Pcre

Pcregrep: a grep with Perl-compatible regular expressions

The PCRE library is a set of functions that implement regular expression pattern matching using the same syntax and semantics as Perl 5. PCRE has its own native API, as well as a set of wrapper functions that correspond to the POSIX regular expression API. The PCRE library is free, even for building commercial software. Development http://gnuwin32.sourceforge.net/packages/pcre.htm pcregrep

a grep with Perl-compatible regular expressions.

pcregrep searches files for character patterns, in the same way as other grep commands do, but it uses the PCRE regular expression library to support patterns that are compatible with the regular expressions of Perl 5. See pcrepattern(3) for a full description of syntax and semantics of the regular expressions that PCRE supports. Patterns, whether supplied on the command line or in a separate file, are given without delimiters. For exam- ple: pcregrep Thursday /etc/motd If you attempt to use delimiters (for example, by sur- rounding a pattern with slashes, as is common in Perl scripts), they are interpreted as part of the pattern. Quotes can of course be used on the command line because they are interpreted by the shell, and indeed they are required if a pattern contains white space or shell metacharacters. The first argument that follows any option settings is treated as the single pattern to be matched when neither -e nor -f is present. Conversely, when one or both of these options are used to specify patterns, all argu- ments are treated as path names. At least one of -e, -f, or an argument pattern must be provided. If no files are specified, pcregrep reads the standard input. The standard input can also be referenced by a name consisting of a single hyphen. For example: pcregrep some-pattern /file1 - /file3 By default, each line that matches the pattern is copied to the standard output, and if there is more than one file, the file name is output at the start of each line. However, there are options that can change how pcregrep behaves. In particular, the -M option makes it possible to search for patterns that span line boundaries. What defines a line boundary is controlled by the -N (--new- line) option. Patterns are limited to 8K or BUFSIZ characters, whichever is the greater. BUFSIZ is defined in <stdio.h>. If the LC_ALL or LC_CTYPE environment variable is set, pcregrep uses the value to set a locale when calling the PCRE library. The --locale option can be used to over- ride this. Pcretest

a program for testing Perl-compatible regular expressions

pcretest was written as a test program for the PCRE regular expression library itself, but it can also be used for experimenting with regular expressions. This document describes the features of the test program; for details of the regular expressions themselves, see the pcrepattern documentation. For details of the PCRE library function calls and their options, see the pcreapi documentation.