exp.pl

#!/opt/local/bin/perl

use strict;
use warnings;

use Test::More tests => 2;

my $hoge1 = 'FF330';
my $expect = "\x{FF330}";

my @codes = (
    sub {eval '"\x{' . $_[0] . '}"'},
    sub {chr(hex($_[0]))},
);

foreach my $code (@codes) {
    my $hoge2 = $code->($hoge1);
    is($hoge2, $expect);
}

Makefile

test:
	@prove exp.pl