nested case statements in linux

[lifeisgreat20009]

the simple script below is not working after i implemented a case statement within another..plz tell me where the problem lies...

My script is as follows

#!/bin/bash
# A menu driven Shell script which has following options
# Contents of /etc/passwd
# List of users currently logged
# Simple Calculator
# Exit
# As per option do the job
while :
do
 clear
 echo "   M A I N - M E N U"
 echo "1. Contents of /etc/passwd"
 echo "2. List of users currently logged"
 echo "3. Simple Calculator"
 echo "4. Exit"
 echo -n "Please enter option [1 - 4]"
 read opt
 case $opt in
  1) echo "************ Conents of /etc/passwd *************";
     more /etc/passwd;;
  2) echo "*********** List of users currently logged";
     who | more;;
  3) a=$1
op="$2"
b=$3
 
if [ $# -lt 3 ]
then
    echo "$0 num1  opr num2"
    echo "opr can be +, -, / , x"
    exit 1
fi
 
case "$op" in
    +) echo $(( $a + $b ));;
    -) echo $(( $a - $b ));;
    /) echo $(( $a / $b ));;
    x) echo $(( $a * $b ));;
    *) echo "Error ";;
esac
     echo "Press [enter] key to continue. . .";
     read enterKey;;
  4) echo "Bye $USER";
     exit 1;;
  *) echo "$opt is an invaild option. Please select option between 1-4 only";
     echo "Press [enter] key to continue. . .";
     read enterKey;;
esac
done
 

[numberwhun]

@lifeisgreat20009
I think you are a bit confused in all that you are trying to do with this script. First, I have never seen anyone try to nest case statements. Even if they did try though, wouldn't it make sense to nest it inside of one of the options from the previous menu?

Also, for #3, your simple calculator, it errors out because it expects input, but from where? Also, #2 doesn't even print anything and if it does, its so very fast it cannot be seen. Making the program wait till a key is pressed might be a good idea.

Regards,

Jeff

[kaarthikeyapreyan]

Hey where is the error, the script runs fine for me
I removed the clear to visualize the output of #1 and #2
and for #3 I ran the program the way it wanted it to be run

./case.sh 1 + 5

and i don get an error ?