function sqlplus {
	local USER=SYS
	local PASS=<default_password>
	local NET
	local HOST=localhost
	local PORT
	local SID=<default_sid>
	local ROLE=SYSDBA
	local EDITION
	local DEFAULT_DOCKER_IMAGE=oracle/database:12.2.0.1-ee
	local DOCKER_IMAGE
	local DOCKER_CONTAINER

	# read the options
	local TEMP=`getopt -o 'u:p:n:h:P:s:r::e:d:D:' --long 'user:,pass:,net:,host:,port:,sid:,role::,edition:,docker-run:,docker-exec:' -n 'sqlplus' -- "$@"`
	eval set -- "$TEMP"

	# extract options and their arguments into variables.
	while true ; do
		case "$1" in
			-u|--user)
				case "$2" in
					"") shift 2 ;;
					*) USER=$2 ; shift 2 ;;
				esac ;;
			-p|--pass)
				case "$2" in
					"") shift 2 ;;
					*) PASS=$2 ; shift 2 ;;
				esac ;;
			-n|--net)
				case "$2" in
					"") shift 2 ;;
					*) NET=$2 ; shift 2 ;;
				esac ;;
			-h|--host)
				case "$2" in
					"") shift 2 ;;
					*) HOST=$2 ; shift 2 ;;
				esac ;;
			-P|--port)
				case "$2" in
					"") shift 2 ;;
					*) PORT=$2 ; shift 2 ;;
				esac ;;
			-s|--sid)
				case "$2" in
					"") shift 2 ;;
					*) SID=$2 ; shift 2 ;;
				esac ;;
			-r|--role)
				case "$2" in
					"") shift 2 ;;
					SYSDBA|SYSOPER|SYSASM) ROLE=$2 ; shift 2 ;;
					*) echo "role must be blank, or one of SYSDBA, SYSOPER, or SYSASM" ; exit 1 ;;
				esac ;;
			-e|--edition)
				case "$2" in
					"") shift 2 ;;
					*) EDITION=$2 ; shift 2 ;;
				esac ;;
			-d|--docker-run)
				if [ -n "$DOCKER_CONTAINER" ]; then
					echo "only one of docker-run or docker-exec can be specified" ; exit 1
				fi
				case "$2" in
					"") DOCKER_IMAGE=$DEFAULT_DOCKER_IMAGE ; shift 2 ;;
					*) DOCKER_IMAGE=$2 ; shift 2 ;;
				esac ;;
			-D|--docker-exec)
				if [ -n "$DOCKER_IMAGE" ]; then
					echo "only one of docker-run or docker-exec can be specified" ; exit 1
				fi
				case "$2" in
					"") echo "no container name specified, ignoring $1" ; shift 2 ;;
					*) DOCKER_CONTAINER=$2 ; shift 2 ;;
				esac ;;
			--) shift ; break ;;
			*) echo "Internal error!" ; exit 1 ;;
		esac
	done
	local ARGS=/
	if [ -n "$USER" ]; then
		ARGS=$USER
		if [ -n "$PASS" ]; then
			ARGS=$ARGS/$PASS
		fi
		if [ -n "$NET" ]; then
			ARGS=$ARGS@$NET
		else
			if [ -n "$HOST" ]; then
				ARGS=$ARGS@$HOST
				if [ -n "$PORT" ]; then
					ARGS=$ARGS:$PORT
				fi
				if [ -n "$SID" ]; then
					ARGS=$ARGS/$SID
				fi
			fi
		fi
	fi
	if [ -n "$ROLE" ]; then
		ARGS="$ARGS AS $ROLE"
	fi
	if [ -n "$EDITION" ]; then
		ARGS="$ARGS EDITION=$EDITION"
	fi
	ARGS="$ARGS $@"

	if [ -n "$DOCKER_IMAGE" ]; then
       		echo "/bin/docker run --rm -it $DOCKER_IMAGE sqlplus $ARGS"
       		rlwrap /bin/docker run --rm -it $DOCKER_IMAGE sqlplus $ARGS
	elif [ -n "$DOCKER_CONTAINER" ]; then
		echo "/bin/docker exec -it $DOCKER_CONTAINER sqlplus $ARGS"
		rlwrap /bin/docker exec -it $DOCKER_CONTAINER sqlplus $ARGS
	else
		echo "sqlplus $ARGS"
		rlwrap $ORACLE_HOME/bin/sqlplus $ARGS
	fi
}