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1  NAME  PCRETEST(1)                                                        PCRETEST(1)
2       pcretest - a program  for  testing  Perl-compatible  regular  
      expressions.  
3    
4    
5    NAME
6           pcretest - a program for testing Perl-compatible regular expressions.
7    
8  SYNOPSIS  SYNOPSIS
      pcretest [-d] [-i] [-m] [-o osize] [-p] [-t] [source]  [des-  
      tination]  
9    
10       pcretest was written as a test program for the PCRE  regular         pcretest [-C] [-d] [-i] [-m] [-o osize] [-p] [-t] [source]
11       expression  library  itself,  but  it  can  also be used for              [destination]
      experimenting  with  regular  expressions.  This  man   page  
      describes  the  features of the test program; for details of  
      the regular expressions themselves, see the pcre man page.  
12    
13           pcretest  was written as a test program for the PCRE regular expression
14           library itself, but it can also be used for experimenting with  regular
15           expressions.  This document describes the features of the test program;
16           for details of the regular expressions themselves, see the  pcrepattern
17           documentation. For details of the PCRE library function calls and their
18           options, see the pcreapi documentation.
19    
20    
21  OPTIONS  OPTIONS
      -d        Behave as if each regex had the /D  modifier  (see  
                below); the internal form is output after compila-  
                tion.  
   
      -i        Behave as if  each  regex  had  the  /I  modifier;  
                information  about  the  compiled pattern is given  
                after compilation.  
   
      -m        Output the size of each compiled pattern after  it  
                has been compiled. This is equivalent to adding /M  
                to each regular expression. For compatibility with  
                earlier  versions of pcretest, -s is a synonym for  
                -m.  
   
      -o osize  Set the number of elements in  the  output  vector  
                that  is  used  when calling PCRE to be osize. The  
                default value is 45, which is enough for  14  cap-  
                turing  subexpressions.  The  vector  size  can be  
                changed for individual matching calls by including  
                \O in the data line (see below).  
   
      -p        Behave as if each regex has /P modifier; the POSIX  
                wrapper  API  is  used  to  call PCRE. None of the  
                other options has any effect when -p is set.  
   
      -t        Run each compile, study,  and  match  20000  times  
                with  a  timer, and output resulting time per com-  
                pile or match (in milliseconds).  Do  not  set  -t  
                with -m, because you will then get the size output  
                20000 times and the timing will be distorted.  
22    
23           -C        Output the version number of the PCRE library, and all avail-
24                     able   information  about  the  optional  features  that  are
25                     included, and then exit.
26    
27           -d        Behave as if each regex had  the  /D  (debug)  modifier;  the
28                     internal form is output after compilation.
29    
30           -i        Behave  as  if  each  regex  had the /I modifier; information
31                     about the compiled pattern is given after compilation.
32    
33           -m        Output the size of each compiled pattern after  it  has  been
34                     compiled.  This  is  equivalent  to adding /M to each regular
35                     expression.  For  compatibility  with  earlier  versions   of
36                     pcretest, -s is a synonym for -m.
37    
38           -o osize  Set  the number of elements in the output vector that is used
39                     when calling pcre_exec() to be osize. The  default  value  is
40                     45, which is enough for 14 capturing subexpressions. The vec-
41                     tor size can be changed  for  individual  matching  calls  by
42                     including \O in the data line (see below).
43    
44           -p        Behave  as  if  each regex has /P modifier; the POSIX wrapper
45                     API is used to call PCRE. None of the other options  has  any
46                     effect when -p is set.
47    
48           -t        Run  each  compile, study, and match many times with a timer,
49                     and output resulting time per compile or match (in  millisec-
50                     onds).  Do  not set -m with -t, because you will then get the
51                     size output a zillion times, and  the  timing  will  be  dis-
52                     torted.
53    
54    
55  DESCRIPTION  DESCRIPTION
      If pcretest is given two filename arguments, it  reads  from  
      the  first and writes to the second. If it is given only one  
   
   
   
   
 SunOS 5.8                 Last change:                          1  
   
   
   
      filename argument, it reads from that  file  and  writes  to  
      stdout. Otherwise, it reads from stdin and writes to stdout,  
      and prompts for each line of input, using  "re>"  to  prompt  
      for  regular  expressions,  and  "data>"  to prompt for data  
      lines.  
   
