Re: Xlib: connection to ":0.0" refused by server?

On Sunday 25 August 2002 23:24, [email protected] wrote:
> On Sun, Aug 25, 2002 at 06:11:25PM -0400, Bob Paddock wrote:
> > If I'm logged in as 'bob' and I su root, then try to start some thing
> > like emacs I get this:
> >
> >
> > root@bob cups # emacs error_log&
> > [1] 6860
> > root@bob cups # Xlib: connection to ":0.0" refused by server
> > Xlib: No protocol specified
> >
> > emacs: Cannot connect to X server :0.0.
> > Check the DISPLAY environment variable or use `-d'.
> > Also use the `xhost' program to verify that it is set to permit
> > connections from your machine. [This is the same machine!?]

I you use 'su -' it will clear all environment variables such as DISPLAY, and 
you will be able to use a text mode emacs.

> before you su, type 'xhost +localhost'

Eeeek. It depends on the configuration of your machine (of course), but using 
xhost like that is likely to be a security problem. It means that any process 
on your machine can connect to your X server to snoop on your windows, record 
keystrokes, etc.

You may want to look at ssh, which can perform secure X forwarding.
'ssh -l root localhost' will let you run X emacs as root, without the security 
hole.