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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 "[-C] [-d] [-dfa] [-i] [-m] [-o osize] [-p] [-t] [source]"
8    .ti +5n
9    .B "[destination]"
10    .P
11    \fBpcretest\fP was written as a test program for the PCRE regular expression
12  library itself, but it can also be used for experimenting with regular  library itself, but it can also be used for experimenting with regular
13  expressions. This document describes the features of the test program; for  expressions. This document describes the features of the test program; for
14  details of the regular expressions themselves, see the  details of the regular expressions themselves, see the
15  .\" HREF  .\" HREF
16  \fBpcrepattern\fR  \fBpcrepattern\fP
17  .\"  .\"
18  documentation. For details of PCRE and its options, see the  documentation. For details of the PCRE library function calls and their
19    options, see the
20  .\" HREF  .\" HREF
21  \fBpcreapi\fR  \fBpcreapi\fP
22  .\"  .\"
23  documentation.  documentation.
24    .
25    .
26  .SH OPTIONS  .SH OPTIONS
27  .rs  .rs
 .sp  
28  .TP 10  .TP 10
29  \fB-C\fR  \fB-C\fP
30  Output the version number of the PCRE library, and all available information  Output the version number of the PCRE library, and all available information
31  about the optional features that are included, and then exit.  about the optional features that are included, and then exit.
32  .TP 10  .TP 10
33  \fB-d\fR  \fB-d\fP
34  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
35  form is output after compilation.  form is output after compilation.
36  .TP 10  .TP 10
37  \fB-i\fR  \fB-dfa\fP
38  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
39    alternative matching function, \fBpcre_dfa_exec()\fP, to be used instead of the
40    standard \fBpcre_exec()\fP function (more detail is given below).
41    .TP 10
42    \fB-i\fP
43    Behave as if each regex has the \fB/I\fP modifier; information about the
44  compiled pattern is given after compilation.  compiled pattern is given after compilation.
45  .TP 10  .TP 10
46  \fB-m\fR  \fB-m\fP
47  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
48  equivalent to adding /M to each regular expression. For compatibility with  equivalent to adding \fB/M\fP to each regular expression. For compatibility
49  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.
50  .TP 10  .TP 10
51  \fB-o\fR \fIosize\fR  \fB-o\fP \fIosize\fP
52  Set the number of elements in the output vector that is used when calling PCRE  Set the number of elements in the output vector that is used when calling
53  to be \fIosize\fR. The default value is 45, which is enough for 14 capturing  \fBpcre_exec()\fP to be \fIosize\fP. The default value is 45, which is enough
54  subexpressions. The vector size can be changed for individual matching calls by  for 14 capturing subexpressions. The vector size can be changed for individual
55  including \\O in the data line (see below).  matching calls by including \eO in the data line (see below).
56  .TP 10  .TP 10
57  \fB-p\fR  \fB-p\fP
58  Behave as if each regex has \fB/P\fR modifier; the POSIX wrapper API is used  Behave as if each regex has the \fB/P\fP modifier; the POSIX wrapper API is
59  to call PCRE. None of the other options has any effect when \fB-p\fR is set.  used to call PCRE. None of the other options has any effect when \fB-p\fP is
60    set.
61  .TP 10  .TP 10
62  \fB-t\fR  \fB-t\fP
63  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
64  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
65  \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
66  will be distorted.  timing will be distorted.
67    .
68    .
69  .SH DESCRIPTION  .SH DESCRIPTION
70  .rs  .rs
71  .sp  .sp
72  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
73  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
74  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
75  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
76  expressions, and "data>" to prompt for data lines.  expressions, and "data>" to prompt for data lines.
77    .P
78  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
79  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
80  lines to be matched against the pattern.  lines to be matched against the pattern.
81    .P
82  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
83  multiple-line matches, you have to use the \\n escape sequence in a single line  multiple-line matches, you have to use the \en escape sequence in a single line
84  of input to encode the newline characters. The maximum length of data line is  of input to encode the newline characters. The maximum length of data line is
85  30,000 characters.  30,000 characters.
