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revision 53 by nigel, Sat Feb 24 21:39:42 2007 UTC revision 576 by ph10, Sun Nov 21 18:45:10 2010 UTC
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2  .SH NAME  .SH NAME
3  pcretest - a program for testing Perl-compatible regular expressions.  pcretest - a program for testing Perl-compatible regular expressions.
4  .SH SYNOPSIS  .SH SYNOPSIS
5  .B pcretest "[-d] [-i] [-m] [-o osize] [-p] [-t] [source] [destination]"  .rs
6    .sp
7  \fBpcretest\fR was written as a test program for the PCRE regular expression  .B pcretest "[options] [source] [destination]"
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  library itself, but it can also be used for experimenting with regular
11  expressions. This man page describes the features of the test program; for  expressions. This document describes the features of the test program; for
12  details of the regular expressions themselves, see the \fBpcre\fR man page.  details of the regular expressions themselves, see the
13    .\" HREF
14    \fBpcrepattern\fP
15    .\"
16    documentation. For details of the PCRE library function calls and their
17    options, see the
18    .\" HREF
19    \fBpcreapi\fP
20    .\"
21    documentation.
22    .
23    .
24  .SH OPTIONS  .SH OPTIONS
25    .rs
26  .TP 10  .TP 10
27  \fB-d\fR  \fB-b\fP
28  Behave as if each regex had the \fB/D\fR modifier (see below); the internal  Behave as if each regex has the \fB/B\fP (show bytecode) modifier; the internal
29  form is output after compilation.  form is output after compilation.
30  .TP 10  .TP 10
31  \fB-i\fR  \fB-C\fP
32  Behave as if each regex had the \fB/I\fR modifier; information about the  Output the version number of the PCRE library, and all available information
33    about the optional features that are included, and then exit.
34    .TP 10
35    \fB-d\fP
36    Behave as if each regex has the \fB/D\fP (debug) modifier; the internal
37    form and information about the compiled pattern is output after compilation;
38    \fB-d\fP is equivalent to \fB-b -i\fP.
39    .TP 10
40    \fB-dfa\fP
41    Behave as if each data line contains the \eD escape sequence; this causes the
42    alternative matching function, \fBpcre_dfa_exec()\fP, to be used instead of the
43    standard \fBpcre_exec()\fP function (more detail is given below).
44    .TP 10
45    \fB-help\fP
46    Output a brief summary these options and then exit.
47    .TP 10
48    \fB-i\fP
49    Behave as if each regex has the \fB/I\fP modifier; information about the
50  compiled pattern is given after compilation.  compiled pattern is given after compilation.
51  .TP 10  .TP 10
52  \fB-m\fR  \fB-M\fP
53    Behave as if each data line contains the \eM escape sequence; this causes
54    PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
55    calling \fBpcre_exec()\fP repeatedly with different limits.
56    .TP 10
57    \fB-m\fP
58  Output the size of each compiled pattern after it has been compiled. This is  Output the size of each compiled pattern after it has been compiled. This is
59  equivalent to adding /M to each regular expression. For compatibility with  equivalent to adding \fB/M\fP to each regular expression. For compatibility
60  earlier versions of pcretest, \fB-s\fR is a synonym for \fB-m\fR.  with earlier versions of pcretest, \fB-s\fP is a synonym for \fB-m\fP.
61    .TP 10
62    \fB-o\fP \fIosize\fP
63    Set the number of elements in the output vector that is used when calling
64    \fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP to be \fIosize\fP. The default value
65    is 45, which is enough for 14 capturing subexpressions for \fBpcre_exec()\fP or
66    22 different matches for \fBpcre_dfa_exec()\fP. The vector size can be
67    changed for individual matching calls by including \eO in the data line (see
68    below).
69  .TP 10  .TP 10
70  \fB-o\fR \fIosize\fR  \fB-p\fP
71  Set the number of elements in the output vector that is used when calling PCRE  Behave as if each regex has the \fB/P\fP modifier; the POSIX wrapper API is
72  to be \fIosize\fR. The default value is 45, which is enough for 14 capturing  used to call PCRE. None of the other options has any effect when \fB-p\fP is
73  subexpressions. The vector size can be changed for individual matching calls by  set.
74  including \\O in the data line (see below).  .TP 10
75  .TP 10  \fB-q\fP
76  \fB-p\fR  Do not output the version number of \fBpcretest\fP at the start of execution.
77  Behave as if each regex has \fB/P\fR modifier; the POSIX wrapper API is used  .TP 10
78  to call PCRE. None of the other options has any effect when \fB-p\fR is set.  \fB-S\fP \fIsize\fP
79  .TP 10  On Unix-like systems, set the size of the runtime stack to \fIsize\fP
80  \fB-t\fR  megabytes.
81  Run each compile, study, and match 20000 times with a timer, and output  .TP 10
82  resulting time per compile or match (in milliseconds). Do not set \fB-t\fR with  \fB-t\fP
83  \fB-m\fR, because you will then get the size output 20000 times and the timing  Run each compile, study, and match many times with a timer, and output
84  will be distorted.  resulting time per compile or match (in milliseconds). Do not set \fB-m\fP with
85    \fB-t\fP, because you will then get the size output a zillion times, and the
86    timing will be distorted. You can control the number of iterations that are
87    used for timing by following \fB-t\fP with a number (as a separate item on the
88    command line). For example, "-t 1000" would iterate 1000 times. The default is
89    to iterate 500000 times.
90    .TP 10
91    \fB-tm\fP
92    This is like \fB-t\fP except that it times only the matching phase, not the
93    compile or study phases.
94    .
95    .
