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revision 53 by nigel, Sat Feb 24 21:39:42 2007 UTC revision 231 by ph10, Tue Sep 11 11:15:33 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/<anycrlf>\fP      PCRE_NEWLINE_ANYCRLF
172      \fB/<any>\fP          PCRE_NEWLINE_ANY
173      \fB/<bsr_anycrlf>\fP  PCRE_BSR_ANYCRLF
174      \fB/<bsr_unicode>\fP  PCRE_BSR_UNICODE
175    .sp
176    Those specifying line ending sequences are literal strings as shown, but the
177    letters can be in either case. This example sets multiline matching with CRLF
178    as the line ending sequence:
179    .sp
180      /^abc/m<crlf>
181    .sp
182    Details of the meanings of these PCRE options are given in the
183    .\" HREF
184    \fBpcreapi\fP
185    .\"
186    documentation.
187    .
188    .
189    .SS "Finding all matches in a string"
190    .rs
191    .sp
192  Searching for all possible matches within each subject string can be requested  Searching for all possible matches within each subject string can be requested
193  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
194  again to search the remainder of the subject string. The difference between  again to search the remainder of the subject string. The difference between
195  \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
196  \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
197  (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
198  substring. This makes a difference to the matching process if the pattern  substring. This makes a difference to the matching process if the pattern
199  begins with a lookbehind assertion (including \\b or \\B).  begins with a lookbehind assertion (including \eb or \eB).
200    .P
201  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
202  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
203  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.
204  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
205  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
206  \fB/g\fR modifier or the \fBsplit()\fR function.  \fB/g\fP modifier or the \fBsplit()\fP function.
207    .
208  There are a number of other modifiers for controlling the way \fBpcretest\fR  .
209    .SS "Other modifiers"
210    .rs
211    .sp
212    There are yet more modifiers for controlling the way \fBpcretest\fP
213  operates.  operates.
214    .P
215  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
216  matched the entire pattern, pcretest should in addition output the remainder of  matched the entire pattern, pcretest should in addition output the remainder of
217  the subject string. This is useful for tests where the subject contains  the subject string. This is useful for tests where the subject contains
218  multiple copies of the same substring.  multiple copies of the same substring.
219    .P
220  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
221    output a representation of the compiled byte code after compilation. Normally
222    this information contains length and offset values; however, if \fB/Z\fP is
223    also present, this data is replaced by spaces. This is a special feature for
224    use in the automatic test scripts; it ensures that the same output is generated
225    for different internal link sizes.
226    .P
227    The \fB/L\fP modifier must be followed directly by the name of a locale, for
228  example,  example,
229    .sp
230    /pattern/Lfr    /pattern/Lfr_FR
231    .sp
232  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,
233  \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
234  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
235  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
236  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.
237    .P
238  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
239  compiled expression (whether it is anchored, has a fixed first character, and  compiled pattern (whether it is anchored, has a fixed first character, and
240  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
241  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.
242  studied, the results of that are also output.  .P
243    The \fB/D\fP modifier is a PCRE debugging feature, and is equivalent to
244  The \fB/D\fR modifier is a PCRE debugging feature, which also assumes \fB/I\fR.  \fB/BI\fP, that is, both the \fB/B\fP and the \fB/I\fP modifiers.
245  It causes the internal form of compiled regular expressions to be output after  .P
246  compilation.  The \fB/F\fP modifier causes \fBpcretest\fP to flip the byte order of the
247    fields in the compiled pattern that contain 2-byte and 4-byte numbers. This
248  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
249    that were compiled on a host with a different endianness. This feature is not
250    available when the POSIX interface to PCRE is being used, that is, when the
251    \fB/P\fP pattern modifier is specified. See also the section about saving and
252    reloading compiled patterns below.
253    .P
254    The \fB/S\fP modifier causes \fBpcre_study()\fP to be called after the
255  expression has been compiled, and the results used when the expression is  expression has been compiled, and the results used when the expression is
256  matched.  matched.
257    .P
258  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
259  pattern to be output.  pattern to be output.
