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1.1 misho 1: PCRETEST(1) PCRETEST(1)
2:
3:
4: NAME
5: pcretest - a program for testing Perl-compatible regular expressions.
6:
7:
8: SYNOPSIS
9:
10: pcretest [options] [input file [output file]]
11:
12: pcretest was written as a test program for the PCRE regular expression
13: library itself, but it can also be used for experimenting with regular
14: expressions. This document describes the features of the test program;
15: for details of the regular expressions themselves, see the pcrepattern
16: documentation. For details of the PCRE library function calls and their
1.1.1.2 misho 17: options, see the pcreapi and pcre16 documentation. The input for
18: pcretest is a sequence of regular expression patterns and strings to be
19: matched, as described below. The output shows the result of each match.
20: Options on the command line and the patterns control PCRE options and
21: exactly what is output.
22:
23:
24: PCRE's 8-BIT and 16-BIT LIBRARIES
25:
26: From release 8.30, two separate PCRE libraries can be built. The origi-
27: nal one supports 8-bit character strings, whereas the newer 16-bit
28: library supports character strings encoded in 16-bit units. The
29: pcretest program can be used to test both libraries. However, it is
30: itself still an 8-bit program, reading 8-bit input and writing 8-bit
31: output. When testing the 16-bit library, the patterns and data strings
32: are converted to 16-bit format before being passed to the PCRE library
33: functions. Results are converted to 8-bit for output.
34:
35: References to functions and structures of the form pcre[16]_xx below
36: mean "pcre_xx when using the 8-bit library or pcre16_xx when using the
37: 16-bit library".
1.1 misho 38:
39:
40: COMMAND LINE OPTIONS
41:
1.1.1.2 misho 42: -16 If both the 8-bit and the 16-bit libraries have been built,
43: this option causes the 16-bit library to be used. If only the
44: 16-bit library has been built, this is the default (so has no
45: effect). If only the 8-bit library has been built, this
46: option causes an error.
47:
48: -b Behave as if each pattern has the /B (show byte code) modi-
1.1 misho 49: fier; the internal form is output after compilation.
50:
51: -C Output the version number of the PCRE library, and all avail-
1.1.1.2 misho 52: able information about the optional features that are
53: included, and then exit. All other options are ignored.
54:
55: -C option Output information about a specific build-time option, then
56: exit. This functionality is intended for use in scripts such
57: as RunTest. The following options output the value indicated:
58:
59: linksize the internal link size (2, 3, or 4)
60: newline the default newline setting:
61: CR, LF, CRLF, ANYCRLF, or ANY
62:
63: The following options output 1 for true or zero for false:
64:
65: jit just-in-time support is available
66: pcre16 the 16-bit library was built
67: pcre8 the 8-bit library was built
68: ucp Unicode property support is available
69: utf UTF-8 and/or UTF-16 support is available
1.1 misho 70:
1.1.1.2 misho 71: -d Behave as if each pattern has the /D (debug) modifier; the
72: internal form and information about the compiled pattern is
1.1 misho 73: output after compilation; -d is equivalent to -b -i.
74:
1.1.1.2 misho 75: -dfa Behave as if each data line contains the \D escape sequence;
1.1 misho 76: this causes the alternative matching function,
1.1.1.2 misho 77: pcre[16]_dfa_exec(), to be used instead of the standard
78: pcre[16]_exec() function (more detail is given below).
1.1 misho 79:
80: -help Output a brief summary these options and then exit.
81:
1.1.1.2 misho 82: -i Behave as if each pattern has the /I modifier; information
1.1 misho 83: about the compiled pattern is given after compilation.
84:
1.1.1.2 misho 85: -M Behave as if each data line contains the \M escape sequence;
86: this causes PCRE to discover the minimum MATCH_LIMIT and
87: MATCH_LIMIT_RECURSION settings by calling pcre[16]_exec()
88: repeatedly with different limits.
89:
90: -m Output the size of each compiled pattern after it has been
91: compiled. This is equivalent to adding /M to each regular
92: expression. The size is given in bytes for both libraries.
93:
94: -o osize Set the number of elements in the output vector that is used
95: when calling pcre[16]_exec() or pcre[16]_dfa_exec() to be
96: osize. The default value is 45, which is enough for 14 cap-
97: turing subexpressions for pcre[16]_exec() or 22 different
98: matches for pcre[16]_dfa_exec(). The vector size can be
99: changed for individual matching calls by including \O in the
100: data line (see below).
101:
102: -p Behave as if each pattern has the /P modifier; the POSIX
103: wrapper API is used to call PCRE. None of the other options
104: has any effect when -p is set. This option can be used only
105: with the 8-bit library.
1.1 misho 106:
107: -q Do not output the version number of pcretest at the start of
108: execution.
109:
110: -S size On Unix-like systems, set the size of the run-time stack to
111: size megabytes.
