Bash - A boilerplate for a bash script

bash-script-boilerblate.sh

#!/bin/bash

ACTION=$1

function help(){
    echo -e \
    "Usage:
        1. Export ESSENTIAL_VARIABLE varible with...
        $ export ESSENTIAL_VARIABLE=<KEY_PATH>
        
        2. Encrypt or decrypt your files
            Encrypt all .dec.yaml files
            $ ./secret --encrypt
        
            Decrypt all .enc.yaml files
            $ ./secret --decrypt"
}

if [ -z $ESSENTIAL_VARIABLE ]
then
    echo "Failure. You need to export ESSENTIAL_VARIABLE variable before proceed"
    exit 1
fi

case "$ACTION" in
    "--encrypt")
        echo "Encrypting..."
    ;;
    "--decrypt")
        echo "Decrypting..."
    ;;
    *)
        echo -e "Error: Command $ACTION not found!!! \n"
        help
    ;;
esac