eval takes a string as its argument, and evaluates it as if you'd typed that string on a command line.
eval $(docker-machine env)
docker stop $(docker ps -a -q)
docker rm $(docker ps -a -q)
docker rmi $(docker images -q)
docker inspect -f '{{ .Mounts }}' CONTAINERNAME
docker volume rm $(docker volume ls -qf dangling=true)
docker images | awk '{print $1}'|grep -v "REPOSITORY" |xargs -L1 docker pull
curl -L https://raw.githubusercontent.com/docker/compose/$(docker-compose version --short)/contrib/completion/bash/docker-compose > /etc/bash_completion.d/docker-compose