Annotation of embedaddon/pcre/doc/pcretest.1, revision 1.1.1.3
1.1.1.3 ! misho 1: .TH PCRETEST 1 "21 February 2012" "PCRE 8.31"
1.1 misho 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: .\"
1.1.1.2 misho 21: and
22: .\" HREF
23: \fBpcre16\fP
24: .\"
1.1 misho 25: 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: options and exactly what is output.
29: .
30: .
1.1.1.2 misho 31: .SH "PCRE's 8-BIT and 16-BIT LIBRARIES"
32: .rs
33: .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"
1.1 misho 49: .rs
50: .TP 10
1.1.1.2 misho 51: \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
1.1 misho 57: \fB-b\fP
58: Behave as if each pattern has the \fB/B\fP (show byte code) modifier; the
59: internal form is output after compilation.
60: .TP 10
61: \fB-C\fP
62: Output the version number of the PCRE library, and all available information
1.1.1.2 misho 63: about the optional features that are included, and then exit. All other options
64: are ignored.
65: .TP 10
66: \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
1.1 misho 82: .TP 10
83: \fB-d\fP
84: Behave as if each pattern has the \fB/D\fP (debug) modifier; the internal
85: form and information about the compiled pattern is output after compilation;
86: \fB-d\fP is equivalent to \fB-b -i\fP.
87: .TP 10
88: \fB-dfa\fP
89: Behave as if each data line contains the \eD escape sequence; this causes the
1.1.1.2 misho 90: 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).
1.1 misho 92: .TP 10
93: \fB-help\fP
94: Output a brief summary these options and then exit.
95: .TP 10
96: \fB-i\fP
97: Behave as if each pattern has the \fB/I\fP modifier; information about the
98: compiled pattern is given after compilation.
99: .TP 10
100: \fB-M\fP
101: Behave as if each data line contains the \eM escape sequence; this causes
102: PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
1.1.1.2 misho 103: calling \fBpcre[16]_exec()\fP repeatedly with different limits.
1.1 misho 104: .TP 10
105: \fB-m\fP
106: Output the size of each compiled pattern after it has been compiled. This is
1.1.1.2 misho 107: equivalent to adding \fB/M\fP to each regular expression. The size is given in
108: bytes for both libraries.
1.1 misho 109: .TP 10
110: \fB-o\fP \fIosize\fP
111: Set the number of elements in the output vector that is used when calling
1.1.1.2 misho 112: \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).
1.1 misho 117: .TP 10
118: \fB-p\fP
119: Behave as if each pattern has the \fB/P\fP modifier; the POSIX wrapper API is
120: used to call PCRE. None of the other options has any effect when \fB-p\fP is
1.1.1.2 misho 121: set. This option can be used only with the 8-bit library.
1.1 misho 122: .TP 10
123: \fB-q\fP
124: Do not output the version number of \fBpcretest\fP at the start of execution.
125: .TP 10
126: \fB-S\fP \fIsize\fP
127: On Unix-like systems, set the size of the run-time stack to \fIsize\fP
128: megabytes.
129: .TP 10
130: \fB-s\fP or \fB-s+\fP
131: Behave as if each pattern has the \fB/S\fP modifier; in other words, force each
1.1.1.3 ! misho 132: pattern to be studied. If \fB-s+\fP is used, all the JIT compile options are
1.1.1.2 misho 133: passed to \fBpcre[16]_study()\fP, causing just-in-time optimization to be set
1.1.1.3 ! misho 134: up if it is available, for both full and partial matching. Specific JIT compile
! 135: options can be selected by following \fB-s+\fP with a digit in the range 1 to
! 136: 7, which selects the JIT compile modes as follows:
! 137: .sp
! 138: 1 normal match only
! 139: 2 soft partial match only
! 140: 3 normal match and soft partial match
! 141: 4 hard partial match only
! 142: 6 soft and hard partial match
! 143: 7 all three modes (default)
! 144: .sp
! 145: If \fB-s++\fP is used instead of \fB-s+\fP (with or without a following digit),
! 146: the text "(JIT)" is added to the first output line after a match or no match
! 147: when JIT-compiled code was actually used.
! 148: .P
! 149: If the \fB/I\fP or \fB/D\fP option is present on a pattern (requesting output
! 150: about the compiled pattern), information about the result of studying is not
! 151: included when studying is caused only by \fB-s\fP and neither \fB-i\fP nor
! 152: \fB-d\fP is present on the command line. This behaviour means that the output
! 153: from tests that are run with and without \fB-s\fP should be identical, except
! 154: when options that output information about the actual running of a match are
! 155: set.
1.1.1.2 misho 156: .sp
157: The \fB-M\fP, \fB-t\fP, and \fB-tm\fP options, which give information about
158: resources used, are likely to produce different output with and without
159: \fB-s\fP. Output may also differ if the \fB/C\fP option is present on an
160: individual pattern. This uses callouts to trace the the matching process, and
161: this may be different between studied and non-studied patterns. If the pattern
162: contains (*MARK) items there may also be differences, for the same reason. The
163: \fB-s\fP command line option can be overridden for specific patterns that
164: should never be studied (see the \fB/S\fP pattern modifier below).
1.1 misho 165: .TP 10
166: \fB-t\fP
167: Run each compile, study, and match many times with a timer, and output
168: resulting time per compile or match (in milliseconds). Do not set \fB-m\fP with
169: \fB-t\fP, because you will then get the size output a zillion times, and the
170: timing will be distorted. You can control the number of iterations that are
171: used for timing by following \fB-t\fP with a number (as a separate item on the
172: command line). For example, "-t 1000" would iterate 1000 times. The default is
173: to iterate 500000 times.
