812 ph10 647 0: abc
813     .sp
814     The mark changes between matching "a" and "b", but stays the same for the rest
815     of the match, so nothing more is output. If, as a result of backtracking, the
816     mark reverts to being unset, the text "<unset>" is output.
817     .P
818 nigel 75 The callout function in \fBpcretest\fP returns zero (carry on matching) by
819 nigel 77 default, but you can use a \eC item in a data line (as described above) to
820 ph10 647 change this and other parameters of the callout.
821 nigel 75 .P
822     Inserting callouts can be helpful when using \fBpcretest\fP to check
823     complicated regular expressions. For further information about callouts, see
824     the
825     .\" HREF
826     \fBpcrecallout\fP
827     .\"
828     documentation.
829     .
830     .
831 nigel 93 .
832     .SH "NON-PRINTING CHARACTERS"
833     .rs
834     .sp
835     When \fBpcretest\fP is outputting text in the compiled version of a pattern,
836     bytes other than 32-126 are always treated as non-printing characters are are
837     therefore shown as hex escapes.
838     .P
839     When \fBpcretest\fP is outputting text that is a matched part of a subject
840     string, it behaves in the same way, unless a different locale has been set for
841     the pattern (using the \fB/L\fP modifier). In this case, the \fBisprint()\fP
842     function to distinguish printing and non-printing characters.
843     .
844     .
845     .
846 nigel 75 .SH "SAVING AND RELOADING COMPILED PATTERNS"
847     .rs
848     .sp
849     The facilities described in this section are not available when the POSIX
850 ph10 599 interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
851 ph10 691 specified.
852 nigel 75 .P
853     When the POSIX interface is not in use, you can cause \fBpcretest\fP to write a
854     compiled pattern to a file, by following the modifiers with > and a file name.
855     For example:
856     .sp
857     /pattern/im >/some/file
858     .sp
859     See the
860     .\" HREF
861     \fBpcreprecompile\fP
862     .\"
863     documentation for a discussion about saving and re-using compiled patterns.
864 ph10 678 Note that if the pattern was successfully studied with JIT optimization, the
865     JIT data cannot be saved.
866 nigel 75 .P
867     The data that is written is binary. The first eight bytes are the length of the
868     compiled pattern data followed by the length of the optional study data, each
869     written as four bytes in big-endian order (most significant byte first). If
870     there is no study data (either the pattern was not studied, or studying did not
871     return any data), the second length is zero. The lengths are followed by an
872     exact copy of the compiled pattern. If there is additional study data, this
873 ph10 678 (excluding any JIT data) follows immediately after the compiled pattern. After
874     writing the file, \fBpcretest\fP expects to read a new pattern.
875 nigel 75 .P
876 ph10 599 A saved pattern can be reloaded into \fBpcretest\fP by specifying < and a file
877 nigel 75 name instead of a pattern. The name of the file must not contain a < character,
878     as otherwise \fBpcretest\fP will interpret the line as a pattern delimited by <
879     characters.
880     For example:
881     .sp
882     re> </some/file
883 ph10 612 Compiled pattern loaded from /some/file
884 nigel 75 No study data
885     .sp
886 ph10 678 If the pattern was previously studied with the JIT optimization, the JIT
887     information cannot be saved and restored, and so is lost. When the pattern has
888     been loaded, \fBpcretest\fP proceeds to read data lines in the usual way.
889 nigel 75 .P
890     You can copy a file written by \fBpcretest\fP to a different host and reload it
891     there, even if the new host has opposite endianness to the one on which the
892     pattern was compiled. For example, you can compile on an i86 machine and run on
893 ph10 866 a SPARC machine. When a pattern is reloaded on a host with different
894     endianness, the confirmation message is changed to:
895     .sp
896     Compiled pattern (byte-inverted) loaded from /some/file
897     .sp
898     The test suite contains some saved pre-compiled patterns with different
899     endianness. These are reloaded using "<!" instead of just "<". This suppresses
900     the "(byte-inverted)" text so that the output is the same on all hosts. It also
901     forces debugging output once the pattern has been reloaded.
902 nigel 75 .P
903     File names for saving and reloading can be absolute or relative, but note that
904     the shell facility of expanding a file name that starts with a tilde (~) is not
905     available.
906     .P
907     The ability to save and reload files in \fBpcretest\fP is intended for testing
908     and experimentation. It is not intended for production use because only a
909     single pattern can be written to a file. Furthermore, there is no facility for
910     supplying custom character tables for use with a reloaded pattern. If the
911     original pattern was compiled with custom tables, an attempt to match a subject
912     string using a reloaded pattern is likely to cause \fBpcretest\fP to crash.
913     Finally, if you attempt to load a file that is not in the correct format, the
914     result is undefined.
915     .
916     .
917 nigel 93 .SH "SEE ALSO"
918     .rs
919     .sp
920 ph10 866 \fBpcre\fP(3), \fBpcre16\fP(3), \fBpcreapi\fP(3), \fBpcrecallout\fP(3),
921     \fBpcrejit\fP, \fBpcrematching\fP(3), \fBpcrepartial\fP(d),
922     \fBpcrepattern\fP(3), \fBpcreprecompile\fP(3).
923 nigel 93 .
924     .
925 nigel 53 .SH AUTHOR
926 nigel 63 .rs
927     .sp
928 ph10 99 .nf
929 nigel 77 Philip Hazel
930 ph10 99 University Computing Service
931 nigel 93 Cambridge CB2 3QH, England.
932 ph10 99 .fi
933     .
934     .
935     .SH REVISION
936     .rs
937     .sp
938     .nf
939 ph10 866 Last updated: 13 January 2012
940     Copyright (c) 1997-2012 University of Cambridge.
941 ph10 99 .fi

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