When I try to log in to mysql using `mysql -u root -p` it gives me this error:

```
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

```

I have looked in the directory and the file isn't there. I have looked around and people have said that sqld has to be running but I don't know how to start it.