octal_decoder.pl

#!/usr/bin/env perl
use warnings;

while (read STDIN, my $octets, 3) {
    # converts the 3 octal numbers to equivalent decimal number and then said
    # decimal number into its hex equivalent.
    $hex_fmt = sprintf "%02x", oct($octets);
    # print out hex in raw hex byte values.
    print pack("H*", $hex_fmt);
}

UPDATE
0xa0 is newline in hex. So just use that when appropriate.