#!/usr/bin/perl
use strict;
use warnings;
my $sw = lc shift
   or die "search word required\n";

my $count = 0;
open WORDS, "/usr/share/dict/words"
     or die "can't open words file\n";
while (<WORDS>) {
    chomp;
    printf "%3d %s\n", ++$count, $_ if index($sw,lc $_) > -1;
}
close WORDS;