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revision 73 by nigel, Sat Feb 24 21:40:30 2007 UTC revision 211 by ph10, Thu Aug 9 09:52:43 2007 UTC
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1  PCRETEST(1)                                                        PCRETEST(1)  PCRETEST(1)                                                        PCRETEST(1)
2    
3    
   
4  NAME  NAME
5         pcretest - a program for testing Perl-compatible regular expressions.         pcretest - a program for testing Perl-compatible regular expressions.
6    
7    
8  SYNOPSIS  SYNOPSIS
9         pcretest [-d] [-i] [-m] [-o osize] [-p] [-t] [source] [destination]  
10           pcretest [options] [source] [destination]
11    
12         pcretest  was written as a test program for the PCRE regular expression         pcretest  was written as a test program for the PCRE regular expression
13         library itself, but it can also be used for experimenting with  regular         library itself, but it can also be used for experimenting with  regular
14         expressions.  This document describes the features of the test program;         expressions.  This document describes the features of the test program;
15         for details of the regular expressions themselves, see the  pcrepattern         for details of the regular expressions themselves, see the  pcrepattern
16         documentation.  For  details  of  PCRE and its options, see the pcreapi         documentation. For details of the PCRE library function calls and their
17         documentation.         options, see the pcreapi documentation.
18    
19    
20  OPTIONS  OPTIONS
21    
22           -b        Behave as if each regex has the /B (show bytecode)  modifier;
23                     the internal form is output after compilation.
24    
25         -C        Output the version number of the PCRE library, and all avail-         -C        Output the version number of the PCRE library, and all avail-
26                   able   information  about  the  optional  features  that  are                   able  information  about  the  optional  features  that   are
27                   included, and then exit.                   included, and then exit.
28    
29         -d        Behave as if each regex had the /D modifier (see below);  the         -d        Behave  as  if  each  regex  has the /D (debug) modifier; the
30                   internal form is output after compilation.                   internal form and information about the compiled  pattern  is
31                     output after compilation; -d is equivalent to -b -i.
32    
33           -dfa      Behave  as if each data line contains the \D escape sequence;
34                     this    causes    the    alternative    matching    function,
35                     pcre_dfa_exec(),   to   be   used  instead  of  the  standard
36                     pcre_exec() function (more detail is given below).
37    
38         -i        Behave  as  if  each  regex  had the /I modifier; information         -help     Output a brief summary these options and then exit.
39    
40           -i        Behave as if each regex  has  the  /I  modifier;  information
41                   about the compiled pattern is given after compilation.                   about the compiled pattern is given after compilation.
42    
43         -m        Output the size of each compiled pattern after  it  has  been         -m        Output  the  size  of each compiled pattern after it has been
44                   compiled.  This  is  equivalent  to adding /M to each regular                   compiled. This is equivalent to adding  /M  to  each  regular
45                   expression.  For  compatibility  with  earlier  versions   of                   expression.   For  compatibility  with  earlier  versions  of
46                   pcretest, -s is a synonym for -m.                   pcretest, -s is a synonym for -m.
47    
48         -o osize  Set  the number of elements in the output vector that is used         -o osize  Set the number of elements in the output vector that is  used
49                   when calling PCRE to be osize. The default value is 45, which                   when  calling pcre_exec() or pcre_dfa_exec() to be osize. The
50                   is  enough  for  14 capturing subexpressions. The vector size                   default value is 45, which is enough for 14 capturing  subex-
51                   can be changed for individual matching calls by including  \O                   pressions   for  pcre_exec()  or  22  different  matches  for
52                   in the data line (see below).                   pcre_dfa_exec(). The vector size can be changed for  individ-
53                     ual  matching  calls  by  including  \O in the data line (see
54         -p        Behave  as  if  each regex has /P modifier; the POSIX wrapper                   below).
55                   API is used to call PCRE. None of the other options  has  any  
56                   effect when -p is set.         -p        Behave as if each regex has the /P modifier; the POSIX  wrap-
57                     per  API  is used to call PCRE. None of the other options has
58         -t        Run  each  compile, study, and match many times with a timer,                   any effect when -p is set.
59                   and output resulting time per compile or match (in  millisec-  
60                   onds).  Do  not set -t with -m, because you will then get the         -q        Do not output the version number of pcretest at the start  of
61                   size output 20000 times and the timing will be distorted.                   execution.
62    
63           -S size   On  Unix-like  systems,  set the size of the runtime stack to
64                     size megabytes.
