$s = '0123456789'; printf "%x\n", unpack 'Q', pack 'P', $s while $s =~ /\G./g; # 55fd180fcc60 # 55fd18107f30 # 55fd18107ed0 # 55fd180e6700 # 55fd180fcc60 # 55fd18107f30 # 55fd18107ed0 # 55fd180e6700 # 55fd180fcc60 # 55fd18107f30