use strict;
use warnings;

open FILE, ">output.dat";
my $data = "\xff\x01\x67";
print FILE unpack("H*",$data);
close FILE;


##</code><code>##

use strict;
use warnings;

open FO, ">test.out";
my $data = "\xff\x01\x67";
print FO $data,"\n";
close FO;

open FI, "<test.out";
while ( <FI> ) {
    chomp;
    print unpack("H*",$_), "\n";
}
close FI;