tcsh random number from /dev/random and /dev/urandom

Question

I am trying to figure out how to generate random from using /dev/random and /dev/urandom in tcsh. After I do head -c 1 /dev/random, I get a random byte. How do I turn this byte into actual number?

Answer 1

$ head -c 1 /dev/urandom | od -t u1 | cut -c9-

That will give you a random integer between 0 and 255 inclusive.

Answer 2

My apologies for redirecting your question in advance but despite not using it for your script, bash can be handy here if you have it:

bash -c 'echo $RANDOM'

will return a random integer. You can use therefore:

RANDOM=`bash -c 'echo $RANDOM'`

from within a tcsh script to achieve the same variable.

Answer 3

this works in csh OS X -> generate 1 number between 2 and 10 and assign it to random:

set random = `jot -r 1 2 10`
echo "random number $random was generated"