/[pcre]/code/trunk/doc/pcretest.1
ViewVC logotype

Diff of /code/trunk/doc/pcretest.1

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 63 by nigel, Sat Feb 24 21:40:03 2007 UTC revision 91 by nigel, Sat Feb 24 21:41:34 2007 UTC
# Line 2  Line 2 
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 document 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  details of the regular expressions themselves, see the
13  .\" HREF  .\" HREF
14  \fBpcrepattern\fR  \fBpcrepattern\fP
15  .\"  .\"
16  documentation. For details of PCRE and its options, see the  documentation. For details of the PCRE library function calls and their
17    options, see the
18  .\" HREF  .\" HREF
19  \fBpcreapi\fR  \fBpcreapi\fP
20  .\"  .\"
21  documentation.  documentation.
22    .
23    .
24  .SH OPTIONS  .SH OPTIONS
25  .rs  .rs
 .sp  
26  .TP 10  .TP 10
27  \fB-C\fR  \fB-C\fP
28  Output the version number of the PCRE library, and all available information  Output the version number of the PCRE library, and all available information
29  about the optional features that are included, and then exit.  about the optional features that are included, and then exit.
30  .TP 10  .TP 10
31  \fB-d\fR  \fB-d\fP
32  Behave as if each regex had the \fB/D\fR modifier (see below); the internal  Behave as if each regex has the \fB/D\fP (debug) modifier; the internal
33  form is output after compilation.  form is output after compilation.
34  .TP 10  .TP 10
35  \fB-i\fR  \fB-dfa\fP
36  Behave as if each regex had the \fB/I\fR modifier; information about the  Behave as if each data line contains the \eD escape sequence; this causes the
37    alternative matching function, \fBpcre_dfa_exec()\fP, to be used instead of the
38    standard \fBpcre_exec()\fP function (more detail is given below).
39    .TP 10
40    \fB-i\fP
41    Behave as if each regex has the \fB/I\fP modifier; information about the
42  compiled pattern is given after compilation.  compiled pattern is given after compilation.
43  .TP 10  .TP 10
44  \fB-m\fR  \fB-m\fP
45  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
46  equivalent to adding /M to each regular expression. For compatibility with  equivalent to adding \fB/M\fP to each regular expression. For compatibility
47  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.
48    .TP 10
49    \fB-o\fP \fIosize\fP
50    Set the number of elements in the output vector that is used when calling
51    \fBpcre_exec()\fP to be \fIosize\fP. The default value is 45, which is enough
52    for 14 capturing subexpressions. The vector size can be changed for individual
53    matching calls by including \eO in the data line (see below).
54  .TP 10  .TP 10
55  \fB-o\fR \fIosize\fR  \fB-p\fP
56  Set the number of elements in the output vector that is used when calling PCRE  Behave as if each regex has the \fB/P\fP modifier; the POSIX wrapper API is
57  to be \fIosize\fR. The default value is 45, which is enough for 14 capturing  used to call PCRE. None of the other options has any effect when \fB-p\fP is
58  subexpressions. The vector size can be changed for individual matching calls by  set.
 including \\O in the data line (see below).  
59  .TP 10  .TP 10
60  \fB-p\fR  \fB-q\fP
61  Behave as if each regex has \fB/P\fR modifier; the POSIX wrapper API is used  Do not output the version number of \fBpcretest\fP at the start of execution.
 to call PCRE. None of the other options has any effect when \fB-p\fR is set.  
62  .TP 10  .TP 10
63  \fB-t\fR  \fB-S\fP \fIsize\fP
64    On Unix-like systems, set the size of the runtime stack to \fIsize\fP
65    megabytes.
66    .TP 10
67    \fB-t\fP
68  Run each compile, study, and match many times with a timer, and output  Run each compile, study, and match many times with a timer, and output
69  resulting time per compile or match (in milliseconds). Do not set \fB-t\fR with  resulting time per compile or match (in milliseconds). Do not set \fB-m\fP with
70  \fB-m\fR, because you will then get the size output 20000 times and the timing  \fB-t\fP, because you will then get the size output a zillion times, and the
71  will be distorted.  timing will be distorted.
72    .
73    .
