Bash: Scripting - part 4- while getopts abcd opt

#!/bin/bash
#
while getopts abcdh opt
do
        case "$opt" in
                a)
                        DIR=/etc/
                        echo "Option: a"
                        echo "Break out of case structure: option a"
                        sleep 1
                        echo "..." ;;
                b)
                        DIR=/var/
                        echo "Option: b"
                        echo "Break out of case structure: option b"
                        sleep 1
                        echo "..." ;;
                c)
                        DIR=/proc
                        echo "Option: c"
                        echo "Break out of case structure: option c"
                        sleep 1
                        echo "..." ;;
                d)
                        DIR=~/
                        echo "Option: d"
                        echo "Break out of case structure: option d"
                        sleep 1
                        echo "..." ;;
                h)
                        echo "-a: List /etc/"
                        echo "-b: List /var/"
                        echo "-c: List /proc/"
                        echo "-d: List Current User's Home Directory"
                        exit 0 ;;
                *)
                        echo "Select valid option"
                        echo
                        echo "For menu, select option "h""
                        exit 0 ;;
        esac
done

echo "Script continues to end"
echo
echo "Option $@ selected"
echo
cd $DIR
echo "Directory: $PWD"
sleep 3
ls -l | less











Results:

$ ./getopts11b.sh -h
-a: List /etc/
-b: List /var/
-c: List /proc/
-d: List Current User's Home Directory







$ ./getopts11b.sh -w
./getopts11b.sh: illegal option -- w
Select valid option
For menu, select option h