      The program handles any number of sets of input on a  single  
      input  file.  Each set starts with a regular expression, and  
      continues with any  number  of  data  lines  to  be  matched  
      against  the  pattern.  An empty line signals the end of the  
      data lines, at which point a new regular expression is read.  
      The  regular  expressions  are  given  enclosed  in any non-  
      alphameric delimiters other than backslash, for example  
   
        /(a|bc)x+yz/  
   
      White space before the initial delimiter is ignored. A regu-  
      lar expression may be continued over several input lines, in  
      which case the newline characters are included within it. It  
      is  possible  to include the delimiter within the pattern by  
      escaping it, for example  
   
        /abc\/def/  
   
      If you do so, the escape and the delimiter form part of  the  
      pattern,  but  since  delimiters  are always non-alphameric,  
      this does not affect its interpretation.  If the terminating  
      delimiter  is immediately followed by a backslash, for exam-  
      ple,  
   
        /abc/\  
   
      then a backslash is added to the end of the pattern. This is  
      done  to  provide  a way of testing the error condition that  
      arises if a pattern finishes with a backslash, because  
   
        /abc\/  
   
      is interpreted as the first line of a  pattern  that  starts  
      with  "abc/",  causing  pcretest  to read the next line as a  
      continuation of the regular expression.  
56    
57           If  pcretest  is  given two filename arguments, it reads from the first
58           and writes to the second. If it is given only one filename argument, it
59           reads  from  that  file  and writes to stdout. Otherwise, it reads from
60           stdin and writes to stdout, and prompts for each line of  input,  using
61           "re>" to prompt for regular expressions, and "data>" to prompt for data
62           lines.
63    
64           The program handles any number of sets of input on a single input file.
65           Each  set starts with a regular expression, and continues with any num-
66           ber of data lines to be matched against the pattern.
67    
68           Each data line is matched separately and independently. If you want  to
69           do  multiple-line  matches, you have to use the \n escape sequence in a
70           single line of input to encode  the  newline  characters.  The  maximum
71           length of data line is 30,000 characters.
72    
73           An  empty  line signals the end of the data lines, at which point a new
74           regular expression is read. The regular expressions are given  enclosed
75           in any non-alphanumeric delimiters other than backslash, for example
76    
77             /(a|bc)x+yz/
78    
79           White  space before the initial delimiter is ignored. A regular expres-
80           sion may be continued over several input lines, in which case the  new-
81           line  characters  are included within it. It is possible to include the
82           delimiter within the pattern by escaping it, for example
83    
84             /abc\/def/
85    
86           If you do so, the escape and the delimiter form part  of  the  pattern,
87           but  since delimiters are always non-alphanumeric, this does not affect
88           its interpretation.  If the terminating delimiter is  immediately  fol-
89           lowed by a backslash, for example,
90    
91             /abc/\
92    
93           then  a  backslash  is added to the end of the pattern. This is done to
94           provide a way of testing the error condition that arises if  a  pattern
95           finishes with a backslash, because
96    
97             /abc\/
98    
99           is  interpreted as the first line of a pattern that starts with "abc/",
100           causing pcretest to read the next line as a continuation of the regular
101           expression.
102    
103    
104  PATTERN MODIFIERS  PATTERN MODIFIERS
      The pattern may be followed by i, m, s,  or  x  to  set  the  
      PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED  
      options, respectively. For example:  
   
        /caseless/i  
   
      These modifier letters have the same effect as  they  do  in  
      Perl.  There  are  others which set PCRE options that do not  
      correspond  to  anything  in  Perl:   /A,  /E,  and  /X  set  
      PCRE_ANCHORED,  PCRE_DOLLAR_ENDONLY,  and PCRE_EXTRA respec-  
      tively.  
   