74  .SH DESCRIPTION  .SH DESCRIPTION
75  .rs  .rs
76  .sp  .sp
77  If \fBpcretest\fR is given two filename arguments, it reads from the first and  If \fBpcretest\fP is given two filename arguments, it reads from the first and
78  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
79  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
80  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
81  expressions, and "data>" to prompt for data lines.  expressions, and "data>" to prompt for data lines.
82    .P
83  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
84  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
85  lines to be matched against the pattern.  lines to be matched against the pattern.
86    .P
87  Each line is matched separately and independently. If you want to do  Each data line is matched separately and independently. If you want to do
88  multiple-line matches, you have to use the \\n escape sequence in a single line  multi-line matches, you have to use the \en escape sequence (or \er or \er\en,
89  of input to encode the newline characters. The maximum length of data line is  depending on the newline setting) in a single line of input to encode the
90  30,000 characters.  newline characters. There is no limit on the length of data lines; the input
91    buffer is automatically extended if it is too small.
92    .P
93  An empty line signals the end of the data lines, at which point a new regular  An empty line signals the end of the data lines, at which point a new regular
94  expression is read. The regular expressions are given enclosed in any  expression is read. The regular expressions are given enclosed in any
95  non-alphameric delimiters other than backslash, for example  non-alphanumeric delimiters other than backslash, for example:
96    .sp
97    /(a|bc)x+yz/    /(a|bc)x+yz/
98    .sp
99  White space before the initial delimiter is ignored. A regular expression may  White space before the initial delimiter is ignored. A regular expression may
100  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
101  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
102  by escaping it, for example  by escaping it, for example
103    .sp
104    /abc\\/def/    /abc\e/def/
105    .sp
106  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
107  delimiters are always non-alphameric, this does not affect its interpretation.  delimiters are always non-alphanumeric, this does not affect its interpretation.
108  If the terminating delimiter is immediately followed by a backslash, for  If the terminating delimiter is immediately followed by a backslash, for
109  example,  example,
110    .sp
111    /abc/\\    /abc/\e
112    .sp
113  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
114  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
115  backslash, because  backslash, because
116    .sp
117    /abc\\/    /abc\e/
118    .sp
119  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
120  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.
121    .
122  .SH PATTERN MODIFIERS  .
123    .SH "PATTERN MODIFIERS"
124  .rs  .rs
125  .sp  .sp
126  The pattern may be followed by \fBi\fR, \fBm\fR, \fBs\fR, or \fBx\fR to set the  A pattern may be followed by any number of modifiers, which are mostly single
127  PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options,  characters. Following Perl usage, these are referred to below as, for example,
128  respectively. For example:  "the \fB/i\fP modifier", even though the delimiter of the pattern need not
129    always be a slash, and no slash is used when writing modifiers. Whitespace may
130    appear between the final pattern delimiter and the first modifier, and between
131    the modifiers themselves.
132    .P
133    The \fB/i\fP, \fB/m\fP, \fB/s\fP, and \fB/x\fP modifiers set the PCRE_CASELESS,
134    PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
135    \fBpcre_compile()\fP is called. These four modifier letters have the same
136    effect as they do in Perl. For example:
137    .sp
138    /caseless/i    /caseless/i
139    .sp
140  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
141  others which set PCRE options that do not correspond to anything in Perl:  not correspond to anything in Perl:
142  \fB/A\fR, \fB/E\fR, and \fB/X\fR set PCRE_ANCHORED, PCRE_DOLLAR_ENDONLY, and  .sp
143  PCRE_EXTRA respectively.    \fB/A\fP       PCRE_ANCHORED
144      \fB/C\fP       PCRE_AUTO_CALLOUT
145      \fB/E\fP       PCRE_DOLLAR_ENDONLY
146      \fB/f\fP       PCRE_FIRSTLINE
147      \fB/J\fP       PCRE_DUPNAMES
148      \fB/N\fP       PCRE_NO_AUTO_CAPTURE
149      \fB/U\fP       PCRE_UNGREEDY
150      \fB/X\fP       PCRE_EXTRA
151      \fB/<cr>\fP    PCRE_NEWLINE_CR
152      \fB/<lf>\fP    PCRE_NEWLINE_LF
153      \fB/<crlf>\fP  PCRE_NEWLINE_CRLF
154    .sp
155    Those specifying line endings are literal strings as shown. Details of the
156    meanings of these PCRE options are given in the
157    .\" HREF
158    \fBpcreapi\fP
159    .\"
160    documentation.
