my $crc = crc64(\$output); ## Add crc check to output data sub crc64 ## Add crc check to output data { my $data = shift; my $crc = ""; my $len = length($$data); my $pos = 0; while ( $pos < $len ) { $crc = $crc ^ ( substr($$data,$pos,8) ); $pos += 8; } return ( $crc ); }