96  .SH DESCRIPTION  .SH DESCRIPTION
97    .rs
98  If \fBpcretest\fR is given two filename arguments, it reads from the first and  .sp
99    If \fBpcretest\fP is given two filename arguments, it reads from the first and
100  writes to the second. If it is given only one filename argument, it reads from  writes to the second. If it is given only one filename argument, it reads from
101  that file and writes to stdout. Otherwise, it reads from stdin and writes to  that file and writes to stdout. Otherwise, it reads from stdin and writes to
102  stdout, and prompts for each line of input, using "re>" to prompt for regular  stdout, and prompts for each line of input, using "re>" to prompt for regular
103  expressions, and "data>" to prompt for data lines.  expressions, and "data>" to prompt for data lines.
104    .P
105    When \fBpcretest\fP is built, a configuration option can specify that it should
106    be linked with the \fBlibreadline\fP library. When this is done, if the input
107    is from a terminal, it is read using the \fBreadline()\fP function. This
108    provides line-editing and history facilities. The output from the \fB-help\fP
109    option states whether or not \fBreadline()\fP will be used.
110    .P
111  The program handles any number of sets of input on a single input file. Each  The program handles any number of sets of input on a single input file. Each
112  set starts with a regular expression, and continues with any number of data  set starts with a regular expression, and continues with any number of data
113  lines to be matched against the pattern. An empty line signals the end of the  lines to be matched against the pattern.
114  data lines, at which point a new regular expression is read. The regular  .P
115  expressions are given enclosed in any non-alphameric delimiters other than  Each data line is matched separately and independently. If you want to do
116  backslash, for example  multi-line matches, you have to use the \en escape sequence (or \er or \er\en,
117    etc., depending on the newline setting) in a single line of input to encode the
118    newline sequences. There is no limit on the length of data lines; the input
119    buffer is automatically extended if it is too small.
120    .P
121    An empty line signals the end of the data lines, at which point a new regular
122    expression is read. The regular expressions are given enclosed in any
123    non-alphanumeric delimiters other than backslash, for example:
124    .sp
125    /(a|bc)x+yz/    /(a|bc)x+yz/
126    .sp
127  White space before the initial delimiter is ignored. A regular expression may  White space before the initial delimiter is ignored. A regular expression may
128  be continued over several input lines, in which case the newline characters are  be continued over several input lines, in which case the newline characters are
129  included within it. It is possible to include the delimiter within the pattern  included within it. It is possible to include the delimiter within the pattern
130  by escaping it, for example  by escaping it, for example
131    .sp
132    /abc\\/def/    /abc\e/def/
133    .sp
134  If you do so, the escape and the delimiter form part of the pattern, but since  If you do so, the escape and the delimiter form part of the pattern, but since
135  delimiters are always non-alphameric, this does not affect its interpretation.  delimiters are always non-alphanumeric, this does not affect its interpretation.
136  If the terminating delimiter is immediately followed by a backslash, for  If the terminating delimiter is immediately followed by a backslash, for
137  example,  example,
138    .sp
139    /abc/\\    /abc/\e
140    .sp
141  then a backslash is added to the end of the pattern. This is done to provide a  then a backslash is added to the end of the pattern. This is done to provide a
142  way of testing the error condition that arises if a pattern finishes with a  way of testing the error condition that arises if a pattern finishes with a
143  backslash, because  backslash, because
144    .sp
145    /abc\\/    /abc\e/
146    .sp
147  is interpreted as the first line of a pattern that starts with "abc/", causing  is interpreted as the first line of a pattern that starts with "abc/", causing
148  pcretest to read the next line as a continuation of the regular expression.  pcretest to read the next line as a continuation of the regular expression.
149    .
150    .
151  .SH PATTERN MODIFIERS  .SH "PATTERN MODIFIERS"
152    .rs
153  The pattern may be followed by \fBi\fR, \fBm\fR, \fBs\fR, or \fBx\fR to set the  .sp
154  PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options,  A pattern may be followed by any number of modifiers, which are mostly single
155  respectively. For example:  characters. Following Perl usage, these are referred to below as, for example,
156    "the \fB/i\fP modifier", even though the delimiter of the pattern need not
157    always be a slash, and no slash is used when writing modifiers. Whitespace may
158    appear between the final pattern delimiter and the first modifier, and between
159    the modifiers themselves.