260    .P
261  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
262  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
263  \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
264  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
265  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.
266    .P
267  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
268  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,
269  character handling in PCRE, provided that it was compiled with this support  provided that it was compiled with this support enabled. This modifier also
270  enabled. This modifier also causes any non-printing characters in output  causes any non-printing characters in output strings to be printed using the
271  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.
272  sequences.  .P
273    If the \fB/?\fP modifier is used with \fB/8\fP, it causes \fBpcretest\fP to
274    call \fBpcre_compile()\fP with the PCRE_NO_UTF8_CHECK option, to suppress the
275  .SH DATA LINES  checking of the string for UTF-8 validity.
276    .
277  Before each data line is passed to \fBpcre_exec()\fR, leading and trailing  .
278  whitespace is removed, and it is then scanned for \\ escapes. The following are  .SH "DATA LINES"
279    .rs
280    .sp
281    Before each data line is passed to \fBpcre_exec()\fP, leading and trailing
282    whitespace is removed, and it is then scanned for \e escapes. Some of these are
283    pretty esoteric features, intended for checking out some of the more
284    complicated features of PCRE. If you are just testing "ordinary" regular
285    expressions, you probably don't need any of these. The following escapes are
286  recognized:  recognized:
287    .sp
288    \\a         alarm (= BEL)    \ea         alarm (BEL, \ex07)
289    \\b         backspace    \eb         backspace (\ex08)
290    \\e         escape    \ee         escape (\ex27)
291    \\f         formfeed    \ef         formfeed (\ex0c)
292    \\n         newline    \en         newline (\ex0a)
293    \\r         carriage return  .\" JOIN
294    \\t         tab    \eqdd       set the PCRE_MATCH_LIMIT limit to dd
295    \\v         vertical tab                 (any number of digits)
296    \\nnn       octal character (up to 3 octal digits)    \er         carriage return (\ex0d)
297    \\xhh       hexadecimal character (up to 2 hex digits)    \et         tab (\ex09)
298    \\x{hh...}  hexadecimal UTF-8 character    \ev         vertical tab (\ex0b)
299      \ennn       octal character (up to 3 octal digits)
300    \\A         pass the PCRE_ANCHORED option to \fBpcre_exec()\fR    \exhh       hexadecimal character (up to 2 hex digits)
301    \\B         pass the PCRE_NOTBOL option to \fBpcre_exec()\fR  .\" JOIN
302    \\Cdd       call pcre_copy_substring() for substring dd    \ex{hh...}  hexadecimal character, any number of digits
303                  after a successful match (any decimal number                 in UTF-8 mode
304                  less than 32)  .\" JOIN
305    \\Gdd       call pcre_get_substring() for substring dd    \eA         pass the PCRE_ANCHORED option to \fBpcre_exec()\fP
306                  after a successful match (any decimal number                 or \fBpcre_dfa_exec()\fP
307                  less than 32)  .\" JOIN
308    \\L         call pcre_get_substringlist() after a    \eB         pass the PCRE_NOTBOL option to \fBpcre_exec()\fP
309                  successful match                 or \fBpcre_dfa_exec()\fP
310    \\N         pass the PCRE_NOTEMPTY option to \fBpcre_exec()\fR  .\" JOIN
311    \\Odd       set the size of the output vector passed to    \eCdd       call pcre_copy_substring() for substring dd
312                  \fBpcre_exec()\fR to dd (any number of decimal                 after a successful match (number less than 32)
313                  digits)  .\" JOIN
314    \\Z         pass the PCRE_NOTEOL option to \fBpcre_exec()\fR    \eCname     call pcre_copy_named_substring() for substring
315                   "name" after a successful match (name termin-
316  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)
317  option (or defaulted to 45); \\O applies only to the call of \fBpcre_exec()\fR  .\" JOIN
318  for the line in which it appears.    \eC+        show the current captured substrings at callout
319                   time
320  A backslash followed by anything else just escapes the anything else. If the    \eC-        do not supply a callout function
