how i replicate perl's empty functionality c#?

i am perplexing reconstruct perl book c# nonetheless have problem formulating checksum value aim component needs.

in perl checksum distributed controlling unpack function:

while (<package>) {
    $checksum += unpack("%32c*", $_);
}
$checksum %= 32767;
close(package);

where package .tar record quarrel stream

i need replicate c# nonetheless can't means replicating unpack function.

all assistance appreciated!

(i know there many improved checksum calculations accessible nonetheless can't change aim component can't change calculation)

code1