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PCRESAMPLE(3)									    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 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 substrings.

       If  the -g option is given on the command line, the program then goes on to check for fur-
       ther 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 the PCRE  library.  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: 17 November 2010
       Copyright (c) 1997-2010 University of Cambridge.

										    PCRESAMPLE(3)
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