The following scripts allow cleaning a Docker host, and stopping and deleting containers and images.

Stop all containers:

#!/bin/bash

CONTAINERS=$(docker ps -a | tail -n+2 | cut -d" " -f1)
if [ "$CONTAINERS" == "" ]; then
        exit
fi
docker stop $CONTAINERS

Stop and delete all containers:

#!/bin/bash

CONTAINERS=$(docker ps -a | tail -n+2 | cut -d" " -f1)
if [ "$CONTAINERS" == "" ]; then
        exit
fi
docker stop $CONTAINERS
docker rm $CONTAINERS

Delete all unused images:

#!/bin/bash

IMAGES=$(docker images | awk '{ print $3 }'| tail -n+2)
if [ "$IMAGES" == "" ]; then
        exit
fi
docker rmi $IMAGES &> /dev/null