read FILE, $myinput, 12;
my($var1, $var2, $var3, $var4) = unpack('A3A3A3A3', $myinput);
$var1 = unpack ('N', "\x00" . $var1);
$var2 = unpack ('N', "\x00" . $var2);
$var3 = unpack ('N', "\x00" . $var3);
$var4 = unpack ('N', "\x00" . $var4);
print "$var1\n";
print "$var2\n";
print "$var3\n";
print "$var4\n";

##</code><code>##

Use of uninitialized value in concatenation (.) or string at myscript.pl line 20.