112:
113: -s or -s+ Behave as if each pattern has the /S modifier; in other
1.1.1.3 ! misho 114: words, force each pattern to be studied. If -s+ is used, all
! 115: the JIT compile options are passed to pcre[16]_study(), caus-
! 116: ing just-in-time optimization to be set up if it is avail-
! 117: able, for both full and partial matching. Specific JIT com-
! 118: pile options can be selected by following -s+ with a digit in
! 119: the range 1 to 7, which selects the JIT compile modes as fol-
! 120: lows:
! 121:
! 122: 1 normal match only
! 123: 2 soft partial match only
! 124: 3 normal match and soft partial match
! 125: 4 hard partial match only
! 126: 6 soft and hard partial match
! 127: 7 all three modes (default)
! 128:
! 129: If -s++ is used instead of -s+ (with or without a following
! 130: digit), the text "(JIT)" is added to the first output line
! 131: after a match or no match when JIT-compiled code was actually
! 132: used.
! 133:
! 134: If the /I or /D option is present on a pattern (requesting output about
! 135: the compiled pattern), information about the result of studying is not
! 136: included when studying is caused only by -s and neither -i nor -d is
! 137: present on the command line. This behaviour means that the output from
! 138: tests that are run with and without -s should be identical, except when
! 139: options that output information about the actual running of a match are
! 140: set.
! 141:
! 142: The -M, -t, and -tm options, which give information about resources
! 143: used, are likely to produce different output with and without -s. Out-
! 144: put may also differ if the /C option is present on an individual pat-
! 145: tern. This uses callouts to trace the the matching process, and this
! 146: may be different between studied and non-studied patterns. If the pat-
! 147: tern contains (*MARK) items there may also be differences, for the same
! 148: reason. The -s command line option can be overridden for specific pat-
! 149: terns that should never be studied (see the /S pattern modifier below).
! 150:
! 151: -t Run each compile, study, and match many times with a timer,
! 152: and output resulting time per compile or match (in millisec-
! 153: onds). Do not set -m with -t, because you will then get the
! 154: size output a zillion times, and the timing will be dis-
! 155: torted. You can control the number of iterations that are
! 156: used for timing by following -t with a number (as a separate
1.1 misho 157: item on the command line). For example, "-t 1000" would iter-
158: ate 1000 times. The default is to iterate 500000 times.
159:
160: -tm This is like -t except that it times only the matching phase,
161: not the compile or study phases.
162:
163:
164: DESCRIPTION
165:
1.1.1.3 ! misho 166: If pcretest is given two filename arguments, it reads from the first
1.1 misho 167: and writes to the second. If it is given only one filename argument, it
1.1.1.3 ! misho 168: reads from that file and writes to stdout. Otherwise, it reads from
! 169: stdin and writes to stdout, and prompts for each line of input, using
1.1 misho 170: "re>" to prompt for regular expressions, and "data>" to prompt for data
171: lines.
172:
1.1.1.3 ! misho 173: When pcretest is built, a configuration option can specify that it
! 174: should be linked with the libreadline library. When this is done, if
1.1 misho 175: the input is from a terminal, it is read using the readline() function.
1.1.1.3 ! misho 176: This provides line-editing and history facilities. The output from the
1.1 misho 177: -help option states whether or not readline() will be used.
178:
179: The program handles any number of sets of input on a single input file.
1.1.1.3 ! misho 180: Each set starts with a regular expression, and continues with any num-
1.1 misho 181: ber of data lines to be matched against the pattern.
182:
1.1.1.3 ! misho 183: Each data line is matched separately and independently. If you want to
1.1 misho 184: do multi-line matches, you have to use the \n escape sequence (or \r or
185: \r\n, etc., depending on the newline setting) in a single line of input
1.1.1.3 ! misho 186: to encode the newline sequences. There is no limit on the length of
! 187: data lines; the input buffer is automatically extended if it is too
1.1 misho 188: small.
189:
1.1.1.3 ! misho 190: An empty line signals the end of the data lines, at which point a new
! 191: regular expression is read. The regular expressions are given enclosed
1.1 misho 192: in any non-alphanumeric delimiters other than backslash, for example:
193:
194: /(a|bc)x+yz/
195:
1.1.1.3 ! misho 196: White space before the initial delimiter is ignored. A regular expres-
! 197: sion may be continued over several input lines, in which case the new-
! 198: line characters are included within it. It is possible to include the
1.1 misho 199: delimiter within the pattern by escaping it, for example
200:
201: /abc\/def/
202:
1.1.1.3 ! misho 203: If you do so, the escape and the delimiter form part of the pattern,
! 204: but since delimiters are always non-alphanumeric, this does not affect
! 205: its interpretation. If the terminating delimiter is immediately fol-
1.1 misho 206: lowed by a backslash, for example,
207:
208: /abc/\
209:
1.1.1.3 ! misho 210: then a backslash is added to the end of the pattern. This is done to
! 211: provide a way of testing the error condition that arises if a pattern
1.1 misho 212: finishes with a backslash, because
213:
214: /abc\/
215:
1.1.1.3 ! misho 216: is interpreted as the first line of a pattern that starts with "abc/",
1.1 misho 217: causing pcretest to read the next line as a continuation of the regular
218: expression.
219:
220:
221: PATTERN MODIFIERS
222:
1.1.1.3 ! misho 223: A pattern may be followed by any number of modifiers, which are mostly
! 224: single characters. Following Perl usage, these are referred to below
! 225: as, for example, "the /i modifier", even though the delimiter of the
! 226: pattern need not always be a slash, and no slash is used when writing
! 227: modifiers. White space may appear between the final pattern delimiter
1.1 misho 228: and the first modifier, and between the modifiers themselves.
