write a menu driven shell script to implement the following UNIX commands.

// Before execution the script please create two directories and and insert file names using cat command //

clear
opt=y
while [ $opt=y ]
do
clear
echo "--Menu Driven program--"
echo
echo
echo "1. USAGE OF TAIL COMMAND"
echo
echo "2. USAGE OF CMP COMMAND"
echo
echo "3. USAGE OF UNIQ COMMAND"
echo
echo "4. USAGE OF RM-R COMMAND"
echo
printf "Enter your choice"
read ch
case $ch in
1) clear
   echo "Tail displays line from bottom of the file"
   echo
   printf "Enter no. of lines to display "
   read lin
   echo
   echo last $lin lines of file str1
   echo "--------------------------------"
   echo
    tail -$lin file1 ;;
2) clear
    echo "cmp compare two files and gives the point of difference"
    echo "-----------------------------"
    echo
    echo file1 and file2 are compared
    echo
    cmp file1 file2 ;;
3) clear
   echo
   echo "Uniq eliminate adjacent duplicate lines"
   echo "--------------------------------"
   echo
   echo "unique line of jj"
   echo
   cat file1 | sort | uniq ;;
4) clear
   echo
   echo "rm -r delete the directory along with contents"
   echo "--------------------------------"
   echo
   echo "Enter subdir name"
   read subdir
   mkdir $subdir
   cd $subdir
   touch file1 file2
   echo current dir is `pwd`
   cd ..
   if rm -r $subdir
   then
   echo $subdir removed successfully
   fi ;;
*) clear  
   echo invalid choice ;;
   esac
   echo "Continue?"
   read opt
   done