174: .TP 10
175: \fB-tm\fP
176: This is like \fB-t\fP except that it times only the matching phase, not the
177: compile or study phases.
178: .
179: .
180: .SH DESCRIPTION
181: .rs
182: .sp
183: If \fBpcretest\fP is given two filename arguments, it reads from the first and
184: writes to the second. If it is given only one filename argument, it reads from
185: that file and writes to stdout. Otherwise, it reads from stdin and writes to
186: stdout, and prompts for each line of input, using "re>" to prompt for regular
187: expressions, and "data>" to prompt for data lines.
188: .P
189: When \fBpcretest\fP is built, a configuration option can specify that it should
190: be linked with the \fBlibreadline\fP library. When this is done, if the input
191: is from a terminal, it is read using the \fBreadline()\fP function. This
192: provides line-editing and history facilities. The output from the \fB-help\fP
193: option states whether or not \fBreadline()\fP will be used.
194: .P
195: The program handles any number of sets of input on a single input file. Each
196: set starts with a regular expression, and continues with any number of data
197: lines to be matched against the pattern.
198: .P
199: Each data line is matched separately and independently. If you want to do
200: multi-line matches, you have to use the \en escape sequence (or \er or \er\en,
201: etc., depending on the newline setting) in a single line of input to encode the
202: newline sequences. There is no limit on the length of data lines; the input
203: buffer is automatically extended if it is too small.
204: .P
205: An empty line signals the end of the data lines, at which point a new regular
206: expression is read. The regular expressions are given enclosed in any
207: non-alphanumeric delimiters other than backslash, for example:
208: .sp
209: /(a|bc)x+yz/
210: .sp
211: White space before the initial delimiter is ignored. A regular expression may
212: be continued over several input lines, in which case the newline characters are
213: included within it. It is possible to include the delimiter within the pattern
214: by escaping it, for example
215: .sp
216: /abc\e/def/
217: .sp
218: If you do so, the escape and the delimiter form part of the pattern, but since
219: delimiters are always non-alphanumeric, this does not affect its interpretation.
220: If the terminating delimiter is immediately followed by a backslash, for
221: example,
222: .sp
223: /abc/\e
224: .sp
225: then a backslash is added to the end of the pattern. This is done to provide a
226: way of testing the error condition that arises if a pattern finishes with a
227: backslash, because
228: .sp
229: /abc\e/
230: .sp
231: is interpreted as the first line of a pattern that starts with "abc/", causing
232: pcretest to read the next line as a continuation of the regular expression.
233: .
234: .
235: .SH "PATTERN MODIFIERS"
236: .rs
237: .sp
238: A pattern may be followed by any number of modifiers, which are mostly single
239: characters. Following Perl usage, these are referred to below as, for example,
240: "the \fB/i\fP modifier", even though the delimiter of the pattern need not
241: always be a slash, and no slash is used when writing modifiers. White space may
242: appear between the final pattern delimiter and the first modifier, and between
243: the modifiers themselves.
244: .P
245: The \fB/i\fP, \fB/m\fP, \fB/s\fP, and \fB/x\fP modifiers set the PCRE_CASELESS,
246: PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
1.1.1.2 misho 247: \fBpcre[16]_compile()\fP is called. These four modifier letters have the same
1.1 misho 248: effect as they do in Perl. For example:
249: .sp
250: /caseless/i
251: .sp
252: The following table shows additional modifiers for setting PCRE compile-time
253: options that do not correspond to anything in Perl:
254: .sp
1.1.1.2 misho 255: \fB/8\fP PCRE_UTF8 ) when using the 8-bit
256: \fB/?\fP PCRE_NO_UTF8_CHECK ) library
257: .sp
258: \fB/8\fP PCRE_UTF16 ) when using the 16-bit
259: \fB/?\fP PCRE_NO_UTF16_CHECK ) library
260: .sp
1.1 misho 261: \fB/A\fP PCRE_ANCHORED
262: \fB/C\fP PCRE_AUTO_CALLOUT
263: \fB/E\fP PCRE_DOLLAR_ENDONLY
264: \fB/f\fP PCRE_FIRSTLINE
265: \fB/J\fP PCRE_DUPNAMES
266: \fB/N\fP PCRE_NO_AUTO_CAPTURE
267: \fB/U\fP PCRE_UNGREEDY
268: \fB/W\fP PCRE_UCP
269: \fB/X\fP PCRE_EXTRA
270: \fB/Y\fP PCRE_NO_START_OPTIMIZE
271: \fB/<JS>\fP PCRE_JAVASCRIPT_COMPAT
272: \fB/<cr>\fP PCRE_NEWLINE_CR
273: \fB/<lf>\fP PCRE_NEWLINE_LF
274: \fB/<crlf>\fP PCRE_NEWLINE_CRLF
275: \fB/<anycrlf>\fP PCRE_NEWLINE_ANYCRLF
276: \fB/<any>\fP PCRE_NEWLINE_ANY
277: \fB/<bsr_anycrlf>\fP PCRE_BSR_ANYCRLF
278: \fB/<bsr_unicode>\fP PCRE_BSR_UNICODE
279: .sp
280: The modifiers that are enclosed in angle brackets are literal strings as shown,
281: including the angle brackets, but the letters within can be in either case.