65    
66           -t        Run each compile, study, and match many times with  a  timer,
67                     and  output resulting time per compile or match (in millisec-
68                     onds). Do not set -m with -t, because you will then  get  the
69                     size  output  a  zillion  times,  and the timing will be dis-
70                     torted. You can control the number  of  iterations  that  are
71                     used  for timing by following -t with a number (as a separate
72                     item on the command line). For example, "-t 1000" would iter-
73                     ate 1000 times. The default is to iterate 500000 times.
74    
75           -tm       This is like -t except that it times only the matching phase,
76                     not the compile or study phases.
77    
78    
79  DESCRIPTION  DESCRIPTION
# Line 63  DESCRIPTION Line 89  DESCRIPTION
89         Each set starts with a regular expression, and continues with any  num-         Each set starts with a regular expression, and continues with any  num-
90         ber of data lines to be matched against the pattern.         ber of data lines to be matched against the pattern.
91    
92         Each  line  is  matched separately and independently. If you want to do         Each  data line is matched separately and independently. If you want to
93         multiple-line matches, you have to use the \n escape sequence in a sin-         do multi-line matches, you have to use the \n escape sequence (or \r or
94         gle  line of input to encode the newline characters. The maximum length         \r\n, etc., depending on the newline setting) in a single line of input
95         of data line is 30,000 characters.         to encode the newline sequences. There is no limit  on  the  length  of
96           data  lines;  the  input  buffer is automatically extended if it is too
97           small.
98    
99         An empty line signals the end of the data lines, at which point  a  new         An empty line signals the end of the data lines, at which point  a  new
100         regular  expression is read. The regular expressions are given enclosed         regular  expression is read. The regular expressions are given enclosed
101         in any non-alphameric delimiters other than backslash, for example         in any non-alphanumeric delimiters other than backslash, for example:
102    
103           /(a|bc)x+yz/           /(a|bc)x+yz/
104    
# Line 82  DESCRIPTION Line 110  DESCRIPTION
110           /abc\/def/           /abc\/def/
111    
112         If  you  do  so, the escape and the delimiter form part of the pattern,         If  you  do  so, the escape and the delimiter form part of the pattern,
113         but since delimiters are always non-alphameric, this  does  not  affect         but since delimiters are always non-alphanumeric, this does not  affect
114         its  interpretation.   If the terminating delimiter is immediately fol-         its  interpretation.   If the terminating delimiter is immediately fol-
115         lowed by a backslash, for example,         lowed by a backslash, for example,
116    
# Line 101  DESCRIPTION Line 129  DESCRIPTION
129    
130  PATTERN MODIFIERS  PATTERN MODIFIERS
131    
132         The pattern may be followed by i, m, s, or x to set the  PCRE_CASELESS,         A pattern may be followed by any number of modifiers, which are  mostly
133         PCRE_MULTILINE,  PCRE_DOTALL,  or  PCRE_EXTENDED options, respectively.         single  characters.  Following  Perl usage, these are referred to below
134         For example:         as, for example, "the /i modifier", even though the  delimiter  of  the
135           pattern  need  not always be a slash, and no slash is used when writing
136           modifiers. Whitespace may appear between the  final  pattern  delimiter
137           and the first modifier, and between the modifiers themselves.
138    
139           The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,
140           PCRE_DOTALL, or PCRE_EXTENDED  options,  respectively,  when  pcre_com-
141           pile()  is  called. These four modifier letters have the same effect as
142           they do in Perl. For example:
143    
144           /caseless/i           /caseless/i
145    
146         These modifier letters have the same effect as they do in  Perl.  There         The following table shows additional modifiers for setting PCRE options
147         are  others that set PCRE options that do not correspond to anything in         that do not correspond to anything in Perl:
