| .TH PCRE2SAMPLE 3 "20 October 2014" "PCRE2 10.00" |
| .SH NAME |
| PCRE2 - Perl-compatible regular expressions (revised API) |
| .SH "PCRE2 SAMPLE PROGRAM" |
| .rs |
| .sp |
| A simple, complete demonstration program to get you started with using PCRE2 is |
| supplied in the file \fIpcre2demo.c\fP in the \fBsrc\fP directory in the PCRE2 |
| distribution. A listing of this program is given in the |
| .\" HREF |
| \fBpcre2demo\fP |
| .\" |
| documentation. If you do not have a copy of the PCRE2 distribution, you can |
| save this listing to re-create the contents of \fIpcre2demo.c\fP. |
| .P |
| 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. |
| .P |
| 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. |
| .P |
| 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: |
| .sp |
| gcc -o pcre2demo pcre2demo.c -lpcre2-8 |
| .sp |
| 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 |
| \fI/usr/local\fP, you can compile the demonstration program using a command |
| like this: |
| .sp |
| .\" JOINSH |
| gcc -o pcre2demo -I/usr/local/include pcre2demo.c \e |
| -L/usr/local/lib -lpcre2-8 |
| .sp |
| .P |
| Once you have compiled and linked the demonstration program, you can run simple |
| tests like this: |
| .sp |
| ./pcre2demo 'cat|dog' 'the cat sat on the mat' |
| ./pcre2demo -g 'cat|dog' 'the dog sat on the cat' |
| .sp |
| Note that there is a much more comprehensive test program, called |
| .\" HREF |
| \fBpcre2test\fP, |
| .\" |
| which supports many more facilities for testing regular expressions using the |
| PCRE2 libraries. The |
| .\" HREF |
| \fBpcre2demo\fP |
| .\" |
| program is provided as a simple coding example. |
| .P |
| If you try to run |
| .\" HREF |
| \fBpcre2demo\fP |
| .\" |
| when PCRE2 is not installed in the standard library directory, you may get an |
| error like this on some operating systems (e.g. Solaris): |
| .sp |
| ld.so.1: a.out: fatal: libpcre2.so.0: open failed: No such file or directory |
| .sp |
| This is caused by the way shared library support works on those systems. You |
| need to add |
| .sp |
| -R/usr/local/lib |
| .sp |
| (for example) to the compile command to get round this problem. |
| . |
| . |
| .SH AUTHOR |
| .rs |
| .sp |
| .nf |
| Philip Hazel |
| University Computing Service |
| Cambridge, England. |
| .fi |
| . |
| . |
| .SH REVISION |
| .rs |
| .sp |
| .nf |
| Last updated: 20 October 2014 |
| Copyright (c) 1997-2014 University of Cambridge. |
| .fi |