160    .P
161    The \fB/i\fP, \fB/m\fP, \fB/s\fP, and \fB/x\fP modifiers set the PCRE_CASELESS,
162    PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
163    \fBpcre_compile()\fP is called. These four modifier letters have the same
164    effect as they do in Perl. For example:
165    .sp
166    /caseless/i    /caseless/i
167    .sp
168  These modifier letters have the same effect as they do in Perl. There are  The following table shows additional modifiers for setting PCRE compile-time
169  others which set PCRE options that do not correspond to anything in Perl:  options that do not correspond to anything in Perl:
170  \fB/A\fR, \fB/E\fR, and \fB/X\fR set PCRE_ANCHORED, PCRE_DOLLAR_ENDONLY, and  .sp
171  PCRE_EXTRA respectively.    \fB/8\fP              PCRE_UTF8
172      \fB/?\fP              PCRE_NO_UTF8_CHECK
173      \fB/A\fP              PCRE_ANCHORED
174      \fB/C\fP              PCRE_AUTO_CALLOUT
175      \fB/E\fP              PCRE_DOLLAR_ENDONLY
176      \fB/f\fP              PCRE_FIRSTLINE
177      \fB/J\fP              PCRE_DUPNAMES
178      \fB/N\fP              PCRE_NO_AUTO_CAPTURE
179      \fB/U\fP              PCRE_UNGREEDY
180      \fB/W\fP              PCRE_UCP
181      \fB/X\fP              PCRE_EXTRA
182      \fB/Y\fP              PCRE_NO_START_OPTIMIZE
183      \fB/<JS>\fP           PCRE_JAVASCRIPT_COMPAT
184      \fB/<cr>\fP           PCRE_NEWLINE_CR
185      \fB/<lf>\fP           PCRE_NEWLINE_LF
186      \fB/<crlf>\fP         PCRE_NEWLINE_CRLF
187      \fB/<anycrlf>\fP      PCRE_NEWLINE_ANYCRLF
188      \fB/<any>\fP          PCRE_NEWLINE_ANY
189      \fB/<bsr_anycrlf>\fP  PCRE_BSR_ANYCRLF
190      \fB/<bsr_unicode>\fP  PCRE_BSR_UNICODE
191    .sp
192    The modifiers that are enclosed in angle brackets are literal strings as shown,
193    including the angle brackets, but the letters can be in either case. This
194    example sets multiline matching with CRLF as the line ending sequence:
195    .sp
196      /^abc/m<crlf>
197    .sp
198    As well as turning on the PCRE_UTF8 option, the \fB/8\fP modifier also causes
199    any non-printing characters in output strings to be printed using the
200    \ex{hh...} notation if they are valid UTF-8 sequences. Full details of the PCRE
201    options are given in the
202    .\" HREF
203    \fBpcreapi\fP
204    .\"
205    documentation.
206    .
207    .
208    .SS "Finding all matches in a string"
209    .rs
210    .sp
211  Searching for all possible matches within each subject string can be requested  Searching for all possible matches within each subject string can be requested
212  by the \fB/g\fR or \fB/G\fR modifier. After finding a match, PCRE is called  by the \fB/g\fP or \fB/G\fP modifier. After finding a match, PCRE is called
213  again to search the remainder of the subject string. The difference between  again to search the remainder of the subject string. The difference between
214  \fB/g\fR and \fB/G\fR is that the former uses the \fIstartoffset\fR argument to  \fB/g\fP and \fB/G\fP is that the former uses the \fIstartoffset\fP argument to
215  \fBpcre_exec()\fR to start searching at a new point within the entire string  \fBpcre_exec()\fP to start searching at a new point within the entire string
216  (which is in effect what Perl does), whereas the latter passes over a shortened  (which is in effect what Perl does), whereas the latter passes over a shortened
217  substring. This makes a difference to the matching process if the pattern  substring. This makes a difference to the matching process if the pattern
218  begins with a lookbehind assertion (including \\b or \\B).  begins with a lookbehind assertion (including \eb or \eB).
219    .P
220  If any call to \fBpcre_exec()\fR in a \fB/g\fR or \fB/G\fR sequence matches an  If any call to \fBpcre_exec()\fP in a \fB/g\fP or \fB/G\fP sequence matches an
221  empty string, the next call is done with the PCRE_NOTEMPTY and PCRE_ANCHORED  empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
222  flags set in order to search for another, non-empty, match at the same point.  PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
223  If this second match fails, the start offset is advanced by one, and the normal  same point. If this second match fails, the start offset is advanced, and the
224  match is retried. This imitates the way Perl handles such cases when using the  normal match is retried. This imitates the way Perl handles such cases when
225  \fB/g\fR modifier or the \fBsplit()\fR function.  using the \fB/g\fP modifier or the \fBsplit()\fP function. Normally, the start
226    offset is advanced by one character, but if the newline convention recognizes
227  There are a number of other modifiers for controlling the way \fBpcretest\fR  CRLF as a newline, and the current character is CR followed by LF, an advance
228    of two is used.
229    .
230    .
231    .SS "Other modifiers"
232    .rs
233    .sp
234    There are yet more modifiers for controlling the way \fBpcretest\fP
235  operates.  operates.
236    .P
237  The \fB/+\fR modifier requests that as well as outputting the substring that  The \fB/+\fP modifier requests that as well as outputting the substring that
238  matched the entire pattern, pcretest should in addition output the remainder of  matched the entire pattern, pcretest should in addition output the remainder of
239  the subject string. This is useful for tests where the subject contains  the subject string. This is useful for tests where the subject contains
240  multiple copies of the same substring.  multiple copies of the same substring.
241    .P
242  The \fB/L\fR modifier must be followed directly by the name of a locale, for  The \fB/B\fP modifier is a debugging feature. It requests that \fBpcretest\fP
243    output a representation of the compiled byte code after compilation. Normally
244    this information contains length and offset values; however, if \fB/Z\fP is
245    also present, this data is replaced by spaces. This is a special feature for
246    use in the automatic test scripts; it ensures that the same output is generated
247    for different internal link sizes.
248    .P
249    The \fB/D\fP modifier is a PCRE debugging feature, and is equivalent to
250    \fB/BI\fP, that is, both the \fB/B\fP and the \fB/I\fP modifiers.
251    .P
252    The \fB/F\fP modifier causes \fBpcretest\fP to flip the byte order of the
253    fields in the compiled pattern that contain 2-byte and 4-byte numbers. This
254    facility is for testing the feature in PCRE that allows it to execute patterns
255    that were compiled on a host with a different endianness. This feature is not
256    available when the POSIX interface to PCRE is being used, that is, when the
257    \fB/P\fP pattern modifier is specified. See also the section about saving and
258    reloading compiled patterns below.