321  very last character is a backslash, it is ignored. This gives a way of passing  .\" JOIN
322  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
323                   reached
324  If \fB/P\fR was present on the regex, causing the POSIX wrapper API to be used,  .\" JOIN
325  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
326  to be passed to \fBregexec()\fR respectively.                 reached for the nth time
327    .\" JOIN
328  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
329  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
330      \eD         use the \fBpcre_dfa_exec()\fP match function
331      \eF         only shortest match for \fBpcre_dfa_exec()\fP
332    .\" JOIN
333      \eGdd       call pcre_get_substring() for substring dd
334                   after a successful match (number less than 32)
335    .\" JOIN
336      \eGname     call pcre_get_named_substring() for substring
337                   "name" after a successful match (name termin-
338                   ated by next non-alphanumeric character)
339    .\" JOIN
340      \eL         call pcre_get_substringlist() after a
341                   successful match
342    .\" JOIN
343      \eM         discover the minimum MATCH_LIMIT and
344                   MATCH_LIMIT_RECURSION settings
345    .\" JOIN
346      \eN         pass the PCRE_NOTEMPTY option to \fBpcre_exec()\fP
347                   or \fBpcre_dfa_exec()\fP
348    .\" JOIN
349      \eOdd       set the size of the output vector passed to
350                   \fBpcre_exec()\fP to dd (any number of digits)
351    .\" JOIN
352      \eP         pass the PCRE_PARTIAL option to \fBpcre_exec()\fP
353                   or \fBpcre_dfa_exec()\fP
354    .\" JOIN
355      \eQdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
356                   (any number of digits)
357      \eR         pass the PCRE_DFA_RESTART option to \fBpcre_dfa_exec()\fP
358      \eS         output details of memory get/free calls during matching
359    .\" JOIN
360      \eZ         pass the PCRE_NOTEOL option to \fBpcre_exec()\fP
361                   or \fBpcre_dfa_exec()\fP
362    .\" JOIN
363      \e?         pass the PCRE_NO_UTF8_CHECK option to
364                   \fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP
365      \e>dd       start the match at offset dd (any number of digits);
366    .\" JOIN
367                   this sets the \fIstartoffset\fP argument for \fBpcre_exec()\fP
368                   or \fBpcre_dfa_exec()\fP
369    .\" JOIN
370      \e<cr>      pass the PCRE_NEWLINE_CR option to \fBpcre_exec()\fP
371                   or \fBpcre_dfa_exec()\fP
372    .\" JOIN
373      \e<lf>      pass the PCRE_NEWLINE_LF option to \fBpcre_exec()\fP
374                   or \fBpcre_dfa_exec()\fP
375    .\" JOIN
376      \e<crlf>    pass the PCRE_NEWLINE_CRLF option to \fBpcre_exec()\fP
377                   or \fBpcre_dfa_exec()\fP
378    .\" JOIN
379      \e<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to \fBpcre_exec()\fP
380                   or \fBpcre_dfa_exec()\fP
381    .\" JOIN
382      \e<any>     pass the PCRE_NEWLINE_ANY option to \fBpcre_exec()\fP
383                   or \fBpcre_dfa_exec()\fP
384    .sp
385    The escapes that specify line ending sequences are literal strings, exactly as
386    shown. No more than one newline setting should be present in any data line.
387    .P
388    A backslash followed by anything else just escapes the anything else. If
389    the very last character is a backslash, it is ignored. This gives a way of
390    passing an empty line as data, since a real empty line terminates the data
391    input.
392    .P
393    If \eM is present, \fBpcretest\fP calls \fBpcre_exec()\fP several times, with
394    different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP
395    fields of the \fBpcre_extra\fP data structure, until it finds the minimum
396    numbers for each parameter that allow \fBpcre_exec()\fP to complete. The
397    \fImatch_limit\fP number is a measure of the amount of backtracking that takes
398    place, and checking it out can be instructive. For most simple matches, the
399    number is quite small, but for patterns with very large numbers of matching
400    possibilities, it can become large very quickly with increasing length of
401    subject string. The \fImatch_limit_recursion\fP number is a measure of how much
402    stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is needed
403    to complete the match attempt.
