Tristan Matthews | 0461646 | 2013-11-14 16:09:34 -0500 | [diff] [blame] | 1 | .TH PCRESAMPLE 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. A listing of |
| 9 | this program is given in the |
| 10 | .\" HREF |
| 11 | \fBpcredemo\fP |
| 12 | .\" |
| 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. |
| 15 | .P |
| 16 | The program compiles the regular expression that is its first argument, and |
| 17 | matches it against the subject string in its second argument. No PCRE options |
| 18 | are set, and default character tables are used. If matching succeeds, the |
| 19 | program outputs the portion of the subject that matched, together with the |
| 20 | contents of any captured substrings. |
| 21 | .P |
| 22 | If the -g option is given on the command line, the program then goes on to |
| 23 | check for further matches of the same regular expression in the same subject |
| 24 | string. The logic is a little bit tricky because of the possibility of matching |
| 25 | an empty string. Comments in the code explain what is going on. |
| 26 | .P |
| 27 | If PCRE is installed in the standard include and library directories for your |
| 28 | operating system, you should be able to compile the demonstration program using |
| 29 | this command: |
| 30 | .sp |
| 31 | gcc -o pcredemo pcredemo.c -lpcre |
| 32 | .sp |
| 33 | If PCRE is installed elsewhere, you may need to add additional options to the |
| 34 | command line. For example, on a Unix-like system that has PCRE installed in |
| 35 | \fI/usr/local\fP, you can compile the demonstration program using a command |
| 36 | like this: |
| 37 | .sp |
| 38 | .\" JOINSH |
| 39 | gcc -o pcredemo -I/usr/local/include pcredemo.c \e |
| 40 | -L/usr/local/lib -lpcre |
| 41 | .sp |
| 42 | In a Windows environment, if you want to statically link the program against a |
| 43 | non-dll \fBpcre.a\fP file, you must uncomment the line that defines PCRE_STATIC |
| 44 | before including \fBpcre.h\fP, because otherwise the \fBpcre_malloc()\fP and |
| 45 | \fBpcre_free()\fP exported functions will be declared |
| 46 | \fB__declspec(dllimport)\fP, with unwanted results. |
| 47 | .P |
| 48 | Once you have compiled and linked the demonstration program, you can run simple |
| 49 | tests like this: |
| 50 | .sp |
| 51 | ./pcredemo 'cat|dog' 'the cat sat on the mat' |
| 52 | ./pcredemo -g 'cat|dog' 'the dog sat on the cat' |
| 53 | .sp |
| 54 | Note that there is a much more comprehensive test program, called |
| 55 | .\" HREF |
| 56 | \fBpcretest\fP, |
| 57 | .\" |
| 58 | which supports many more facilities for testing regular expressions and the |
| 59 | PCRE library. The |
| 60 | .\" HREF |
| 61 | \fBpcredemo\fP |
| 62 | .\" |
| 63 | program is provided as a simple coding example. |
| 64 | .P |
| 65 | If you try to run |
| 66 | .\" HREF |
| 67 | \fBpcredemo\fP |
| 68 | .\" |
| 69 | when PCRE is not installed in the standard library directory, you may get an |
| 70 | error like this on some operating systems (e.g. Solaris): |
| 71 | .sp |
| 72 | ld.so.1: a.out: fatal: libpcre.so.0: open failed: No such file or directory |
| 73 | .sp |
| 74 | This is caused by the way shared library support works on those systems. You |
| 75 | need to add |
| 76 | .sp |
| 77 | -R/usr/local/lib |
| 78 | .sp |
| 79 | (for example) to the compile command to get round this problem. |
| 80 | . |
| 81 | . |
| 82 | .SH AUTHOR |
| 83 | .rs |
| 84 | .sp |
| 85 | .nf |
| 86 | Philip Hazel |
| 87 | University Computing Service |
| 88 | Cambridge CB2 3QH, England. |
| 89 | .fi |
| 90 | . |
| 91 | . |
| 92 | .SH REVISION |
| 93 | .rs |
| 94 | .sp |
| 95 | .nf |
| 96 | Last updated: 17 November 2010 |
| 97 | Copyright (c) 1997-2010 University of Cambridge. |
| 98 | .fi |