148         Perl: /A, /E, /N, /U, and /X  set  PCRE_ANCHORED,  PCRE_DOLLAR_ENDONLY,  
149         PCRE_NO_AUTO_CAPTURE, PCRE_UNGREEDY, and PCRE_EXTRA respectively.           /A          PCRE_ANCHORED
150             /C          PCRE_AUTO_CALLOUT
151             /E          PCRE_DOLLAR_ENDONLY
152             /f          PCRE_FIRSTLINE
153             /J          PCRE_DUPNAMES
154             /N          PCRE_NO_AUTO_CAPTURE
155             /U          PCRE_UNGREEDY
156             /X          PCRE_EXTRA
157             /<cr>       PCRE_NEWLINE_CR
158             /<lf>       PCRE_NEWLINE_LF
159             /<crlf>     PCRE_NEWLINE_CRLF
160             /<anycrlf>  PCRE_NEWLINE_ANYCRLF
161             /<any>      PCRE_NEWLINE_ANY
162    
163           Those  specifying  line ending sequencess are literal strings as shown.
164           This example sets multiline matching  with  CRLF  as  the  line  ending
165           sequence:
166    
167             /^abc/m<crlf>
168    
169         Searching  for  all  possible matches within each subject string can be         Details  of the meanings of these PCRE options are given in the pcreapi
170         requested by the /g or /G modifier. After  finding  a  match,  PCRE  is         documentation.
171    
172       Finding all matches in a string
173    
174           Searching for all possible matches within each subject  string  can  be
175           requested  by  the  /g  or  /G modifier. After finding a match, PCRE is
176         called again to search the remainder of the subject string. The differ-         called again to search the remainder of the subject string. The differ-
177         ence between /g and /G is that the former uses the startoffset argument         ence between /g and /G is that the former uses the startoffset argument
178         to  pcre_exec()  to  start  searching  at a new point within the entire         to pcre_exec() to start searching at a  new  point  within  the  entire
179         string (which is in effect what Perl does), whereas the  latter  passes         string  (which  is in effect what Perl does), whereas the latter passes
180         over  a  shortened  substring.  This makes a difference to the matching         over a shortened substring. This makes a  difference  to  the  matching
181         process if the pattern begins with a lookbehind assertion (including \b         process if the pattern begins with a lookbehind assertion (including \b
182         or \B).         or \B).
183    
184         If  any  call  to  pcre_exec()  in a /g or /G sequence matches an empty         If any call to pcre_exec() in a /g or  /G  sequence  matches  an  empty
185         string, the next call is done with the PCRE_NOTEMPTY and  PCRE_ANCHORED         string,  the next call is done with the PCRE_NOTEMPTY and PCRE_ANCHORED
186         flags  set in order to search for another, non-empty, match at the same         flags set in order to search for another, non-empty, match at the  same
187         point.  If this second match fails, the start  offset  is  advanced  by         point.   If  this  second  match fails, the start offset is advanced by
188         one,  and  the normal match is retried. This imitates the way Perl han-         one, and the normal match is retried. This imitates the way  Perl  han-
189         dles such cases when using the /g modifier or the split() function.         dles such cases when using the /g modifier or the split() function.
190    
191         There are a number of other modifiers for controlling the way  pcretest     Other modifiers
192         operates.  
193           There are yet more modifiers for controlling the way pcretest operates.
194    
195         The  /+ modifier requests that as well as outputting the substring that         The /+ modifier requests that as well as outputting the substring  that
196         matched the entire pattern, pcretest  should  in  addition  output  the         matched  the  entire  pattern,  pcretest  should in addition output the
197         remainder  of  the  subject  string. This is useful for tests where the         remainder of the subject string. This is useful  for  tests  where  the
198         subject contains multiple copies of the same substring.         subject contains multiple copies of the same substring.
199    
200           The  /B modifier is a debugging feature. It requests that pcretest out-
201           put a representation of the compiled byte code after compilation.  Nor-
202           mally  this  information contains length and offset values; however, if
203           /Z is also present, this data is replaced by spaces. This is a  special
204           feature for use in the automatic test scripts; it ensures that the same
205           output is generated for different internal link sizes.
206    
207         The /L modifier must be followed directly by the name of a locale,  for         The /L modifier must be followed directly by the name of a locale,  for
208         example,         example,
209    
210           /pattern/Lfr           /pattern/Lfr_FR
211    
212         For  this reason, it must be the last modifier letter. The given locale         For this reason, it must be the last modifier. The given locale is set,
213         is set, pcre_maketables() is called to build a set of character  tables         pcre_maketables() is called to build a set of character tables for  the
214         for  the locale, and this is then passed to pcre_compile() when compil-         locale,  and  this  is then passed to pcre_compile() when compiling the
215         ing the regular expression. Without an /L modifier, NULL is  passed  as         regular expression. Without an /L  modifier,  NULL  is  passed  as  the
216         the tables pointer; that is, /L applies only to the expression on which         tables  pointer; that is, /L applies only to the expression on which it
217         it appears.         appears.