229:
230: The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,
1.1.1.2 misho 231: PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when pcre[16]_com-
1.1.1.3 ! misho 232: pile() is called. These four modifier letters have the same effect as
1.1 misho 233: they do in Perl. For example:
234:
235: /caseless/i
236:
1.1.1.3 ! misho 237: The following table shows additional modifiers for setting PCRE com-
1.1 misho 238: pile-time options that do not correspond to anything in Perl:
239:
1.1.1.2 misho 240: /8 PCRE_UTF8 ) when using the 8-bit
241: /? PCRE_NO_UTF8_CHECK ) library
242:
243: /8 PCRE_UTF16 ) when using the 16-bit
244: /? PCRE_NO_UTF16_CHECK ) library
245:
1.1 misho 246: /A PCRE_ANCHORED
247: /C PCRE_AUTO_CALLOUT
248: /E PCRE_DOLLAR_ENDONLY
249: /f PCRE_FIRSTLINE
250: /J PCRE_DUPNAMES
251: /N PCRE_NO_AUTO_CAPTURE
252: /U PCRE_UNGREEDY
253: /W PCRE_UCP
254: /X PCRE_EXTRA
255: /Y PCRE_NO_START_OPTIMIZE
256: /<JS> PCRE_JAVASCRIPT_COMPAT
257: /<cr> PCRE_NEWLINE_CR
258: /<lf> PCRE_NEWLINE_LF
259: /<crlf> PCRE_NEWLINE_CRLF
260: /<anycrlf> PCRE_NEWLINE_ANYCRLF
261: /<any> PCRE_NEWLINE_ANY
262: /<bsr_anycrlf> PCRE_BSR_ANYCRLF
263: /<bsr_unicode> PCRE_BSR_UNICODE
264:
1.1.1.3 ! misho 265: The modifiers that are enclosed in angle brackets are literal strings
! 266: as shown, including the angle brackets, but the letters within can be
! 267: in either case. This example sets multiline matching with CRLF as the
1.1 misho 268: line ending sequence:
269:
270: /^abc/m<CRLF>
271:
1.1.1.3 ! misho 272: As well as turning on the PCRE_UTF8/16 option, the /8 modifier causes
! 273: all non-printing characters in output strings to be printed using the
! 274: \x{hh...} notation. Otherwise, those less than 0x100 are output in hex
1.1.1.2 misho 275: without the curly brackets.
276:
1.1.1.3 ! misho 277: Full details of the PCRE options are given in the pcreapi documenta-
1.1.1.2 misho 278: tion.
1.1 misho 279:
280: Finding all matches in a string
281:
1.1.1.3 ! misho 282: Searching for all possible matches within each subject string can be
! 283: requested by the /g or /G modifier. After finding a match, PCRE is
1.1 misho 284: called again to search the remainder of the subject string. The differ-
285: ence between /g and /G is that the former uses the startoffset argument
1.1.1.3 ! misho 286: to pcre[16]_exec() to start searching at a new point within the entire
! 287: string (which is in effect what Perl does), whereas the latter passes
! 288: over a shortened substring. This makes a difference to the matching
1.1 misho 289: process if the pattern begins with a lookbehind assertion (including \b
290: or \B).
291:
1.1.1.3 ! misho 292: If any call to pcre[16]_exec() in a /g or /G sequence matches an empty
! 293: string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
! 294: PCRE_ANCHORED flags set in order to search for another, non-empty,
! 295: match at the same point. If this second match fails, the start offset
! 296: is advanced, and the normal match is retried. This imitates the way
1.1 misho 297: Perl handles such cases when using the /g modifier or the split() func-
1.1.1.3 ! misho 298: tion. Normally, the start offset is advanced by one character, but if
! 299: the newline convention recognizes CRLF as a newline, and the current
1.1 misho 300: character is CR followed by LF, an advance of two is used.
301:
302: Other modifiers
303:
304: There are yet more modifiers for controlling the way pcretest operates.
305:
1.1.1.3 ! misho 306: The /+ modifier requests that as well as outputting the substring that
! 307: matched the entire pattern, pcretest should in addition output the
! 308: remainder of the subject string. This is useful for tests where the
! 309: subject contains multiple copies of the same substring. If the + modi-
! 310: fier appears twice, the same action is taken for captured substrings.
! 311: In each case the remainder is output on the following line with a plus
! 312: character following the capture number. Note that this modifier must
! 313: not immediately follow the /S modifier because /S+ and /S++ have other
! 314: meanings.
1.1 misho 315:
1.1.1.2 misho 316: The /= modifier requests that the values of all potential captured
317: parentheses be output after a match. By default, only those up to the
318: highest one actually used in the match are output (corresponding to the
319: return code from pcre[16]_exec()). Values in the offsets vector corre-
320: sponding to higher numbers should be set to -1, and these are output as
321: "<unset>". This modifier gives a way of checking that this is happen-
322: ing.
323:
324: The /B modifier is a debugging feature. It requests that pcretest out-
325: put a representation of the compiled code after compilation. Normally
326: this information contains length and offset values; however, if /Z is
327: also present, this data is replaced by spaces. This is a special fea-
328: ture for use in the automatic test scripts; it ensures that the same
1.1 misho 329: output is generated for different internal link sizes.
