How to make a statement that checks if something is divisible by something else without a remainder (BASH)

Solution 1:

You can use a simpler syntax in Bash than some of the others shown here:

#!/bin/bash
read -p "Enter a number " number    # read can output the prompt for you.
if (( $number % 5 == 0 ))           # no need for brackets
then
    echo "Your number is divisible by 5"
else
    echo "Your number is not divisible by 5"
fi

Solution 2:

No bc needed as long as it's integer math (you'll need bc for floating point though): In bash, the (( )) operator works like expr.

As others have pointed out the operation you want is modulo (%).

#!/bin/bash  

echo "Enter a number"
read number

if [ $(( $number % 5 )) -eq 0 ] ; then
   echo "Your number is divisible by 5"
else
   echo "Your number is not divisible by 5"
fi