Linux Script to generate random numbers in a given range

Generating random numbers is common recruitment in number of scripts. bash by default gives a variable $RANDOM which when accessed gives a random number between 0 and 32767.

$ echo $RANDOM 4945 $ echo $RANDOM 15819

There might be situations where we might need random numbers between a range of smaller numbers or between zero and a smaller number than 32767. Here is a script which can be used to generate random numbers between any range of numbers.

It takes as input the lower limit and the upper limit of the random numbers required and then generates the required number of random numbers with in the range.

random_numbers

#!/bin/bash echo "Enter range of numbers between which random numbers is required " echo "lower limit=" read lower echo "upper limit=" read upper echo "How many random numbers do you need" read num diff=$((upper-lower)) echo "Random numbers are " for((i=0;i<num;i++)) do temp=$(($RANDOM % diff)) rand=$((temp + lower)) echo $rand done

save the script as random_numbers.sh,give it execute permissions. chmod 777 random_numbers.sh

Now execute the script to generate the random numbers

$./random_numbers Enter range of numbers between which random numbers is required lower limit= 20 upper limit= 100 How many random numbers do you need 5 Random numbers are 24 37 20 95 62

Thus we can see we can generate any number of random numbers with in any given range, using the script.