Bourne shell: Generating Random Number without Modulo Bias

Command: 

$ cat rand_nobias.sh


Result:

#!/bin/sh

numlines=$1;

randmax=32767;

max=$((($randmax/$numlines)*$numlines)); 

rand=$RANDOM;

until [ $rand -lt $max ] 

do 

rand=$RANDOM;

done 

echo $rand;