      Searching for  all  possible  matches  within  each  subject  
      string  can  be  requested  by  the /g or /G modifier. After  
      finding  a  match,  PCRE  is  called  again  to  search  the  
      remainder  of  the subject string. The difference between /g  
      and /G is that the former uses the startoffset  argument  to  
      pcre_exec()  to  start  searching  at a new point within the  
      entire string (which is in effect what Perl  does),  whereas  
      the  latter  passes over a shortened substring. This makes a  
      difference to the matching process  if  the  pattern  begins  
      with a lookbehind assertion (including \b or \B).  
   
      If any call to pcre_exec() in a /g or /G sequence matches an  
      empty  string,  the next call is done with the PCRE_NOTEMPTY  
      and PCRE_ANCHORED flags set in order to search for  another,  
      non-empty,  match  at  the same point.  If this second match  
      fails, the start offset is advanced by one, and  the  normal  
      match  is  retried.  This imitates the way Perl handles such  
      cases when using the /g modifier or the split() function.  
   
      There are a number of other modifiers  for  controlling  the  
      way pcretest operates.  
   
      The /+ modifier requests that as well as outputting the sub-  
      string  that  matched the entire pattern, pcretest should in  
      addition output the remainder of the subject string. This is  
      useful  for tests where the subject contains multiple copies  
      of the same substring.  
   
      The /L modifier must be followed directly by the name  of  a  
      locale, for example,  
   
        /pattern/Lfr  
   
      For this reason, it must be the last  modifier  letter.  The  
      given  locale is set, pcre_maketables() is called to build a  
      set of character tables for the locale,  and  this  is  then  
      passed  to pcre_compile() when compiling the regular expres-  
      sion. Without an /L modifier, NULL is passed as  the  tables  
      pointer; that is, /L applies only to the expression on which  
      it appears.  
   
      The /I modifier requests that  pcretest  output  information  
      about the compiled expression (whether it is anchored, has a  
      fixed first character, and so on). It does this  by  calling  
      pcre_fullinfo()  after  compiling an expression, and output-  
      ting the information it gets back. If the  pattern  is  stu-  
      died, the results of that are also output.  
      The /D modifier is a  PCRE  debugging  feature,  which  also  
      assumes /I.  It causes the internal form of compiled regular  
      expressions to be output after compilation.  
   
      The /S modifier causes pcre_study() to be called  after  the  
      expression  has been compiled, and the results used when the  
      expression is matched.  
   
      The /M modifier causes the size of memory block used to hold  
      the compiled pattern to be output.  
   
      The /P modifier causes pcretest to call PCRE via  the  POSIX  
      wrapper  API  rather than its native API. When this is done,  
      all other modifiers except  /i,  /m,  and  /+  are  ignored.  
      REG_ICASE is set if /i is present, and REG_NEWLINE is set if  
      /m    is    present.    The    wrapper    functions    force  
      PCRE_DOLLAR_ENDONLY    always,    and   PCRE_DOTALL   unless  
      REG_NEWLINE is set.  
   