259    .P
260    The \fB/I\fP modifier requests that \fBpcretest\fP output information about the
261    compiled pattern (whether it is anchored, has a fixed first character, and
262    so on). It does this by calling \fBpcre_fullinfo()\fP after compiling a
263    pattern. If the pattern is studied, the results of that are also output.
264    .P
265    The \fB/K\fP modifier requests \fBpcretest\fP to show names from backtracking
266    control verbs that are returned from calls to \fBpcre_exec()\fP. It causes
267    \fBpcretest\fP to create a \fBpcre_extra\fP block if one has not already been
268    created by a call to \fBpcre_study()\fP, and to set the PCRE_EXTRA_MARK flag
269    and the \fBmark\fP field within it, every time that \fBpcre_exec()\fP is
270    called. If the variable that the \fBmark\fP field points to is non-NULL for a
271    match, non-match, or partial match, \fBpcretest\fP prints the string to which
272    it points. For a match, this is shown on a line by itself, tagged with "MK:".
273    For a non-match it is added to the message.
274    .P
275    The \fB/L\fP modifier must be followed directly by the name of a locale, for
276  example,  example,
277    .sp
278    /pattern/Lfr    /pattern/Lfr_FR
279    .sp
280  For this reason, it must be the last modifier letter. The given locale is set,  For this reason, it must be the last modifier. The given locale is set,
281  \fBpcre_maketables()\fR is called to build a set of character tables for the  \fBpcre_maketables()\fP is called to build a set of character tables for the
282  locale, and this is then passed to \fBpcre_compile()\fR when compiling the  locale, and this is then passed to \fBpcre_compile()\fP when compiling the
283  regular expression. Without an \fB/L\fR modifier, NULL is passed as the tables  regular expression. Without an \fB/L\fP (or \fB/T\fP) modifier, NULL is passed
284  pointer; that is, \fB/L\fR applies only to the expression on which it appears.  as the tables pointer; that is, \fB/L\fP applies only to the expression on
285    which it appears.
286  The \fB/I\fR modifier requests that \fBpcretest\fR output information about the  .P
287  compiled expression (whether it is anchored, has a fixed first character, and  The \fB/M\fP modifier causes the size of memory block used to hold the compiled
288  so on). It does this by calling \fBpcre_fullinfo()\fR after compiling an  pattern to be output.
289  expression, and outputting the information it gets back. If the pattern is  .P
290  studied, the results of that are also output.  The \fB/S\fP modifier causes \fBpcre_study()\fP to be called after the
   
 The \fB/D\fR modifier is a PCRE debugging feature, which also assumes \fB/I\fR.  
 It causes the internal form of compiled regular expressions to be output after  
 compilation.  
   
 The \fB/S\fR modifier causes \fBpcre_study()\fR to be called after the  
291  expression has been compiled, and the results used when the expression is  expression has been compiled, and the results used when the expression is
292  matched.  matched.
293    .P
294  The \fB/M\fR modifier causes the size of memory block used to hold the compiled  The \fB/T\fP modifier must be followed by a single digit. It causes a specific
295  pattern to be output.  set of built-in character tables to be passed to \fBpcre_compile()\fP. It is
296    used in the standard PCRE tests to check behaviour with different character
297  The \fB/P\fR modifier causes \fBpcretest\fR to call PCRE via the POSIX wrapper  tables. The digit specifies the tables as follows:
298  API rather than its native API. When this is done, all other modifiers except  .sp
299  \fB/i\fR, \fB/m\fR, and \fB/+\fR are ignored. REG_ICASE is set if \fB/i\fR is    0   the default ASCII tables, as distributed in
300  present, and REG_NEWLINE is set if \fB/m\fR is present. The wrapper functions          pcre_chartables.c.dist
301  force PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set.    1   a set of tables defining ISO 8859 characters
302    .sp
303  The \fB/8\fR modifier causes \fBpcretest\fR to call PCRE with the PCRE_UTF8  In table 1, some characters whose codes are greater than 128 are identified as
304  option set. This turns on the (currently incomplete) support for UTF-8  letters, digits, spaces, etc.
305  character handling in PCRE, provided that it was compiled with this support  .
306  enabled. This modifier also causes any non-printing characters in output  .
307  strings to be printed using the \\x{hh...} notation if they are valid UTF-8  .SS "Using the POSIX wrapper API"
308  sequences.  .rs
309    .sp
310    The \fB/P\fP modifier causes \fBpcretest\fP to call PCRE via the POSIX wrapper
311  .SH DATA LINES  API rather than its native API. When \fB/P\fP is set, the following modifiers
312    set options for the \fBregcomp()\fP function:
313  Before each data line is passed to \fBpcre_exec()\fR, leading and trailing  .sp
314  whitespace is removed, and it is then scanned for \\ escapes. The following are    /i    REG_ICASE
315      /m    REG_NEWLINE
316      /N    REG_NOSUB
317      /s    REG_DOTALL     )
318      /U    REG_UNGREEDY   ) These options are not part of
319      /W    REG_UCP        )   the POSIX standard
320      /8    REG_UTF8       )
321    .sp
322    The \fB/+\fP modifier works as described above. All other modifiers are
323    ignored.
324    .
325    .