282: This example sets multiline matching with CRLF as the line ending sequence:
283: .sp
284: /^abc/m<CRLF>
285: .sp
1.1.1.2 misho 286: As well as turning on the PCRE_UTF8/16 option, the \fB/8\fP modifier causes
287: all non-printing characters in output strings to be printed using the
288: \ex{hh...} notation. Otherwise, those less than 0x100 are output in hex without
289: the curly brackets.
290: .P
291: Full details of the PCRE options are given in the
1.1 misho 292: .\" HREF
293: \fBpcreapi\fP
294: .\"
295: documentation.
296: .
297: .
298: .SS "Finding all matches in a string"
299: .rs
300: .sp
301: Searching for all possible matches within each subject string can be requested
302: by the \fB/g\fP or \fB/G\fP modifier. After finding a match, PCRE is called
303: again to search the remainder of the subject string. The difference between
304: \fB/g\fP and \fB/G\fP is that the former uses the \fIstartoffset\fP argument to
1.1.1.2 misho 305: \fBpcre[16]_exec()\fP to start searching at a new point within the entire
306: string (which is in effect what Perl does), whereas the latter passes over a
307: shortened substring. This makes a difference to the matching process if the
308: pattern begins with a lookbehind assertion (including \eb or \eB).
1.1 misho 309: .P
1.1.1.2 misho 310: If any call to \fBpcre[16]_exec()\fP in a \fB/g\fP or \fB/G\fP sequence matches
311: an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
1.1 misho 312: PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
313: same point. If this second match fails, the start offset is advanced, and the
314: normal match is retried. This imitates the way Perl handles such cases when
315: using the \fB/g\fP modifier or the \fBsplit()\fP function. Normally, the start
316: offset is advanced by one character, but if the newline convention recognizes
317: CRLF as a newline, and the current character is CR followed by LF, an advance
318: of two is used.
319: .
320: .
321: .SS "Other modifiers"
322: .rs
323: .sp
324: There are yet more modifiers for controlling the way \fBpcretest\fP
325: operates.
326: .P
327: The \fB/+\fP modifier requests that as well as outputting the substring that
328: matched the entire pattern, \fBpcretest\fP should in addition output the
329: remainder of the subject string. This is useful for tests where the subject
330: contains multiple copies of the same substring. If the \fB+\fP modifier appears
331: twice, the same action is taken for captured substrings. In each case the
332: remainder is output on the following line with a plus character following the
333: capture number. Note that this modifier must not immediately follow the /S
1.1.1.3 ! misho 334: modifier because /S+ and /S++ have other meanings.
1.1 misho 335: .P
336: The \fB/=\fP modifier requests that the values of all potential captured
1.1.1.2 misho 337: parentheses be output after a match. By default, only those up to the highest
338: one actually used in the match are output (corresponding to the return code
339: from \fBpcre[16]_exec()\fP). Values in the offsets vector corresponding to
340: higher numbers should be set to -1, and these are output as "<unset>". This
341: modifier gives a way of checking that this is happening.
1.1 misho 342: .P
343: The \fB/B\fP modifier is a debugging feature. It requests that \fBpcretest\fP
1.1.1.2 misho 344: output a representation of the compiled code after compilation. Normally this
345: information contains length and offset values; however, if \fB/Z\fP is also
346: present, this data is replaced by spaces. This is a special feature for use in
347: the automatic test scripts; it ensures that the same output is generated for
348: different internal link sizes.
1.1 misho 349: .P
350: The \fB/D\fP modifier is a PCRE debugging feature, and is equivalent to
351: \fB/BI\fP, that is, both the \fB/B\fP and the \fB/I\fP modifiers.
352: .P
353: The \fB/F\fP modifier causes \fBpcretest\fP to flip the byte order of the
1.1.1.2 misho 354: 2-byte and 4-byte fields in the compiled pattern. This facility is for testing
355: the feature in PCRE that allows it to execute patterns that were compiled on a
356: host with a different endianness. This feature is not available when the POSIX
357: interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
358: specified. See also the section about saving and reloading compiled patterns
359: below.
1.1 misho 360: .P
361: The \fB/I\fP modifier requests that \fBpcretest\fP output information about the
362: compiled pattern (whether it is anchored, has a fixed first character, and
1.1.1.2 misho 363: so on). It does this by calling \fBpcre[16]_fullinfo()\fP after compiling a
1.1 misho 364: pattern. If the pattern is studied, the results of that are also output.
365: .P
366: The \fB/K\fP modifier requests \fBpcretest\fP to show names from backtracking
1.1.1.2 misho 367: control verbs that are returned from calls to \fBpcre[16]_exec()\fP. It causes
368: \fBpcretest\fP to create a \fBpcre[16]_extra\fP block if one has not already
369: been created by a call to \fBpcre[16]_study()\fP, and to set the
370: PCRE_EXTRA_MARK flag and the \fBmark\fP field within it, every time that
371: \fBpcre[16]_exec()\fP is called. If the variable that the \fBmark\fP field
372: points to is non-NULL for a match, non-match, or partial match, \fBpcretest\fP
373: prints the string to which it points. For a match, this is shown on a line by
374: itself, tagged with "MK:". For a non-match it is added to the message.
1.1 misho 375: .P
376: The \fB/L\fP modifier must be followed directly by the name of a locale, for
377: example,
378: .sp
379: /pattern/Lfr_FR
380: .sp
381: For this reason, it must be the last modifier. The given locale is set,
1.1.1.2 misho 382: \fBpcre[16]_maketables()\fP is called to build a set of character tables for
383: the locale, and this is then passed to \fBpcre[16]_compile()\fP when compiling
384: the regular expression. Without an \fB/L\fP (or \fB/T\fP) modifier, NULL is
385: passed as the tables pointer; that is, \fB/L\fP applies only to the expression
386: on which it appears.