      The /8 modifier  causes  pcretest  to  call  PCRE  with  the  
      PCRE_UTF8  option  set.  This turns on the (currently incom-  
      plete) support for UTF-8 character handling  in  PCRE,  pro-  
      vided  that  it was compiled with this support enabled. This  
      modifier also causes any non-printing characters  in  output  
      strings  to  be printed using the \x{hh...} notation if they  
      are valid UTF-8 sequences.  
105    
106           A  pattern may be followed by any number of modifiers, which are mostly
107           single characters. Following Perl usage, these are  referred  to  below
108           as,  for  example,  "the /i modifier", even though the delimiter of the
109           pattern need not always be a slash, and no slash is used  when  writing
110           modifiers.  Whitespace  may  appear between the final pattern delimiter
111           and the first modifier, and between the modifiers themselves.
112    
113           The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,
114           PCRE_DOTALL,  or  PCRE_EXTENDED  options,  respectively, when pcre_com-
115           pile() is called. These four modifier letters have the same  effect  as
116           they do in Perl. For example:
117    
118             /caseless/i
119    
120           The following table shows additional modifiers for setting PCRE options
121           that do not correspond to anything in Perl:
122    
123             /A    PCRE_ANCHORED
124             /C    PCRE_AUTO_CALLOUT
125             /E    PCRE_DOLLAR_ENDONLY
126             /N    PCRE_NO_AUTO_CAPTURE
127             /U    PCRE_UNGREEDY
128             /X    PCRE_EXTRA
129    
130           Searching for all possible matches within each subject  string  can  be
131           requested  by  the  /g  or  /G modifier. After finding a match, PCRE is
132           called again to search the remainder of the subject string. The differ-
133           ence between /g and /G is that the former uses the startoffset argument
134           to pcre_exec() to start searching at a  new  point  within  the  entire
135           string  (which  is in effect what Perl does), whereas the latter passes
136           over a shortened substring. This makes a  difference  to  the  matching
137           process if the pattern begins with a lookbehind assertion (including \b
138           or \B).
139    
140           If any call to pcre_exec() in a /g or  /G  sequence  matches  an  empty
141           string,  the next call is done with the PCRE_NOTEMPTY and PCRE_ANCHORED
142           flags set in order to search for another, non-empty, match at the  same
143           point.   If  this  second  match fails, the start offset is advanced by
144           one, and the normal match is retried. This imitates the way  Perl  han-
145           dles such cases when using the /g modifier or the split() function.
146    
147           There are yet more modifiers for controlling the way pcretest operates.
148    
149           The /+ modifier requests that as well as outputting the substring  that
150           matched  the  entire  pattern,  pcretest  should in addition output the
151           remainder of the subject string. This is useful  for  tests  where  the
152           subject contains multiple copies of the same substring.
153    
154           The  /L modifier must be followed directly by the name of a locale, for
155           example,
156    
157             /pattern/Lfr_FR
158    
159           For this reason, it must be the last modifier. The given locale is set,
160           pcre_maketables()  is called to build a set of character tables for the
161           locale, and this is then passed to pcre_compile()  when  compiling  the
162           regular  expression.  Without  an  /L  modifier,  NULL is passed as the
163           tables pointer; that is, /L applies only to the expression on which  it
164           appears.
165    
166           The  /I  modifier  requests  that pcretest output information about the
167           compiled pattern (whether it is anchored, has a fixed first  character,
168           and  so  on). It does this by calling pcre_fullinfo() after compiling a
169           pattern. If the pattern is studied, the results of that are  also  out-
170           put.
171    
172           The /D modifier is a PCRE debugging feature, which also assumes /I.  It
173           causes the internal form of compiled regular expressions to  be  output
174           after compilation. If the pattern was studied, the information returned
175           is also output.
176    
177           The /F modifier causes pcretest to flip the byte order of the fields in
178           the  compiled  pattern  that  contain  2-byte  and 4-byte numbers. This
179           facility is for testing the feature in PCRE that allows it  to  execute
180           patterns that were compiled on a host with a different endianness. This
181           feature is not available when the POSIX  interface  to  PCRE  is  being
182           used,  that is, when the /P pattern modifier is specified. See also the
183           section about saving and reloading compiled patterns below.
184    
185           The /S modifier causes pcre_study() to be called after  the  expression
186           has been compiled, and the results used when the expression is matched.
187    
188           The /M modifier causes the size of memory block used to hold  the  com-
189           piled pattern to be output.
190    
191           The  /P modifier causes pcretest to call PCRE via the POSIX wrapper API
192           rather than its native API. When this  is  done,  all  other  modifiers
193           except  /i,  /m, and /+ are ignored. REG_ICASE is set if /i is present,
194           and REG_NEWLINE is set if /m is present. The  wrapper  functions  force
195           PCRE_DOLLAR_ENDONLY  always, and PCRE_DOTALL unless REG_NEWLINE is set.
196    
197           The /8 modifier causes pcretest to call PCRE with the PCRE_UTF8  option
198           set.  This  turns on support for UTF-8 character handling in PCRE, pro-
199           vided that it was compiled with this  support  enabled.  This  modifier
200           also causes any non-printing characters in output strings to be printed
201           using the \x{hh...} notation if they are valid UTF-8 sequences.
202    
203           If the /? modifier  is  used  with  /8,  it  causes  pcretest  to  call
204           pcre_compile()  with  the  PCRE_NO_UTF8_CHECK  option,  to suppress the
205           checking of the string for UTF-8 validity.
206    
207    
208  DATA LINES  DATA LINES
      Before each data line is passed to pcre_exec(), leading  and  
      trailing whitespace is removed, and it is then scanned for \  
      escapes. The following are recognized:  
   
