Run the command 'openssl rand -hex 16' to generate a random 16-character hexadecimal string, store it in the variable 'u', and then echo the value of 'u' followed by the command 'date +%s.%N' to get the current timestamp in seconds and nanoseconds.
curl -L 'u=`openssl rand -hex 16`;echo $u' | xargs date +%s.%N