echo "Enter File Name"
read fname
echo "
   1) Count character,words and lines
   2) Display content in reverse
   3) Count particular word
   4) Convert upper to lower
   5) Convert lower to upper

echo "Enter Choice: "
read ch
case $ch in
1)
        echo Total Character:
        wc -c $fname
        echo Total Words:
        wc -w $fname
        echo Total Lines:
        wc -l $fname
        ;;
2)
        rev $fname
        ;;
3)
        echo Enter word to find
       read w
        echo Frequency:
        grep  -c "$w" $fname
        ;;
4)
        echo Enter Text
        read text
        echo $text | tr "[A-Z]" "[a-z]"
        ;;
5)
        echo Enter Text
        read text
        echo $text | tr "[a-z]" "[A-Z]"
        ;;
*)
        echo Wrong Choice
        ;;
esac


output:

$ sh fileOp.sh
Enter File Name
testData.txt

     1) Count character,words and lines
     2) Display content in reverse
     3) Count particular word
     4) Convert upper to lower
     5) Convert lower to upper
  
Enter Choice:
1
Total Character:
     36 testData.txt
Total Words:
      5 testData.txt
Total Lines:
      2 testData.txt

Enter Choice:
2
etis
.etis moc.elpmaxe-xatnys si tI

Enter Choice:
3
Enter word to find site
Frequency:
2

Enter Choice:
4
Enter Text
NONE
none

Enter Choice:
5
Enter Text
null
NULL