How to Launch Remote X11 Applications 
	from the prime workstations or other remote Unix Servers

== 1. General Steps

Suppose you are running a local X server on 
"local.cs.ohiou.edu:0.0" and you wish to raunch a remote X11 
application (for example, xcalc) from "p2.cs.ohiou.edu".

1. run "xhost + p2.cs.ohiou.edu" on local.

2. create a remote ssh or telnet session to p2.cs.ohiou.edu

3. in the remote session, do "export 
DISPLAY=local.cs.ohiou.edu:0.0" if you are running bash. If 
you are running csh or another shell, run "bash" first, or 
follow the shell documentation to set the environment 
variable. (It's "setenv DISPLAY local.cs.ohiou.edu:0.0" in 
csh.)

4. in the remote session, launch the remote X11 application (xcalc&)


== 2. Launch Remote X11 Applications on a prime workstation

Suppose you are working on bin00101 and wish to lauch a 
remote X11 application running on p2. Replace 
"local.cs.ohiou.edu" in Section 1 with "bin00101.cs.ohiou.edu".


== 3. Launch Remote X11 Applications on a Windows machine

Windows does not have a native X server. You need to install 
a X server such as XFree86, available in the cygwin package 
(http://www.cygwin.com/). X server exceed has been installed 
on many EECS computers.

Once you launch the X server, you can follow the steps in 
Section 1 to launch remote X applications.

In cygwin, to start the local X11 server, issue command 
"startx" in cygwin command windows. If this command does not 
exist, most likely you didn't install the XFree86 package 
with cygwin. In this case, run "cygwin-setup.exe", select 
the package, and install XFree86.


== 4. Launch Remote X11 Applications on Mac OS X

Mac OS X has a built-in X11 Server. The instructions in 
Section 1 should be sufficient, although I couldn't say for 
sure as I don't have a Mac OS X machine to test on. If you 
have a Mac OS X and knows how to do this, send me the steps 
and I will put them here.

         Ok, I read your file. You asked if someone knows how to do 
         this on Mac  OS X, now I do. First you have to download X11, 
         it does not come built  into Mac OS X (at least I didn't 
         have it on mine until I downloaded  it). Information on 
         obtaining and installing X11 (it's free) is at 
         http://www.apple.com/macosx/x11/. After you install it, you 
         just open a  terminal window in X11 and perform the steps 
         you give in the file. It  works, and I was able to verify 
         that my program for the GUI assignment  works properly on 
         p2.
         
         Jason Yerardi
	

== 5. Set up the DISPLAY environment variable automatically

In your .bashrc file, assuming you use bash, if you include 
the following script, the DISPLAY variable can be set up 
automatically for you each time you log on.

    # Set the DISPLAY variable handling remote logins 
    who am i | grep '(' > /dev/null
    if [ $? -eq 0 ]; then        
            # remotely logged in 
            export DISPLAY=`who am i | sed 's/.*(\(.*\)).*/\1/'`
            # Append ":0" or ":1" if not already there
            echo $DISPLAY | grep : > /dev/null
            if [ $? -eq 1 ]; then
                 export DISPLAY=${DISPLAY}:0.0
            fi                   
    fi                           
    #echo DISPLAY=$DISPLAY        

	
== For more information, See:

Josh's Linux Guide - Remote X: 
	http://jgo.local.net/LinuxGuide/linux-X-remote.html 	
or 	http://gibsons.future.easyspace.com/LinuxGuide/linux-X-remote.html



--Chang Liu, 
Tue Apr 08 15:40:40 EDT 2003