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revision 53 by nigel, Sat Feb 24 21:39:42 2007 UTC revision 116 by ph10, Fri Mar 9 15:23:02 2007 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  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
70    \fB-q\fP
71    Do not output the version number of \fBpcretest\fP at the start of execution.
72    .TP 10
73    \fB-S\fP \fIsize\fP
74    On Unix-like systems, set the size of the runtime stack to \fIsize\fP
75    megabytes.
76    .TP 10
77    \fB-t\fP
78    Run each compile, study, and match many times with a timer, and output
79    resulting time per compile or match (in milliseconds). Do not set \fB-m\fP with
80    \fB-t\fP, because you will then get the size output a zillion times, and the
81    timing will be distorted. You can control the number of iterations that are
82    used for timing by following \fB-t\fP with a number (as a separate item on the
83    command line). For example, "-t 1000" would iterate 1000 times. The default is
84    to iterate 500000 times.
85  .TP 10  .TP 10
86  \fB-o\fR \fIosize\fR  \fB-tm\fP
87  Set the number of elements in the output vector that is used when calling PCRE  This is like \fB-t\fP except that it times only the matching phase, not the
88  to be \fIosize\fR. The default value is 45, which is enough for 14 capturing  compile or study phases.
89  subexpressions. The vector size can be changed for individual matching calls by  .
90  including \\O in the data line (see below).  .
 .TP 10  
 \fB-p\fR  
 Behave as if each regex has \fB/P\fR modifier; the POSIX wrapper API is used  
 to call PCRE. None of the other options has any effect when \fB-p\fR is set.  
 .TP 10  
 \fB-t\fR  
 Run each compile, study, and match 20000 times with a timer, and output  
 resulting time per compile or match (in milliseconds). Do not set \fB-t\fR with  
 \fB-m\fR, because you will then get the size output 20000 times and the timing  
 will be distorted.  
   
   
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. Normally
218    this information contains length and offset values; however, if \fB/Z\fP is
219    also present, this data is replaced by spaces. This is a special feature for
220    use in the automatic test scripts; it ensures that the same output is generated
221    for different internal link sizes.
222    .P
223    The \fB/L\fP modifier must be followed directly by the name of a locale, for
224  example,  example,
225    .sp
226    /pattern/Lfr    /pattern/Lfr_FR
227    .sp
228  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,
229  \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
230  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
231  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
232  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.
233    .P
234  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
235  compiled expression (whether it is anchored, has a fixed first character, and  compiled pattern (whether it is anchored, has a fixed first character, and
236  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
237  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.
238  studied, the results of that are also output.  .P
239    The \fB/D\fP modifier is a PCRE debugging feature, and is equivalent to
240  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.
241  It causes the internal form of compiled regular expressions to be output after  .P
242  compilation.  The \fB/F\fP modifier causes \fBpcretest\fP to flip the byte order of the
243    fields in the compiled pattern that contain 2-byte and 4-byte numbers. This
244  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
245    that were compiled on a host with a different endianness. This feature is not
246    available when the POSIX interface to PCRE is being used, that is, when the
247    \fB/P\fP pattern modifier is specified. See also the section about saving and
248    reloading compiled patterns below.
249    .P
250    The \fB/S\fP modifier causes \fBpcre_study()\fP to be called after the
251  expression has been compiled, and the results used when the expression is  expression has been compiled, and the results used when the expression is
252  matched.  matched.
253    .P
254  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
255  pattern to be output.  pattern to be output.
256    .P
257  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
258  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
259  \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
260  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
261  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.
262    .P
263  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
264  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,
265  character handling in PCRE, provided that it was compiled with this support  provided that it was compiled with this support enabled. This modifier also
266  enabled. This modifier also causes any non-printing characters in output  causes any non-printing characters in output strings to be printed using the
267  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.
268  sequences.  .P
269    If the \fB/?\fP modifier is used with \fB/8\fP, it causes \fBpcretest\fP to
270    call \fBpcre_compile()\fP with the PCRE_NO_UTF8_CHECK option, to suppress the
271  .SH DATA LINES  checking of the string for UTF-8 validity.
272    .
