Bash Snippets

Fail if no arguments given

if ! [ "$1" ]; then
    echo "No arguments given! Exiting."
    exit 1
fi

oder:

if [ -z "$1" ] || [ -n "$2" ];  then
        echo "Script takes password as exactly one argument, exiting."
        exit 1
fi

Fail if Umgebungsvariable nicht gesetzt

check_env(){   [ -z "${!1}" ] && echo "$1 not defined" && exit 1; }
check_env blablub