Shell program to check Whether a given string is a Palindrome or Not

#!/bin/bash

read -p "Enter string>> " str1
str2=`echo $str1 | rev`

if [ $str1 == $str2 ]
then
	echo "Palindrome"
else
	echo "Not a palindrome"
fi


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Additional Info:
We can use 
lowerstr=$(echo $s | tr "[:upper:]" "[:lower:]") 
to covert given string to lowercase
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