#! /usr/bin/perl use 5.010; use strict; use warnings; use File::Map qw/map_file advise/; die "Not enough arguments given\n" if @ARGV < 2; my $regex = shift; $regex = qr/$regex/; for my $filename (@ARGV) { map_file my($map), $filename; advise $map, 'sequential'; my $match = $map =~ $regex ? "" : "n't"; say "File '$filename' does$match match"; }