330:
1.1.1.2 misho 331: The /D modifier is a PCRE debugging feature, and is equivalent to /BI,
1.1 misho 332: that is, both the /B and the /I modifiers.
333:
1.1.1.2 misho 334: The /F modifier causes pcretest to flip the byte order of the 2-byte
335: and 4-byte fields in the compiled pattern. This facility is for testing
336: the feature in PCRE that allows it to execute patterns that were com-
337: piled on a host with a different endianness. This feature is not avail-
338: able when the POSIX interface to PCRE is being used, that is, when the
339: /P pattern modifier is specified. See also the section about saving and
340: reloading compiled patterns below.
341:
342: The /I modifier requests that pcretest output information about the
343: compiled pattern (whether it is anchored, has a fixed first character,
344: and so on). It does this by calling pcre[16]_fullinfo() after compiling
345: a pattern. If the pattern is studied, the results of that are also out-
1.1 misho 346: put.
347:
1.1.1.2 misho 348: The /K modifier requests pcretest to show names from backtracking con-
349: trol verbs that are returned from calls to pcre[16]_exec(). It causes
350: pcretest to create a pcre[16]_extra block if one has not already been
351: created by a call to pcre[16]_study(), and to set the PCRE_EXTRA_MARK
352: flag and the mark field within it, every time that pcre[16]_exec() is
353: called. If the variable that the mark field points to is non-NULL for a
354: match, non-match, or partial match, pcretest prints the string to which
355: it points. For a match, this is shown on a line by itself, tagged with
356: "MK:". For a non-match it is added to the message.
1.1 misho 357:
1.1.1.2 misho 358: The /L modifier must be followed directly by the name of a locale, for
1.1 misho 359: example,
360:
361: /pattern/Lfr_FR
362:
363: For this reason, it must be the last modifier. The given locale is set,
1.1.1.2 misho 364: pcre[16]_maketables() is called to build a set of character tables for
365: the locale, and this is then passed to pcre[16]_compile() when compil-
366: ing the regular expression. Without an /L (or /T) modifier, NULL is
367: passed as the tables pointer; that is, /L applies only to the expres-
368: sion on which it appears.
369:
370: The /M modifier causes the size in bytes of the memory block used to
371: hold the compiled pattern to be output. This does not include the size
372: of the pcre[16] block; it is just the actual compiled data. If the pat-
373: tern is successfully studied with the PCRE_STUDY_JIT_COMPILE option,
374: the size of the JIT compiled code is also output.
375:
376: If the /S modifier appears once, it causes pcre[16]_study() to be
377: called after the expression has been compiled, and the results used
378: when the expression is matched. If /S appears twice, it suppresses
379: studying, even if it was requested externally by the -s command line
380: option. This makes it possible to specify that certain patterns are
381: always studied, and others are never studied, independently of -s. This
382: feature is used in the test files in a few cases where the output is
383: different when the pattern is studied.
384:
385: If the /S modifier is immediately followed by a + character, the call
1.1.1.3 ! misho 386: to pcre[16]_study() is made with all the JIT study options, requesting
! 387: just-in-time optimization support if it is available, for both normal
! 388: and partial matching. If you want to restrict the JIT compiling modes,
! 389: you can follow /S+ with a digit in the range 1 to 7:
! 390:
! 391: 1 normal match only
! 392: 2 soft partial match only
! 393: 3 normal match and soft partial match
! 394: 4 hard partial match only
! 395: 6 soft and hard partial match
! 396: 7 all three modes (default)
! 397:
! 398: If /S++ is used instead of /S+ (with or without a following digit), the
! 399: text "(JIT)" is added to the first output line after a match or no
! 400: match when JIT-compiled code was actually used.
! 401:
! 402: Note that there is also an independent /+ modifier; it must not be
! 403: given immediately after /S or /S+ because this will be misinterpreted.
! 404:
! 405: If JIT studying is successful, the compiled JIT code will automatically
! 406: be used when pcre[16]_exec() is run, except when incompatible run-time
! 407: options are specified. For more details, see the pcrejit documentation.
! 408: See also the \J escape sequence below for a way of setting the size of
! 409: the JIT stack.
1.1.1.2 misho 410:
411: The /T modifier must be followed by a single digit. It causes a spe-
412: cific set of built-in character tables to be passed to pcre[16]_com-
413: pile(). It is used in the standard PCRE tests to check behaviour with
414: different character tables. The digit specifies the tables as follows:
1.1 misho 415:
416: 0 the default ASCII tables, as distributed in
417: pcre_chartables.c.dist
418: 1 a set of tables defining ISO 8859 characters
419:
1.1.1.2 misho 420: In table 1, some characters whose codes are greater than 128 are iden-
1.1 misho 421: tified as letters, digits, spaces, etc.
