1 .TH PCRESAMPLE 3 "10 January 2012" "PCRE 8.30"
3 PCRE - Perl-compatible regular expressions
4 .SH "PCRE SAMPLE PROGRAM"
7 A simple, complete demonstration program, to get you started with using PCRE,
8 is supplied in the file \fIpcredemo.c\fP in the PCRE distribution. A listing of
9 this program is given in the
13 documentation. If you do not have a copy of the PCRE distribution, you can save
14 this listing to re-create \fIpcredemo.c\fP.
16 The demonstration program, which uses the original PCRE 8-bit library, compiles
17 the regular expression that is its first argument, and matches it against the
18 subject string in its second argument. No PCRE options are set, and default
19 character tables are used. If matching succeeds, the program outputs the
20 portion of the subject that matched, together with the contents of any captured
23 If the -g option is given on the command line, the program then goes on to
24 check for further matches of the same regular expression in the same subject
25 string. The logic is a little bit tricky because of the possibility of matching
26 an empty string. Comments in the code explain what is going on.
28 If PCRE is installed in the standard include and library directories for your
29 operating system, you should be able to compile the demonstration program using
32 gcc -o pcredemo pcredemo.c -lpcre
34 If PCRE is installed elsewhere, you may need to add additional options to the
35 command line. For example, on a Unix-like system that has PCRE installed in
36 \fI/usr/local\fP, you can compile the demonstration program using a command
40 gcc -o pcredemo -I/usr/local/include pcredemo.c \e
41 -L/usr/local/lib -lpcre
43 In a Windows environment, if you want to statically link the program against a
44 non-dll \fBpcre.a\fP file, you must uncomment the line that defines PCRE_STATIC
45 before including \fBpcre.h\fP, because otherwise the \fBpcre_malloc()\fP and
46 \fBpcre_free()\fP exported functions will be declared
47 \fB__declspec(dllimport)\fP, with unwanted results.
49 Once you have compiled and linked the demonstration program, you can run simple
52 ./pcredemo 'cat|dog' 'the cat sat on the mat'
53 ./pcredemo -g 'cat|dog' 'the dog sat on the cat'
55 Note that there is a much more comprehensive test program, called
59 which supports many more facilities for testing regular expressions and both
64 program is provided as a simple coding example.
70 when PCRE is not installed in the standard library directory, you may get an
71 error like this on some operating systems (e.g. Solaris):
73 ld.so.1: a.out: fatal: libpcre.so.0: open failed: No such file or directory
75 This is caused by the way shared library support works on those systems. You
80 (for example) to the compile command to get round this problem.
88 University Computing Service
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97 Last updated: 10 January 2012
98 Copyright (c) 1997-2012 University of Cambridge.