273  Before each data line is passed to \fBpcre_exec()\fR, leading and trailing  .
274  whitespace is removed, and it is then scanned for \\ escapes. The following are  .SH "DATA LINES"
275    .rs
276    .sp
277    Before each data line is passed to \fBpcre_exec()\fP, leading and trailing
278    whitespace is removed, and it is then scanned for \e escapes. Some of these are
279    pretty esoteric features, intended for checking out some of the more
280    complicated features of PCRE. If you are just testing "ordinary" regular
281    expressions, you probably don't need any of these. The following escapes are
282  recognized:  recognized:
283    .sp
284    \\a         alarm (= BEL)    \ea         alarm (BEL, \ex07)
285    \\b         backspace    \eb         backspace (\ex08)
286    \\e         escape    \ee         escape (\ex27)
287    \\f         formfeed    \ef         formfeed (\ex0c)
288    \\n         newline    \en         newline (\ex0a)
289    \\r         carriage return  .\" JOIN
290    \\t         tab    \eqdd       set the PCRE_MATCH_LIMIT limit to dd
291    \\v         vertical tab                 (any number of digits)
292    \\nnn       octal character (up to 3 octal digits)    \er         carriage return (\ex0d)
293    \\xhh       hexadecimal character (up to 2 hex digits)    \et         tab (\ex09)
294    \\x{hh...}  hexadecimal UTF-8 character    \ev         vertical tab (\ex0b)
295      \ennn       octal character (up to 3 octal digits)
296    \\A         pass the PCRE_ANCHORED option to \fBpcre_exec()\fR    \exhh       hexadecimal character (up to 2 hex digits)
297    \\B         pass the PCRE_NOTBOL option to \fBpcre_exec()\fR  .\" JOIN
298    \\Cdd       call pcre_copy_substring() for substring dd    \ex{hh...}  hexadecimal character, any number of digits
299                  after a successful match (any decimal number                 in UTF-8 mode
300                  less than 32)  .\" JOIN
301    \\Gdd       call pcre_get_substring() for substring dd    \eA         pass the PCRE_ANCHORED option to \fBpcre_exec()\fP
302                  after a successful match (any decimal number                 or \fBpcre_dfa_exec()\fP
303                  less than 32)  .\" JOIN
304    \\L         call pcre_get_substringlist() after a    \eB         pass the PCRE_NOTBOL option to \fBpcre_exec()\fP
305                  successful match                 or \fBpcre_dfa_exec()\fP
306    \\N         pass the PCRE_NOTEMPTY option to \fBpcre_exec()\fR  .\" JOIN
307    \\Odd       set the size of the output vector passed to    \eCdd       call pcre_copy_substring() for substring dd
308                  \fBpcre_exec()\fR to dd (any number of decimal                 after a successful match (number less than 32)
309                  digits)  .\" JOIN
310    \\Z         pass the PCRE_NOTEOL option to \fBpcre_exec()\fR    \eCname     call pcre_copy_named_substring() for substring
311                   "name" after a successful match (name termin-
312  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)
313  option (or defaulted to 45); \\O applies only to the call of \fBpcre_exec()\fR  .\" JOIN
314  for the line in which it appears.    \eC+        show the current captured substrings at callout
315                   time
316  A backslash followed by anything else just escapes the anything else. If the    \eC-        do not supply a callout function
317  very last character is a backslash, it is ignored. This gives a way of passing  .\" JOIN
318  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
319                   reached
320  If \fB/P\fR was present on the regex, causing the POSIX wrapper API to be used,  .\" JOIN
321  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
322  to be passed to \fBregexec()\fR respectively.                 reached for the nth time
323    .\" JOIN
324  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
325  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
326      \eD         use the \fBpcre_dfa_exec()\fP match function
327      \eF         only shortest match for \fBpcre_dfa_exec()\fP
328    .\" JOIN
329      \eGdd       call pcre_get_substring() for substring dd
330                   after a successful match (number less than 32)
331    .\" JOIN
332      \eGname     call pcre_get_named_substring() for substring
333                   "name" after a successful match (name termin-
334                   ated by next non-alphanumeric character)
335    .\" JOIN
336      \eL         call pcre_get_substringlist() after a
337                   successful match
338    .\" JOIN
339      \eM         discover the minimum MATCH_LIMIT and
340                   MATCH_LIMIT_RECURSION settings
341    .\" JOIN
342      \eN         pass the PCRE_NOTEMPTY option to \fBpcre_exec()\fP
343                   or \fBpcre_dfa_exec()\fP
344    .\" JOIN
345      \eOdd       set the size of the output vector passed to
346                   \fBpcre_exec()\fP to dd (any number of digits)
347    .\" JOIN
348      \eP         pass the PCRE_PARTIAL option to \fBpcre_exec()\fP
349                   or \fBpcre_dfa_exec()\fP
350    .\" JOIN
351      \eQdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
352                   (any number of digits)
353      \eR         pass the PCRE_DFA_RESTART option to \fBpcre_dfa_exec()\fP
354      \eS         output details of memory get/free calls during matching
355    .\" JOIN
356      \eZ         pass the PCRE_NOTEOL option to \fBpcre_exec()\fP
357                   or \fBpcre_dfa_exec()\fP
358    .\" JOIN
359      \e?         pass the PCRE_NO_UTF8_CHECK option to
360                   \fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP
361      \e>dd       start the match at offset dd (any number of digits);
362    .\" JOIN
363                   this sets the \fIstartoffset\fP argument for \fBpcre_exec()\fP
364                   or \fBpcre_dfa_exec()\fP
365    .\" JOIN
366      \e<cr>      pass the PCRE_NEWLINE_CR option to \fBpcre_exec()\fP
367                   or \fBpcre_dfa_exec()\fP
368    .\" JOIN
369      \e<lf>      pass the PCRE_NEWLINE_LF option to \fBpcre_exec()\fP
370                   or \fBpcre_dfa_exec()\fP
371    .\" JOIN
372      \e<crlf>    pass the PCRE_NEWLINE_CRLF option to \fBpcre_exec()\fP
373                   or \fBpcre_dfa_exec()\fP
374    .\" JOIN
375      \e<any>     pass the PCRE_NEWLINE_ANY option to \fBpcre_exec()\fP
376                   or \fBpcre_dfa_exec()\fP
377    .sp
378    The escapes that specify line ending sequences are literal strings, exactly as
379    shown. No more than one newline setting should be present in any data line.