        \a         alarm (= BEL)  
        \b         backspace  
        \e         escape  
        \f         formfeed  
        \n         newline  
        \r         carriage return  
        \t         tab  
        \v         vertical tab  
        \nnn       octal character (up to 3 octal digits)  
        \xhh       hexadecimal character (up to 2 hex digits)  
        \x{hh...}  hexadecimal UTF-8 character  
   
        \A         pass the PCRE_ANCHORED option to pcre_exec()  
        \B         pass the PCRE_NOTBOL option to pcre_exec()  
        \Cdd       call pcre_copy_substring() for substring dd  
                      after a successful match (any decimal number  
                      less than 32)  
        \Gdd       call pcre_get_substring() for substring dd  
   
                      after a successful match (any decimal number  
                      less than 32)  
        \L         call pcre_get_substringlist() after a  
                      successful match  
        \N         pass the PCRE_NOTEMPTY option to pcre_exec()  
        \Odd       set the size of the output vector passed to  
                      pcre_exec() to dd (any number of decimal  
                      digits)  
        \Z         pass the PCRE_NOTEOL option to pcre_exec()  
   
      When \O is used, it may be higher or lower than the size set  
      by  the  -O  option (or defaulted to 45); \O applies only to  
      the call of pcre_exec() for the line in which it appears.  
   
      A backslash followed by anything else just escapes the  any-  
      thing else. If the very last character is a backslash, it is  
      ignored. This gives a way of passing an empty line as  data,  
      since a real empty line terminates the data input.  
   
      If /P was present on the regex, causing  the  POSIX  wrapper  
      API  to  be  used,  only  B,  and Z have any effect, causing  
      REG_NOTBOL and REG_NOTEOL to be passed to regexec()  respec-  
      tively.  
   
