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53 lines
1.9 KiB
Groff
53 lines
1.9 KiB
Groff
.TH PCRE 3
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.SH NAME
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PCRE - Perl-compatible regular expressions
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.SH PCRE SAMPLE PROGRAM
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.rs
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.sp
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A simple, complete demonstration program, to get you started with using PCRE,
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is supplied in the file \fIpcredemo.c\fR in the PCRE distribution.
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The program compiles the regular expression that is its first argument, and
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matches it against the subject string in its second argument. No PCRE options
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are set, and default character tables are used. If matching succeeds, the
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program outputs the portion of the subject that matched, together with the
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contents of any captured substrings.
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If the -g option is given on the command line, the program then goes on to
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check for further matches of the same regular expression in the same subject
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string. The logic is a little bit tricky because of the possibility of matching
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an empty string. Comments in the code explain what is going on.
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On a Unix system that has PCRE installed in \fI/usr/local\fR, you can compile
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the demonstration program using a command like this:
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gcc -o pcredemo pcredemo.c -I/usr/local/include \\
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-L/usr/local/lib -lpcre
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Then you can run simple tests like this:
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./pcredemo 'cat|dog' 'the cat sat on the mat'
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./pcredemo -g 'cat|dog' 'the dog sat on the cat'
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Note that there is a much more comprehensive test program, called
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\fBpcretest\fR, which supports many more facilities for testing regular
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expressions and the PCRE library. The \fBpcredemo\fR program is provided as a
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simple coding example.
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On some operating systems (e.g. Solaris) you may get an error like this when
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you try to run \fBpcredemo\fR:
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ld.so.1: a.out: fatal: libpcre.so.0: open failed: No such file or directory
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This is caused by the way shared library support works on those systems. You
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need to add
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-R/usr/local/lib
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to the compile command to get round this problem.
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.in 0
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Last updated: 28 January 2003
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.br
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Copyright (c) 1997-2003 University of Cambridge.
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