PCRESAMPLE(3)             OpenBSD Programmer's Manual            PCRESAMPLE(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 pcredemo.c in the PCRE distribution. A
       listing of this program is given in the pcredemo documentation. If you
       do not have a copy of the PCRE distribution, you can save this listing
       to re-create pcredemo.c.

       The demonstration program, which uses the original PCRE 8-bit library,
       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 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
       possibility 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 operating system, you should be able to compile the
       demonstration program 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

       In a Windows environment, if you want to statically link the program
       against a non-dll pcre.a file, you must uncomment the line that defines
       PCRE_STATIC before including pcre.h, because otherwise the
       pcre_malloc() and pcre_free() exported functions will be declared
       __declspec(dllimport), with unwanted results.

       Once you have compiled and linked 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 both PCRE libraries. The pcredemo program is provided
       as a simple coding example.

       If you try to run pcredemo when PCRE is not installed in the standard
       library directory, you may get an error like this on some operating
       systems (e.g. Solaris):

         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

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

AUTHOR

       Philip Hazel
       University Computing Service
       Cambridge CB2 3QH, England.

REVISION

       Last updated: 10 January 2012
       Copyright (c) 1997-2012 University of Cambridge.



                                                                 PCRESAMPLE(3)