380    .P
381    A backslash followed by anything else just escapes the anything else. If
382    the very last character is a backslash, it is ignored. This gives a way of
383    passing an empty line as data, since a real empty line terminates the data
384    input.
385    .P
386    If \eM is present, \fBpcretest\fP calls \fBpcre_exec()\fP several times, with
387    different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP
388    fields of the \fBpcre_extra\fP data structure, until it finds the minimum
389    numbers for each parameter that allow \fBpcre_exec()\fP to complete. The
390    \fImatch_limit\fP number is a measure of the amount of backtracking that takes
391    place, and checking it out can be instructive. For most simple matches, the
392    number is quite small, but for patterns with very large numbers of matching
393    possibilities, it can become large very quickly with increasing length of
394    subject string. The \fImatch_limit_recursion\fP number is a measure of how much
395    stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is needed
396    to complete the match attempt.
397    .P
398    When \eO is used, the value specified may be higher or lower than the size set
399    by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to
400    the call of \fBpcre_exec()\fP for the line in which it appears.
401    .P
402    If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper
403    API to be used, the only option-setting sequences that have any effect are \eB
404    and \eZ, causing REG_NOTBOL and REG_NOTEOL, respectively, to be passed to
405    \fBregexec()\fP.
406    .P
407    The use of \ex{hh...} to represent UTF-8 characters is not dependent on the use
408    of the \fB/8\fP modifier on the pattern. It is recognized always. There may be
409  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
410  six bytes, encoded according to the UTF-8 rules.  six bytes, encoded according to the UTF-8 rules.
411    .
412    .
413  .SH OUTPUT FROM PCRETEST  .SH "THE ALTERNATIVE MATCHING FUNCTION"
414    .rs
415    .sp
416    By default, \fBpcretest\fP uses the standard PCRE matching function,
417    \fBpcre_exec()\fP to match each data line. From release 6.0, PCRE supports an
418    alternative matching function, \fBpcre_dfa_test()\fP, which operates in a
419    different way, and has some restrictions. The differences between the two
420    functions are described in the
421    .\" HREF
422    \fBpcrematching\fP
423    .\"
424    documentation.
425    .P
426    If a data line contains the \eD escape sequence, or if the command line
427    contains the \fB-dfa\fP option, the alternative matching function is called.
428    This function finds all possible matches at a given point. If, however, the \eF
429    escape sequence is present in the data line, it stops after the first match is
430    found. This is always the shortest possible match.
431    .
432    .
433    .SH "DEFAULT OUTPUT FROM PCRETEST"
434    .rs
435    .sp
436    This section describes the output when the normal matching function,
437    \fBpcre_exec()\fP, is being used.
438    .P
439  When a match succeeds, pcretest outputs the list of captured substrings that  When a match succeeds, pcretest outputs the list of captured substrings that
440  \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
441  the whole pattern. Here is an example of an interactive pcretest run.  the whole pattern. Otherwise, it outputs "No match" or "Partial match"
442    when \fBpcre_exec()\fP returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PARTIAL,
443    respectively, and otherwise the PCRE negative error number. Here is an example
444    of an interactive \fBpcretest\fP run.
