Bash program to check if the Number is a Palindrome

Given a number num, find whether the given number is palindrome or not using Bash Scripting. Examples:

Input : 
666
Output :
Number is palindrome

Input :
45667
Output :
Number is NOT palindrome

Approach To find the given number is palindrome just check if the number is same from beginning and the end. Reverse the number to check if the number reversed is equal to the original number or not, if yes than echo Number is palindrome otherwise echo Number is NOT palindrome .

BASH

num=545

# Storing the remainder
s=0

# Store number in reverse
# order
rev=""

# Store original number
# in another variable
temp=$num

while [ $num -gt 0 ]
do
    # Get Remainder
    s=$(( $num % 10 ))

    # Get next digit
    num=$(( $num / 10 ))

    # Store previous number and
    # current digit in reverse
    rev=$( echo ${rev}${s} )
done

if [ $temp -eq $rev ];
then
    echo "Number is palindrome"
else
    echo "Number is NOT palindrome"
fi

Output:

Number is palindrome

Time complexity: O(logn) as while loop would run for logn times

Auxiliary space: O(1)