      The use of \x{hh...} to represent UTF-8  characters  is  not  
      dependent  on  the use of the /8 modifier on the pattern. It  
      is recognized always. There may be any number of hexadecimal  
      digits  inside  the  braces.  The  result is from one to six  
      bytes, encoded according to the UTF-8 rules.  
209    
210           Before each data line is passed to pcre_exec(),  leading  and  trailing
211           whitespace  is  removed,  and it is then scanned for \ escapes. Some of
212           these are pretty esoteric features, intended for checking out  some  of
213           the  more  complicated features of PCRE. If you are just testing "ordi-
214           nary" regular expressions, you probably don't need any  of  these.  The
215           following escapes are recognized:
216    
217             \a         alarm (= BEL)
218             \b         backspace
219             \e         escape
220             \f         formfeed
221             \n         newline
222             \r         carriage return
223             \t         tab
224             \v         vertical tab
225             \nnn       octal character (up to 3 octal digits)
226             \xhh       hexadecimal character (up to 2 hex digits)
227             \x{hh...}  hexadecimal character, any number of digits
228                          in UTF-8 mode
229             \A         pass the PCRE_ANCHORED option to pcre_exec()
230             \B         pass the PCRE_NOTBOL option to pcre_exec()
231             \Cdd       call pcre_copy_substring() for substring dd
232                          after a successful match (number less than 32)
233             \Cname     call pcre_copy_named_substring() for substring
234                          "name" after a successful match (name termin-
235                          ated by next non alphanumeric character)
236             \C+        show the current captured substrings at callout
237                          time
238             \C-        do not supply a callout function
239             \C!n       return 1 instead of 0 when callout number n is
240                          reached
241             \C!n!m     return 1 instead of 0 when callout number n is
242                          reached for the nth time
243             \C*n       pass the number n (may be negative) as callout
244                          data; this is used as the callout return value
245             \Gdd       call pcre_get_substring() for substring dd
246                          after a successful match (number less than 32)
247             \Gname     call pcre_get_named_substring() for substring
248                          "name" after a successful match (name termin-
249                          ated by next non-alphanumeric character)
250             \L         call pcre_get_substringlist() after a
251                          successful match
252             \M         discover the minimum MATCH_LIMIT setting
253             \N         pass the PCRE_NOTEMPTY option to pcre_exec()
254             \Odd       set the size of the output vector passed to
255                          pcre_exec() to dd (any number of digits)
256             \P         pass the PCRE_PARTIAL option to pcre_exec()
257             \S         output details of memory get/free calls during matching
258             \Z         pass the PCRE_NOTEOL option to pcre_exec()
259             \?         pass the PCRE_NO_UTF8_CHECK option to
260                          pcre_exec()
261             \>dd       start the match at offset dd (any number of digits);
262                          this sets the startoffset argument for pcre_exec()
263    
264           A  backslash  followed by anything else just escapes the anything else.
265           If the very last character is a backslash, it is ignored. This gives  a
266           way  of  passing  an empty line as data, since a real empty line termi-
267           nates the data input.
268    
269           If \M is present, pcretest calls pcre_exec() several times,  with  dif-
270           ferent  values  in  the match_limit field of the pcre_extra data struc-
271           ture, until it finds the minimum number that is needed for  pcre_exec()
272           to  complete.  This  number is a measure of the amount of recursion and
273           backtracking that takes place, and checking it out can be  instructive.
274           For  most  simple  matches, the number is quite small, but for patterns
275           with very large numbers of matching possibilities, it can become  large
276           very quickly with increasing length of subject string.
277    
278           When  \O  is  used, the value specified may be higher or lower than the
279           size set by the -O command line option (or defaulted to 45); \O applies
280           only to the call of pcre_exec() for the line in which it appears.
281    
282           If  the /P modifier was present on the pattern, causing the POSIX wrap-
283           per API to be used, only \B and \Z have any effect, causing  REG_NOTBOL
284           and REG_NOTEOL to be passed to regexec() respectively.
285    
286           The  use of \x{hh...} to represent UTF-8 characters is not dependent on
287           the use of the /8 modifier on the pattern.  It  is  recognized  always.
288           There  may  be  any number of hexadecimal digits inside the braces. The
289           result is from one to six bytes, encoded according to the UTF-8  rules.
290    
291    
292  OUTPUT FROM PCRETEST  OUTPUT FROM PCRETEST
      When a match succeeds, pcretest outputs the list of captured  
      substrings  that pcre_exec() returns, starting with number 0  
      for the string that matched the whole pattern.  Here  is  an  
      example of an interactive pcretest run.  
   
