perl -le 'print unpack("N", pack("H8",substr("0"x8 . "641e0100",-8)));
perl -le 'print unpack("N", pack("H8",substr("0"x8 . "641e0100",-8)));'
perl -le 'print unpack("N", pack("H8",substr("0"x8 . "641e01",-8)));'
perl -e "print hex('641e0100')"
perl -e "print hex('641e01')"
perl -e "print unpack('V',pack 'V', hex('641e01'))"
perl -e "print unpack('V', '0x641e01')"
perl -e "print unpack('N', '0x641e01')"
perl -e "print unpack('n', '0x641e01')"
perl -e "print unpack('h', '0x641e0100')"
perl -e "print unpack('h*', '0x641e0100')"
perl -e "print pack('h*', '0x641e0100')"