[SOLVED] How to get a random string of 32 hexadecimal digits through command line?

Issue

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?

Solution

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.

Answered By - Renaud Pacalet

Answer Checked By - David Goodson (WPSolving Volunteer)