387: .P
388: The \fB/M\fP modifier causes the size in bytes of the memory block used to hold
389: the compiled pattern to be output. This does not include the size of the
390: \fBpcre[16]\fP block; it is just the actual compiled data. If the pattern is
391: successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the
392: JIT compiled code is also output.
1.1 misho 393: .P
1.1.1.2 misho 394: If the \fB/S\fP modifier appears once, it causes \fBpcre[16]_study()\fP to be
1.1 misho 395: called after the expression has been compiled, and the results used when the
396: expression is matched. If \fB/S\fP appears twice, it suppresses studying, even
397: if it was requested externally by the \fB-s\fP command line option. This makes
398: it possible to specify that certain patterns are always studied, and others are
399: never studied, independently of \fB-s\fP. This feature is used in the test
400: files in a few cases where the output is different when the pattern is studied.
401: .P
402: If the \fB/S\fP modifier is immediately followed by a + character, the call to
1.1.1.3 ! misho 403: \fBpcre[16]_study()\fP is made with all the JIT study options, requesting
! 404: just-in-time optimization support if it is available, for both normal and
! 405: partial matching. If you want to restrict the JIT compiling modes, you can
! 406: follow \fB/S+\fP with a digit in the range 1 to 7:
! 407: .sp
! 408: 1 normal match only
! 409: 2 soft partial match only
! 410: 3 normal match and soft partial match
! 411: 4 hard partial match only
! 412: 6 soft and hard partial match
! 413: 7 all three modes (default)
! 414: .sp
! 415: If \fB/S++\fP is used instead of \fB/S+\fP (with or without a following digit),
! 416: the text "(JIT)" is added to the first output line after a match or no match
! 417: when JIT-compiled code was actually used.
! 418: .P
! 419: Note that there is also an independent \fB/+\fP modifier; it must not be given
! 420: immediately after \fB/S\fP or \fB/S+\fP because this will be misinterpreted.
! 421: .P
! 422: If JIT studying is successful, the compiled JIT code will automatically be used
! 423: when \fBpcre[16]_exec()\fP is run, except when incompatible run-time options
! 424: are specified. For more details, see the
1.1 misho 425: .\" HREF
426: \fBpcrejit\fP
427: .\"
428: documentation. See also the \fB\eJ\fP escape sequence below for a way of
429: setting the size of the JIT stack.
430: .P
431: The \fB/T\fP modifier must be followed by a single digit. It causes a specific
1.1.1.2 misho 432: set of built-in character tables to be passed to \fBpcre[16]_compile()\fP. It
433: is used in the standard PCRE tests to check behaviour with different character
1.1 misho 434: tables. The digit specifies the tables as follows:
435: .sp
436: 0 the default ASCII tables, as distributed in
437: pcre_chartables.c.dist
438: 1 a set of tables defining ISO 8859 characters
439: .sp
440: In table 1, some characters whose codes are greater than 128 are identified as
441: letters, digits, spaces, etc.
442: .
443: .
444: .SS "Using the POSIX wrapper API"
445: .rs
446: .sp
447: The \fB/P\fP modifier causes \fBpcretest\fP to call PCRE via the POSIX wrapper
1.1.1.2 misho 448: API rather than its native API. This supports only the 8-bit library. When
449: \fB/P\fP is set, the following modifiers set options for the \fBregcomp()\fP
450: function:
1.1 misho 451: .sp
452: /i REG_ICASE
453: /m REG_NEWLINE
454: /N REG_NOSUB
455: /s REG_DOTALL )
456: /U REG_UNGREEDY ) These options are not part of
457: /W REG_UCP ) the POSIX standard
458: /8 REG_UTF8 )
459: .sp
460: The \fB/+\fP modifier works as described above. All other modifiers are
461: ignored.
462: .
463: .
