Prime Number

Algorithm
Step 1 : Start
Step 2 : Read the value of n
Step 3 : Initialize i to 2
Step 4 : If n is divisible by i then
Print “Not Prime” and Stop
Step 5 : Increment i by 1
Step 6 : Repeat steps 4 and 5 until i 􀁤 n/2
Step 7 : Print "Prime"
Step 8 : Stop

Program (prime.sh)
# Prime number using exit
echo -n "Enter the number : "
read n
i=2
m=`expr $n / 2`

until [ $i -gt $m ]
do
q=`expr $n % $i`
if [ $q -eq 0 ]
then
echo "Not a Prime number"
exit
fi
i=`expr $i + 1`
done
echo "Prime number"

Output
[vijai@localhost loops]$ sh prime.sh
Enter the number : 17
Prime number