326    .SH "DATA LINES"
327    .rs
328    .sp
329    Before each data line is passed to \fBpcre_exec()\fP, leading and trailing
330    whitespace is removed, and it is then scanned for \e escapes. Some of these are
331    pretty esoteric features, intended for checking out some of the more
332    complicated features of PCRE. If you are just testing "ordinary" regular
333    expressions, you probably don't need any of these. The following escapes are
334  recognized:  recognized:
335    .sp
336    \\a         alarm (= BEL)    \ea         alarm (BEL, \ex07)
337    \\b         backspace    \eb         backspace (\ex08)
338    \\e         escape    \ee         escape (\ex27)
339    \\f         formfeed    \ef         formfeed (\ex0c)
340    \\n         newline    \en         newline (\ex0a)
341    \\r         carriage return  .\" JOIN
342    \\t         tab    \eqdd       set the PCRE_MATCH_LIMIT limit to dd
343    \\v         vertical tab                 (any number of digits)
344    \\nnn       octal character (up to 3 octal digits)    \er         carriage return (\ex0d)
345    \\xhh       hexadecimal character (up to 2 hex digits)    \et         tab (\ex09)
346    \\x{hh...}  hexadecimal UTF-8 character    \ev         vertical tab (\ex0b)
347      \ennn       octal character (up to 3 octal digits)
348    \\A         pass the PCRE_ANCHORED option to \fBpcre_exec()\fR                 always a byte unless > 255 in UTF-8 mode
349    \\B         pass the PCRE_NOTBOL option to \fBpcre_exec()\fR    \exhh       hexadecimal byte (up to 2 hex digits)
350    \\Cdd       call pcre_copy_substring() for substring dd  .\" JOIN
351                  after a successful match (any decimal number    \ex{hh...}  hexadecimal character, any number of digits
352                  less than 32)                 in UTF-8 mode
353    \\Gdd       call pcre_get_substring() for substring dd  .\" JOIN
354                  after a successful match (any decimal number    \eA         pass the PCRE_ANCHORED option to \fBpcre_exec()\fP
355                  less than 32)                 or \fBpcre_dfa_exec()\fP
356    \\L         call pcre_get_substringlist() after a  .\" JOIN
357                  successful match    \eB         pass the PCRE_NOTBOL option to \fBpcre_exec()\fP
358    \\N         pass the PCRE_NOTEMPTY option to \fBpcre_exec()\fR                 or \fBpcre_dfa_exec()\fP
359    \\Odd       set the size of the output vector passed to  .\" JOIN
360                  \fBpcre_exec()\fR to dd (any number of decimal    \eCdd       call pcre_copy_substring() for substring dd
361                  digits)                 after a successful match (number less than 32)
362    \\Z         pass the PCRE_NOTEOL option to \fBpcre_exec()\fR  .\" JOIN
363      \eCname     call pcre_copy_named_substring() for substring
364  When \\O is used, it may be higher or lower than the size set by the \fB-O\fR                 "name" after a successful match (name termin-
365  option (or defaulted to 45); \\O applies only to the call of \fBpcre_exec()\fR                 ated by next non alphanumeric character)
366  for the line in which it appears.  .\" JOIN
367      \eC+        show the current captured substrings at callout
368  A backslash followed by anything else just escapes the anything else. If the                 time
369  very last character is a backslash, it is ignored. This gives a way of passing    \eC-        do not supply a callout function
370  an empty line as data, since a real empty line terminates the data input.  .\" JOIN
371      \eC!n       return 1 instead of 0 when callout number n is
372  If \fB/P\fR was present on the regex, causing the POSIX wrapper API to be used,                 reached
373  only \fB\B\fR, and \fB\Z\fR have any effect, causing REG_NOTBOL and REG_NOTEOL  .\" JOIN
374  to be passed to \fBregexec()\fR respectively.    \eC!n!m     return 1 instead of 0 when callout number n is
375                   reached for the nth time
376  The use of \\x{hh...} to represent UTF-8 characters is not dependent on the use  .\" JOIN
377  of the \fB/8\fR modifier on the pattern. It is recognized always. There may be    \eC*n       pass the number n (may be negative) as callout
378                   data; this is used as the callout return value
379      \eD         use the \fBpcre_dfa_exec()\fP match function
380      \eF         only shortest match for \fBpcre_dfa_exec()\fP
381    .\" JOIN
382      \eGdd       call pcre_get_substring() for substring dd
383                   after a successful match (number less than 32)
384    .\" JOIN
385      \eGname     call pcre_get_named_substring() for substring
386                   "name" after a successful match (name termin-
387                   ated by next non-alphanumeric character)
388    .\" JOIN
389      \eL         call pcre_get_substringlist() after a
390                   successful match
391    .\" JOIN
392      \eM         discover the minimum MATCH_LIMIT and
393                   MATCH_LIMIT_RECURSION settings
394    .\" JOIN
395      \eN         pass the PCRE_NOTEMPTY option to \fBpcre_exec()\fP
396                   or \fBpcre_dfa_exec()\fP; if used twice, pass the
397                   PCRE_NOTEMPTY_ATSTART option
398    .\" JOIN
399      \eOdd       set the size of the output vector passed to
400                   \fBpcre_exec()\fP to dd (any number of digits)
401    .\" JOIN
402      \eP         pass the PCRE_PARTIAL_SOFT option to \fBpcre_exec()\fP
403                   or \fBpcre_dfa_exec()\fP; if used twice, pass the
404                   PCRE_PARTIAL_HARD option
405    .\" JOIN
406      \eQdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
407                   (any number of digits)
408      \eR         pass the PCRE_DFA_RESTART option to \fBpcre_dfa_exec()\fP
409      \eS         output details of memory get/free calls during matching
410    .\" JOIN
411      \eY         pass the PCRE_NO_START_OPTIMIZE option to \fBpcre_exec()\fP
412                   or \fBpcre_dfa_exec()\fP
413    .\" JOIN
414      \eZ         pass the PCRE_NOTEOL option to \fBpcre_exec()\fP
415                   or \fBpcre_dfa_exec()\fP
416    .\" JOIN
417      \e?         pass the PCRE_NO_UTF8_CHECK option to
418                   \fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP
419    .\" JOIN
420      \e>dd       start the match at offset dd (optional "-"; then
421                   any number of digits); this sets the \fIstartoffset\fP
422                   argument for \fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP
423    .\" JOIN
424      \e<cr>      pass the PCRE_NEWLINE_CR option to \fBpcre_exec()\fP
425                   or \fBpcre_dfa_exec()\fP
426    .\" JOIN
427      \e<lf>      pass the PCRE_NEWLINE_LF option to \fBpcre_exec()\fP
428                   or \fBpcre_dfa_exec()\fP
429    .\" JOIN
430      \e<crlf>    pass the PCRE_NEWLINE_CRLF option to \fBpcre_exec()\fP
431                   or \fBpcre_dfa_exec()\fP
432    .\" JOIN
433      \e<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to \fBpcre_exec()\fP
434                   or \fBpcre_dfa_exec()\fP
435    .\" JOIN
436      \e<any>     pass the PCRE_NEWLINE_ANY option to \fBpcre_exec()\fP
437                   or \fBpcre_dfa_exec()\fP
438    .sp
439    Note that \exhh always specifies one byte, even in UTF-8 mode; this makes it
440    possible to construct invalid UTF-8 sequences for testing purposes. On the
441    other hand, \ex{hh} is interpreted as a UTF-8 character in UTF-8 mode,
442    generating more than one byte if the value is greater than 127. When not in
443    UTF-8 mode, it generates one byte for values less than 256, and causes an error
444    for greater values.
