Use this line in your shell:

dd if=/dev/random count=16 bs=1 2> /dev/null | xxd -ps

the output should look like(!) this:

2e3b6eb498ff125a5f1bbb4cbf35c43d

dd copies 16 bytes (count=16) from /dev/random and pipes stdout to xxd which formats the 16 bytes to a hex-string. have fun! =)