Your code is checking each line in the file with the input string. For that another way to do is, get all permutations from the input string, then compare each line in the file with all the permutations you got.

To get all permutations, you can use Math::Combinatorics. Get all permutations into an array and you can use grep to compare.

I have updated your code and is working fine for me. The code I updated is

#!/usr/bin/perl
use strict;
use warnings;
use Math::Combinatorics; #to get all combinations

my $input = <STDIN>;
my @inputarray = split('',$input);

my $file = 'wordlist.txt';
open(INFO, $file);
my @lines = <INFO>;
close(INFO);

my @permutations= map { join "", @$_ } permute(@inputarray );# Get all
+ permutations of input string

my %dup;
@dup{@permutations}= ();
my @tacobell= grep { exists $dup{$_} } @lines; # Check if any of the c
+ombinations exists in file

print join ("\n",@tacobell);

exit();
[download]

Update: Fixed typo.

Cheers !

--VC