445    .P
446    The escapes that specify line ending sequences are literal strings, exactly as
447    shown. No more than one newline setting should be present in any data line.
448    .P
449    A backslash followed by anything else just escapes the anything else. If
450    the very last character is a backslash, it is ignored. This gives a way of
451    passing an empty line as data, since a real empty line terminates the data
452    input.
453    .P
454    If \eM is present, \fBpcretest\fP calls \fBpcre_exec()\fP several times, with
455    different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP
456    fields of the \fBpcre_extra\fP data structure, until it finds the minimum
457    numbers for each parameter that allow \fBpcre_exec()\fP to complete. The
458    \fImatch_limit\fP number is a measure of the amount of backtracking that takes
459    place, and checking it out can be instructive. For most simple matches, the
460    number is quite small, but for patterns with very large numbers of matching
461    possibilities, it can become large very quickly with increasing length of
462    subject string. The \fImatch_limit_recursion\fP number is a measure of how much
463    stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is needed
464    to complete the match attempt.
465    .P
466    When \eO is used, the value specified may be higher or lower than the size set
467    by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to
468    the call of \fBpcre_exec()\fP for the line in which it appears.
469    .P
470    If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper
471    API to be used, the only option-setting sequences that have any effect are \eB,
472    \eN, and \eZ, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
473    to be passed to \fBregexec()\fP.
474    .P
475    The use of \ex{hh...} to represent UTF-8 characters is not dependent on the use
476    of the \fB/8\fP modifier on the pattern. It is recognized always. There may be
477  any number of hexadecimal digits inside the braces. The result is from one to  any number of hexadecimal digits inside the braces. The result is from one to
478  six bytes, encoded according to the UTF-8 rules.  six bytes, encoded according to the original UTF-8 rules of RFC 2279. This
479    allows for values in the range 0 to 0x7FFFFFFF. Note that not all of those are
480    valid Unicode code points, or indeed valid UTF-8 characters according to the
481  .SH OUTPUT FROM PCRETEST  later rules in RFC 3629.
482    .
483    .
484    .SH "THE ALTERNATIVE MATCHING FUNCTION"
485    .rs
486    .sp
487    By default, \fBpcretest\fP uses the standard PCRE matching function,
488    \fBpcre_exec()\fP to match each data line. From release 6.0, PCRE supports an
489    alternative matching function, \fBpcre_dfa_test()\fP, which operates in a
490    different way, and has some restrictions. The differences between the two
491    functions are described in the
492    .\" HREF
493    \fBpcrematching\fP
494    .\"
495    documentation.
496    .P
497    If a data line contains the \eD escape sequence, or if the command line
498    contains the \fB-dfa\fP option, the alternative matching function is called.
499    This function finds all possible matches at a given point. If, however, the \eF
500    escape sequence is present in the data line, it stops after the first match is
501    found. This is always the shortest possible match.
502    .
503    .
504    .SH "DEFAULT OUTPUT FROM PCRETEST"
505    .rs
506    .sp
507    This section describes the output when the normal matching function,
508    \fBpcre_exec()\fP, is being used.
509    .P
510  When a match succeeds, pcretest outputs the list of captured substrings that  When a match succeeds, pcretest outputs the list of captured substrings that
511  \fBpcre_exec()\fR returns, starting with number 0 for the string that matched  \fBpcre_exec()\fP returns, starting with number 0 for the string that matched
512  the whole pattern. Here is an example of an interactive pcretest run.  the whole pattern. Otherwise, it outputs "No match" when the return is
513    PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
514    substring when \fBpcre_exec()\fP returns PCRE_ERROR_PARTIAL. (Note that this is
515    the entire substring that was inspected during the partial match; it may
516    include characters before the actual match start if a lookbehind assertion,
517    \eK, \eb, or \eB was involved.) For any other returns, it outputs the PCRE
518    negative error number. Here is an example of an interactive \fBpcretest\fP run.