464: .SH "DATA LINES"
465: .rs
466: .sp
1.1.1.2 misho 467: Before each data line is passed to \fBpcre[16]_exec()\fP, leading and trailing
1.1 misho 468: white space is removed, and it is then scanned for \e escapes. Some of these
469: are pretty esoteric features, intended for checking out some of the more
470: complicated features of PCRE. If you are just testing "ordinary" regular
471: expressions, you probably don't need any of these. The following escapes are
472: recognized:
473: .sp
474: \ea alarm (BEL, \ex07)
475: \eb backspace (\ex08)
476: \ee escape (\ex27)
477: \ef form feed (\ex0c)
478: \en newline (\ex0a)
479: .\" JOIN
480: \eqdd set the PCRE_MATCH_LIMIT limit to dd
481: (any number of digits)
482: \er carriage return (\ex0d)
483: \et tab (\ex09)
484: \ev vertical tab (\ex0b)
1.1.1.2 misho 485: \ennn octal character (up to 3 octal digits); always
486: a byte unless > 255 in UTF-8 or 16-bit mode
1.1 misho 487: \exhh hexadecimal byte (up to 2 hex digits)
1.1.1.2 misho 488: \ex{hh...} hexadecimal character (any number of hex digits)
1.1 misho 489: .\" JOIN
1.1.1.2 misho 490: \eA pass the PCRE_ANCHORED option to \fBpcre[16]_exec()\fP
491: or \fBpcre[16]_dfa_exec()\fP
1.1 misho 492: .\" JOIN
1.1.1.2 misho 493: \eB pass the PCRE_NOTBOL option to \fBpcre[16]_exec()\fP
494: or \fBpcre[16]_dfa_exec()\fP
1.1 misho 495: .\" JOIN
1.1.1.2 misho 496: \eCdd call pcre[16]_copy_substring() for substring dd
1.1 misho 497: after a successful match (number less than 32)
498: .\" JOIN
1.1.1.2 misho 499: \eCname call pcre[16]_copy_named_substring() for substring
1.1 misho 500: "name" after a successful match (name termin-
501: ated by next non alphanumeric character)
502: .\" JOIN
503: \eC+ show the current captured substrings at callout
504: time
505: \eC- do not supply a callout function
506: .\" JOIN
507: \eC!n return 1 instead of 0 when callout number n is
508: reached
509: .\" JOIN
510: \eC!n!m return 1 instead of 0 when callout number n is
511: reached for the nth time
512: .\" JOIN
513: \eC*n pass the number n (may be negative) as callout
514: data; this is used as the callout return value
1.1.1.2 misho 515: \eD use the \fBpcre[16]_dfa_exec()\fP match function
516: \eF only shortest match for \fBpcre[16]_dfa_exec()\fP
1.1 misho 517: .\" JOIN
1.1.1.2 misho 518: \eGdd call pcre[16]_get_substring() for substring dd
1.1 misho 519: after a successful match (number less than 32)
520: .\" JOIN
1.1.1.2 misho 521: \eGname call pcre[16]_get_named_substring() for substring
1.1 misho 522: "name" after a successful match (name termin-
523: ated by next non-alphanumeric character)
524: .\" JOIN
525: \eJdd set up a JIT stack of dd kilobytes maximum (any
526: number of digits)
527: .\" JOIN
1.1.1.2 misho 528: \eL call pcre[16]_get_substringlist() after a
1.1 misho 529: successful match
530: .\" JOIN
531: \eM discover the minimum MATCH_LIMIT and
532: MATCH_LIMIT_RECURSION settings
533: .\" JOIN
1.1.1.2 misho 534: \eN pass the PCRE_NOTEMPTY option to \fBpcre[16]_exec()\fP
535: or \fBpcre[16]_dfa_exec()\fP; if used twice, pass the
1.1 misho 536: PCRE_NOTEMPTY_ATSTART option
537: .\" JOIN
538: \eOdd set the size of the output vector passed to
1.1.1.2 misho 539: \fBpcre[16]_exec()\fP to dd (any number of digits)
1.1 misho 540: .\" JOIN
1.1.1.2 misho 541: \eP pass the PCRE_PARTIAL_SOFT option to \fBpcre[16]_exec()\fP
542: or \fBpcre[16]_dfa_exec()\fP; if used twice, pass the
1.1 misho 543: PCRE_PARTIAL_HARD option
544: .\" JOIN
545: \eQdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd
546: (any number of digits)
1.1.1.2 misho 547: \eR pass the PCRE_DFA_RESTART option to \fBpcre[16]_dfa_exec()\fP
1.1 misho 548: \eS output details of memory get/free calls during matching
549: .\" JOIN
1.1.1.2 misho 550: \eY pass the PCRE_NO_START_OPTIMIZE option to \fBpcre[16]_exec()\fP
551: or \fBpcre[16]_dfa_exec()\fP
1.1 misho 552: .\" JOIN
1.1.1.2 misho 553: \eZ pass the PCRE_NOTEOL option to \fBpcre[16]_exec()\fP
554: or \fBpcre[16]_dfa_exec()\fP
1.1 misho 555: .\" JOIN
1.1.1.2 misho 556: \e? pass the PCRE_NO_UTF[8|16]_CHECK option to
557: \fBpcre[16]_exec()\fP or \fBpcre[16]_dfa_exec()\fP
1.1 misho 558: .\" JOIN
559: \e>dd start the match at offset dd (optional "-"; then
560: any number of digits); this sets the \fIstartoffset\fP
1.1.1.2 misho 561: argument for \fBpcre[16]_exec()\fP or \fBpcre[16]_dfa_exec()\fP
1.1 misho 562: .\" JOIN
1.1.1.2 misho 563: \e<cr> pass the PCRE_NEWLINE_CR option to \fBpcre[16]_exec()\fP
564: or \fBpcre[16]_dfa_exec()\fP
1.1 misho 565: .\" JOIN
1.1.1.2 misho 566: \e<lf> pass the PCRE_NEWLINE_LF option to \fBpcre[16]_exec()\fP
567: or \fBpcre[16]_dfa_exec()\fP
1.1 misho 568: .\" JOIN
1.1.1.2 misho 569: \e<crlf> pass the PCRE_NEWLINE_CRLF option to \fBpcre[16]_exec()\fP
570: or \fBpcre[16]_dfa_exec()\fP
1.1 misho 571: .\" JOIN
1.1.1.2 misho 572: \e<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to \fBpcre[16]_exec()\fP
573: or \fBpcre[16]_dfa_exec()\fP
1.1 misho 574: .\" JOIN
1.1.1.2 misho 575: \e<any> pass the PCRE_NEWLINE_ANY option to \fBpcre[16]_exec()\fP
576: or \fBpcre[16]_dfa_exec()\fP
1.1 misho 577: .sp
1.1.1.2 misho 578: The use of \ex{hh...} is not dependent on the use of the \fB/8\fP modifier on
579: the pattern. It is recognized always. There may be any number of hexadecimal
580: digits inside the braces; invalid values provoke error messages.