86    .P
87  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
88  expression is read. The regular expressions are given enclosed in any  expression is read. The regular expressions are given enclosed in any
89  non-alphameric delimiters other than backslash, for example  non-alphanumeric delimiters other than backslash, for example
90    .sp
91    /(a|bc)x+yz/    /(a|bc)x+yz/
92    .sp
93  White space before the initial delimiter is ignored. A regular expression may  White space before the initial delimiter is ignored. A regular expression may
94  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
95  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
96  by escaping it, for example  by escaping it, for example
97    .sp
98    /abc\\/def/    /abc\e/def/
99    .sp
100  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
101  delimiters are always non-alphameric, this does not affect its interpretation.  delimiters are always non-alphanumeric, this does not affect its interpretation.
102  If the terminating delimiter is immediately followed by a backslash, for  If the terminating delimiter is immediately followed by a backslash, for
103  example,  example,
104    .sp
105    /abc/\\    /abc/\e
106    .sp
107  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
108  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
109  backslash, because  backslash, because
110    .sp
111    /abc\\/    /abc\e/
112    .sp
113  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
114  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.
115    .
116  .SH PATTERN MODIFIERS  .
117    .SH "PATTERN MODIFIERS"
118  .rs  .rs
119  .sp  .sp
120  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
121  PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options,  characters. Following Perl usage, these are referred to below as, for example,
122  respectively. For example:  "the \fB/i\fP modifier", even though the delimiter of the pattern need not
123    always be a slash, and no slash is used when writing modifiers. Whitespace may
124    appear between the final pattern delimiter and the first modifier, and between
125    the modifiers themselves.
126    .P
127    The \fB/i\fP, \fB/m\fP, \fB/s\fP, and \fB/x\fP modifiers set the PCRE_CASELESS,
128    PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
129    \fBpcre_compile()\fP is called. These four modifier letters have the same
130    effect as they do in Perl. For example:
131    .sp
132    /caseless/i    /caseless/i
133    .sp
134  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
135  others which set PCRE options that do not correspond to anything in Perl:  not correspond to anything in Perl:
136  \fB/A\fR, \fB/E\fR, and \fB/X\fR set PCRE_ANCHORED, PCRE_DOLLAR_ENDONLY, and  .sp
137  PCRE_EXTRA respectively.    \fB/A\fP    PCRE_ANCHORED
138      \fB/C\fP    PCRE_AUTO_CALLOUT
139      \fB/E\fP    PCRE_DOLLAR_ENDONLY
140      \fB/f\fP    PCRE_FIRSTLINE
141      \fB/N\fP    PCRE_NO_AUTO_CAPTURE
142      \fB/U\fP    PCRE_UNGREEDY
143      \fB/X\fP    PCRE_EXTRA
144    .sp
145  Searching for all possible matches within each subject string can be requested  Searching for all possible matches within each subject string can be requested
146  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
147  again to search the remainder of the subject string. The difference between  again to search the remainder of the subject string. The difference between
148  \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
149  \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
150  (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
151  substring. This makes a difference to the matching process if the pattern  substring. This makes a difference to the matching process if the pattern
152  begins with a lookbehind assertion (including \\b or \\B).  begins with a lookbehind assertion (including \eb or \eB).
153    .P
154  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
155  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
156  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.
157  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
158  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
159  \fB/g\fR modifier or the \fBsplit()\fR function.  \fB/g\fP modifier or the \fBsplit()\fP function.
160    .P
161  There are a number of other modifiers for controlling the way \fBpcretest\fR  There are yet more modifiers for controlling the way \fBpcretest\fP
162  operates.  operates.
163    .P
164  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
165  matched the entire pattern, pcretest should in addition output the remainder of  matched the entire pattern, pcretest should in addition output the remainder of
166  the subject string. This is useful for tests where the subject contains  the subject string. This is useful for tests where the subject contains
167  multiple copies of the same substring.  multiple copies of the same substring.
