A CLIENTSERVER MODEL

A CLIENT/SERVER MODEL

X uses a client/server model. The actual windowing system acts as the server, and the graphical programs act as the clients . When you're on a box running an X server and are starting graphical applications like xterm or xemacs on that same box, the client/server interaction is rather transparent. The server portion of X listens on a socket (an IP address and port combination), much like other services. The client, for example xterm, connects to the server in order to display the appropriate window. In the case of xterm , the window is merely a command-line terminal displayed in X. Scroll bars, contextual menus , and the mouse pointer are all handled by the window manager. So, in this scenario your graphical desktop appears to work just as it would if you were using a Microsoft Windows system.

But what if you're running an X server on HOST1, you're in a secure shell session on HOST2, and you want to run xemacs on HOST2? You need a way to tell the xemacs client on HOST2 to use the X server on HOST1 to display itself. If you think about it, this is backward from most client/server thinking. Usually, if you are on a system and need access to a remote resource, you use a local client application to connect to a remote server that provides the resource. With X, however, you have to run the server on your local system and then have the remote resource (the client) connect to you . In other words, you send the remote client from HOST2 to your local server on HOST1 in order to interact with the client as if you were physically using HOST2.



Anti-Hacker Tool Kit
Anti-Hacker Tool Kit, Third Edition
ISBN: 0072262877
EAN: 2147483647
Year: 2006
Pages: 175

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