161    .
162    .
163    .SS "Finding all matches in a string"
164    .rs
165    .sp
166  Searching for all possible matches within each subject string can be requested  Searching for all possible matches within each subject string can be requested
167  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
168  again to search the remainder of the subject string. The difference between  again to search the remainder of the subject string. The difference between
169  \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
170  \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
171  (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
172  substring. This makes a difference to the matching process if the pattern  substring. This makes a difference to the matching process if the pattern
173  begins with a lookbehind assertion (including \\b or \\B).  begins with a lookbehind assertion (including \eb or \eB).
174    .P
175  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
176  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
177  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.
178  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
179  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
180  \fB/g\fR modifier or the \fBsplit()\fR function.  \fB/g\fP modifier or the \fBsplit()\fP function.
181    .
182  There are a number of other modifiers for controlling the way \fBpcretest\fR  .
183    .SS "Other modifiers"
184    .rs
185    .sp
186    There are yet more modifiers for controlling the way \fBpcretest\fP
187  operates.  operates.
188    .P
189  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
190  matched the entire pattern, pcretest should in addition output the remainder of  matched the entire pattern, pcretest should in addition output the remainder of
191  the subject string. This is useful for tests where the subject contains  the subject string. This is useful for tests where the subject contains
192  multiple copies of the same substring.  multiple copies of the same substring.
193    .P
194  The \fB/L\fR modifier must be followed directly by the name of a locale, for  The \fB/L\fP modifier must be followed directly by the name of a locale, for
195  example,  example,
196    .sp
197    /pattern/Lfr    /pattern/Lfr_FR
198    .sp
199  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,
200  \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
201  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
202  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
203  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.
204    .P
205  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
206  compiled expression (whether it is anchored, has a fixed first character, and  compiled pattern (whether it is anchored, has a fixed first character, and
207  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
208  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.
209  studied, the results of that are also output.  .P
210    The \fB/D\fP modifier is a PCRE debugging feature, which also assumes \fB/I\fP.
 The \fB/D\fR modifier is a PCRE debugging feature, which also assumes \fB/I\fR.  
211  It causes the internal form of compiled regular expressions to be output after  It causes the internal form of compiled regular expressions to be output after
212  compilation. If the pattern was studied, the information returned is also  compilation. If the pattern was studied, the information returned is also
213  output.  output.
214    .P
215  The \fB/S\fR modifier causes \fBpcre_study()\fR to be called after the  The \fB/F\fP modifier causes \fBpcretest\fP to flip the byte order of the
216    fields in the compiled pattern that contain 2-byte and 4-byte numbers. This
217    facility is for testing the feature in PCRE that allows it to execute patterns
218    that were compiled on a host with a different endianness. This feature is not
219    available when the POSIX interface to PCRE is being used, that is, when the
220    \fB/P\fP pattern modifier is specified. See also the section about saving and
221    reloading compiled patterns below.
222    .P
223    The \fB/S\fP modifier causes \fBpcre_study()\fP to be called after the
224  expression has been compiled, and the results used when the expression is  expression has been compiled, and the results used when the expression is
225  matched.  matched.
226    .P
227  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
228  pattern to be output.  pattern to be output.
229    .P
230  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
231  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
232  \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
233  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
234  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.
235    .P
236  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
237  option set. This turns on support for UTF-8 character handling in PCRE,  option set. This turns on support for UTF-8 character handling in PCRE,
238  provided that it was compiled with this support enabled. This modifier also  provided that it was compiled with this support enabled. This modifier also
239  causes any non-printing characters in output strings to be printed using the  causes any non-printing characters in output strings to be printed using the
240  \\x{hh...} notation if they are valid UTF-8 sequences.  \ex{hh...} notation if they are valid UTF-8 sequences.
241    .P
242  .SH CALLOUTS  If the \fB/?\fP modifier is used with \fB/8\fP, it causes \fBpcretest\fP to
243  .rs  call \fBpcre_compile()\fP with the PCRE_NO_UTF8_CHECK option, to suppress the
244  .sp  checking of the string for UTF-8 validity.