        $ pcretest  
        PCRE version 2.06 08-Jun-1999  
   
          re> /^abc(\d+)/  
        data> abc123  
         0: abc123  
         1: 123  
        data> xyz  
        No match  
   
      If the strings contain any non-printing characters, they are  
      output  as  \0x  escapes,  or  as  \x{...} escapes if the /8  
      modifier was present on the pattern. If the pattern has  the  
      /+  modifier, then the output for substring 0 is followed by  
      the the rest of the subject string, identified by "0+"  like  
      this:  
   
          re> /cat/+  
        data> cataract  
         0: cat  
         0+ aract  
   
      If the pattern has the /g or /G  modifier,  the  results  of  
      successive  matching  attempts  are output in sequence, like  
      this:  
   
          re> /\Bi(\w\w)/g  
        data> Mississippi  
         0: iss  
         1: ss  
         0: iss  
         1: ss  
         0: ipp  
         1: pp  
   
      "No match" is output only if the first match attempt fails.  
   
      If any of the sequences \C, \G, or \L are present in a  data  
      line  that is successfully matched, the substrings extracted  
      by the convenience functions are output  with  C,  G,  or  L  
      after the string number instead of a colon. This is in addi-  
      tion to the normal full list. The string  length  (that  is,  
      the  return  from  the  extraction  function)  is  given  in  
      parentheses after each string for \C and \G.  
   
