[switch statement] This is how to do switch statements in bash script #bash

switch.sh

#!/bin/bash

function main() {
	case $1 in
    	a)
            echo "You typed in 'a'!"
            ;;
            
        b | 'd')
            # This fallthrough operator is introduced in Bash v4.
            # Otherwise, you need to use if statements.
            echo "Fall through statement"
            ;&
            
        c)
            echo "You typed in 'c'?"
            ;;
        	
        *)
            # This is the default case
            echo "Usage: $0 {a|b|c|d}"
            exit 1
    esac
}

main "$@"