245  If the pattern contains any callout requests, \fBpcretest\fR's callout function  .
246  will be called. By default, it displays the callout number, and the start and  .
247  current positions in the text at the callout time. For example, the output  .SH "DATA LINES"
   
   --->pqrabcdef  
     0    ^  ^  
   
 indicates that callout number 0 occurred for a match attempt starting at the  
 fourth character of the subject string, when the pointer was at the seventh  
 character. The callout function returns zero (carry on matching) by default.  
   
 Inserting callouts may be helpful when using \fBpcretest\fR to check  
 complicated regular expressions. For further information about callouts, see  
 the  
 .\" HREF  
 \fBpcrecallout\fR  
 .\"  
 documentation.  
   
 For testing the PCRE library, additional control of callout behaviour is  
 available via escape sequences in the data, as described in the following  
 section. In particular, it is possible to pass in a number as callout data (the  
 default is zero). If the callout function receives a non-zero number, it  
 returns that value instead of zero.  
   
 .SH DATA LINES  
248  .rs  .rs
249  .sp  .sp
250  Before each data line is passed to \fBpcre_exec()\fR, leading and trailing  Before each data line is passed to \fBpcre_exec()\fP, leading and trailing
251  whitespace is removed, and it is then scanned for \\ escapes. Some of these are  whitespace is removed, and it is then scanned for \e escapes. Some of these are
252  pretty esoteric features, intended for checking out some of the more  pretty esoteric features, intended for checking out some of the more
253  complicated features of PCRE. If you are just testing "ordinary" regular  complicated features of PCRE. If you are just testing "ordinary" regular
254  expressions, you probably don't need any of these. The following escapes are  expressions, you probably don't need any of these. The following escapes are
255  recognized:  recognized:
256    .sp
257    \\a         alarm (= BEL)    \ea         alarm (= BEL)
258    \\b         backspace    \eb         backspace
259    \\e         escape    \ee         escape
260    \\f         formfeed    \ef         formfeed
261    \\n         newline    \en         newline
262    \\r         carriage return  .\" JOIN
263    \\t         tab    \eqdd       set the PCRE_MATCH_LIMIT limit to dd
264    \\v         vertical tab                 (any number of digits)
265    \\nnn       octal character (up to 3 octal digits)    \er         carriage return
266    \\xhh       hexadecimal character (up to 2 hex digits)    \et         tab
267    \\x{hh...}  hexadecimal character, any number of digits    \ev         vertical tab
268      \ennn       octal character (up to 3 octal digits)
269      \exhh       hexadecimal character (up to 2 hex digits)
270    .\" JOIN
271      \ex{hh...}  hexadecimal character, any number of digits
272                 in UTF-8 mode                 in UTF-8 mode
273    \\A         pass the PCRE_ANCHORED option to \fBpcre_exec()\fR  .\" JOIN
274    \\B         pass the PCRE_NOTBOL option to \fBpcre_exec()\fR    \eA         pass the PCRE_ANCHORED option to \fBpcre_exec()\fP
275    \\Cdd       call pcre_copy_substring() for substring dd                 or \fBpcre_dfa_exec()\fP
276                 after a successful match (any decimal number  .\" JOIN
277                 less than 32)    \eB         pass the PCRE_NOTBOL option to \fBpcre_exec()\fP
278    \\Cname     call pcre_copy_named_substring() for substring                 or \fBpcre_dfa_exec()\fP
279    .\" JOIN
280      \eCdd       call pcre_copy_substring() for substring dd
281                   after a successful match (number less than 32)
282    .\" JOIN
283      \eCname     call pcre_copy_named_substring() for substring
284                 "name" after a successful match (name termin-                 "name" after a successful match (name termin-
285                 ated by next non alphanumeric character)                 ated by next non alphanumeric character)
286    \\C+        show the current captured substrings at callout  .\" JOIN
287      \eC+        show the current captured substrings at callout
288                 time                 time
289    \\C-        do not supply a callout function    \eC-        do not supply a callout function
290    \\C!n       return 1 instead of 0 when callout number n is  .\" JOIN
291      \eC!n       return 1 instead of 0 when callout number n is
292                 reached                 reached
293    \\C!n!m     return 1 instead of 0 when callout number n is  .\" JOIN
294      \eC!n!m     return 1 instead of 0 when callout number n is