445    .sp
446    $ pcretest    $ pcretest
447    PCRE version 2.06 08-Jun-1999    PCRE version 7.0 30-Nov-2006
448    .sp
449      re> /^abc(\\d+)/      re> /^abc(\ed+)/
450    data> abc123    data> abc123
451     0: abc123     0: abc123
452     1: 123     1: 123
453    data> xyz    data> xyz
454    No match    No match
455    .sp
456  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
457  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
458  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
459  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
460  "0+" like this:  the the rest of the subject string, identified by "0+" like this:
461    .sp
462      re> /cat/+      re> /cat/+
463    data> cataract    data> cataract
464     0: cat     0: cat
465     0+ aract     0+ aract
466    .sp
467  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
468  matching attempts are output in sequence, like this:  matching attempts are output in sequence, like this:
469    .sp
470      re> /\\Bi(\\w\\w)/g      re> /\eBi(\ew\ew)/g
471    data> Mississippi    data> Mississippi
472     0: iss     0: iss
473     1: ss     1: ss
# Line 251  matching attempts are output in sequence Line 475  matching attempts are output in sequence
475     1: ss     1: ss
476     0: ipp     0: ipp
477     1: pp     1: pp
478    .sp
479  "No match" is output only if the first match attempt fails.  "No match" is output only if the first match attempt fails.
480    .P
481  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
482  data line that is successfully matched, the substrings extracted by the  data line that is successfully matched, the substrings extracted by the
483  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
484  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
485  length (that is, the return from the extraction function) is given in  length (that is, the return from the extraction function) is given in
486  parentheses after each string for \fB\\C\fR and \fB\\G\fR.  parentheses after each string for \fB\eC\fP and \fB\eG\fP.
487    .P
488  Note that while patterns can be continued over several lines (a plain ">"  Note that whereas patterns can be continued over several lines (a plain ">"
489  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
490  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
491    the newline sequence setting).
492    .
493    .
494    .
495    .SH "OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION"
496    .rs
497    .sp
498    When the alternative matching function, \fBpcre_dfa_exec()\fP, is used (by
499    means of the \eD escape sequence or the \fB-dfa\fP command line option), the
500    output consists of a list of all the matches that start at the first point in
501    the subject where there is at least one match. For example:
502    .sp
503        re> /(tang|tangerine|tan)/
504      data> yellow tangerine\eD
505       0: tangerine
506       1: tang
507       2: tan
508    .sp
509    (Using the normal matching function on this data finds only "tang".) The
510    longest matching string is always given first (and numbered zero).
511    .P
512    If \fB/g\fP is present on the pattern, the search for further matches resumes
513    at the end of the longest match. For example:
514    .sp
515        re> /(tang|tangerine|tan)/g
516      data> yellow tangerine and tangy sultana\eD
517       0: tangerine
518       1: tang
519       2: tan
520       0: tang
521       1: tan
522       0: tan
523    .sp
524    Since the matching function does not support substring capture, the escape
525    sequences that are concerned with captured substrings are not relevant.
526    .
527    .
528    .SH "RESTARTING AFTER A PARTIAL MATCH"
529    .rs
530    .sp
531    When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
532    indicating that the subject partially matched the pattern, you can restart the
533    match with additional subject data by means of the \eR escape sequence. For
534    example:
535    .sp
536        re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
537      data> 23ja\eP\eD
538      Partial match: 23ja
539      data> n05\eR\eD
540       0: n05
541    .sp
542    For further information about partial matching, see the
543    .\" HREF
544    \fBpcrepartial\fP
545    .\"
546    documentation.
547    .
548    .
549    .SH CALLOUTS
550    .rs
551    .sp
552    If the pattern contains any callout requests, \fBpcretest\fP's callout function
553    is called during matching. This works with both matching functions. By default,
554    the called function displays the callout number, the start and current
555    positions in the text at the callout time, and the next pattern item to be
556    tested. For example, the output
557    .sp
558      --->pqrabcdef
559        0    ^  ^     \ed
560    .sp
561    indicates that callout number 0 occurred for a match attempt starting at the
562    fourth character of the subject string, when the pointer was at the seventh
563    character of the data, and when the next pattern item was \ed. Just one
564    circumflex is output if the start and current positions are the same.
565    .P
566    Callouts numbered 255 are assumed to be automatic callouts, inserted as a
567    result of the \fB/C\fP pattern modifier. In this case, instead of showing the
568    callout number, the offset in the pattern, preceded by a plus, is output. For
569    example:
570    .sp
571        re> /\ed?[A-E]\e*/C
572      data> E*
573      --->E*
574       +0 ^      \ed?
