Kind of a terribly ineffecient way of going about things given there is already a country code conversion class that comes with perl. Locale::Country already has this functionality, but in addition, it also supplies reverse functionality (country name -> code mapping), as well as arrays of all the codes.

Here's an example app I whipped up in a couple minutes:
Code:
#!/usr/bin/perl
use strict;
use Locale::Country;
my ($code, $country);
$code = $ARGV[0];
if (length($code) < 1) {
  print "Please supply a country code.\n";
  exit;
}
chomp($code);
$country = code2country($code);
if (defined $country) {
  print "Code '$code' is $country\n";
} else {
  print "'$code' is not a valid country code!\n";
}