295                 reached for the nth time                 reached for the nth time
296    \\C*n       pass the number n (may be negative) as callout  .\" JOIN
297                 data    \eC*n       pass the number n (may be negative) as callout
298    \\Gdd       call pcre_get_substring() for substring dd                 data; this is used as the callout return value
299                 after a successful match (any decimal number    \eD         use the \fBpcre_dfa_exec()\fP match function
300                 less than 32)    \eF         only shortest match for \fBpcre_dfa_exec()\fP
301    \\Gname     call pcre_get_named_substring() for substring  .\" JOIN
302      \eGdd       call pcre_get_substring() for substring dd
303                   after a successful match (number less than 32)
304    .\" JOIN
305      \eGname     call pcre_get_named_substring() for substring
306                 "name" after a successful match (name termin-                 "name" after a successful match (name termin-
307                 ated by next non-alphanumeric character)                 ated by next non-alphanumeric character)
308    \\L         call pcre_get_substringlist() after a  .\" JOIN
309      \eL         call pcre_get_substringlist() after a
310                 successful match                 successful match
311    \\M         discover the minimum MATCH_LIMIT setting  .\" JOIN
312    \\N         pass the PCRE_NOTEMPTY option to \fBpcre_exec()\fR    \eM         discover the minimum MATCH_LIMIT and
313    \\Odd       set the size of the output vector passed to                 MATCH_LIMIT_RECURSION settings
314                 \fBpcre_exec()\fR to dd (any number of decimal  .\" JOIN
315                 digits)    \eN         pass the PCRE_NOTEMPTY option to \fBpcre_exec()\fP
316    \\Z         pass the PCRE_NOTEOL option to \fBpcre_exec()\fR                 or \fBpcre_dfa_exec()\fP
317    .\" JOIN
318  If \\M is present, \fBpcretest\fR calls \fBpcre_exec()\fR several times, with    \eOdd       set the size of the output vector passed to
319  different values in the \fImatch_limit\fR field of the \fBpcre_extra\fR data                 \fBpcre_exec()\fP to dd (any number of digits)
320  structure, until it finds the minimum number that is needed for  .\" JOIN
321  \fBpcre_exec()\fR to complete. This number is a measure of the amount of    \eP         pass the PCRE_PARTIAL option to \fBpcre_exec()\fP
322  recursion and backtracking that takes place, and checking it out can be                 or \fBpcre_dfa_exec()\fP
323  instructive. For most simple matches, the number is quite small, but for  .\" JOIN
324  patterns with very large numbers of matching possibilities, it can become large    \eQdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
325  very quickly with increasing length of subject string.                 (any number of digits)
326      \eR         pass the PCRE_DFA_RESTART option to \fBpcre_dfa_exec()\fP
327  When \\O is used, it may be higher or lower than the size set by the \fB-O\fR    \eS         output details of memory get/free calls during matching
328  option (or defaulted to 45); \\O applies only to the call of \fBpcre_exec()\fR  .\" JOIN
329  for the line in which it appears.    \eZ         pass the PCRE_NOTEOL option to \fBpcre_exec()\fP
330                   or \fBpcre_dfa_exec()\fP
331    .\" JOIN
332      \e?         pass the PCRE_NO_UTF8_CHECK option to
333                   \fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP
334      \e>dd       start the match at offset dd (any number of digits);
335    .\" JOIN
336                   this sets the \fIstartoffset\fP argument for \fBpcre_exec()\fP
337                   or \fBpcre_dfa_exec()\fP
338    .\" JOIN
339      \e<cr>      pass the PCRE_NEWLINE_CR option to \fBpcre_exec()\fP
340                   or \fBpcre_dfa_exec()\fP
341    .\" JOIN
342      \e<lf>      pass the PCRE_NEWLINE_LF option to \fBpcre_exec()\fP
343                   or \fBpcre_dfa_exec()\fP
344    .\" JOIN
345      \e<crlf>    pass the PCRE_NEWLINE_CRLF option to \fBpcre_exec()\fP
346                   or \fBpcre_dfa_exec()\fP
347    .sp
348    The escapes that specify line endings are literal strings, exactly as shown.
349  A backslash followed by anything else just escapes the anything else. If the  A backslash followed by anything else just escapes the anything else. If the
350  very last character is a backslash, it is ignored. This gives a way of passing  very last character is a backslash, it is ignored. This gives a way of passing
351  an empty line as data, since a real empty line terminates the data input.  an empty line as data, since a real empty line terminates the data input.