      Note that while patterns can be continued over several lines  
      (a  plain  ">" prompt is used for continuations), data lines  
      may not. However newlines can be included in data  by  means  
      of the \n escape.  
293    
294           When a match succeeds, pcretest outputs the list of captured substrings
295           that pcre_exec() returns, starting with number 0 for  the  string  that
296           matched the whole pattern. Otherwise, it outputs "No match" or "Partial
297           match" when pcre_exec() returns PCRE_ERROR_NOMATCH  or  PCRE_ERROR_PAR-
298           TIAL,  respectively, and otherwise the PCRE negative error number. Here
299           is an example of an interactive pcretest run.
300    
301             $ pcretest
302             PCRE version 5.00 07-Sep-2004
303    
304               re> /^abc(\d+)/
305             data> abc123
306              0: abc123
307              1: 123
308             data> xyz
309             No match
310    
311           If the strings contain any non-printing characters, they are output  as
312           \0x  escapes,  or  as \x{...} escapes if the /8 modifier was present on
313           the pattern. If the pattern has the /+ modifier, the  output  for  sub-
314           string  0 is followed by the the rest of the subject string, identified
315           by "0+" like this:
316    
317               re> /cat/+
318             data> cataract
319              0: cat
320              0+ aract
321    
322           If the pattern has the /g or /G modifier,  the  results  of  successive
323           matching attempts are output in sequence, like this:
324    
325               re> /\Bi(\w\w)/g
326             data> Mississippi
327              0: iss
328              1: ss
329              0: iss
330              1: ss
331              0: ipp
332              1: pp
333    
334           "No match" is output only if the first match attempt fails.
335    
336           If  any  of the sequences \C, \G, or \L are present in a data line that
337           is successfully matched, the substrings extracted  by  the  convenience
338           functions are output with C, G, or L after the string number instead of
339           a colon. This is in addition to the normal full list. The string length
340           (that  is,  the return from the extraction function) is given in paren-
341           theses after each string for \C and \G.
342    
343           Note that while patterns can be continued over several lines  (a  plain
344           ">" prompt is used for continuations), data lines may not. However new-
345           lines can be included in data by means of the \n escape.
346    
347    
348    CALLOUTS
349    
350           If the pattern contains any callout requests, pcretest's callout  func-
351           tion  is  called  during  matching. By default, it displays the callout
352           number, the start and current positions in  the  text  at  the  callout
353           time, and the next pattern item to be tested. For example, the output
354    
355             --->pqrabcdef
356               0    ^  ^     \d
357    
358           indicates  that  callout number 0 occurred for a match attempt starting
359           at the fourth character of the subject string, when the pointer was  at
360           the  seventh  character of the data, and when the next pattern item was
361           \d. Just one circumflex is output if the start  and  current  positions
362           are the same.
363    
364           Callouts numbered 255 are assumed to be automatic callouts, inserted as
365           a result of the /C pattern modifier. In this case, instead  of  showing
366           the  callout  number, the offset in the pattern, preceded by a plus, is
367           output. For example:
368    
369               re> /\d?[A-E]\*/C
370             data> E*
371             --->E*
372              +0 ^      \d?
373              +3 ^      [A-E]
374              +8 ^^     \*
375             +10 ^ ^
376              0: E*
377    
378           The callout function in pcretest returns zero (carry  on  matching)  by
379           default, but you can use an \C item in a data line (as described above)
380           to change this.
381    
382           Inserting callouts can be helpful when using pcretest to check  compli-
383           cated  regular expressions. For further information about callouts, see
384           the pcrecallout documentation.
385    
386    
387    SAVING AND RELOADING COMPILED PATTERNS
388    
389           The facilities described in this section are  not  available  when  the
390           POSIX inteface to PCRE is being used, that is, when the /P pattern mod-
391           ifier is specified.
392    
393           When the POSIX interface is not in use, you can cause pcretest to write
394           a  compiled  pattern to a file, by following the modifiers with > and a
395           file name.  For example:
396    
397             /pattern/im >/some/file
398    
399           See the pcreprecompile documentation for a discussion about saving  and
400           re-using compiled patterns.
401    
402           The  data  that  is  written  is  binary. The first eight bytes are the
403           length of the compiled pattern data  followed  by  the  length  of  the
404           optional  study  data,  each  written as four bytes in big-endian order
405           (most significant byte first). If there is no study  data  (either  the
406           pattern was not studied, or studying did not return any data), the sec-
407           ond length is zero. The lengths are followed by an exact  copy  of  the
408           compiled pattern. If there is additional study data, this follows imme-
409           diately after the compiled pattern. After writing  the  file,  pcretest
410           expects to read a new pattern.
411    
412           A saved pattern can be reloaded into pcretest by specifing < and a file
413           name instead of a pattern. The name of the file must not  contain  a  <
414           character,  as  otherwise pcretest will interpret the line as a pattern
415           delimited by < characters.  For example:
416    
417              re> </some/file
418             Compiled regex loaded from /some/file
419             No study data
420    
421           When the pattern has been loaded, pcretest proceeds to read data  lines
422           in the usual way.
423    
424           You  can copy a file written by pcretest to a different host and reload
425           it there, even if the new host has opposite endianness to  the  one  on
426           which  the pattern was compiled. For example, you can compile on an i86
427           machine and run on a SPARC machine.
428    
429           File names for saving and reloading can be absolute  or  relative,  but
430           note  that the shell facility of expanding a file name that starts with
431           a tilde (~) is not available.
432    
433           The ability to save and reload files in pcretest is intended for  test-
434           ing  and experimentation. It is not intended for production use because
435           only a single pattern can be written to a file. Furthermore,  there  is
436           no  facility  for  supplying  custom  character  tables  for use with a
437           reloaded pattern. If the original  pattern  was  compiled  with  custom
438           tables,  an  attempt to match a subject string using a reloaded pattern
439           is likely to cause pcretest to crash.  Finally, if you attempt to  load
440           a file that is not in the correct format, the result is undefined.
441    
442    
443  AUTHOR  AUTHOR
      Philip Hazel <ph10@cam.ac.uk>  
      University Computing Service,  
      New Museums Site,  
      Cambridge CB2 3QG, England.  
      Phone: +44 1223 334714  
444    
445       Last updated: 15 August 2001         Philip Hazel <ph10@cam.ac.uk>
446       Copyright (c) 1997-2001 University of Cambridge.         University Computing Service,
447           Cambridge CB2 3QG, England.
448    
449    Last updated: 10 September 2004
450    Copyright (c) 1997-2004 University of Cambridge.
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