404    .P
405    When \eO is used, the value specified may be higher or lower than the size set
406    by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to
407    the call of \fBpcre_exec()\fP for the line in which it appears.
408    .P
409    If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper
410    API to be used, the only option-setting sequences that have any effect are \eB
411    and \eZ, causing REG_NOTBOL and REG_NOTEOL, respectively, to be passed to
412    \fBregexec()\fP.
413    .P
414    The use of \ex{hh...} to represent UTF-8 characters is not dependent on the use
415    of the \fB/8\fP modifier on the pattern. It is recognized always. There may be
416  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
417  six bytes, encoded according to the UTF-8 rules.  six bytes, encoded according to the original UTF-8 rules of RFC 2279. This
418    allows for values in the range 0 to 0x7FFFFFFF. Note that not all of those are
419    valid Unicode code points, or indeed valid UTF-8 characters according to the
420  .SH OUTPUT FROM PCRETEST  later rules in RFC 3629.
421    .
422    .
423    .SH "THE ALTERNATIVE MATCHING FUNCTION"
424    .rs
425    .sp
426    By default, \fBpcretest\fP uses the standard PCRE matching function,
427    \fBpcre_exec()\fP to match each data line. From release 6.0, PCRE supports an
428    alternative matching function, \fBpcre_dfa_test()\fP, which operates in a
429    different way, and has some restrictions. The differences between the two
430    functions are described in the
431    .\" HREF
432    \fBpcrematching\fP
433    .\"
434    documentation.
435    .P
436    If a data line contains the \eD escape sequence, or if the command line
437    contains the \fB-dfa\fP option, the alternative matching function is called.
438    This function finds all possible matches at a given point. If, however, the \eF
439    escape sequence is present in the data line, it stops after the first match is
440    found. This is always the shortest possible match.
441    .
442    .
443    .SH "DEFAULT OUTPUT FROM PCRETEST"
444    .rs
445    .sp
446    This section describes the output when the normal matching function,
447    \fBpcre_exec()\fP, is being used.
448    .P
449  When a match succeeds, pcretest outputs the list of captured substrings that  When a match succeeds, pcretest outputs the list of captured substrings that
450  \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
451  the whole pattern. Here is an example of an interactive pcretest run.  the whole pattern. Otherwise, it outputs "No match" or "Partial match"
452    when \fBpcre_exec()\fP returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PARTIAL,
453    respectively, and otherwise the PCRE negative error number. Here is an example
454    of an interactive \fBpcretest\fP run.
455    .sp
456    $ pcretest    $ pcretest
457    PCRE version 2.06 08-Jun-1999    PCRE version 7.0 30-Nov-2006
458    .sp
459      re> /^abc(\\d+)/      re> /^abc(\ed+)/
460    data> abc123    data> abc123
461     0: abc123     0: abc123
462     1: 123     1: 123
463    data> xyz    data> xyz
464    No match    No match
465    .sp
466  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
467  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
468  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
469  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
470  "0+" like this:  the the rest of the subject string, identified by "0+" like this:
471    .sp
472      re> /cat/+      re> /cat/+
473    data> cataract    data> cataract
474     0: cat     0: cat
475     0+ aract     0+ aract
476    .sp
477  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
478  matching attempts are output in sequence, like this:  matching attempts are output in sequence, like this:
479    .sp
480      re> /\\Bi(\\w\\w)/g      re> /\eBi(\ew\ew)/g
481    data> Mississippi    data> Mississippi
482     0: iss     0: iss
483     1: ss     1: ss
# Line 251  matching attempts are output in sequence Line 485  matching attempts are output in sequence
485     1: ss     1: ss
486     0: ipp     0: ipp
487     1: pp     1: pp
488    .sp
489  "No match" is output only if the first match attempt fails.  "No match" is output only if the first match attempt fails.