352    .P
353  If \fB/P\fR was present on the regex, causing the POSIX wrapper API to be used,  If \eM is present, \fBpcretest\fP calls \fBpcre_exec()\fP several times, with
354  only \fB\B\fR, and \fB\Z\fR have any effect, causing REG_NOTBOL and REG_NOTEOL  different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP
355  to be passed to \fBregexec()\fR respectively.  fields of the \fBpcre_extra\fP data structure, until it finds the minimum
356    numbers for each parameter that allow \fBpcre_exec()\fP to complete. The
357  The use of \\x{hh...} to represent UTF-8 characters is not dependent on the use  \fImatch_limit\fP number is a measure of the amount of backtracking that takes
358  of the \fB/8\fR modifier on the pattern. It is recognized always. There may be  place, and checking it out can be instructive. For most simple matches, the
359    number is quite small, but for patterns with very large numbers of matching
360    possibilities, it can become large very quickly with increasing length of
361    subject string. The \fImatch_limit_recursion\fP number is a measure of how much
362    stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is needed
363    to complete the match attempt.
364    .P
365    When \eO is used, the value specified may be higher or lower than the size set
366    by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to
367    the call of \fBpcre_exec()\fP for the line in which it appears.
368    .P
369    If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper
370    API to be used, the only option-setting sequences that have any effect are \eB
371    and \eZ, causing REG_NOTBOL and REG_NOTEOL, respectively, to be passed to
372    \fBregexec()\fP.
373    .P
374    The use of \ex{hh...} to represent UTF-8 characters is not dependent on the use
375    of the \fB/8\fP modifier on the pattern. It is recognized always. There may be
376  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
377  six bytes, encoded according to the UTF-8 rules.  six bytes, encoded according to the UTF-8 rules.
378    .
379  .SH OUTPUT FROM PCRETEST  .
380    .SH "THE ALTERNATIVE MATCHING FUNCTION"
381  .rs  .rs
382  .sp  .sp
383    By default, \fBpcretest\fP uses the standard PCRE matching function,
384    \fBpcre_exec()\fP to match each data line. From release 6.0, PCRE supports an
385    alternative matching function, \fBpcre_dfa_test()\fP, which operates in a
386    different way, and has some restrictions. The differences between the two
387    functions are described in the
388    .\" HREF
389    \fBpcrematching\fP
390    .\"
391    documentation.
392    .P
393    If a data line contains the \eD escape sequence, or if the command line
394    contains the \fB-dfa\fP option, the alternative matching function is called.
395    This function finds all possible matches at a given point. If, however, the \eF
396    escape sequence is present in the data line, it stops after the first match is
397    found. This is always the shortest possible match.
398    .
399    .
400    .SH "DEFAULT OUTPUT FROM PCRETEST"
401    .rs
402    .sp
403    This section describes the output when the normal matching function,
404    \fBpcre_exec()\fP, is being used.
405    .P
406  When a match succeeds, pcretest outputs the list of captured substrings that  When a match succeeds, pcretest outputs the list of captured substrings that
407  \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
408  the whole pattern. Here is an example of an interactive pcretest run.  the whole pattern. Otherwise, it outputs "No match" or "Partial match"
409    when \fBpcre_exec()\fP returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PARTIAL,
410    respectively, and otherwise the PCRE negative error number. Here is an example
411    of an interactive \fBpcretest\fP run.
