Perl Find Words

From Regex Regular Expression Encyclopedia

You can use this recipe for finding single words in a block of text. The expression will find only complete words surrounded by spaces.

[edit] code

#!/usr/bin/perl -w
use strict;
 
open( FILE, $ARGV[0] ) || die "Cannot open file!";
 
my $i = 0;
 
while ( <FILE> )
{
    $i++;
    next unless /\bword\b/;
    print "Found word at line $i\n";
}
 
close( FILE );

[edit] How It Works

A special character class in Perl, \b, allows you to easily search for whole words. This is an advantage because without doing a whole bunch of extra work you can make sure that a search for word, for example, doesn't yield unexpected matches such as sword.

You can easily break the regular expression shown here into the following: