Nah, your problem is not in the seek, but it is here: 
@list = split('', $read);

foreach (@list) {
    $key = sprintf("%s%2.2x", $key, $_);
    print $key, "\n";
}

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In Perl, characters are not numbers, but single character strings. Instead of @list = split('', $read); you can do 
@list = unpack 'C*', $read;

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and proceed as you did; or rewrite the loop, for example like this: 
@list = split('', $read); 
$key = join "", map { sprintf "%2.2x", ord } @list;

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Or rewrite both, to a blend of the two: 
@list = unpack 'C*', $read; 
$key = join "", map { sprintf "%2.2x", $_ } @list;

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In reply to Re^3: Translating ANSI C to Perl by bart
in thread Translating ANSI C to Perl by otaviof

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