PHP Unpack a single byte from a binary string

Question

I have a raw string of bytes $b coming from

$b=sha1($k,true);

I need to know the value of $b[$ix]. The only way I've found is

$arr=unpack('Cw',$b[$ix]);
$value=$arr["w"];

But for such elemental operation it seems too much overload.

Is there a more straight way to access the bytes in a raw string?

Answer 1

Ascii value:

$b=sha1($k,true);
echo ord($b[$ix]);