218    
219         The /I modifier requests that pcretest  output  information  about  the         The /I modifier requests that pcretest  output  information  about  the
220         compiled  expression (whether it is anchored, has a fixed first charac-         compiled  pattern (whether it is anchored, has a fixed first character,
221         ter, and so on). It does this by calling pcre_fullinfo() after  compil-         and so on). It does this by calling pcre_fullinfo() after  compiling  a
222         ing  an expression, and outputting the information it gets back. If the         pattern.  If  the pattern is studied, the results of that are also out-
223         pattern is studied, the results of that are also output.         put.
224    
225         The /D modifier is a PCRE debugging feature, which also assumes /I.  It         The /D modifier is a PCRE debugging feature, and is equivalent to  /BI,
226         causes  the  internal form of compiled regular expressions to be output         that is, both the /B and the /I modifiers.
227         after compilation. If the pattern was studied, the information returned  
228         is also output.         The /F modifier causes pcretest to flip the byte order of the fields in
229           the compiled pattern that  contain  2-byte  and  4-byte  numbers.  This
230           facility  is  for testing the feature in PCRE that allows it to execute
231           patterns that were compiled on a host with a different endianness. This
232           feature  is  not  available  when  the POSIX interface to PCRE is being
233           used, that is, when the /P pattern modifier is specified. See also  the
234           section about saving and reloading compiled patterns below.
235    
236         The  /S  modifier causes pcre_study() to be called after the expression         The  /S  modifier causes pcre_study() to be called after the expression
237         has been compiled, and the results used when the expression is matched.         has been compiled, and the results used when the expression is matched.
# Line 183  PATTERN MODIFIERS Line 256  PATTERN MODIFIERS
256         checking of the string for UTF-8 validity.         checking of the string for UTF-8 validity.
257    
258    
 CALLOUTS  
   
        If  the pattern contains any callout requests, pcretest's callout func-  
        tion will be called. By default, it displays the  callout  number,  and  
        the  start  and  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 pcretest to check compli-  
        cated regular expressions. For further information about callouts,  see  
        the pcrecallout documentation.  
   
        For  testing  the PCRE library, additional control of callout behaviour  
        is available via escape sequences in the data, as described in the fol-  
        lowing  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.  
   
   
259  DATA LINES  DATA LINES
260    
261         Before  each  data  line is passed to pcre_exec(), leading and trailing         Before  each  data  line is passed to pcre_exec(), leading and trailing
# Line 218  DATA LINES Line 265  DATA LINES
265         nary"  regular  expressions,  you probably don't need any of these. The         nary"  regular  expressions,  you probably don't need any of these. The
266         following escapes are recognized:         following escapes are recognized:
267    
268           \a         alarm (= BEL)           \a         alarm (BEL, \x07)
269           \b         backspace           \b         backspace (\x08)
270           \e         escape           \e         escape (\x27)
271           \f         formfeed           \f         formfeed (\x0c)
272           \n         newline           \n         newline (\x0a)
273           \r         carriage return           \qdd       set the PCRE_MATCH_LIMIT limit to dd
274           \t         tab                        (any number of digits)
275           \v         vertical tab           \r         carriage return (\x0d)
276             \t         tab (\x09)
277             \v         vertical tab (\x0b)
278           \nnn       octal character (up to 3 octal digits)           \nnn       octal character (up to 3 octal digits)
279           \xhh       hexadecimal character (up to 2 hex digits)           \xhh       hexadecimal character (up to 2 hex digits)
280           \x{hh...}  hexadecimal character, any number of digits           \x{hh...}  hexadecimal character, any number of digits
281                        in UTF-8 mode                        in UTF-8 mode
282           \A         pass the PCRE_ANCHORED option to pcre_exec()           \A         pass the PCRE_ANCHORED option to pcre_exec()
283                          or pcre_dfa_exec()
284           \B         pass the PCRE_NOTBOL option to pcre_exec()           \B         pass the PCRE_NOTBOL option to pcre_exec()
285                          or pcre_dfa_exec()
286           \Cdd       call pcre_copy_substring() for substring dd           \Cdd       call pcre_copy_substring() for substring dd
287                        after a successful match (any decimal number                        after a successful match (number less than 32)
                       less than 32)  
288           \Cname     call pcre_copy_named_substring() for substring           \Cname     call pcre_copy_named_substring() for substring
289                        "name" after a successful match (name termin-                        "name" after a successful match (name termin-