168    .P
169  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
170  example,  example,
171    .sp
172    /pattern/Lfr    /pattern/Lfr_FR
173    .sp
174  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,
175  \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
176  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
177  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
178  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.
179    .P
180  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
181  compiled expression (whether it is anchored, has a fixed first character, and  compiled pattern (whether it is anchored, has a fixed first character, and
182  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
183  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.
184  studied, the results of that are also output.  .P
185    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.  
186  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
187  compilation. If the pattern was studied, the information returned is also  compilation. If the pattern was studied, the information returned is also
188  output.  output.
189    .P
190  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
191    fields in the compiled pattern that contain 2-byte and 4-byte numbers. This
192    facility is for testing the feature in PCRE that allows it to execute patterns
193    that were compiled on a host with a different endianness. This feature is not
194    available when the POSIX interface to PCRE is being used, that is, when the
195    \fB/P\fP pattern modifier is specified. See also the section about saving and
196    reloading compiled patterns below.
197    .P
198    The \fB/S\fP modifier causes \fBpcre_study()\fP to be called after the
199  expression has been compiled, and the results used when the expression is  expression has been compiled, and the results used when the expression is
200  matched.  matched.
201    .P
202  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
203  pattern to be output.  pattern to be output.
204    .P
205  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
206  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
207  \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
208  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
209  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.
210    .P
211  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
212  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,
213  provided that it was compiled with this support enabled. This modifier also  provided that it was compiled with this support enabled. This modifier also
214  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
215  \\x{hh...} notation if they are valid UTF-8 sequences.  \ex{hh...} notation if they are valid UTF-8 sequences.
216    .P
217  .SH CALLOUTS  If the \fB/?\fP modifier is used with \fB/8\fP, it causes \fBpcretest\fP to
218    call \fBpcre_compile()\fP with the PCRE_NO_UTF8_CHECK option, to suppress the
219    checking of the string for UTF-8 validity.
220    .
221    .
222    .SH "DATA LINES"
223  .rs  .rs
224  .sp  .sp
225  If the pattern contains any callout requests, \fBpcretest\fR's callout function  Before each data line is passed to \fBpcre_exec()\fP, leading and trailing
226  will be called. By default, it displays the callout number, and the start and  whitespace is removed, and it is then scanned for \e escapes. Some of these are
 current positions in the text at the callout time. For example, the output  
   
   --->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  
 .rs  
 .sp  
 Before each data line is passed to \fBpcre_exec()\fR, leading and trailing  
 whitespace is removed, and it is then scanned for \\ escapes. Some of these are  
227  pretty esoteric features, intended for checking out some of the more  pretty esoteric features, intended for checking out some of the more
228  complicated features of PCRE. If you are just testing "ordinary" regular  complicated features of PCRE. If you are just testing "ordinary" regular
229  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
230  recognized:  recognized:
231    .sp
232    \\a         alarm (= BEL)    \ea         alarm (= BEL)
233    \\b         backspace    \eb         backspace
234    \\e         escape    \ee         escape
235    \\f         formfeed    \ef         formfeed
236    \\n         newline    \en         newline
237    \\r         carriage return    \er         carriage return
238    \\t         tab    \et         tab
239    \\v         vertical tab    \ev         vertical tab
240    \\nnn       octal character (up to 3 octal digits)    \ennn       octal character (up to 3 octal digits)
241    \\xhh       hexadecimal character (up to 2 hex digits)    \exhh       hexadecimal character (up to 2 hex digits)
