On Sat, 7 Dec 2002, Jim Christiansen wrote: >Ok, so what I'm understanding is that a linux host system >without X installed can be accessed from another computer, >remotely, using ssh and its X system to operate an X session >from the host? >From the very beginning of X back in the early 1980s, X was designed to be a network transparent window system. X uses a client/server model to accomplish this. The X server, is what controls your video card and display, and handles keyboard and mouse input among other things. The X server provides a mechanism for arbitrating access to shared resources amongst X client applications. An X 'client' is simply an X application linked to the standard Xlib library and other libraries that are part of the X window system. The application talks to the X server through either a local UNIX socket, or using TCP/IP to instruct the server to create and destroy windows, draw lines, text, etc. and to receive input events, etc. The X server and the X client applications are often ran on the same computer as is the case of a modern Linux desktop, and in this case, the X application running on your computer talks to the X server through a local UNIX socket. Since X is network transparent however, there is no requirement that the application be ran on the local computer the X server is running on. As long as a remote host computer has the necessary X libraries and other libs that the X applications need to run installed, you can run remote X applications and have them display over the network to a local display. The X11 protocol is what passes over the wire, be it ethernet, or be it a local UNIX socket. There are a variety of ways in which one can run remote X applications using the native X11 protocol, but by far the easiest method is to do so by using ssh with X11 forwarding, which is enabled by default in Red Hat Linux. In order to run any X application on a remote computer, simply open up a local shell in gnome-terminal/konsole/xterm/etc. and ssh to the remote host, then type in the name of any X application. Assuming the remote ssh server is configured to the Red Hat supplied default settings of allowing X11 forwarding, then depending on the speed of your network connection, the X application should pop up on your display. This feature of X is one of the things that was designed right into the core of X from the very start, and is one of X's greatest advantages over other GUI systems like Windows for example. ssh just makes it a whole heck of a lot easier. If the above does not work, perhaps the ssh server or client is disabling X11 forwarding by default. In this case, invoke it as "ssh -X remotehost.com" instead. Hope this helps. -- Mike A. Harris ftp://people.redhat.com/mharris OS Systems Engineer - XFree86 maintainer - Red Hat -- Psyche-list mailing list Psyche-list@redhat.com https://listman.redhat.com/mailman/listinfo/psyche-list
