/usr/man2/cat.3/pcresample.3.Z

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 pcredemo.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  match-
       ing  succeeds,  the  program  outputs  the  portion of the subject that
       matched, together with the contents of any captured substrings.

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

       If PCRE is installed in the standard include  and  library  directories
       for  your  system, you should be able to compile the demonstration pro-
       gram using this command:

         gcc -o pcredemo pcredemo.c -lpcre

       If PCRE is installed elsewhere, you may need to add additional  options
       to  the  command line. For example, on a Unix-like system that has PCRE
       installed in /usr/local, you  can  compile  the  demonstration  program
       using a command like this:

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

       Once  you  have  compiled the demonstration program, 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), when PCRE is not installed in
       the standard library directory, 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  sys-
       tems. You need to add

         -R/usr/local/lib

       (for example) to the compile command to get round this problem.

Last updated: 09 September 2004
Copyright (c) 1997-2004 University of Cambridge.

                                                                 PCRESAMPLE(3)