242    \\x{hh...}  hexadecimal character, any number of digits  .\" JOIN
243      \ex{hh...}  hexadecimal character, any number of digits
244                 in UTF-8 mode                 in UTF-8 mode
245    \\A         pass the PCRE_ANCHORED option to \fBpcre_exec()\fR    \eA         pass the PCRE_ANCHORED option to \fBpcre_exec()\fP
246    \\B         pass the PCRE_NOTBOL option to \fBpcre_exec()\fR    \eB         pass the PCRE_NOTBOL option to \fBpcre_exec()\fP
247    \\Cdd       call pcre_copy_substring() for substring dd  .\" JOIN
248                 after a successful match (any decimal number    \eCdd       call pcre_copy_substring() for substring dd
249                 less than 32)                 after a successful match (number less than 32)
250    \\Cname     call pcre_copy_named_substring() for substring  .\" JOIN
251      \eCname     call pcre_copy_named_substring() for substring
252                 "name" after a successful match (name termin-                 "name" after a successful match (name termin-
253                 ated by next non alphanumeric character)                 ated by next non alphanumeric character)
254    \\C+        show the current captured substrings at callout  .\" JOIN
255      \eC+        show the current captured substrings at callout
256                 time                 time
257    \\C-        do not supply a callout function    \eC-        do not supply a callout function
258    \\C!n       return 1 instead of 0 when callout number n is  .\" JOIN
259      \eC!n       return 1 instead of 0 when callout number n is
260                 reached                 reached
261    \\C!n!m     return 1 instead of 0 when callout number n is  .\" JOIN
262      \eC!n!m     return 1 instead of 0 when callout number n is
263                 reached for the nth time                 reached for the nth time
264    \\C*n       pass the number n (may be negative) as callout  .\" JOIN
265                 data    \eC*n       pass the number n (may be negative) as callout
266    \\Gdd       call pcre_get_substring() for substring dd                 data; this is used as the callout return value
267                 after a successful match (any decimal number    \eD         use the \fBpcre_dfa_exec()\fP match function
268                 less than 32)    \eF         only shortest match for \fBpcre_dfa_exec()\fP
269    \\Gname     call pcre_get_named_substring() for substring  .\" JOIN
270      \eGdd       call pcre_get_substring() for substring dd
271                   after a successful match (number less than 32)
272    .\" JOIN
273      \eGname     call pcre_get_named_substring() for substring
274                 "name" after a successful match (name termin-                 "name" after a successful match (name termin-
275                 ated by next non-alphanumeric character)                 ated by next non-alphanumeric character)
276    \\L         call pcre_get_substringlist() after a  .\" JOIN
277      \eL         call pcre_get_substringlist() after a
278                 successful match                 successful match
279    \\M         discover the minimum MATCH_LIMIT setting    \eM         discover the minimum MATCH_LIMIT setting
280    \\N         pass the PCRE_NOTEMPTY option to \fBpcre_exec()\fR    \eN         pass the PCRE_NOTEMPTY option to \fBpcre_exec()\fP
281    \\Odd       set the size of the output vector passed to  .\" JOIN
282                 \fBpcre_exec()\fR to dd (any number of decimal    \eOdd       set the size of the output vector passed to
283                 digits)                 \fBpcre_exec()\fP to dd (any number of digits)
284    \\Z         pass the PCRE_NOTEOL option to \fBpcre_exec()\fR  .\" JOIN
285      \eP         pass the PCRE_PARTIAL option to \fBpcre_exec()\fP
286  If \\M is present, \fBpcretest\fR calls \fBpcre_exec()\fR several times, with                 or \fBpcre_dfa_exec()\fP
287  different values in the \fImatch_limit\fR field of the \fBpcre_extra\fR data    \eR         pass the PCRE_DFA_RESTART option to \fBpcre_dfa_exec()\fP
288      \eS         output details of memory get/free calls during matching
289      \eZ         pass the PCRE_NOTEOL option to \fBpcre_exec()\fP
290    .\" JOIN
291      \e?         pass the PCRE_NO_UTF8_CHECK option to
292                   \fBpcre_exec()\fP
293      \e>dd       start the match at offset dd (any number of digits);
294                   this sets the \fIstartoffset\fP argument for \fBpcre_exec()\fP
295    .sp
296    A backslash followed by anything else just escapes the anything else. If the
297    very last character is a backslash, it is ignored. This gives a way of passing
298    an empty line as data, since a real empty line terminates the data input.
