Write a script which reads a text file and output the following Count of character, words and lines. File in reverse. Frequency of particular word in the file. Lower case letter in place of upper case letter.

clear
echo "Enter File Name :="
read filename
echo "1. Number Of Character"
echo "2. Number Of Words"
echo "3. Number Of Lines"
echo "4. File In Reverse"
echo "5. Fequency Of Particular Word"
echo "6. Convert Upper Case to Lower Case"
echo "Enter Your Choice :="
read ch
case $ch in
1)
echo "Total Number Of Characters are : " `cat $filename |wc -c`
;;
2)
echo "Total Number Of Words are : " `cat $filename |wc -w`
;;
3)
echo "Total Number Of Lines are : " `cat $filename |wc -l`
;;
4)
revstr=""
while read -n1 ch;
do
revstr="$ch$revstr"
done<$filename
echo "File In Reverse Order : "
echo $revstr
;;
5)
clear
echo "Enter Word To Search : "
read search
filename="veer.txt"
str=`grep -i "$search" $filename`
`echo $str | tr '[A-Z]' '[a-z]'>file.txt`
i=1
count=0
len=`echo $str | wc -c`
echo "length is $len"
search=`echo $search|tr '[A-Z]' '[a-z]'`
echo "SEARCH WORD:$search"
i=1
while read -n1 ch;
do
if [ "$ch" == " " ] || [ $i -eq $len ];then
if [ "$word" == "$search" ];then
count=`expr $count + 1`
fi
word=""
else
word="$word$ch"
fi
i=`expr $i + 1`
done<file.txt
echo "TOTAL NO OF WORDS ARE:$count"
;;
6)
`cat $filename | tr '[A-Z]' '[a-z]'>file.txt`
`cat file.txt > $filename`
echo "ALL CHARACTER CONVERTED TO LOWER CASE"
;;
*)
echo "Enter poper Values "
esac