290                        ated by next non alphanumeric character)                        ated by next non alphanumeric character)
# Line 246  DATA LINES Line 296  DATA LINES
296           \C!n!m     return 1 instead of 0 when callout number n is           \C!n!m     return 1 instead of 0 when callout number n is
297                        reached for the nth time                        reached for the nth time
298           \C*n       pass the number n (may be negative) as callout           \C*n       pass the number n (may be negative) as callout
299                        data                        data; this is used as the callout return value
300             \D         use the pcre_dfa_exec() match function
301             \F         only shortest match for pcre_dfa_exec()
302           \Gdd       call pcre_get_substring() for substring dd           \Gdd       call pcre_get_substring() for substring dd
303                        after a successful match (any decimal number                        after a successful match (number less than 32)
                       less than 32)  
304           \Gname     call pcre_get_named_substring() for substring           \Gname     call pcre_get_named_substring() for substring
305                        "name" after a successful match (name termin-                        "name" after a successful match (name termin-
306                        ated by next non-alphanumeric character)                        ated by next non-alphanumeric character)
307           \L         call pcre_get_substringlist() after a           \L         call pcre_get_substringlist() after a
308                        successful match                        successful match
309           \M         discover the minimum MATCH_LIMIT setting           \M         discover the minimum MATCH_LIMIT and
310                          MATCH_LIMIT_RECURSION settings
311           \N         pass the PCRE_NOTEMPTY option to pcre_exec()           \N         pass the PCRE_NOTEMPTY option to pcre_exec()
312                          or pcre_dfa_exec()
313           \Odd       set the size of the output vector passed to           \Odd       set the size of the output vector passed to
314                        pcre_exec() to dd (any number of decimal                        pcre_exec() to dd (any number of digits)
315                        digits)           \P         pass the PCRE_PARTIAL option to pcre_exec()
316                          or pcre_dfa_exec()
317             \Qdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
318                          (any number of digits)
319             \R         pass the PCRE_DFA_RESTART option to pcre_dfa_exec()
320           \S         output details of memory get/free calls during matching           \S         output details of memory get/free calls during matching
321           \Z         pass the PCRE_NOTEOL option to pcre_exec()           \Z         pass the PCRE_NOTEOL option to pcre_exec()
322                          or pcre_dfa_exec()
323           \?         pass the PCRE_NO_UTF8_CHECK option to           \?         pass the PCRE_NO_UTF8_CHECK option to
324                        pcre_exec()                        pcre_exec() or pcre_dfa_exec()
325             \>dd       start the match at offset dd (any number of digits);
326         If \M is present, pcretest calls pcre_exec() several times,  with  dif-                        this sets the startoffset argument for pcre_exec()
327         ferent  values  in  the match_limit field of the pcre_extra data struc-                        or pcre_dfa_exec()
328         ture, until it finds the minimum number that is needed for  pcre_exec()           \<cr>      pass the PCRE_NEWLINE_CR option to pcre_exec()
329         to  complete.  This  number is a measure of the amount of recursion and                        or pcre_dfa_exec()
330         backtracking that takes place, and checking it out can be  instructive.           \<lf>      pass the PCRE_NEWLINE_LF option to pcre_exec()
331         For  most  simple  matches, the number is quite small, but for patterns                        or pcre_dfa_exec()
332         with very large numbers of matching possibilities, it can become  large           \<crlf>    pass the PCRE_NEWLINE_CRLF option to pcre_exec()
333         very quickly with increasing length of subject string.                        or pcre_dfa_exec()
334             \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to pcre_exec()
335         When  \O is used, it may be higher or lower than the size set by the -O                        or pcre_dfa_exec()
336         option (or defaulted to 45); \O applies only to the call of pcre_exec()           \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()
337         for the line in which it appears.                        or pcre_dfa_exec()
338    
339         A  backslash  followed by anything else just escapes the anything else.         The escapes that specify line ending  sequences  are  literal  strings,
340         If the very last character is a backslash, it is ignored. This gives  a         exactly as shown. No more than one newline setting should be present in
341         way  of  passing  an empty line as data, since a real empty line termi-         any data line.
342    
343           A backslash followed by anything else just escapes the  anything  else.
344           If  the very last character is a backslash, it is ignored. This gives a
345           way of passing an empty line as data, since a real  empty  line  termi-
346         nates the data input.         nates the data input.