299    .P
300    If \eM is present, \fBpcretest\fP calls \fBpcre_exec()\fP several times, with
301    different values in the \fImatch_limit\fP field of the \fBpcre_extra\fP data
302  structure, until it finds the minimum number that is needed for  structure, until it finds the minimum number that is needed for
303  \fBpcre_exec()\fR to complete. This number is a measure of the amount of  \fBpcre_exec()\fP to complete. This number is a measure of the amount of
304  recursion and backtracking that takes place, and checking it out can be  recursion and backtracking that takes place, and checking it out can be
305  instructive. For most simple matches, the number is quite small, but for  instructive. For most simple matches, the number is quite small, but for
306  patterns with very large numbers of matching possibilities, it can become large  patterns with very large numbers of matching possibilities, it can become large
307  very quickly with increasing length of subject string.  very quickly with increasing length of subject string.
308    .P
309  When \\O is used, it may be higher or lower than the size set by the \fB-O\fR  When \eO is used, the value specified may be higher or lower than the size set
310  option (or defaulted to 45); \\O applies only to the call of \fBpcre_exec()\fR  by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to
311  for the line in which it appears.  the call of \fBpcre_exec()\fP for the line in which it appears.
312    .P
313  A backslash followed by anything else just escapes the anything else. If the  If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper
314  very last character is a backslash, it is ignored. This gives a way of passing  API to be used, only \eB and \eZ have any effect, causing REG_NOTBOL and
315  an empty line as data, since a real empty line terminates the data input.  REG_NOTEOL to be passed to \fBregexec()\fP respectively.
316    .P
317  If \fB/P\fR was present on the regex, causing the POSIX wrapper API to be used,  The use of \ex{hh...} to represent UTF-8 characters is not dependent on the use
318  only \fB\B\fR, and \fB\Z\fR have any effect, causing REG_NOTBOL and REG_NOTEOL  of the \fB/8\fP modifier on the pattern. It is recognized always. There may be
 to be passed to \fBregexec()\fR respectively.  
   
 The use of \\x{hh...} to represent UTF-8 characters is not dependent on the use  
 of the \fB/8\fR modifier on the pattern. It is recognized always. There may be  
319  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
320  six bytes, encoded according to the UTF-8 rules.  six bytes, encoded according to the UTF-8 rules.
321    .
322  .SH OUTPUT FROM PCRETEST  .
323    .SH "THE ALTERNATIVE MATCHING FUNCTION"
324    .rs
325    .sp
326    By default, \fBpcretest\fP uses the standard PCRE matching function,
327    \fBpcre_exec()\fP to match each data line. From release 6.0, PCRE supports an
328    alternative matching function, \fBpcre_dfa_test()\fP, which operates in a
329    different way, and has some restrictions. The differences between the two
330    functions are described in the
331    .\" HREF
332    \fBpcrematching\fP
333    .\"
334    documentation.
335    .P
336    If a data line contains the \eD escape sequence, or if the command line
337    contains the \fB-dfa\fP option, the alternative matching function is called.
338    This function finds all possible matches at a given point. If, however, the \eF
339    escape sequence is present in the data line, it stops after the first match is
340    found. This is always the shortest possible match.
341    .
342    .
343    .SH "DEFAULT OUTPUT FROM PCRETEST"
344  .rs  .rs
345  .sp  .sp
346    This section describes the output when the normal matching function,
347    \fBpcre_exec()\fP, is being used.
348    .P
349  When a match succeeds, pcretest outputs the list of captured substrings that  When a match succeeds, pcretest outputs the list of captured substrings that
350  \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
351  the whole pattern. Here is an example of an interactive pcretest run.  the whole pattern. Otherwise, it outputs "No match" or "Partial match"
352    when \fBpcre_exec()\fP returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PARTIAL,
353    respectively, and otherwise the PCRE negative error number. Here is an example
354    of an interactive \fBpcretest\fP run.
