trunk/doc/pcresample.3

.TH PCRE 3
.SH NAME
PCRE - Perl-compatible regular expressions
.SH "PCRE SAMPLE PROGRAM"
.rs
.sp
A simple, complete demonstration program, to get you started with using PCRE,
is supplied in the file \fIpcredemo.c\fP in the PCRE distribution.
.P
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.
.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 PCRE is installed in the standard include and library directories for your
system, you should be able to compile the demonstration program using this
command:
.sp
  gcc -o pcredemo pcredemo.c -lpcre
.sp
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
\fI/usr/local\fP, you can compile the demonstration program using a command
like this:
.sp
.\" JOINSH
  gcc -o pcredemo -I/usr/local/include pcredemo.c \e
      -L/usr/local/lib -lpcre
.sp
Once you have compiled the demonstration program, you can run simple tests like
this:
.sp
  ./pcredemo 'cat|dog' 'the cat sat on the mat'
  ./pcredemo -g 'cat|dog' 'the dog sat on the cat'
.sp
Note that there is a much more comprehensive test program, called
.\" HREF
\fBpcretest\fP,
.\"
which supports many more facilities for testing regular expressions and the
PCRE library. The \fBpcredemo\fP program is provided as a simple coding
example.
.P
On some operating systems (e.g. Solaris), when PCRE is not installed in the
standard library directory, you may get an error like this when you try to run
\fBpcredemo\fP:
.sp
  ld.so.1: a.out: fatal: libpcre.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.
.P
.in 0
Last updated: 09 September 2004
.br
Copyright (c) 1997-2004 University of Cambridge.
1	.TH PCRE 3
2	.SH NAME
3	PCRE - Perl-compatible regular expressions
4	.SH "PCRE SAMPLE PROGRAM"
5	.rs
6	.sp
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.
9	.P
10	The program compiles the regular expression that is its first argument, and
11	matches it against the subject string in its second argument. No PCRE options
12	are set, and default character tables are used. If matching succeeds, the
13	program outputs the portion of the subject that matched, together with the
14	contents of any captured substrings.
15	.P
16	If the -g option is given on the command line, the program then goes on to
17	check for further matches of the same regular expression in the same subject
18	string. The logic is a little bit tricky because of the possibility of matching
19	an empty string. Comments in the code explain what is going on.
20	.P
21	If PCRE is installed in the standard include and library directories for your
22	system, you should be able to compile the demonstration program using this
23	command:
24	.sp
25	gcc -o pcredemo pcredemo.c -lpcre
26	.sp
27	If PCRE is installed elsewhere, you may need to add additional options to the
28	command line. For example, on a Unix-like system that has PCRE installed in
29	\fI/usr/local\fP, you can compile the demonstration program using a command
30	like this:
31	.sp
32	.\" JOINSH
33	gcc -o pcredemo -I/usr/local/include pcredemo.c \e
34	-L/usr/local/lib -lpcre
35	.sp
36	Once you have compiled the demonstration program, you can run simple tests like
37	this:
38	.sp
39	./pcredemo 'cat\|dog' 'the cat sat on the mat'
40	./pcredemo -g 'cat\|dog' 'the dog sat on the cat'
41	.sp
42	Note that there is a much more comprehensive test program, called
43	.\" HREF
44	\fBpcretest\fP,
45	.\"
46	which supports many more facilities for testing regular expressions and the
47	PCRE library. The \fBpcredemo\fP program is provided as a simple coding
48	example.
49	.P
50	On some operating systems (e.g. Solaris), when PCRE is not installed in the
51	standard library directory, you may get an error like this when you try to run
52	\fBpcredemo\fP:
53	.sp
54	ld.so.1: a.out: fatal: libpcre.so.0: open failed: No such file or directory
55	.sp
56	This is caused by the way shared library support works on those systems. You
57	need to add
58	.sp
59	-R/usr/local/lib
60	.sp
61	(for example) to the compile command to get round this problem.
62	.P
63	.in 0
64	Last updated: 09 September 2004
65	.br
66	Copyright (c) 1997-2004 University of Cambridge.