Shell Programming and Scripting

$s1 = "83 C4 0C 85 C0 75 ??";
$r1 = "83 C4 0C 85 C0 90 90";

$s1 = convert($s1);
$r1 = convert($r1);

sub convert
{
    $i =  shift(@_);
    $i =~ s#(\w\w)#\\x\{\1\}#g;
    $i =~ s#(\?\?)#\.#g;
    $i =~ s#\s##g;
    return $i;
}

open(IN,$file);
binmode(IN);
read(IN,$bin,$filesize);
close(IN);

$bin =~ s/$s1/$r1/;
print $bin;

$s1 = "\x83\xC4\x0C\x85\xC0\x75."; 
$r1 = "\x83\xC4\x0C\x85\xC0\x90\x90";  

open(IN,$file); 
binmode(IN); 
read(IN,$bin,$filesize); 
close(IN);  

$bin =~ s/$s1/$r1/; 
print $bin;