422:
423: Using the POSIX wrapper API
424:
1.1.1.2 misho 425: The /P modifier causes pcretest to call PCRE via the POSIX wrapper API
426: rather than its native API. This supports only the 8-bit library. When
427: /P is set, the following modifiers set options for the regcomp() func-
428: tion:
1.1 misho 429:
430: /i REG_ICASE
431: /m REG_NEWLINE
432: /N REG_NOSUB
433: /s REG_DOTALL )
434: /U REG_UNGREEDY ) These options are not part of
435: /W REG_UCP ) the POSIX standard
436: /8 REG_UTF8 )
437:
438: The /+ modifier works as described above. All other modifiers are
439: ignored.
440:
441:
442: DATA LINES
443:
1.1.1.2 misho 444: Before each data line is passed to pcre[16]_exec(), leading and trail-
445: ing white space is removed, and it is then scanned for \ escapes. Some
446: of these are pretty esoteric features, intended for checking out some
447: of the more complicated features of PCRE. If you are just testing
448: "ordinary" regular expressions, you probably don't need any of these.
449: The following escapes are recognized:
1.1 misho 450:
451: \a alarm (BEL, \x07)
452: \b backspace (\x08)
453: \e escape (\x27)
454: \f form feed (\x0c)
455: \n newline (\x0a)
456: \qdd set the PCRE_MATCH_LIMIT limit to dd
457: (any number of digits)
458: \r carriage return (\x0d)
459: \t tab (\x09)
460: \v vertical tab (\x0b)
1.1.1.2 misho 461: \nnn octal character (up to 3 octal digits); always
462: a byte unless > 255 in UTF-8 or 16-bit mode
1.1 misho 463: \xhh hexadecimal byte (up to 2 hex digits)
1.1.1.2 misho 464: \x{hh...} hexadecimal character (any number of hex digits)
465: \A pass the PCRE_ANCHORED option to pcre[16]_exec()
466: or pcre[16]_dfa_exec()
467: \B pass the PCRE_NOTBOL option to pcre[16]_exec()
468: or pcre[16]_dfa_exec()
469: \Cdd call pcre[16]_copy_substring() for substring dd
1.1 misho 470: after a successful match (number less than 32)
1.1.1.2 misho 471: \Cname call pcre[16]_copy_named_substring() for substring
1.1 misho 472: "name" after a successful match (name termin-
473: ated by next non alphanumeric character)
474: \C+ show the current captured substrings at callout
475: time
476: \C- do not supply a callout function
477: \C!n return 1 instead of 0 when callout number n is
478: reached
479: \C!n!m return 1 instead of 0 when callout number n is
480: reached for the nth time
481: \C*n pass the number n (may be negative) as callout
482: data; this is used as the callout return value
1.1.1.2 misho 483: \D use the pcre[16]_dfa_exec() match function
484: \F only shortest match for pcre[16]_dfa_exec()
485: \Gdd call pcre[16]_get_substring() for substring dd
1.1 misho 486: after a successful match (number less than 32)
1.1.1.2 misho 487: \Gname call pcre[16]_get_named_substring() for substring
1.1 misho 488: "name" after a successful match (name termin-
489: ated by next non-alphanumeric character)
490: \Jdd set up a JIT stack of dd kilobytes maximum (any
491: number of digits)
1.1.1.2 misho 492: \L call pcre[16]_get_substringlist() after a
1.1 misho 493: successful match
494: \M discover the minimum MATCH_LIMIT and
495: MATCH_LIMIT_RECURSION settings
1.1.1.2 misho 496: \N pass the PCRE_NOTEMPTY option to pcre[16]_exec()
497: or pcre[16]_dfa_exec(); if used twice, pass the
1.1 misho 498: PCRE_NOTEMPTY_ATSTART option
499: \Odd set the size of the output vector passed to
1.1.1.2 misho 500: pcre[16]_exec() to dd (any number of digits)
501: \P pass the PCRE_PARTIAL_SOFT option to pcre[16]_exec()
502: or pcre[16]_dfa_exec(); if used twice, pass the
1.1 misho 503: PCRE_PARTIAL_HARD option
504: \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd
505: (any number of digits)
1.1.1.2 misho 506: \R pass the PCRE_DFA_RESTART option to pcre[16]_dfa_exec()
1.1 misho 507: \S output details of memory get/free calls during matching
1.1.1.2 misho 508: \Y pass the PCRE_NO_START_OPTIMIZE option to pcre[16]_exec()
509: or pcre[16]_dfa_exec()
510: \Z pass the PCRE_NOTEOL option to pcre[16]_exec()
511: or pcre[16]_dfa_exec()
512: \? pass the PCRE_NO_UTF[8|16]_CHECK option to
513: pcre[16]_exec() or pcre[16]_dfa_exec()
1.1 misho 514: \>dd start the match at offset dd (optional "-"; then
515: any number of digits); this sets the startoffset
1.1.1.2 misho 516: argument for pcre[16]_exec() or pcre[16]_dfa_exec()
517: \<cr> pass the PCRE_NEWLINE_CR option to pcre[16]_exec()
518: or pcre[16]_dfa_exec()
519: \<lf> pass the PCRE_NEWLINE_LF option to pcre[16]_exec()
520: or pcre[16]_dfa_exec()
521: \<crlf> pass the PCRE_NEWLINE_CRLF option to pcre[16]_exec()
522: or pcre[16]_dfa_exec()
523: \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to pcre[16]_exec()
524: or pcre[16]_dfa_exec()
525: \<any> pass the PCRE_NEWLINE_ANY option to pcre[16]_exec()
526: or pcre[16]_dfa_exec()
527:
528: The use of \x{hh...} is not dependent on the use of the /8 modifier on
529: the pattern. It is recognized always. There may be any number of hexa-
530: decimal digits inside the braces; invalid values provoke error mes-
531: sages.
