anagram

#!/usr/bin/env perl

use strict;
use warnings;
use 5.014;

my $letters = lc sort_letters(shift);

my $dict = shift // '/usr/share/dict/words';

open my $words_in, '<', $dict;
while (<$words_in>) {
    say if lc(sort_letters($_)) eq $letters;
}

sub sort_letters {
    my $letters = shift;
    return join '', sort split //, $letters;
}