Bash program to check if the Number is a Prime or not

Given a number, the task is to find whether the given number is prime or not using Bash Scripting.

**Examples:**

Input:N = 43Output:PrimeInput:N = 35Output:Not Prime

**Prime Numbers:**

A prime number is a whole number greater than **1**, which is only divisible by 1 and itself. First few prime numbers are : 2 3 5 7 11 13 17 19 23 …..

**Approach:**

We run a loop from 2 to number/2 and check if there is any factor of the number. If we find any factor then the number is composite otherwise prime.

**Implementation:**

`#storing the number to be checked` `number=43` `i=2` ` ` `#flag variable` `f=0` ` ` `#running a loop from 2 to number/2` `while` `test` `$i -` `le` ``` `expr` `$number / 2` ` `do` ` ` `#checking if i is factor of number` `if` `test` ``` `expr` `$number % $i` -` `eq` `0 ` `then` `f=1` `fi` ` ` `#increment the loop variable` `i=`` `expr` `$i + 1`` `done` `if` `test` `$f -` `eq` `1 ` `then` `echo` `"Not Prime"` `else` `echo` `"Prime"` `fi` |

**Output:**

Prime