581: .P
582: Note that \exhh specifies one byte rather than one character in UTF-8 mode;
583: this makes it possible to construct invalid UTF-8 sequences for testing
584: purposes. On the other hand, \ex{hh} is interpreted as a UTF-8 character in
585: UTF-8 mode, generating more than one byte if the value is greater than 127.
586: When testing the 8-bit library not in UTF-8 mode, \ex{hh} generates one byte
587: for values less than 256, and causes an error for greater values.
588: .P
589: In UTF-16 mode, all 4-digit \ex{hhhh} values are accepted. This makes it
590: possible to construct invalid UTF-16 sequences for testing purposes.
1.1 misho 591: .P
592: The escapes that specify line ending sequences are literal strings, exactly as
593: shown. No more than one newline setting should be present in any data line.
594: .P
595: A backslash followed by anything else just escapes the anything else. If
596: the very last character is a backslash, it is ignored. This gives a way of
597: passing an empty line as data, since a real empty line terminates the data
598: input.
599: .P
600: The \fB\eJ\fP escape provides a way of setting the maximum stack size that is
601: used by the just-in-time optimization code. It is ignored if JIT optimization
602: is not being used. Providing a stack that is larger than the default 32K is
603: necessary only for very complicated patterns.
604: .P
1.1.1.2 misho 605: If \eM is present, \fBpcretest\fP calls \fBpcre[16]_exec()\fP several times,
606: with different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP
607: fields of the \fBpcre[16]_extra\fP data structure, until it finds the minimum
608: numbers for each parameter that allow \fBpcre[16]_exec()\fP to complete without
1.1 misho 609: error. Because this is testing a specific feature of the normal interpretive
1.1.1.2 misho 610: \fBpcre[16]_exec()\fP execution, the use of any JIT optimization that might
611: have been set up by the \fB/S+\fP qualifier of \fB-s+\fP option is disabled.
1.1 misho 612: .P
613: The \fImatch_limit\fP number is a measure of the amount of backtracking
614: that takes place, and checking it out can be instructive. For most simple
615: matches, the number is quite small, but for patterns with very large numbers of
616: matching possibilities, it can become large very quickly with increasing length
617: of subject string. The \fImatch_limit_recursion\fP number is a measure of how
618: much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
619: needed to complete the match attempt.
620: .P
621: When \eO is used, the value specified may be higher or lower than the size set
622: by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to
1.1.1.2 misho 623: the call of \fBpcre[16]_exec()\fP for the line in which it appears.
1.1 misho 624: .P
625: If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper
626: API to be used, the only option-setting sequences that have any effect are \eB,
627: \eN, and \eZ, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
628: to be passed to \fBregexec()\fP.
629: .
630: .
631: .SH "THE ALTERNATIVE MATCHING FUNCTION"
632: .rs
633: .sp
634: By default, \fBpcretest\fP uses the standard PCRE matching function,
1.1.1.2 misho 635: \fBpcre[16]_exec()\fP to match each data line. PCRE also supports an
636: alternative matching function, \fBpcre[16]_dfa_test()\fP, which operates in a
1.1 misho 637: different way, and has some restrictions. The differences between the two
638: functions are described in the
639: .\" HREF
640: \fBpcrematching\fP
641: .\"
642: documentation.
643: .P
644: If a data line contains the \eD escape sequence, or if the command line
1.1.1.2 misho 645: contains the \fB-dfa\fP option, the alternative matching function is used.
1.1 misho 646: This function finds all possible matches at a given point. If, however, the \eF
647: escape sequence is present in the data line, it stops after the first match is
648: found. This is always the shortest possible match.
649: .
650: .
651: .SH "DEFAULT OUTPUT FROM PCRETEST"
652: .rs
653: .sp
654: This section describes the output when the normal matching function,
1.1.1.2 misho 655: \fBpcre[16]_exec()\fP, is being used.
1.1 misho 656: .P
657: When a match succeeds, \fBpcretest\fP outputs the list of captured substrings
1.1.1.2 misho 658: that \fBpcre[16]_exec()\fP returns, starting with number 0 for the string that
1.1 misho 659: matched the whole pattern. Otherwise, it outputs "No match" when the return is
660: PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
1.1.1.2 misho 661: substring when \fBpcre[16]_exec()\fP returns PCRE_ERROR_PARTIAL. (Note that
662: this is the entire substring that was inspected during the partial match; it
663: may include characters before the actual match start if a lookbehind assertion,
1.1 misho 664: \eK, \eb, or \eB was involved.) For any other return, \fBpcretest\fP outputs
665: the PCRE negative error number and a short descriptive phrase. If the error is
1.1.1.2 misho 666: a failed UTF string check, the offset of the start of the failing character and
667: the reason code are also output, provided that the size of the output vector is
668: at least two. Here is an example of an interactive \fBpcretest\fP run.
1.1 misho 669: .sp
670: $ pcretest
671: PCRE version 8.13 2011-04-30
672: .sp
673: re> /^abc(\ed+)/
674: data> abc123
675: 0: abc123
676: 1: 123
677: data> xyz
678: No match
679: .sp
680: Unset capturing substrings that are not followed by one that is set are not
1.1.1.2 misho 681: returned by \fBpcre[16]_exec()\fP, and are not shown by \fBpcretest\fP. In the
1.1 misho 682: following example, there are two capturing substrings, but when the first data
683: line is matched, the second, unset substring is not shown. An "internal" unset
684: substring is shown as "<unset>", as for the second data line.
