NAME

       PCRE2 - Perl-compatible regular expressions (revised API)

PCRE2 SAMPLE PROGRAM

       A  simple,  complete demonstration program to get you started with using PCRE2 is supplied
       in the file pcre2demo.c in the src directory in the PCRE2 distribution. A listing of  this
       program  is  given  in the pcre2demo documentation. If you do not have a copy of the PCRE2
       distribution, you can save this listing to re-create the contents of pcre2demo.c.

       The demonstration program, which uses  the  PCRE2  8-bit  library,  compiles  the  regular
       expression  that  is  its first argument, and matches it against the subject string in its
       second argument. No PCRE2 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  PCRE2  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 pcre2demo pcre2demo.c -lpcre2-8

       If PCRE2 is installed elsewhere, you may need to add additional  options  to  the  command
       line.  For  example, on a Unix-like system that has PCRE2 installed in /usr/local, you can
       compile the demonstration program using a command like this:

         gcc -o pcre2demo -I/usr/local/include pcre2demo.c \
             -L/usr/local/lib -lpcre2-8

       Once you have compiled and linked the demonstration program, you can run simple tests like
       this:

         ./pcre2demo 'cat|dog' 'the cat sat on the mat'
         ./pcre2demo -g 'cat|dog' 'the dog sat on the cat'

       Note  that  there  is  a  much  more  comprehensive  test program, called pcre2test, which
       supports many more facilities for testing regular expressions using the  PCRE2  libraries.
       The pcre2demo program is provided as a simple coding example.

       If you try to run pcre2demo when PCRE2 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: libpcre2.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, England.

REVISION

       Last updated: 20 October 2014
       Copyright (c) 1997-2014 University of Cambridge.