347    
348         If /P was present on the regex, causing the POSIX  wrapper  API  to  be         If  \M  is present, pcretest calls pcre_exec() several times, with dif-
349         used,  only  0  causing  REG_NOTBOL  and  REG_NOTEOL  to  be  passed to         ferent values in the match_limit and  match_limit_recursion  fields  of
350         regexec() respectively.         the  pcre_extra  data structure, until it finds the minimum numbers for
351           each parameter that allow pcre_exec() to complete. The match_limit num-
352           ber  is  a  measure of the amount of backtracking that takes place, and
353           checking it out can be instructive. For most simple matches, the number
354           is  quite  small,  but for patterns with very large numbers of matching
355           possibilities, it can become large very quickly with increasing  length
356           of subject string. The match_limit_recursion number is a measure of how
357           much stack (or, if PCRE is compiled with  NO_RECURSE,  how  much  heap)
358           memory is needed to complete the match attempt.
359    
360           When  \O  is  used, the value specified may be higher or lower than the
361           size set by the -O command line option (or defaulted to 45); \O applies
362           only to the call of pcre_exec() for the line in which it appears.
363    
364           If  the /P modifier was present on the pattern, causing the POSIX wrap-
365           per API to be used, the only option-setting  sequences  that  have  any
366           effect  are \B and \Z, causing REG_NOTBOL and REG_NOTEOL, respectively,
367           to be passed to regexec().
368    
369         The use of \x{hh...} to represent UTF-8 characters is not dependent  on         The use of \x{hh...} to represent UTF-8 characters is not dependent  on
370         the  use  of  the  /8 modifier on the pattern. It is recognized always.         the  use  of  the  /8 modifier on the pattern. It is recognized always.
371         There may be any number of hexadecimal digits inside  the  braces.  The         There may be any number of hexadecimal digits inside  the  braces.  The
372         result  is from one to six bytes, encoded according to the UTF-8 rules.         result  is  from  one  to  six bytes, encoded according to the original
373           UTF-8 rules of RFC 2279. This allows for  values  in  the  range  0  to
374           0x7FFFFFFF.  Note  that not all of those are valid Unicode code points,
375           or indeed valid UTF-8 characters according to the later  rules  in  RFC
376           3629.
377    
378    
379    THE ALTERNATIVE MATCHING FUNCTION
380    
381           By   default,  pcretest  uses  the  standard  PCRE  matching  function,
382           pcre_exec() to match each data line. From release 6.0, PCRE supports an
383           alternative  matching  function,  pcre_dfa_test(),  which operates in a
384           different way, and has some restrictions. The differences  between  the
385           two functions are described in the pcrematching documentation.
386    
387           If  a data line contains the \D escape sequence, or if the command line
388           contains the -dfa option, the alternative matching function is  called.
389           This function finds all possible matches at a given point. If, however,
390           the \F escape sequence is present in the data line, it stops after  the
391           first match is found. This is always the shortest possible match.
392    
393  OUTPUT FROM PCRETEST  
394    DEFAULT OUTPUT FROM PCRETEST
395    
396           This  section  describes  the output when the normal matching function,
397           pcre_exec(), is being used.
398    
399         When a match succeeds, pcretest outputs the list of captured substrings         When a match succeeds, pcretest outputs the list of captured substrings
400         that  pcre_exec()  returns,  starting with number 0 for the string that         that  pcre_exec()  returns,  starting with number 0 for the string that
401         matched the whole  pattern.  Here  is  an  example  of  an  interactive         matched the whole pattern. Otherwise, it outputs "No match" or "Partial
402         pcretest run.         match"  when  pcre_exec() returns PCRE_ERROR_NOMATCH or PCRE_ERROR_PAR-
403           TIAL, respectively, and otherwise the PCRE negative error number.  Here
404           is an example of an interactive pcretest run.
405    
406           $ pcretest           $ pcretest
407           PCRE version 4.00 08-Jan-2003           PCRE version 7.0 30-Nov-2006
408    
409             re> /^abc(\d+)/             re> /^abc(\d+)/
410           data> abc123           data> abc123
# Line 312  OUTPUT FROM PCRETEST Line 415  OUTPUT FROM PCRETEST
415    
416         If  the strings contain any non-printing characters, they are output as         If  the strings contain any non-printing characters, they are output as
417         \0x escapes, or as \x{...} escapes if the /8 modifier  was  present  on         \0x escapes, or as \x{...} escapes if the /8 modifier  was  present  on
418         the  pattern.  If  the pattern has the /+ modifier, then the output for         the  pattern.  See below for the definition of non-printing characters.