685: .sp
686: re> /(a)|(b)/
687: data> a
688: 0: a
689: 1: a
690: data> b
691: 0: b
692: 1: <unset>
693: 2: b
694: .sp
1.1.1.2 misho 695: If the strings contain any non-printing characters, they are output as \exhh
696: escapes if the value is less than 256 and UTF mode is not set. Otherwise they
697: are output as \ex{hh...} escapes. See below for the definition of non-printing
698: characters. If the pattern has the \fB/+\fP modifier, the output for substring
699: 0 is followed by the the rest of the subject string, identified by "0+" like
700: this:
1.1 misho 701: .sp
702: re> /cat/+
703: data> cataract
704: 0: cat
705: 0+ aract
706: .sp
707: If the pattern has the \fB/g\fP or \fB/G\fP modifier, the results of successive
708: matching attempts are output in sequence, like this:
709: .sp
710: re> /\eBi(\ew\ew)/g
711: data> Mississippi
712: 0: iss
713: 1: ss
714: 0: iss
715: 1: ss
716: 0: ipp
717: 1: pp
718: .sp
719: "No match" is output only if the first match attempt fails. Here is an example
720: of a failure message (the offset 4 that is specified by \e>4 is past the end of
721: the subject string):
722: .sp
723: re> /xyz/
724: data> xyz\e>4
725: Error -24 (bad offset value)
726: .P
727: If any of the sequences \fB\eC\fP, \fB\eG\fP, or \fB\eL\fP are present in a
728: data line that is successfully matched, the substrings extracted by the
729: convenience functions are output with C, G, or L after the string number
730: instead of a colon. This is in addition to the normal full list. The string
731: length (that is, the return from the extraction function) is given in
732: parentheses after each string for \fB\eC\fP and \fB\eG\fP.
733: .P
734: Note that whereas patterns can be continued over several lines (a plain ">"
735: prompt is used for continuations), data lines may not. However newlines can be
736: included in data by means of the \en escape (or \er, \er\en, etc., depending on
737: the newline sequence setting).
738: .
739: .
740: .
741: .SH "OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION"
742: .rs
743: .sp
1.1.1.2 misho 744: When the alternative matching function, \fBpcre[16]_dfa_exec()\fP, is used (by
1.1 misho 745: means of the \eD escape sequence or the \fB-dfa\fP command line option), the
746: output consists of a list of all the matches that start at the first point in
747: the subject where there is at least one match. For example:
748: .sp
749: re> /(tang|tangerine|tan)/
750: data> yellow tangerine\eD
751: 0: tangerine
752: 1: tang
753: 2: tan
754: .sp
755: (Using the normal matching function on this data finds only "tang".) The
756: longest matching string is always given first (and numbered zero). After a
757: PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
758: partially matching substring. (Note that this is the entire substring that was
759: inspected during the partial match; it may include characters before the actual
760: match start if a lookbehind assertion, \eK, \eb, or \eB was involved.)
761: .P
762: If \fB/g\fP is present on the pattern, the search for further matches resumes
763: at the end of the longest match. For example:
764: .sp
765: re> /(tang|tangerine|tan)/g
766: data> yellow tangerine and tangy sultana\eD
767: 0: tangerine
768: 1: tang
769: 2: tan
770: 0: tang
771: 1: tan
772: 0: tan
773: .sp
774: Since the matching function does not support substring capture, the escape
775: sequences that are concerned with captured substrings are not relevant.
776: .
777: .
778: .SH "RESTARTING AFTER A PARTIAL MATCH"
779: .rs
780: .sp
781: When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
782: indicating that the subject partially matched the pattern, you can restart the
783: match with additional subject data by means of the \eR escape sequence. For
784: example:
785: .sp
786: re> /^\ed?\ed(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\ed\ed$/
787: data> 23ja\eP\eD
788: Partial match: 23ja
789: data> n05\eR\eD
790: 0: n05
791: .sp
792: For further information about partial matching, see the
793: .\" HREF
794: \fBpcrepartial\fP
795: .\"
796: documentation.
797: .
798: .
799: .SH CALLOUTS
800: .rs
801: .sp
802: If the pattern contains any callout requests, \fBpcretest\fP's callout function
803: is called during matching. This works with both matching functions. By default,
804: the called function displays the callout number, the start and current
805: positions in the text at the callout time, and the next pattern item to be
1.1.1.2 misho 806: tested. For example:
1.1 misho 807: .sp
808: --->pqrabcdef
809: 0 ^ ^ \ed
810: .sp
1.1.1.2 misho 811: This output indicates that callout number 0 occurred for a match attempt
812: starting at the fourth character of the subject string, when the pointer was at
813: the seventh character of the data, and when the next pattern item was \ed. Just
814: one circumflex is output if the start and current positions are the same.
1.1 misho 815: .P
816: Callouts numbered 255 are assumed to be automatic callouts, inserted as a
817: result of the \fB/C\fP pattern modifier. In this case, instead of showing the
818: callout number, the offset in the pattern, preceded by a plus, is output. For
819: example:
820: .sp
821: re> /\ed?[A-E]\e*/C
822: data> E*
823: --->E*
824: +0 ^ \ed?
825: +3 ^ [A-E]
826: +8 ^^ \e*
827: +10 ^ ^
828: 0: E*
829: .sp
830: If a pattern contains (*MARK) items, an additional line is output whenever
831: a change of latest mark is passed to the callout function. For example:
832: .sp
833: re> /a(*MARK:X)bc/C
834: data> abc
835: --->abc
836: +0 ^ a
837: +1 ^^ (*MARK:X)
838: +10 ^^ b
839: Latest Mark: X
840: +11 ^ ^ c
841: +12 ^ ^
842: 0: abc
843: .sp
844: The mark changes between matching "a" and "b", but stays the same for the rest
845: of the match, so nothing more is output. If, as a result of backtracking, the
846: mark reverts to being unset, the text "<unset>" is output.
