/usr/bin/perl -w

use strict;
use Regexp::Assemble;

my $re = Regexp::Assemble->new->add( qw[ fee fie foe fum ] );

while( <DATA> ) {
    chomp;
    if( /($re)/ ) {
        print "Here be giants: $1\n";
    }
}

print $re->as_string, "\n";

__DATA__
feedbag
airfield
foe
fumble
blorp