419         substring 0 is followed by the the rest of the subject string,  identi-         If the pattern has the /+ modifier, the output for substring 0 is  fol-
420         fied by "0+" like this:         lowed  by  the  the rest of the subject string, identified by "0+" like
421           this:
422    
423             re> /cat/+             re> /cat/+
424           data> cataract           data> cataract
425            0: cat            0: cat
426            0+ aract            0+ aract
427    
428         If  the  pattern  has  the /g or /G modifier, the results of successive         If the pattern has the /g or /G modifier,  the  results  of  successive
429         matching attempts are output in sequence, like this:         matching attempts are output in sequence, like this:
430    
431             re> /\Bi(\w\w)/g             re> /\Bi(\w\w)/g
# Line 335  OUTPUT FROM PCRETEST Line 439  OUTPUT FROM PCRETEST
439    
440         "No match" is output only if the first match attempt fails.         "No match" is output only if the first match attempt fails.
441    
442         If any of the sequences \C, \G, or \L are present in a data  line  that         If  any  of the sequences \C, \G, or \L are present in a data line that
443         is  successfully  matched,  the substrings extracted by the convenience         is successfully matched, the substrings extracted  by  the  convenience
444         functions are output with C, G, or L after the string number instead of         functions are output with C, G, or L after the string number instead of
445         a colon. This is in addition to the normal full list. The string length         a colon. This is in addition to the normal full list. The string length
446         (that is, the return from the extraction function) is given  in  paren-         (that  is,  the return from the extraction function) is given in paren-
447         theses after each string for \C and \G.         theses after each string for \C and \G.
448    
449         Note  that  while patterns can be continued over several lines (a plain         Note that whereas patterns can be continued over several lines (a plain
450         ">" prompt is used for continuations), data lines may not. However new-         ">" prompt is used for continuations), data lines may not. However new-
451         lines can be included in data by means of the \n escape.         lines can be included in data by means of the \n escape (or  \r,  \r\n,
452           etc., depending on the newline sequence setting).
453    
454    
455    OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
456    
457           When  the  alternative  matching function, pcre_dfa_exec(), is used (by
458           means of the \D escape sequence or the -dfa command line  option),  the
459           output  consists  of  a list of all the matches that start at the first
460           point in the subject where there is at least one match. For example:
461    
462               re> /(tang|tangerine|tan)/
463             data> yellow tangerine\D
464              0: tangerine
465              1: tang
466              2: tan
467    
468           (Using the normal matching function on this data  finds  only  "tang".)
469           The  longest matching string is always given first (and numbered zero).
470    
471           If /g is present on the pattern, the search for further matches resumes
472           at the end of the longest match. For example:
473    
474               re> /(tang|tangerine|tan)/g
475             data> yellow tangerine and tangy sultana\D
476              0: tangerine
477              1: tang
478              2: tan
479              0: tang
480              1: tan
481              0: tan
482    
483           Since  the  matching  function  does not support substring capture, the
484           escape sequences that are concerned with captured  substrings  are  not
485           relevant.
486    
487    
488    RESTARTING AFTER A PARTIAL MATCH
489    
490           When the alternative matching function has given the PCRE_ERROR_PARTIAL
491           return, indicating that the subject partially matched the pattern,  you
492           can  restart  the match with additional subject data by means of the \R
493           escape sequence. For example:
494    
495               re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
496             data> 23ja\P\D
497             Partial match: 23ja
498             data> n05\R\D
499              0: n05
500    
501           For further information about partial  matching,  see  the  pcrepartial
502           documentation.
503    
504    
505    CALLOUTS
506    
507           If  the pattern contains any callout requests, pcretest's callout func-
508           tion is called during matching. This works  with  both  matching  func-
509           tions. By default, the called function displays the callout number, the
510           start and current positions in the text at the callout  time,  and  the
511           next pattern item to be tested. For example, the output
512    
513             --->pqrabcdef
514               0    ^  ^     \d
515    
516           indicates  that  callout number 0 occurred for a match attempt starting
517           at the fourth character of the subject string, when the pointer was  at
518           the  seventh  character of the data, and when the next pattern item was
519           \d. Just one circumflex is output if the start  and  current  positions
520           are the same.