355    .sp
356    $ pcretest    $ pcretest
357    PCRE version 4.00 08-Jan-2003    PCRE version 5.00 07-Sep-2004
358    .sp
359      re> /^abc(\\d+)/      re> /^abc(\ed+)/
360    data> abc123    data> abc123
361     0: abc123     0: abc123
362     1: 123     1: 123
363    data> xyz    data> xyz
364    No match    No match
365    .sp
366  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
367  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
368  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
369  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
370  "0+" like this:  this:
371    .sp
372      re> /cat/+      re> /cat/+
373    data> cataract    data> cataract
374     0: cat     0: cat
375     0+ aract     0+ aract
376    .sp
377  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
378  matching attempts are output in sequence, like this:  matching attempts are output in sequence, like this:
379    .sp
380      re> /\\Bi(\\w\\w)/g      re> /\eBi(\ew\ew)/g
381    data> Mississippi    data> Mississippi
382     0: iss     0: iss
383     1: ss     1: ss
# Line 327  matching attempts are output in sequence Line 385  matching attempts are output in sequence
385     1: ss     1: ss
386     0: ipp     0: ipp
387     1: pp     1: pp
388    .sp
389  "No match" is output only if the first match attempt fails.  "No match" is output only if the first match attempt fails.
390    .P
391  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
392  data line that is successfully matched, the substrings extracted by the  data line that is successfully matched, the substrings extracted by the
393  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
394  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
395  length (that is, the return from the extraction function) is given in  length (that is, the return from the extraction function) is given in
396  parentheses after each string for \fB\\C\fR and \fB\\G\fR.  parentheses after each string for \fB\eC\fP and \fB\eG\fP.
397    .P
398  Note that while patterns can be continued over several lines (a plain ">"  Note that while patterns can be continued over several lines (a plain ">"
399  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
400  included in data by means of the \\n escape.  included in data by means of the \en escape.
401    .
402    .
403    .SH "OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION"
404    .rs
405    .sp
406    When the alternative matching function, \fBpcre_dfa_exec()\fP, is used (by
407    means of the \eD escape sequence or the \fB-dfa\fP command line option), the
408    output consists of a list of all the matches that start at the first point in
409    the subject where there is at least one match. For example:
410    .sp
411        re> /(tang|tangerine|tan)/
412      data> yellow tangerine\eD
413       0: tangerine
414       1: tang
415       2: tan
416    .sp
417    (Using the normal matching function on this data finds only "tang".) The
418    longest matching string is always given first (and numbered zero).
419    .P
420    If \fB/g\P is present on the pattern, the search for further matches resumes
421    at the end of the longest match. For example:
422    .sp
423        re> /(tang|tangerine|tan)/g
424      data> yellow tangerine and tangy sultana\eD
425       0: tangerine
426       1: tang
427       2: tan
428       0: tang
429       1: tan
430       0: tan
431    .sp
432    Since the matching function does not support substring capture, the escape
433    sequences that are concerned with captured substrings are not relevant.
434    .
435    .
436    .SH "RESTARTING AFTER A PARTIAL MATCH"
437    .rs
438    .sp
439    When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
440    indicating that the subject partially matched the pattern, you can restart the
441    match with additional subject data by means of the \eR escape sequence. For
442    example:
443    .sp
444        re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
445      data> 23ja\eP\eD
446      Partial match: 23ja
447      data> n05\eR\eD
448       0: n05
449    .sp
450    For further information about partial matching, see the
451    .\" HREF
452    \fBpcrepartial\fP
453    .\"
454    documentation.
455    .
456    .
457    .SH CALLOUTS
458    .rs
459    .sp
460    If the pattern contains any callout requests, \fBpcretest\fP's callout function
461    is called during matching. This works with both matching functions. By default,
462    the called function displays the callout number, the start and current
463    positions in the text at the callout time, and the next pattern item to be
464    tested. For example, the output
465    .sp
466      --->pqrabcdef
467        0    ^  ^     \ed
468    .sp
469    indicates that callout number 0 occurred for a match attempt starting at the
470    fourth character of the subject string, when the pointer was at the seventh
471    character of the data, and when the next pattern item was \ed. Just one
472    circumflex is output if the start and current positions are the same.
