As noted by MeowChow the devil is in the details:

#!/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;
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This will get groups of chars that match A-Za-z0-9 only and then prints out the sorted hash. I have added the $! var in the die which contains Perl's error message and sort the keys. I have added us strict, -w and the my declarations. Also note that printf was a typo. I meant print.

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print