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

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