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

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