412    .sp
413    $ pcretest    $ pcretest
414    PCRE version 4.00 08-Jan-2003    PCRE version 5.00 07-Sep-2004
415    .sp
416      re> /^abc(\\d+)/      re> /^abc(\ed+)/
417    data> abc123    data> abc123
418     0: abc123     0: abc123
419     1: 123     1: 123
420    data> xyz    data> xyz
421    No match    No match
422    .sp
423  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
424  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
425  pattern. If the pattern has the \fB/+\fR modifier, then the output for  pattern. If the pattern has the \fB/+\fP modifier, the output for substring 0
426  substring 0 is followed by the the rest of the subject string, identified by  is followed by the the rest of the subject string, identified by "0+" like
427  "0+" like this:  this:
428    .sp
429      re> /cat/+      re> /cat/+
430    data> cataract    data> cataract
431     0: cat     0: cat
432     0+ aract     0+ aract
433    .sp
434  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
435  matching attempts are output in sequence, like this:  matching attempts are output in sequence, like this:
436    .sp
437      re> /\\Bi(\\w\\w)/g      re> /\eBi(\ew\ew)/g
438    data> Mississippi    data> Mississippi
439     0: iss     0: iss
440     1: ss     1: ss
# Line 327  matching attempts are output in sequence Line 442  matching attempts are output in sequence
442     1: ss     1: ss
443     0: ipp     0: ipp
444     1: pp     1: pp
445    .sp
446  "No match" is output only if the first match attempt fails.  "No match" is output only if the first match attempt fails.
447    .P
448  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
449  data line that is successfully matched, the substrings extracted by the  data line that is successfully matched, the substrings extracted by the
450  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
451  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
452  length (that is, the return from the extraction function) is given in  length (that is, the return from the extraction function) is given in
453  parentheses after each string for \fB\\C\fR and \fB\\G\fR.  parentheses after each string for \fB\eC\fP and \fB\eG\fP.
454    .P
455  Note that while patterns can be continued over several lines (a plain ">"  Note that while patterns can be continued over several lines (a plain ">"
456  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
457  included in data by means of the \\n escape.  included in data by means of the \en escape (or \er or \er\en for those newline
458    settings).
459    .
460    .
461    .SH "OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION"
462    .rs
463    .sp
464    When the alternative matching function, \fBpcre_dfa_exec()\fP, is used (by
465    means of the \eD escape sequence or the \fB-dfa\fP command line option), the
466    output consists of a list of all the matches that start at the first point in
467    the subject where there is at least one match. For example:
468    .sp
469        re> /(tang|tangerine|tan)/
470      data> yellow tangerine\eD
471       0: tangerine
472       1: tang
473       2: tan
474    .sp
475    (Using the normal matching function on this data finds only "tang".) The
476    longest matching string is always given first (and numbered zero).
477    .P
478    If \fB/g\P is present on the pattern, the search for further matches resumes
479    at the end of the longest match. For example:
480    .sp
481        re> /(tang|tangerine|tan)/g
482      data> yellow tangerine and tangy sultana\eD
483       0: tangerine
484       1: tang
485       2: tan
486       0: tang
487       1: tan
488       0: tan
489    .sp
490    Since the matching function does not support substring capture, the escape
491    sequences that are concerned with captured substrings are not relevant.
492    .
493    .
494    .SH "RESTARTING AFTER A PARTIAL MATCH"
495    .rs
496    .sp
497    When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
498    indicating that the subject partially matched the pattern, you can restart the
499    match with additional subject data by means of the \eR escape sequence. For
500    example:
501    .sp
502        re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
503      data> 23ja\eP\eD
504      Partial match: 23ja
505      data> n05\eR\eD
506       0: n05
507    .sp
508    For further information about partial matching, see the
509    .\" HREF
510    \fBpcrepartial\fP
511    .\"
512    documentation.
513    .
514    .
515    .SH CALLOUTS
516    .rs
517    .sp
518    If the pattern contains any callout requests, \fBpcretest\fP's callout function
519    is called during matching. This works with both matching functions. By default,
520    the called function displays the callout number, the start and current
521    positions in the text at the callout time, and the next pattern item to be
522    tested. For example, the output
523    .sp
524      --->pqrabcdef
525        0    ^  ^     \ed
526    .sp
527    indicates that callout number 0 occurred for a match attempt starting at the
528    fourth character of the subject string, when the pointer was at the seventh
529    character of the data, and when the next pattern item was \ed. Just one
530    circumflex is output if the start and current positions are the same.
