Linux Xserver: linux graphic interface principle

Linux Xserver: The linux graphic interface principle MoblinCore is built on the GnomeMobile platform. I used to play Linux. the submitted content has nothing to do with images. I don't even need to start Xwindows. after I start the system, I directly enter the text command line. so I have little knowledge about this. I need to learn more... X server in linux: The linux graphic interface principle Moblin Core is built on the Gnome Mobile platform. I used to play Linux. the submitted content has nothing to do with images. even Xwindows does not need to be started. after I start the system, I directly enter the text command line. so I have little knowledge about this. I need to learn about it. strictly speaking, the term Linux only represents the Linux kernel, but in fact people are used to using Linux to describe the entire Linux kernel, it also uses GNU engineering tools and database operating systems (also known as GNU/Linux ). Linux software based on these components is called the Linux release version. Generally, a Linux release kit contains a large number of software, such as software development tools, databases, Web servers (such as Apache), X windows, and desktop environments (such as GNOME and KDE ), office kits (such as OpenOffice.org. The GNU component can run on the Linux kernel. The entire kernel is based on the GNU General Public License, that is, the General Pubic License (GPL), but the Linux kernel is not part of the GNU program. I. linux itself has no graphic interface. the implementation of the current graphic interface is only implemented by linux applications: the graphic interface is not part of linux, and linux is just a command line-based operating system, the relationship between linux and Xfree is equivalent to the same DOS and WINDOWS 3.0 in the past. windows 3.0 is not an independent operating system, but a DOS extension, and is an application-level system under DOS, it is not an independent operating system, and XFree is just an application in linux. It is not a part of the system, but the existence of X allows users to use computers conveniently. WINDOWS 95 and later versions are different. their graphic interfaces are part of the operating system. the graphic interfaces are implemented in the system kernel. without a graphic interface, windows will not become windows, but linux is not the same. there is no graphical interface for linux or linux. many WEB servers with linux are not installed with X servers at all. This is also one of the important differences between WINDOWS and linux. 2. X is a protocol, not a specific software. X is a protocol, just like HTTP and IP. This concept is confusing for many beginners and even those who have been learning LINUX for a certain period of time. when an X-based application needs to run and display content, it is connected to the X server, start to talk to the server using the X protocol. For example, if an X application needs to output a circle on the screen, the X application is only responsible for telling the X server where the screen is located and where the color is used to draw a circle, the specific "painting" action, such as how to generate the circle and how to use the driver sequence of the video card, is completed by the X server. X server is also responsible for capturing keyboard and mouse movements. if X server captures the left mouse button and is pressed, it will tell X application: Dear Mr. application, I found that the mouse was pressed. do you have any instructions? The protocol is implemented by specific software. this is what I will talk about below: 3. the relationship between X and XFree86 requires specific software to implement the protocol. Xfree86 is such a "traffic police" that implements agreements according to regulations ". XFree86 is not the only software that implements the X protocol, but a free X server software that implements the X protocol. MOTIF is commonly used in business. now there is XORG, and there are a lot of small X server software written by fans. You can even run X on WINDOWS Server, so that you can run an X application on linux and then display it on another windows system. XFree86 is the most commonly used in LINUX (Xorg is used in the current linux release ). The graphic interface of Apple computer uses the X protocol and is considered to be the best graphic interface for the X protocol. In addition, the implementation of the X protocol is implemented in the system kernel, therefore, the performance is much better, which is why many large 3D graphic design software is on the Apple platform. Since it is a protocol, it certainly has nothing to do with the platform. Therefore, X applications can be displayed on any remote computer with X servers. It is even displayed on windows systems with Xnest servers. However, in most cases, X applications use the X server of the local machine, and then X server outputs the display results to the local display. This is why many people do not understand X as a protocol. 4. what is the relationship between X and X11R6? I wonder if you have noticed the directory/usr/X11R6 for beginners. this is the default installation directory of XFree. X11R6 is actually the meaning of X Protocol version 11 Release 6 (sixth Release of X Protocol 11th. Different versions of the X protocol cannot communicate with each other, but don't worry. the current X server software and X applications both follow X11R6. In addition, XFree86 3.3.6 XFree86 4.3.6 and other versions are the version numbers of the XFree86 software that implements the X protocol. 5. what is the relationship between X Server and WM (window manager. How do you start the graphic interface? If you enter the graphical interface from the very beginning, you can open an XTERM input init 3 to return to the character interface safely. First, enter the following command: # startx starts the graphic interface. what you see is a complete graphic interface operation environment that is used in peacetime. You can maximize, minimize, move, and close the window. Press ctrl + alt + backspace to return to the character interface. Input: # xinit to start the graphic interface again. you can see an XTERM. And cannot be moved. However, you can enter the command in this XTERM to open the X application. if I enter: # mozilla open the browser, what is the difference between the browser and the normal one? He is in the middle of the screen, can not move, can not be minimized, can not maximize, no border. Why is the same X application so different? Because we also started a WM (window manager) when we started the graphic interface with startx. if you use KDE, we started KDE. if you use GNOME, we started GNOME. However, you didn't start WM when starting the GUI with xinit. Do you understand the function of window manager? Its role is to maximize, minimize, move, and close the window. These are not handled by X servers. If you use xinit to start the graphic interface and input twm in xterm, what will happen? Xterm is added with a border. you can move the border to maximize and minimize this xterm. twm is the window manager that comes with XFree86, is a relatively simple and simplest window manager, but it has all the features of the window manager. If you do not enter twm and enter gnome-session, you can start GNOME or enter startkde to start KDE. 6. KDE, gnome kde, and GNOME are the most common graphic interface operating environments in LINUX. they are not just a window manager, but kDE is short for K Desktop Environment. It is not only a window manager, but also a lot of supporting applications and easy-to-use desktop environments, such as the taskbar, Start menu, and desktop icons. GNOME is the abbreviation of GNU Network Object Model Environment. Like KDE, KDE is also a powerful integrated environment. In other UNIX systems, CDE is often used as such an environment. Other small window managers include window maker, after step, blackbox, fvwm, fvwm2, and so on, which are common excellent window managers. There is a window maker in REDHAT9, but it is not installed by default. you can try it. As long as xinit is used for wmaker & again, windowmaker can be used. 7. Summary of linux graphic interface hierarchies linux itself --> X server <-[talk through X protocol]-> Window Manager (integrated desktop environment) --> X application.