490    .P
491  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
492  data line that is successfully matched, the substrings extracted by the  data line that is successfully matched, the substrings extracted by the
493  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
494  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
495  length (that is, the return from the extraction function) is given in  length (that is, the return from the extraction function) is given in
496  parentheses after each string for \fB\\C\fR and \fB\\G\fR.  parentheses after each string for \fB\eC\fP and \fB\eG\fP.
497    .P
498  Note that while patterns can be continued over several lines (a plain ">"  Note that whereas patterns can be continued over several lines (a plain ">"
499  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
500  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
501    the newline sequence setting).
502    .
503    .
504    .
505    .SH "OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION"
506    .rs
507    .sp
508    When the alternative matching function, \fBpcre_dfa_exec()\fP, is used (by
509    means of the \eD escape sequence or the \fB-dfa\fP command line option), the
510    output consists of a list of all the matches that start at the first point in
511    the subject where there is at least one match. For example:
512    .sp
513        re> /(tang|tangerine|tan)/
514      data> yellow tangerine\eD
515       0: tangerine
516       1: tang
517       2: tan
518    .sp
519    (Using the normal matching function on this data finds only "tang".) The
520    longest matching string is always given first (and numbered zero).
521    .P
522    If \fB/g\fP is present on the pattern, the search for further matches resumes
523    at the end of the longest match. For example:
524    .sp
525        re> /(tang|tangerine|tan)/g
526      data> yellow tangerine and tangy sultana\eD
527       0: tangerine
528       1: tang
529       2: tan
530       0: tang
531       1: tan
532       0: tan
533    .sp
534    Since the matching function does not support substring capture, the escape
535    sequences that are concerned with captured substrings are not relevant.
536    .
537    .
538    .SH "RESTARTING AFTER A PARTIAL MATCH"
539    .rs
540    .sp
541    When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
542    indicating that the subject partially matched the pattern, you can restart the
543    match with additional subject data by means of the \eR escape sequence. For
544    example:
545    .sp
546        re> /^\ed?\ed(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\ed\ed$/
547      data> 23ja\eP\eD
548      Partial match: 23ja
549      data> n05\eR\eD
550       0: n05
551    .sp
552    For further information about partial matching, see the
553    .\" HREF
554    \fBpcrepartial\fP
555    .\"
556    documentation.
557    .
558    .
559    .SH CALLOUTS
560    .rs
561    .sp
562    If the pattern contains any callout requests, \fBpcretest\fP's callout function
563    is called during matching. This works with both matching functions. By default,
564    the called function displays the callout number, the start and current
565    positions in the text at the callout time, and the next pattern item to be
566    tested. For example, the output
567    .sp
568      --->pqrabcdef
569        0    ^  ^     \ed
570    .sp
571    indicates that callout number 0 occurred for a match attempt starting at the
572    fourth character of the subject string, when the pointer was at the seventh
573    character of the data, and when the next pattern item was \ed. Just one
574    circumflex is output if the start and current positions are the same.
575    .P
576    Callouts numbered 255 are assumed to be automatic callouts, inserted as a
577    result of the \fB/C\fP pattern modifier. In this case, instead of showing the
578    callout number, the offset in the pattern, preceded by a plus, is output. For
579    example:
580    .sp
581        re> /\ed?[A-E]\e*/C
582      data> E*
583      --->E*
584       +0 ^      \ed?
585       +3 ^      [A-E]
586       +8 ^^     \e*
587      +10 ^ ^
588       0: E*
589    .sp
590    The callout function in \fBpcretest\fP returns zero (carry on matching) by
591    default, but you can use a \eC item in a data line (as described above) to
592    change this.
593    .P
594    Inserting callouts can be helpful when using \fBpcretest\fP to check
595    complicated regular expressions. For further information about callouts, see
596    the
597    .\" HREF
598    \fBpcrecallout\fP
599    .\"
600    documentation.
601    .
602    .
603    .
604    .SH "NON-PRINTING CHARACTERS"
605    .rs
606    .sp
607    When \fBpcretest\fP is outputting text in the compiled version of a pattern,
608    bytes other than 32-126 are always treated as non-printing characters are are
609    therefore shown as hex escapes.