532:
533: Note that \xhh specifies one byte rather than one character in UTF-8
534: mode; this makes it possible to construct invalid UTF-8 sequences for
535: testing purposes. On the other hand, \x{hh} is interpreted as a UTF-8
536: character in UTF-8 mode, generating more than one byte if the value is
537: greater than 127. When testing the 8-bit library not in UTF-8 mode,
538: \x{hh} generates one byte for values less than 256, and causes an error
539: for greater values.
540:
541: In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it
542: possible to construct invalid UTF-16 sequences for testing purposes.
1.1 misho 543:
1.1.1.2 misho 544: The escapes that specify line ending sequences are literal strings,
1.1 misho 545: exactly as shown. No more than one newline setting should be present in
546: any data line.
547:
1.1.1.2 misho 548: A backslash followed by anything else just escapes the anything else.
549: If the very last character is a backslash, it is ignored. This gives a
550: way of passing an empty line as data, since a real empty line termi-
1.1 misho 551: nates the data input.
552:
1.1.1.2 misho 553: The \J escape provides a way of setting the maximum stack size that is
554: used by the just-in-time optimization code. It is ignored if JIT opti-
555: mization is not being used. Providing a stack that is larger than the
1.1 misho 556: default 32K is necessary only for very complicated patterns.
557:
1.1.1.2 misho 558: If \M is present, pcretest calls pcre[16]_exec() several times, with
559: different values in the match_limit and match_limit_recursion fields of
560: the pcre[16]_extra data structure, until it finds the minimum numbers
561: for each parameter that allow pcre[16]_exec() to complete without
562: error. Because this is testing a specific feature of the normal inter-
563: pretive pcre[16]_exec() execution, the use of any JIT optimization that
564: might have been set up by the /S+ qualifier of -s+ option is disabled.
565:
566: The match_limit number is a measure of the amount of backtracking that
567: takes place, and checking it out can be instructive. For most simple
568: matches, the number is quite small, but for patterns with very large
569: numbers of matching possibilities, it can become large very quickly
570: with increasing length of subject string. The match_limit_recursion
571: number is a measure of how much stack (or, if PCRE is compiled with
572: NO_RECURSE, how much heap) memory is needed to complete the match
1.1 misho 573: attempt.
574:
1.1.1.2 misho 575: When \O is used, the value specified may be higher or lower than the
1.1 misho 576: size set by the -O command line option (or defaulted to 45); \O applies
1.1.1.2 misho 577: only to the call of pcre[16]_exec() for the line in which it appears.
1.1 misho 578:
1.1.1.2 misho 579: If the /P modifier was present on the pattern, causing the POSIX wrap-
580: per API to be used, the only option-setting sequences that have any
581: effect are \B, \N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and
1.1 misho 582: REG_NOTEOL, respectively, to be passed to regexec().
583:
584:
585: THE ALTERNATIVE MATCHING FUNCTION
586:
587: By default, pcretest uses the standard PCRE matching function,
1.1.1.2 misho 588: pcre[16]_exec() to match each data line. PCRE also supports an alterna-
589: tive matching function, pcre[16]_dfa_test(), which operates in a dif-
590: ferent way, and has some restrictions. The differences between the two
591: functions are described in the pcrematching documentation.
1.1 misho 592:
593: If a data line contains the \D escape sequence, or if the command line
1.1.1.2 misho 594: contains the -dfa option, the alternative matching function is used.
1.1 misho 595: This function finds all possible matches at a given point. If, however,
596: the \F escape sequence is present in the data line, it stops after the
597: first match is found. This is always the shortest possible match.
598:
599:
600: DEFAULT OUTPUT FROM PCRETEST
601:
602: This section describes the output when the normal matching function,
1.1.1.2 misho 603: pcre[16]_exec(), is being used.
1.1 misho 604:
605: When a match succeeds, pcretest outputs the list of captured substrings
1.1.1.2 misho 606: that pcre[16]_exec() returns, starting with number 0 for the string
607: that matched the whole pattern. Otherwise, it outputs "No match" when
608: the return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the
609: partially matching substring when pcre[16]_exec() returns
610: PCRE_ERROR_PARTIAL. (Note that this is the entire substring that was
611: inspected during the partial match; it may include characters before
612: the actual match start if a lookbehind assertion, \K, \b, or \B was
613: involved.) For any other return, pcretest outputs the PCRE negative
614: error number and a short descriptive phrase. If the error is a failed
615: UTF string check, the offset of the start of the failing character and
616: the reason code are also output, provided that the size of the output
617: vector is at least two. Here is an example of an interactive pcretest
618: run.
1.1 misho 619:
620: $ pcretest
621: PCRE version 8.13 2011-04-30
622:
623: re> /^abc(\d+)/
624: data> abc123
625: 0: abc123
626: 1: 123
627: data> xyz
628: No match
629:
630: Unset capturing substrings that are not followed by one that is set are
1.1.1.2 misho 631: not returned by pcre[16]_exec(), and are not shown by pcretest. In the
632: following example, there are two capturing substrings, but when the
633: first data line is matched, the second, unset substring is not shown.
