Historically I’ve used $RANDOM as a random number source in bash — a bit like :
RAND=$(( $RANDOM % 10 ))
when I’ve needed a random number out of 0,1,2,3,4,5,6,7,8 and 9
one problem with this is that $RANDOM itself is populated between 0 and 32767 by the shell – so it’s not going to give totally even distribution.
Finally, I discovered ‘shuf’ — usage like :
shuf -i 1-100 -n 1
-i RangeFrom-RangeTo
-n how many
So –
RAND=$(( shuf -i 1-10 -n 1))