PCRE(3)                                                   PCRE(3)



NAME
       PCRE - Perl-compatible regular expressions

PCRE SAMPLE PROGRAM

       A  simple,  complete  demonstration  program,  to  get you
       started with using PCRE, is supplied  in  the  file  pcre-
       demo.c in the PCRE distribution.

       The  program  compiles  the regular expression that is its
       first argument, and matches it against the subject  string
       in  its  second  argument.  No  PCRE  options are set, and
       default character tables are used. If  matching  succeeds,
       the  program  outputs  the  portion  of  the  subject that
       matched, together with the contents of any  captured  sub-
       strings.

       If the -g option is given on the command line, the program
       then goes on to check for further matches of the same reg-
       ular expression in the same subject string. The logic is a
       little bit tricky because of the possibility  of  matching
       an  empty  string.  Comments  in  the code explain what is
       going on.

       On a Unix system that has PCRE  installed  in  /usr/local,
       you  can compile the demonstration program using a command
       like this:

         gcc -o pcredemo pcredemo.c -I/usr/local/include \
             -L/usr/local/lib -lpcre

       Then you can run simple tests like this:

         ./pcredemo 'cat|dog' 'the cat sat on the mat'
         ./pcredemo -g 'cat|dog' 'the dog sat on the cat'

       Note that there is a much more comprehensive test program,
       called  pcretest,  which supports many more facilities for
       testing regular expressions  and  the  PCRE  library.  The
       pcredemo program is provided as a simple coding example.

       On  some  operating  systems (e.g. Solaris) you may get an
       error like this when you try to run pcredemo:

         ld.so.1: a.out: fatal:  libpcre.so.0:  open  failed:  No
       such file or directory

       This  is caused by the way shared library support works on
       those systems. You need to add

         -R/usr/local/lib

       to the compile command to get round this problem.

Last updated: 28 January 2003
Copyright (c) 1997-2003 University of Cambridge.



                                                          PCRE(3)