575       +3 ^      [A-E]
576       +8 ^^     \e*
577      +10 ^ ^
578       0: E*
579    .sp
580    The callout function in \fBpcretest\fP returns zero (carry on matching) by
581    default, but you can use a \eC item in a data line (as described above) to
582    change this.
583    .P
584    Inserting callouts can be helpful when using \fBpcretest\fP to check
585    complicated regular expressions. For further information about callouts, see
586    the
587    .\" HREF
588    \fBpcrecallout\fP
589    .\"
590    documentation.
591    .
592    .
593    .
594    .SH "NON-PRINTING CHARACTERS"
595    .rs
596    .sp
597    When \fBpcretest\fP is outputting text in the compiled version of a pattern,
598    bytes other than 32-126 are always treated as non-printing characters are are
599    therefore shown as hex escapes.
600    .P
601    When \fBpcretest\fP is outputting text that is a matched part of a subject
602    string, it behaves in the same way, unless a different locale has been set for
603    the pattern (using the \fB/L\fP modifier). In this case, the \fBisprint()\fP
604    function to distinguish printing and non-printing characters.
605    .
606    .
607    .
608    .SH "SAVING AND RELOADING COMPILED PATTERNS"
609    .rs
610    .sp
611    The facilities described in this section are not available when the POSIX
612    inteface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
613    specified.
614    .P
615    When the POSIX interface is not in use, you can cause \fBpcretest\fP to write a
616    compiled pattern to a file, by following the modifiers with > and a file name.
617    For example:
618    .sp
619      /pattern/im >/some/file
620    .sp
621    See the
622    .\" HREF
623    \fBpcreprecompile\fP
624    .\"
625    documentation for a discussion about saving and re-using compiled patterns.
626    .P
627    The data that is written is binary. The first eight bytes are the length of the
628    compiled pattern data followed by the length of the optional study data, each
629    written as four bytes in big-endian order (most significant byte first). If
630    there is no study data (either the pattern was not studied, or studying did not
631    return any data), the second length is zero. The lengths are followed by an
632    exact copy of the compiled pattern. If there is additional study data, this
633    follows immediately after the compiled pattern. After writing the file,
634    \fBpcretest\fP expects to read a new pattern.
635    .P
636    A saved pattern can be reloaded into \fBpcretest\fP by specifing < and a file
637    name instead of a pattern. The name of the file must not contain a < character,
638    as otherwise \fBpcretest\fP will interpret the line as a pattern delimited by <
639    characters.
640    For example:
641    .sp
642       re> </some/file
643      Compiled regex loaded from /some/file
644      No study data
645    .sp
646    When the pattern has been loaded, \fBpcretest\fP proceeds to read data lines in
647    the usual way.
648    .P
649    You can copy a file written by \fBpcretest\fP to a different host and reload it
650    there, even if the new host has opposite endianness to the one on which the
651    pattern was compiled. For example, you can compile on an i86 machine and run on
652    a SPARC machine.
653    .P
654    File names for saving and reloading can be absolute or relative, but note that
655    the shell facility of expanding a file name that starts with a tilde (~) is not
656    available.
657    .P
658    The ability to save and reload files in \fBpcretest\fP is intended for testing
659    and experimentation. It is not intended for production use because only a
660    single pattern can be written to a file. Furthermore, there is no facility for
661    supplying custom character tables for use with a reloaded pattern. If the
662    original pattern was compiled with custom tables, an attempt to match a subject
663    string using a reloaded pattern is likely to cause \fBpcretest\fP to crash.
664    Finally, if you attempt to load a file that is not in the correct format, the
665    result is undefined.
666    .
667    .
668    .SH "SEE ALSO"
669    .rs
670    .sp
671    \fBpcre\fP(3), \fBpcreapi\fP(3), \fBpcrecallout\fP(3), \fBpcrematching\fP(3),
672    \fBpcrepartial\fP(d), \fPpcrepattern\fP(3), \fBpcreprecompile\fP(3).
673    .
674    .
675  .SH AUTHOR  .SH AUTHOR
676  Philip Hazel <ph10@cam.ac.uk>  .rs
677  .br  .sp
678  University Computing Service,  .nf
679  .br  Philip Hazel
680  New Museums Site,  University Computing Service
681  .br  Cambridge CB2 3QH, England.
682  Cambridge CB2 3QG, England.  .fi
683  .br  .
684  Phone: +44 1223 334714  .
685    .SH REVISION
686  Last updated: 15 August 2001  .rs
687  .br  .sp
688  Copyright (c) 1997-2001 University of Cambridge.  .nf
689    Last updated: 06 March 2007
690    Copyright (c) 1997-2007 University of Cambridge.
691    .fi

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