UNIX for Dummies Questions & Answers

Hi, I am lost in between of some concepts, googling too much made me like this! honestly...

please correct my statements below and if they are correct just mention "correct" or also add extra info please:

1. "X Window System" provides basic access to GUI on unix/linux systems
This GUI can be :
- Desktop (gnome, kde)
- Pure window manager
- basic desktop like CDE
2. Normally when we boot the system the X window system is read from some config file and the display is set and then the desktop shows up (either gnome or kde) -- we never realize the process because they are in background (process of X window start up and configuration)

where these config files are located? or one file only?

3. But when we do not have any desktop like gnome or kde. and we only have shell prompt after booting the system, its time to start the X window manually (Am I right?)

if we do not have the X server installed, we should install it? in each distro it has a different package naming?

after making sure the X window installed... (How to make sure we do have X window? let's say in redhat!)

4. then we should initialize it first by "xinit" ???? (Am I correct)
if we are running window manager we shoudl do this:

xinit -e <absolute path to WM>
5. after xinit we should start the server X by "startx" ????

6. setting the display? what is this display? i can not communicate with this word!!! nobody has explained me anything, and while googling I just grab ideas!!! I dont have a robust understanding from this display setting. then how to export it?

for the above 4,5,6 we can write them down into xinitrc file in home? and then we dont have to run them every time we boot the system? Right?

<< the window x system can only be access locally? right? I can not remote it via putty and try to run it? or set it? right? (again I have to apologize because not a good understanding)

How to stop the window manager? should I kill the process? and then kill the X window?
the process name is xinit?


what can I do to automate all these steps. when I press the button of power-on on my laptop, I want to get my X started and my window manager started as well. is that possible?

can somebody please put my words in a better shape and ordered steps, 1, 2, 3, ..then I promise this post will be a great tutorial!

thanks very much guys,
Messi

There's a pretty good overview at Wikipedia.

The tl;dr version:
The X Window System can be seen as 3 components interacting.

First, there's the server component, whose job is to (basically) tell the graphics card what to draw on the monitor (screen), and reads keyboard and mouse input. Each computer can run multiple server instances, where each uses a distinctive display (defined by the server it belongs to, the size, resolution, color depth, and network port [more on that later]). The server is usually started by the xinit program, which in turn is usually started by the startx shell script, which does some preliminary setup.

The second part is the client, which is the application the user wants to interact with. It can, but doesn't have to, run on the same machine as the server. Window managers and desktops like Xfce, Gnome, KDE, or twm are all clients here, with the main job of providing easier access.

Last but not least is the network protocol, which is the way the client and server communicate with each other. Keyboard and mouse input received by the server is sent to the client, which acts on it (or not ), and as a result sends new drawing instructions back to the server, which then tells the graphics card what to draw. Rinse, repeat.

Modern Linux distributions mostly install the server and some client programs by default, and the server is automatically started at boot as a daemon, with the login manager (XDM, GDM, KDM, ...) as the first client, which then handles user logins, etc. Configuration files for this and other things reside in /etc/X11, or sometimes just in /etc, or some other subdirectories, which is distribution specific.

But in some cases there's no need to install and run a graphical user interface, for example with servers.

But some servers do have the libraries and programs installed that are required to communicate with a remote X11 server. For example, it's possible to install an X11 server on a Windows machine, connect to a remote machine using PuTTY and have a feature called "X11 forwardning" enabled. Here the network communication is tunneled through the SSH connection, and client programs like xeyes are displayed as if running on the Windows machine. With this feature the SSH daemon prepares the environment so that clients can easily connect to the server without any additional setup required by the user.

There are no fundamental difference between all of these. There is a window manager and optional clients.
Not a single file but dozens. Where they are located depends.
It's up to you.
Yes, and you probably want more packages than the raw X server.
Use your package manager.
If xinit is installed and properly configured, it will launch the X server and at least a client. You can set it up to your needs in the ~/.xinirc file. No, xinit launch the X server, startx is a front end to xinit.
X11 is designed to support multiple X servers per machine, multiple screens per X server and clients connecting from remote machines. There must be a way to define where a client should display its windows and things. This is the DISPLAY variable which has the form machine:server.screen .
If you are connecting locally, without using the network, you can omit the left part (machine) or use localhost.
If only one server is running, likely your case, server is 0. If you have only one screen, likely your case too, screen can be omitted.

Code:

export DISPLAY=:0

Having a custom xinitrc is unrelated to the automatic X11 startup.
You can access X11 remotely, set it up and run it through putty, although you wouldn't see anything graphic in your terminal emulator. That depends on how it was launched. In some cases, killing it will finish your X11 session as a consequence.
This isn't something you should routinely do.
Sure, that's the default behavior of most Linux and Unix systems.

guys, thanks for updating my statements. i tried to boot to runlevel 3 and and then ran this:

Code:

xinit -e <path to window manager>

--> it did not workand gave me the beloe error:

-----------------
FATAL: Module fbcon not found
xinit: No such file or directory (errno 2): no program named "xterm" in PATH

specify the program on the command line orn make sure that /usr/bin is in your path

waiting for X server to shutdown
-----------------
i wrote it again without -e and it worked and launched my twm and mwm both but I can't get the xterm running. is it possible that xterm is not installed? I thought xterm should be part of the X window system installation? or am I wrong? then I will have to install xterm as well!

Code:

xinit <path to my window manager>

---------- Post updated at 03:36 AM ---------- Previous update was at 03:35 AM ----------

by the way i never have any file like .xinitrc or .xserverrc...strange!