519    .sp
520    $ pcretest    $ pcretest
521    PCRE version 2.06 08-Jun-1999    PCRE version 7.0 30-Nov-2006
522    .sp
523      re> /^abc(\\d+)/      re> /^abc(\ed+)/
524    data> abc123    data> abc123
525     0: abc123     0: abc123
526     1: 123     1: 123
527    data> xyz    data> xyz
528    No match    No match
529    .sp
530  If the strings contain any non-printing characters, they are output as \\0x  Note that unset capturing substrings that are not followed by one that is set
531  escapes, or as \\x{...} escapes if the \fB/8\fR modifier was present on the  are not returned by \fBpcre_exec()\fP, and are not shown by \fBpcretest\fP. In
532  pattern. If the pattern has the \fB/+\fR modifier, then the output for  the following example, there are two capturing substrings, but when the first
533  substring 0 is followed by the the rest of the subject string, identified by  data line is matched, the second, unset substring is not shown. An "internal"
534  "0+" like this:  unset substring is shown as "<unset>", as for the second data line.
535    .sp
536        re> /(a)|(b)/
537      data> a
538       0: a
539       1: a
540      data> b
541       0: b
542       1: <unset>
543       2: b
544    .sp
545    If the strings contain any non-printing characters, they are output as \e0x
546    escapes, or as \ex{...} escapes if the \fB/8\fP modifier was present on the
547    pattern. See below for the definition of non-printing characters. If the
548    pattern has the \fB/+\fP modifier, the output for substring 0 is followed by
549    the the rest of the subject string, identified by "0+" like this:
550    .sp
551      re> /cat/+      re> /cat/+
552    data> cataract    data> cataract
553     0: cat     0: cat
554     0+ aract     0+ aract
555    .sp
556  If the pattern has the \fB/g\fR or \fB/G\fR modifier, the results of successive  If the pattern has the \fB/g\fP or \fB/G\fP modifier, the results of successive
557  matching attempts are output in sequence, like this:  matching attempts are output in sequence, like this:
558    .sp
559      re> /\\Bi(\\w\\w)/g      re> /\eBi(\ew\ew)/g
560    data> Mississippi    data> Mississippi
561     0: iss     0: iss
562     1: ss     1: ss
# Line 251  matching attempts are output in sequence Line 564  matching attempts are output in sequence
564     1: ss     1: ss
565     0: ipp     0: ipp
566     1: pp     1: pp
567    .sp
568  "No match" is output only if the first match attempt fails.  "No match" is output only if the first match attempt fails.
569    .P
570  If any of the sequences \fB\\C\fR, \fB\\G\fR, or \fB\\L\fR are present in a  If any of the sequences \fB\eC\fP, \fB\eG\fP, or \fB\eL\fP are present in a
571  data line that is successfully matched, the substrings extracted by the  data line that is successfully matched, the substrings extracted by the
572  convenience functions are output with C, G, or L after the string number  convenience functions are output with C, G, or L after the string number
573  instead of a colon. This is in addition to the normal full list. The string  instead of a colon. This is in addition to the normal full list. The string
574  length (that is, the return from the extraction function) is given in  length (that is, the return from the extraction function) is given in
575  parentheses after each string for \fB\\C\fR and \fB\\G\fR.  parentheses after each string for \fB\eC\fP and \fB\eG\fP.
576    .P
577  Note that while patterns can be continued over several lines (a plain ">"  Note that whereas patterns can be continued over several lines (a plain ">"
578  prompt is used for continuations), data lines may not. However newlines can be  prompt is used for continuations), data lines may not. However newlines can be
579  included in data by means of the \\n escape.  included in data by means of the \en escape (or \er, \er\en, etc., depending on
580    the newline sequence setting).
581    .
582    .
583    .
584    .SH "OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION"
585    .rs
586    .sp
587    When the alternative matching function, \fBpcre_dfa_exec()\fP, is used (by
588    means of the \eD escape sequence or the \fB-dfa\fP command line option), the
589    output consists of a list of all the matches that start at the first point in
590    the subject where there is at least one match. For example:
591    .sp
592        re> /(tang|tangerine|tan)/
593      data> yellow tangerine\eD
594       0: tangerine
595       1: tang
596       2: tan
597    .sp
598    (Using the normal matching function on this data finds only "tang".) The
599    longest matching string is always given first (and numbered zero). After a
600    PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
601    partially matching substring. (Note that this is the entire substring that was
602    inspected during the partial match; it may include characters before the actual
603    match start if a lookbehind assertion, \eK, \eb, or \eB was involved.)
604    .P
605    If \fB/g\fP is present on the pattern, the search for further matches resumes
606    at the end of the longest match. For example:
607    .sp
608        re> /(tang|tangerine|tan)/g
609      data> yellow tangerine and tangy sultana\eD
610       0: tangerine
611       1: tang
612       2: tan
613       0: tang
614       1: tan
615       0: tan
616    .sp
617    Since the matching function does not support substring capture, the escape
618    sequences that are concerned with captured substrings are not relevant.
619    .
620    .
621    .SH "RESTARTING AFTER A PARTIAL MATCH"
622    .rs
623    .sp
624    When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
625    indicating that the subject partially matched the pattern, you can restart the
626    match with additional subject data by means of the \eR escape sequence. For
627    example:
628    .sp
629        re> /^\ed?\ed(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\ed\ed$/
630      data> 23ja\eP\eD
631      Partial match: 23ja
632      data> n05\eR\eD
633       0: n05
634    .sp
635    For further information about partial matching, see the
636    .\" HREF
637    \fBpcrepartial\fP
638    .\"
639    documentation.
640    .
641    .