634: An "internal" unset substring is shown as "<unset>", as for the second
1.1 misho 635: data line.
636:
637: re> /(a)|(b)/
638: data> a
639: 0: a
640: 1: a
641: data> b
642: 0: b
643: 1: <unset>
644: 2: b
645:
1.1.1.2 misho 646: If the strings contain any non-printing characters, they are output as
647: \xhh escapes if the value is less than 256 and UTF mode is not set.
648: Otherwise they are output as \x{hh...} escapes. See below for the defi-
649: nition of non-printing characters. If the pattern has the /+ modifier,
650: the output for substring 0 is followed by the the rest of the subject
651: string, identified by "0+" like this:
1.1 misho 652:
653: re> /cat/+
654: data> cataract
655: 0: cat
656: 0+ aract
657:
1.1.1.2 misho 658: If the pattern has the /g or /G modifier, the results of successive
1.1 misho 659: matching attempts are output in sequence, like this:
660:
661: re> /\Bi(\w\w)/g
662: data> Mississippi
663: 0: iss
664: 1: ss
665: 0: iss
666: 1: ss
667: 0: ipp
668: 1: pp
669:
1.1.1.2 misho 670: "No match" is output only if the first match attempt fails. Here is an
671: example of a failure message (the offset 4 that is specified by \>4 is
1.1 misho 672: past the end of the subject string):
673:
674: re> /xyz/
675: data> xyz\>4
676: Error -24 (bad offset value)
677:
1.1.1.2 misho 678: If any of the sequences \C, \G, or \L are present in a data line that
679: is successfully matched, the substrings extracted by the convenience
1.1 misho 680: functions are output with C, G, or L after the string number instead of
681: a colon. This is in addition to the normal full list. The string length
1.1.1.2 misho 682: (that is, the return from the extraction function) is given in paren-
1.1 misho 683: theses after each string for \C and \G.
684:
685: Note that whereas patterns can be continued over several lines (a plain
686: ">" prompt is used for continuations), data lines may not. However new-
1.1.1.2 misho 687: lines can be included in data by means of the \n escape (or \r, \r\n,
1.1 misho 688: etc., depending on the newline sequence setting).
689:
690:
691: OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
692:
1.1.1.2 misho 693: When the alternative matching function, pcre[16]_dfa_exec(), is used
694: (by means of the \D escape sequence or the -dfa command line option),
695: the output consists of a list of all the matches that start at the
696: first point in the subject where there is at least one match. For exam-
697: ple:
1.1 misho 698:
699: re> /(tang|tangerine|tan)/
700: data> yellow tangerine\D
701: 0: tangerine
702: 1: tang
703: 2: tan
704:
705: (Using the normal matching function on this data finds only "tang".)
706: The longest matching string is always given first (and numbered zero).
707: After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-
708: lowed by the partially matching substring. (Note that this is the
709: entire substring that was inspected during the partial match; it may
710: include characters before the actual match start if a lookbehind asser-
711: tion, \K, \b, or \B was involved.)
712:
713: If /g is present on the pattern, the search for further matches resumes
714: at the end of the longest match. For example:
715:
716: re> /(tang|tangerine|tan)/g
717: data> yellow tangerine and tangy sultana\D
718: 0: tangerine
719: 1: tang
720: 2: tan
721: 0: tang
722: 1: tan
723: 0: tan
724:
725: Since the matching function does not support substring capture, the
726: escape sequences that are concerned with captured substrings are not
727: relevant.
728:
729:
730: RESTARTING AFTER A PARTIAL MATCH
731:
732: When the alternative matching function has given the PCRE_ERROR_PARTIAL
733: return, indicating that the subject partially matched the pattern, you
734: can restart the match with additional subject data by means of the \R
735: escape sequence. For example:
736:
737: re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
738: data> 23ja\P\D
739: Partial match: 23ja
740: data> n05\R\D
741: 0: n05
742:
743: For further information about partial matching, see the pcrepartial
744: documentation.
745:
746:
747: CALLOUTS
748:
749: If the pattern contains any callout requests, pcretest's callout func-
750: tion is called during matching. This works with both matching func-
751: tions. By default, the called function displays the callout number, the
752: start and current positions in the text at the callout time, and the
1.1.1.2 misho 753: next pattern item to be tested. For example:
1.1 misho 754:
755: --->pqrabcdef
756: 0 ^ ^ \d
757:
1.1.1.2 misho 758: This output indicates that callout number 0 occurred for a match
759: attempt starting at the fourth character of the subject string, when
760: the pointer was at the seventh character of the data, and when the next
761: pattern item was \d. Just one circumflex is output if the start and
762: current positions are the same.
1.1 misho 763:
764: Callouts numbered 255 are assumed to be automatic callouts, inserted as
765: a result of the /C pattern modifier. In this case, instead of showing
766: the callout number, the offset in the pattern, preceded by a plus, is
767: output. For example:
768:
769: re> /\d?[A-E]\*/C
770: data> E*
771: --->E*
772: +0 ^ \d?
