Bash script template

bash_template.sh

#!/bin/bash -e


usage="USAGE: $0 action [marsnat version]
ACTIONS:
   start - starts the docker instance [takes optional masnat version]
   stop  - stops the docker instance
   restart - restarts the docker instance [takes optional marsnat version]
   bash  - puts you in the docker environment's bash prompt
"

ACTION=""
VERSION=""

while getopts "hs" flag; do
    case $flag in
        h)
            echo "$usage"
            exit 0
            ;;
        s)
            SILENT=1
            ;;
    esac
done

echo "$OPTIND"

for (( x=1; x<$OPTIND; x++ )); do shift "$((OPTIND-1))"; done

ACTION="$1"
VERSION="$2"

if [ "$ACTION" == "" ]; then
    echo "$usage"
    exit 1
fi

echo "action: $ACTION .... version: $VERSION"