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linux

Bash random number generation

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)) 

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