773: +3 ^ [A-E]
774: +8 ^^ \*
775: +10 ^ ^
776: 0: E*
777:
778: If a pattern contains (*MARK) items, an additional line is output when-
779: ever a change of latest mark is passed to the callout function. For
780: example:
781:
782: re> /a(*MARK:X)bc/C
783: data> abc
784: --->abc
785: +0 ^ a
786: +1 ^^ (*MARK:X)
787: +10 ^^ b
788: Latest Mark: X
789: +11 ^ ^ c
790: +12 ^ ^
791: 0: abc
792:
793: The mark changes between matching "a" and "b", but stays the same for
794: the rest of the match, so nothing more is output. If, as a result of
795: backtracking, the mark reverts to being unset, the text "<unset>" is
796: output.
797:
798: The callout function in pcretest returns zero (carry on matching) by
799: default, but you can use a \C item in a data line (as described above)
800: to change this and other parameters of the callout.
801:
802: Inserting callouts can be helpful when using pcretest to check compli-
803: cated regular expressions. For further information about callouts, see
804: the pcrecallout documentation.
805:
806:
807: NON-PRINTING CHARACTERS
808:
809: When pcretest is outputting text in the compiled version of a pattern,
810: bytes other than 32-126 are always treated as non-printing characters
811: are are therefore shown as hex escapes.
812:
813: When pcretest is outputting text that is a matched part of a subject
814: string, it behaves in the same way, unless a different locale has been
815: set for the pattern (using the /L modifier). In this case, the
816: isprint() function to distinguish printing and non-printing characters.
817:
818:
819: SAVING AND RELOADING COMPILED PATTERNS
820:
821: The facilities described in this section are not available when the
822: POSIX interface to PCRE is being used, that is, when the /P pattern
823: modifier is specified.
824:
825: When the POSIX interface is not in use, you can cause pcretest to write
826: a compiled pattern to a file, by following the modifiers with > and a
827: file name. For example:
828:
829: /pattern/im >/some/file
830:
831: See the pcreprecompile documentation for a discussion about saving and
832: re-using compiled patterns. Note that if the pattern was successfully
833: studied with JIT optimization, the JIT data cannot be saved.
834:
835: The data that is written is binary. The first eight bytes are the
836: length of the compiled pattern data followed by the length of the
837: optional study data, each written as four bytes in big-endian order
838: (most significant byte first). If there is no study data (either the
839: pattern was not studied, or studying did not return any data), the sec-
840: ond length is zero. The lengths are followed by an exact copy of the
841: compiled pattern. If there is additional study data, this (excluding
842: any JIT data) follows immediately after the compiled pattern. After
843: writing the file, pcretest expects to read a new pattern.
844:
845: A saved pattern can be reloaded into pcretest by specifying < and a
846: file name instead of a pattern. The name of the file must not contain a
847: < character, as otherwise pcretest will interpret the line as a pattern
848: delimited by < characters. For example:
849:
850: re> </some/file
851: Compiled pattern loaded from /some/file
852: No study data
853:
854: If the pattern was previously studied with the JIT optimization, the
855: JIT information cannot be saved and restored, and so is lost. When the
856: pattern has been loaded, pcretest proceeds to read data lines in the
857: usual way.
858:
859: You can copy a file written by pcretest to a different host and reload
860: it there, even if the new host has opposite endianness to the one on
861: which the pattern was compiled. For example, you can compile on an i86
1.1.1.2 misho 862: machine and run on a SPARC machine. When a pattern is reloaded on a
863: host with different endianness, the confirmation message is changed to:
864:
865: Compiled pattern (byte-inverted) loaded from /some/file
866:
867: The test suite contains some saved pre-compiled patterns with different
868: endianness. These are reloaded using "<!" instead of just "<". This
869: suppresses the "(byte-inverted)" text so that the output is the same on
870: all hosts. It also forces debugging output once the pattern has been
871: reloaded.
1.1 misho 872:
1.1.1.2 misho 873: File names for saving and reloading can be absolute or relative, but
874: note that the shell facility of expanding a file name that starts with
1.1 misho 875: a tilde (~) is not available.
876:
1.1.1.2 misho 877: The ability to save and reload files in pcretest is intended for test-
878: ing and experimentation. It is not intended for production use because
879: only a single pattern can be written to a file. Furthermore, there is
880: no facility for supplying custom character tables for use with a
881: reloaded pattern. If the original pattern was compiled with custom
882: tables, an attempt to match a subject string using a reloaded pattern
883: is likely to cause pcretest to crash. Finally, if you attempt to load
1.1 misho 884: a file that is not in the correct format, the result is undefined.
885:
886:
887: SEE ALSO
888:
1.1.1.2 misho 889: pcre(3), pcre16(3), pcreapi(3), pcrecallout(3), pcrejit, pcrematch-
890: ing(3), pcrepartial(d), pcrepattern(3), pcreprecompile(3).
1.1 misho 891:
892:
893: AUTHOR
894:
895: Philip Hazel
896: University Computing Service
897: Cambridge CB2 3QH, England.
898:
899:
900: REVISION
901:
1.1.1.3 ! misho 902: Last updated: 21 February 2012
1.1.1.2 misho 903: Copyright (c) 1997-2012 University of Cambridge.

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