473    .P
474    Callouts numbered 255 are assumed to be automatic callouts, inserted as a
475    result of the \fB/C\fP pattern modifier. In this case, instead of showing the
476    callout number, the offset in the pattern, preceded by a plus, is output. For
477    example:
478    .sp
479        re> /\ed?[A-E]\e*/C
480      data> E*
481      --->E*
482       +0 ^      \ed?
483       +3 ^      [A-E]
484       +8 ^^     \e*
485      +10 ^ ^
486       0: E*
487    .sp
488    The callout function in \fBpcretest\fP returns zero (carry on matching) by
489    default, but you can use a \eC item in a data line (as described above) to
490    change this.
491    .P
492    Inserting callouts can be helpful when using \fBpcretest\fP to check
493    complicated regular expressions. For further information about callouts, see
494    the
495    .\" HREF
496    \fBpcrecallout\fP
497    .\"
498    documentation.
499    .
500    .
501    .SH "SAVING AND RELOADING COMPILED PATTERNS"
502    .rs
503    .sp
504    The facilities described in this section are not available when the POSIX
505    inteface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
506    specified.
507    .P
508    When the POSIX interface is not in use, you can cause \fBpcretest\fP to write a
509    compiled pattern to a file, by following the modifiers with > and a file name.
510    For example:
511    .sp
512      /pattern/im >/some/file
513    .sp
514    See the
515    .\" HREF
516    \fBpcreprecompile\fP
517    .\"
518    documentation for a discussion about saving and re-using compiled patterns.
519    .P
520    The data that is written is binary. The first eight bytes are the length of the
521    compiled pattern data followed by the length of the optional study data, each
522    written as four bytes in big-endian order (most significant byte first). If
523    there is no study data (either the pattern was not studied, or studying did not
524    return any data), the second length is zero. The lengths are followed by an
525    exact copy of the compiled pattern. If there is additional study data, this
526    follows immediately after the compiled pattern. After writing the file,
527    \fBpcretest\fP expects to read a new pattern.
528    .P
529    A saved pattern can be reloaded into \fBpcretest\fP by specifing < and a file
530    name instead of a pattern. The name of the file must not contain a < character,
531    as otherwise \fBpcretest\fP will interpret the line as a pattern delimited by <
532    characters.
533    For example:
534    .sp
535       re> </some/file
536      Compiled regex loaded from /some/file
537      No study data
538    .sp
539    When the pattern has been loaded, \fBpcretest\fP proceeds to read data lines in
540    the usual way.
541    .P
542    You can copy a file written by \fBpcretest\fP to a different host and reload it
543    there, even if the new host has opposite endianness to the one on which the
544    pattern was compiled. For example, you can compile on an i86 machine and run on
545    a SPARC machine.
546    .P
547    File names for saving and reloading can be absolute or relative, but note that
548    the shell facility of expanding a file name that starts with a tilde (~) is not
549    available.
550    .P
551    The ability to save and reload files in \fBpcretest\fP is intended for testing
552    and experimentation. It is not intended for production use because only a
553    single pattern can be written to a file. Furthermore, there is no facility for
554    supplying custom character tables for use with a reloaded pattern. If the
555    original pattern was compiled with custom tables, an attempt to match a subject
556    string using a reloaded pattern is likely to cause \fBpcretest\fP to crash.
557    Finally, if you attempt to load a file that is not in the correct format, the
558    result is undefined.
559    .
560    .
561  .SH AUTHOR  .SH AUTHOR
562  .rs  .rs
563  .sp  .sp
564  Philip Hazel <ph10@cam.ac.uk>  Philip Hazel
565  .br  .br
566  University Computing Service,  University Computing Service,
567  .br  .br
568  Cambridge CB2 3QG, England.  Cambridge CB2 3QG, England.
569    .P
570  .in 0  .in 0
571  Last updated: 03 February 2003  Last updated: 28 February 2005
572  .br  .br
573  Copyright (c) 1997-2003 University of Cambridge.  Copyright (c) 1997-2005 University of Cambridge.

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