531    .P
532    Callouts numbered 255 are assumed to be automatic callouts, inserted as a
533    result of the \fB/C\fP pattern modifier. In this case, instead of showing the
534    callout number, the offset in the pattern, preceded by a plus, is output. For
535    example:
536    .sp
537        re> /\ed?[A-E]\e*/C
538      data> E*
539      --->E*
540       +0 ^      \ed?
541       +3 ^      [A-E]
542       +8 ^^     \e*
543      +10 ^ ^
544       0: E*
545    .sp
546    The callout function in \fBpcretest\fP returns zero (carry on matching) by
547    default, but you can use a \eC item in a data line (as described above) to
548    change this.
549    .P
550    Inserting callouts can be helpful when using \fBpcretest\fP to check
551    complicated regular expressions. For further information about callouts, see
552    the
553    .\" HREF
554    \fBpcrecallout\fP
555    .\"
556    documentation.
557    .
558    .
559    .SH "SAVING AND RELOADING COMPILED PATTERNS"
560    .rs
561    .sp
562    The facilities described in this section are not available when the POSIX
563    inteface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
564    specified.
565    .P
566    When the POSIX interface is not in use, you can cause \fBpcretest\fP to write a
567    compiled pattern to a file, by following the modifiers with > and a file name.
568    For example:
569    .sp
570      /pattern/im >/some/file
571    .sp
572    See the
573    .\" HREF
574    \fBpcreprecompile\fP
575    .\"
576    documentation for a discussion about saving and re-using compiled patterns.
577    .P
578    The data that is written is binary. The first eight bytes are the length of the
579    compiled pattern data followed by the length of the optional study data, each
580    written as four bytes in big-endian order (most significant byte first). If
581    there is no study data (either the pattern was not studied, or studying did not
582    return any data), the second length is zero. The lengths are followed by an
583    exact copy of the compiled pattern. If there is additional study data, this
584    follows immediately after the compiled pattern. After writing the file,
585    \fBpcretest\fP expects to read a new pattern.
586    .P
587    A saved pattern can be reloaded into \fBpcretest\fP by specifing < and a file
588    name instead of a pattern. The name of the file must not contain a < character,
589    as otherwise \fBpcretest\fP will interpret the line as a pattern delimited by <
590    characters.
591    For example:
592    .sp
593       re> </some/file
594      Compiled regex loaded from /some/file
595      No study data
596    .sp
597    When the pattern has been loaded, \fBpcretest\fP proceeds to read data lines in
598    the usual way.
599    .P
600    You can copy a file written by \fBpcretest\fP to a different host and reload it
601    there, even if the new host has opposite endianness to the one on which the
602    pattern was compiled. For example, you can compile on an i86 machine and run on
603    a SPARC machine.
604    .P
605    File names for saving and reloading can be absolute or relative, but note that
606    the shell facility of expanding a file name that starts with a tilde (~) is not
607    available.
608    .P
609    The ability to save and reload files in \fBpcretest\fP is intended for testing
610    and experimentation. It is not intended for production use because only a
611    single pattern can be written to a file. Furthermore, there is no facility for
612    supplying custom character tables for use with a reloaded pattern. If the
613    original pattern was compiled with custom tables, an attempt to match a subject
614    string using a reloaded pattern is likely to cause \fBpcretest\fP to crash.
615    Finally, if you attempt to load a file that is not in the correct format, the
616    result is undefined.
617    .
618    .
619  .SH AUTHOR  .SH AUTHOR
620  .rs  .rs
621  .sp  .sp
622  Philip Hazel <ph10@cam.ac.uk>  Philip Hazel
623  .br  .br
624  University Computing Service,  University Computing Service,
625  .br  .br
626  Cambridge CB2 3QG, England.  Cambridge CB2 3QG, England.
627    .P
628  .in 0  .in 0
629  Last updated: 03 February 2003  Last updated: 29 June 2006
630  .br  .br
631  Copyright (c) 1997-2003 University of Cambridge.  Copyright (c) 1997-2006 University of Cambridge.

Legend:
Removed from v.63  
changed lines
  Added in v.91

  ViewVC Help
Powered by ViewVC 1.1.5