521    
522           Callouts numbered 255 are assumed to be automatic callouts, inserted as
523           a result of the /C pattern modifier. In this case, instead  of  showing
524           the  callout  number, the offset in the pattern, preceded by a plus, is
525           output. For example:
526    
527               re> /\d?[A-E]\*/C
528             data> E*
529             --->E*
530              +0 ^      \d?
531              +3 ^      [A-E]
532              +8 ^^     \*
533             +10 ^ ^
534              0: E*
535    
536           The callout function in pcretest returns zero (carry  on  matching)  by
537           default,  but you can use a \C item in a data line (as described above)
538           to change this.
539    
540           Inserting callouts can be helpful when using pcretest to check  compli-
541           cated  regular expressions. For further information about callouts, see
542           the pcrecallout documentation.
543    
544    
545    NON-PRINTING CHARACTERS
546    
547           When pcretest is outputting text in the compiled version of a  pattern,
548           bytes  other  than 32-126 are always treated as non-printing characters
549           are are therefore shown as hex escapes.
550    
551           When pcretest is outputting text that is a matched part  of  a  subject
552           string,  it behaves in the same way, unless a different locale has been
553           set for the  pattern  (using  the  /L  modifier).  In  this  case,  the
554           isprint() function to distinguish printing and non-printing characters.
555    
556    
557    SAVING AND RELOADING COMPILED PATTERNS
558    
559           The facilities described in this section are  not  available  when  the
560           POSIX inteface to PCRE is being used, that is, when the /P pattern mod-
561           ifier is specified.
562    
563           When the POSIX interface is not in use, you can cause pcretest to write
564           a  compiled  pattern to a file, by following the modifiers with > and a
565           file name.  For example:
566    
567             /pattern/im >/some/file
568    
569           See the pcreprecompile documentation for a discussion about saving  and
570           re-using compiled patterns.
571    
572           The  data  that  is  written  is  binary. The first eight bytes are the
573           length of the compiled pattern data  followed  by  the  length  of  the
574           optional  study  data,  each  written as four bytes in big-endian order
575           (most significant byte first). If there is no study  data  (either  the
576           pattern was not studied, or studying did not return any data), the sec-
577           ond length is zero. The lengths are followed by an exact  copy  of  the
578           compiled pattern. If there is additional study data, this follows imme-
579           diately after the compiled pattern. After writing  the  file,  pcretest
580           expects to read a new pattern.
581    
582           A saved pattern can be reloaded into pcretest by specifing < and a file
583           name instead of a pattern. The name of the file must not  contain  a  <
584           character,  as  otherwise pcretest will interpret the line as a pattern
585           delimited by < characters.  For example:
586    
587              re> </some/file
588             Compiled regex loaded from /some/file
589             No study data
590    
591           When the pattern has been loaded, pcretest proceeds to read data  lines
592           in the usual way.
593    
594           You  can copy a file written by pcretest to a different host and reload
595           it there, even if the new host has opposite endianness to  the  one  on
596           which  the pattern was compiled. For example, you can compile on an i86
597           machine and run on a SPARC machine.
598    
599           File names for saving and reloading can be absolute  or  relative,  but
600           note  that the shell facility of expanding a file name that starts with
601           a tilde (~) is not available.
602    
603           The ability to save and reload files in pcretest is intended for  test-
604           ing  and experimentation. It is not intended for production use because
605           only a single pattern can be written to a file. Furthermore,  there  is
606           no  facility  for  supplying  custom  character  tables  for use with a
607           reloaded pattern. If the original  pattern  was  compiled  with  custom
608           tables,  an  attempt to match a subject string using a reloaded pattern
609           is likely to cause pcretest to crash.  Finally, if you attempt to  load
610           a file that is not in the correct format, the result is undefined.
611    
612    
613    SEE ALSO
614    
615           pcre(3),  pcreapi(3),  pcrecallout(3), pcrematching(3), pcrepartial(d),
616           pcrepattern(3), pcreprecompile(3).
617    
618    
619  AUTHOR  AUTHOR
620    
621         Philip Hazel <ph10@cam.ac.uk>         Philip Hazel
622         University Computing Service,         University Computing Service
623         Cambridge CB2 3QG, England.         Cambridge CB2 3QH, England.
624    
625    
626    REVISION
627    
628  Last updated: 09 December 2003         Last updated: 09 August 2007
629  Copyright (c) 1997-2003 University of Cambridge.         Copyright (c) 1997-2007 University of Cambridge.

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