610    .P
611    When \fBpcretest\fP is outputting text that is a matched part of a subject
612    string, it behaves in the same way, unless a different locale has been set for
613    the pattern (using the \fB/L\fP modifier). In this case, the \fBisprint()\fP
614    function to distinguish printing and non-printing characters.
615    .
616    .
617    .
618    .SH "SAVING AND RELOADING COMPILED PATTERNS"
619    .rs
620    .sp
621    The facilities described in this section are not available when the POSIX
622    inteface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
623    specified.
624    .P
625    When the POSIX interface is not in use, you can cause \fBpcretest\fP to write a
626    compiled pattern to a file, by following the modifiers with > and a file name.
627    For example:
628    .sp
629      /pattern/im >/some/file
630    .sp
631    See the
632    .\" HREF
633    \fBpcreprecompile\fP
634    .\"
635    documentation for a discussion about saving and re-using compiled patterns.
636    .P
637    The data that is written is binary. The first eight bytes are the length of the
638    compiled pattern data followed by the length of the optional study data, each
639    written as four bytes in big-endian order (most significant byte first). If
640    there is no study data (either the pattern was not studied, or studying did not
641    return any data), the second length is zero. The lengths are followed by an
642    exact copy of the compiled pattern. If there is additional study data, this
643    follows immediately after the compiled pattern. After writing the file,
644    \fBpcretest\fP expects to read a new pattern.
645    .P
646    A saved pattern can be reloaded into \fBpcretest\fP by specifing < and a file
647    name instead of a pattern. The name of the file must not contain a < character,
648    as otherwise \fBpcretest\fP will interpret the line as a pattern delimited by <
649    characters.
650    For example:
651    .sp
652       re> </some/file
653      Compiled regex loaded from /some/file
654      No study data
655    .sp
656    When the pattern has been loaded, \fBpcretest\fP proceeds to read data lines in
657    the usual way.
658    .P
659    You can copy a file written by \fBpcretest\fP to a different host and reload it
660    there, even if the new host has opposite endianness to the one on which the
661    pattern was compiled. For example, you can compile on an i86 machine and run on
662    a SPARC machine.
663    .P
664    File names for saving and reloading can be absolute or relative, but note that
665    the shell facility of expanding a file name that starts with a tilde (~) is not
666    available.
667    .P
668    The ability to save and reload files in \fBpcretest\fP is intended for testing
669    and experimentation. It is not intended for production use because only a
670    single pattern can be written to a file. Furthermore, there is no facility for
671    supplying custom character tables for use with a reloaded pattern. If the
672    original pattern was compiled with custom tables, an attempt to match a subject
673    string using a reloaded pattern is likely to cause \fBpcretest\fP to crash.
674    Finally, if you attempt to load a file that is not in the correct format, the
675    result is undefined.
676    .
677    .
678    .SH "SEE ALSO"
679    .rs
680    .sp
681    \fBpcre\fP(3), \fBpcreapi\fP(3), \fBpcrecallout\fP(3), \fBpcrematching\fP(3),
682    \fBpcrepartial\fP(d), \fBpcrepattern\fP(3), \fBpcreprecompile\fP(3).
683    .
684    .
685  .SH AUTHOR  .SH AUTHOR
686  Philip Hazel <ph10@cam.ac.uk>  .rs
687  .br  .sp
688  University Computing Service,  .nf
689  .br  Philip Hazel
690  New Museums Site,  University Computing Service
691  .br  Cambridge CB2 3QH, England.
692  Cambridge CB2 3QG, England.  .fi
693  .br  .
694  Phone: +44 1223 334714  .
695    .SH REVISION
696  Last updated: 15 August 2001  .rs
697  .br  .sp
698  Copyright (c) 1997-2001 University of Cambridge.  .nf
699    Last updated: 11 September 2007
700    Copyright (c) 1997-2007 University of Cambridge.
701    .fi

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