Easily reuse commands in your shell

Two techniques I love using when working with commands in the shell are quickly running a previous command in my history, and rerunning a previous command, but with sudo.

To quickly rerun a command in your history, simply run `!<history_number>`, e.g.

```bash
$ history

 1451  git pull
 1452  git diff docker-compose.yml
 1453  git checkout -- docker-compose.yml
 1454  vim docker-compose.yml
 1455  docker-compose down
 
$ !1454 # reruns vim docker-compose.yml
```

Next, I often run a command as a user, when I meant to run it as root, `!!` is a shell expression which expands to the last command. e.g.

```bash
$ service docker restart

Failed to restart docker.service: Insufficient privileges

$ sudo !! # will expand to sudo service docker restart
```

gabrielfortuna
April 7, 2021