642    .SH CALLOUTS
643    .rs
644    .sp
645    If the pattern contains any callout requests, \fBpcretest\fP's callout function
646    is called during matching. This works with both matching functions. By default,
647    the called function displays the callout number, the start and current
648    positions in the text at the callout time, and the next pattern item to be
649    tested. For example, the output
650    .sp
651      --->pqrabcdef
652        0    ^  ^     \ed
653    .sp
654    indicates that callout number 0 occurred for a match attempt starting at the
655    fourth character of the subject string, when the pointer was at the seventh
656    character of the data, and when the next pattern item was \ed. Just one
657    circumflex is output if the start and current positions are the same.
658    .P
659    Callouts numbered 255 are assumed to be automatic callouts, inserted as a
660    result of the \fB/C\fP pattern modifier. In this case, instead of showing the
661    callout number, the offset in the pattern, preceded by a plus, is output. For
662    example:
663    .sp
664        re> /\ed?[A-E]\e*/C
665      data> E*
666      --->E*
667       +0 ^      \ed?
668       +3 ^      [A-E]
669       +8 ^^     \e*
670      +10 ^ ^
671       0: E*
672    .sp
673    The callout function in \fBpcretest\fP returns zero (carry on matching) by
674    default, but you can use a \eC item in a data line (as described above) to
675    change this.
676    .P
677    Inserting callouts can be helpful when using \fBpcretest\fP to check
678    complicated regular expressions. For further information about callouts, see
679    the
680    .\" HREF
681    \fBpcrecallout\fP
682    .\"
683    documentation.
684    .
685    .
686    .
687    .SH "NON-PRINTING CHARACTERS"
688    .rs
689    .sp
690    When \fBpcretest\fP is outputting text in the compiled version of a pattern,
691    bytes other than 32-126 are always treated as non-printing characters are are
692    therefore shown as hex escapes.
693    .P
694    When \fBpcretest\fP is outputting text that is a matched part of a subject
695    string, it behaves in the same way, unless a different locale has been set for
696    the pattern (using the \fB/L\fP modifier). In this case, the \fBisprint()\fP
697    function to distinguish printing and non-printing characters.
698    .
699    .
700    .
701    .SH "SAVING AND RELOADING COMPILED PATTERNS"
702    .rs
703    .sp
704    The facilities described in this section are not available when the POSIX
705    inteface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
706    specified.
707    .P
708    When the POSIX interface is not in use, you can cause \fBpcretest\fP to write a
709    compiled pattern to a file, by following the modifiers with > and a file name.
710    For example:
711    .sp
712      /pattern/im >/some/file
713    .sp
714    See the
715    .\" HREF
716    \fBpcreprecompile\fP
717    .\"
718    documentation for a discussion about saving and re-using compiled patterns.
719    .P
720    The data that is written is binary. The first eight bytes are the length of the
721    compiled pattern data followed by the length of the optional study data, each
722    written as four bytes in big-endian order (most significant byte first). If
723    there is no study data (either the pattern was not studied, or studying did not
724    return any data), the second length is zero. The lengths are followed by an
725    exact copy of the compiled pattern. If there is additional study data, this
726    follows immediately after the compiled pattern. After writing the file,
727    \fBpcretest\fP expects to read a new pattern.
728    .P
729    A saved pattern can be reloaded into \fBpcretest\fP by specifing < and a file
730    name instead of a pattern. The name of the file must not contain a < character,
731    as otherwise \fBpcretest\fP will interpret the line as a pattern delimited by <
732    characters.
733    For example:
734    .sp
735       re> </some/file
736      Compiled regex loaded from /some/file
737      No study data
738    .sp
739    When the pattern has been loaded, \fBpcretest\fP proceeds to read data lines in
740    the usual way.
741    .P
742    You can copy a file written by \fBpcretest\fP to a different host and reload it
743    there, even if the new host has opposite endianness to the one on which the
744    pattern was compiled. For example, you can compile on an i86 machine and run on
745    a SPARC machine.
746    .P
747    File names for saving and reloading can be absolute or relative, but note that
748    the shell facility of expanding a file name that starts with a tilde (~) is not
749    available.
750    .P
751    The ability to save and reload files in \fBpcretest\fP is intended for testing
752    and experimentation. It is not intended for production use because only a
753    single pattern can be written to a file. Furthermore, there is no facility for
754    supplying custom character tables for use with a reloaded pattern. If the
755    original pattern was compiled with custom tables, an attempt to match a subject
756    string using a reloaded pattern is likely to cause \fBpcretest\fP to crash.
757    Finally, if you attempt to load a file that is not in the correct format, the
758    result is undefined.
759    .
760    .
761    .SH "SEE ALSO"
762    .rs
763    .sp
764    \fBpcre\fP(3), \fBpcreapi\fP(3), \fBpcrecallout\fP(3), \fBpcrematching\fP(3),
765    \fBpcrepartial\fP(d), \fBpcrepattern\fP(3), \fBpcreprecompile\fP(3).
766    .
767    .
768  .SH AUTHOR  .SH AUTHOR
769  Philip Hazel <ph10@cam.ac.uk>  .rs
770  .br  .sp
771  University Computing Service,  .nf
772  .br  Philip Hazel
773  New Museums Site,  University Computing Service
774  .br  Cambridge CB2 3QH, England.
775  Cambridge CB2 3QG, England.  .fi
776  .br  .
777  Phone: +44 1223 334714  .
778    .SH REVISION
779  Last updated: 15 August 2001  .rs
780  .br  .sp
781  Copyright (c) 1997-2001 University of Cambridge.  .nf
782    Last updated: 21 November 2010
783    Copyright (c) 1997-2010 University of Cambridge.
784    .fi

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