Check given string is palindrome or not using Linux shell script in Ubuntu
Palindrome :The characters read the same backward as forward. Some examples of palindromic words are redivider, deified, civic, radar, level, rotor, kayak, reviver, racecar, madam, and refer.
Method 1
echo Enter Number
read value
reverse=""
len=`echo $value | wc -c`
len=`expr $len - 1`
while test $len -gt 0
do
reversetemp=`expr $value | cut -c $len`
reverse=$reverse$reversetemp
len=`expr $len - 1`
done
if [ $reverse -eq $value ]
then
echo It is palindrome
else
echo It is not palindrome
fi
---------------------------------------------------------------------
Method 2
echo "Enter a String:-"
read str
len=`echo $str | wc -c`
len=`expr $len - 1`
i=1
j=`expr $len / 2`
while test $i -le $j
do
k=`echo $str | cut -c $i`
l=`echo $str | cut -c $len`
if test $k != $l
then
echo "String is not palindrome"
exit
fi
i=`expr $i + 1`
len=`expr $len - 1`
done
echo "String is palindrome"
read str
len=`echo $str | wc -c`
len=`expr $len - 1`
i=1
j=`expr $len / 2`
while test $i -le $j
do
k=`echo $str | cut -c $i`
l=`echo $str | cut -c $len`
if test $k != $l
then
echo "String is not palindrome"
exit
fi
i=`expr $i + 1`
len=`expr $len - 1`
done
echo "String is palindrome"