SSH and Emacs (and some other X clients)

Some people have been having trouble starting emacs when running SSH. It will sometimes come up with the error 'Cannot open Display.' This is because if the DISPLAY environment variable is set emacs assumes you are running X windows. When SSH is set to tunnel X connections (a good thing) it will automatically set the DISPLAY variable, whether you are running an X server or not. There are several solutions to this:

1) Run an X server

Xwin32 for PC or Exodus for Mac. Then emacs will display in its own X window. Note, on slow connections this is inadvisable. Also, if you use an X server, make sure you read the setup guides to configure it properly.

2) Do not forward X connections

By not clicking on the box 'Forward X11 connections' in the SSH setup, SSH will not set the DISPLAY variable. Do this if you don't intend to run an X server often.

3) Unset the DISPLAY variable

You can type: unsetenv DISPLAY at the unix prompt and then emacs will quit trying to come up in an X window.

4) Tell emacs to not use a separate window

Type: emacs -nw to tell emacs to come up in the terminal window.

5) Use another editor

Pico is not as powerful as emacs, but it is more user friendly.