847: .P
848: The callout function in \fBpcretest\fP returns zero (carry on matching) by
849: default, but you can use a \eC item in a data line (as described above) to
850: change this and other parameters of the callout.
851: .P
852: Inserting callouts can be helpful when using \fBpcretest\fP to check
853: complicated regular expressions. For further information about callouts, see
854: the
855: .\" HREF
856: \fBpcrecallout\fP
857: .\"
858: documentation.
859: .
860: .
861: .
862: .SH "NON-PRINTING CHARACTERS"
863: .rs
864: .sp
865: When \fBpcretest\fP is outputting text in the compiled version of a pattern,
866: bytes other than 32-126 are always treated as non-printing characters are are
867: therefore shown as hex escapes.
868: .P
869: When \fBpcretest\fP is outputting text that is a matched part of a subject
870: string, it behaves in the same way, unless a different locale has been set for
871: the pattern (using the \fB/L\fP modifier). In this case, the \fBisprint()\fP
872: function to distinguish printing and non-printing characters.
873: .
874: .
875: .
876: .SH "SAVING AND RELOADING COMPILED PATTERNS"
877: .rs
878: .sp
879: The facilities described in this section are not available when the POSIX
880: interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
881: specified.
882: .P
883: When the POSIX interface is not in use, you can cause \fBpcretest\fP to write a
884: compiled pattern to a file, by following the modifiers with > and a file name.
885: For example:
886: .sp
887: /pattern/im >/some/file
888: .sp
889: See the
890: .\" HREF
891: \fBpcreprecompile\fP
892: .\"
893: documentation for a discussion about saving and re-using compiled patterns.
894: Note that if the pattern was successfully studied with JIT optimization, the
895: JIT data cannot be saved.
896: .P
897: The data that is written is binary. The first eight bytes are the length of the
898: compiled pattern data followed by the length of the optional study data, each
899: written as four bytes in big-endian order (most significant byte first). If
900: there is no study data (either the pattern was not studied, or studying did not
901: return any data), the second length is zero. The lengths are followed by an
902: exact copy of the compiled pattern. If there is additional study data, this
903: (excluding any JIT data) follows immediately after the compiled pattern. After
904: writing the file, \fBpcretest\fP expects to read a new pattern.
905: .P
906: A saved pattern can be reloaded into \fBpcretest\fP by specifying < and a file
907: name instead of a pattern. The name of the file must not contain a < character,
908: as otherwise \fBpcretest\fP will interpret the line as a pattern delimited by <
909: characters.
910: For example:
911: .sp
912: re> </some/file
913: Compiled pattern loaded from /some/file
914: No study data
915: .sp
916: If the pattern was previously studied with the JIT optimization, the JIT
917: information cannot be saved and restored, and so is lost. When the pattern has
918: been loaded, \fBpcretest\fP proceeds to read data lines in the usual way.
919: .P
920: You can copy a file written by \fBpcretest\fP to a different host and reload it
921: there, even if the new host has opposite endianness to the one on which the
922: pattern was compiled. For example, you can compile on an i86 machine and run on
1.1.1.2 misho 923: a SPARC machine. When a pattern is reloaded on a host with different
924: endianness, the confirmation message is changed to:
925: .sp
926: Compiled pattern (byte-inverted) loaded from /some/file
927: .sp
928: The test suite contains some saved pre-compiled patterns with different
929: endianness. These are reloaded using "<!" instead of just "<". This suppresses
930: the "(byte-inverted)" text so that the output is the same on all hosts. It also
931: forces debugging output once the pattern has been reloaded.
1.1 misho 932: .P
933: File names for saving and reloading can be absolute or relative, but note that
934: the shell facility of expanding a file name that starts with a tilde (~) is not
935: available.
936: .P
937: The ability to save and reload files in \fBpcretest\fP is intended for testing
938: and experimentation. It is not intended for production use because only a
939: single pattern can be written to a file. Furthermore, there is no facility for
940: supplying custom character tables for use with a reloaded pattern. If the
941: original pattern was compiled with custom tables, an attempt to match a subject
942: string using a reloaded pattern is likely to cause \fBpcretest\fP to crash.
943: Finally, if you attempt to load a file that is not in the correct format, the
944: result is undefined.
945: .
946: .
947: .SH "SEE ALSO"
948: .rs
949: .sp
1.1.1.2 misho 950: \fBpcre\fP(3), \fBpcre16\fP(3), \fBpcreapi\fP(3), \fBpcrecallout\fP(3),
951: \fBpcrejit\fP, \fBpcrematching\fP(3), \fBpcrepartial\fP(d),
952: \fBpcrepattern\fP(3), \fBpcreprecompile\fP(3).
1.1 misho 953: .
954: .
955: .SH AUTHOR
956: .rs
957: .sp
958: .nf
959: Philip Hazel
960: University Computing Service
961: Cambridge CB2 3QH, England.
962: .fi
963: .
964: .
965: .SH REVISION
966: .rs
967: .sp
968: .nf
1.1.1.3 ! misho 969: Last updated: 21 February 2012
1.1.1.2 misho 970: Copyright (c) 1997-2012 University of Cambridge.
1.1 misho 971: .fi
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