Linux-my new experience

It has been a while since Linux was last used. This is mainly because of two reasons: on the one hand, I have graduated from college, and I am busy writing my papers to find a job. I have no time to take care of my hobbies. On the other hand, I am also the most important one, A second-hand computer (CTR display) I bought during my college career is broken, and my graduation thesis can only be completed on a computer in the college computer room. Now that I graduated from college, I found a job that is neither good nor bad, and started playing Linux again. I mainly want to select a suitable Linux operating system for my future computer (I have not yet purchased a computer, but now I am using a company). Of course, it is also for the purpose of learning. So this time, I started learning about Linux again.

The previous phase of study was during the university, and the redhat9.0 system was used. At that time, I mainly used the software in it, for example, using GCC to compile a small program. Use Apach to set up a Web server, or use Samba to set up a file server, and then perform a routing experiment. In short, these are a process of using Linux. In this process, I realized what is the real multi-tasking and multi-user operating system, especially the multi-user feature. I also learned why bash scripts and commands make Linux a smart operating system. If the graphic interface (all operating systems) is using tools provided by the operating system, using bash or other command interpreters (Sh, tcsh, ssh, etc.) is a language that a computer can understand. Language and tool are two concepts. A language is composed of scattered statements. A tool is a collection of functions combined by statements. In Linux text mode, the command line mode refers to the process of communicating with a computer using statements. scripts written in these languages are also called bash scripts. This feature has the characteristics of language, variables, addressing, reading from the keyboard, console output, and logical judgment, mathematical operations, and loops. Although these features are far different from those of C and C ++, they are good as a script, this is because these features have been fully adapted to the daily management needs of servers. At the same time, I also realized what it is called hitting the world with notepad. In Linux text mode, programs can be customized and interactive. You only need to use the configuration file. These configuration files are composed of characters that humans can understand. In the computer field, this is also called human-readable.
Simbles, which is actually text, uses UTF-8 or ansc encoding. In short, this is a good experience.

This learning process does give me a different feeling. Now I start to learn how to add programs to this system. In Windows, this is easy: download an installation package online and click "Next. But in Linux, this is not easy. I think only those who have installed the tool can understand the tangle process. Maybe you can say that the Installation Tool Yum or apt-Get is always reliable? Can he meet your needs? You have to consider how to customize the yum source server. The RPM installation package is not easy, which means you must solve the file dependency problem. You must keep downloading various support packages at the prompt. There is no way. In the Open Source world, the installation program can only be solved by itself. If you happen to have a circular dependency, you will be able to accept it. (I haven't met it yet. If you do, I will change the RPM package, because not all installation packages are the same ). Another solution is to compile the source code and install it. This does not need to solve the source code problem, but not every source code can be installed smoothly. This is the case when mplayer is installed this time. I changed the source code to four or five sets before compilation was successful. This requires patience and perseverance. Of course, driven by curiosity, these difficulties are nothing. It can only make people more curious, and it also stimulates my desire to solve the problem. This means that when the problem is solved, you will have a sense of accomplishment. Yes. After I compiled the mplayer and installed it, I tried to play the music, and the sound of the sound came out. I stopped thinking and began to enjoy this hard-won song. It was so beautiful. Let's take a look at the time. It's time to go back to rest. But I am still excited for a long time.

In character mode, you can browse images. In fact, this is simple and complex. In other words, the framebuffer provided by Linux is used to display images. In Linux, this is equivalent to the image buffer in DOS, but it cannot be used in Linux. As a complete modern operating system, hardware should not be directly exposed to users, so that users are not managed to use it. Just as after dos interruptions are provided under DOS, IBM announced BIOS interruptions. In fact, this is very dangerous, and it is not conducive to the management of the operating system, because it is prone to excessive authority, which means that any application can bypass the DOS operation interface, rather than let the operating system know, this is not secure for users and data. Therefore, in Linux, the buffer is displayed as a file/dev/fb0 that can be read and written only by the root user. This is a device file. As we all know, there are many such files in the/dev directory of Linux. Do you think of a sentence: everthing
Is file. Yes, Linux is a UNIX system, but it is not UNIX. Therefore, this sentence is also applicable in Linux: everthing is file. Since it is a file, you can use read, write, and execute to specify permissions. For example, root can write the/dev/fb0 file. Generally, users can only read the file. This is why permission denied is displayed when fbv is used to display images in Linux after I log on to a common user! Prompt, but a bunch of garbled characters can be read and displayed. The image is displayed correctly when you log on as the root user. Yes, knowing this is nothing remarkable. But knowing one thing is totally different from doing one thing. Because there are still many details to be aware.

But then again, my learning is inseparable from a good partner, that is, Google. I didn't mean to advertise Google here, and Google didn't need me. However, Google often tells me how others solve these problems. This provides me with a good example, which is really helpful to me. Although Baidu is also helpful, there are not so many results, because these results are complicated. Baidu is used only when Google cannot find it. As an interviewer said, it doesn't matter if you don't know this thing, but it won't work if you don't search for it on Google. In short, thanks to the Internet and Google!