What is the easiest and safest way to logout through tty1?

Hi.

Every once in a while, after the login, i get nothing but a wallpaper and the mouse cursor.

Usually i use a live usb to fix my accoumt, but next time this happens i want a faster way.

I already tried to use the " DISPLAY=:0 gnome-session-quit", but i get this error:

Failed to call logout: The name org.gnome.SessionManager was not provided by any .service files

Am i doing something wrong?

What is the easiest and safest way to log out using the tty?

I'm using 14.04.

Thanks and sorry for my English