#!/usr/bin/perl -w
use strict;

my %codes;

open (FILE, "file.txt") || die "Can't open data file, perl says $!";

while (<FILE>) {
   my @array_codes = /[A-Za-z0-9]+/g;
   foreach my $code_key (@array_codes) {
       $codes{$code_key}++;
   } 
}

print "$_\t$codes{$_}\n" for sort keys %codes;