I'd like to put together a command that will print out a string of 32 hexadecimal digits. I've got a Python script that works:
python -c 'import random ; print "".join(map(lambda t: format(t, "02X"), [random.randrange(256) for x in range(16)]))'
This generates output like:
6EF6B30F9E557F948C402C89002C7C8A
Which is what I need.
On a Mac, I can even do this:
uuidgen | tr -d '-'
However, I don't have access to the more sophisticated scripting languages ruby and python, and I won't be on a Mac (so no uuidgen). I need to stick with more bash'ish tools like sed, awk, /dev/random because I'm on a limited platform. Is there a way to do this?
If you have hexdump then:
hexdump -vn16 -e'4/4 "%08X" 1 "\n"' /dev/urandom
should do the job.
Explanation:
-v to print all data (by default hexdump replaces repetition by *).-n16 to consume 16 bytes of input (32 hex digits = 16 bytes).4/4 "%08X" to iterate four times, consume 4 bytes per iteration and print the corresponding 32 bits value as 8 hex digits, with leading zeros, if needed.1 "\n" to end with a single newline.