Linux learning method sharing

With the expansion of Linux applications, many people have come into contact with Linux. For those who have just come into contact with Linux, they don't know where to start. The following is a Linux system administrator who has read many documents and books about Linux and made a lot of hard efforts to learn Linux. After he really got a formal Linux system management job, he had a deeper understanding of the soul of Linux: service and multi-user. Linux system knowledge is very extensive, but as long as you master the key knowledge, managing it is not as terrible as imagined. In the following, he will systematically introduce to you some of his work experience and summarized experience as a system administrator.

1. Purpose of Learning

Needless to say, the purpose of mastering UNIX through learning Linux is that in this era when the value of network talents has doubled, it is unwise to rely on technology for a living without mastering network and programming technology. When a person hears about Linux for the first time and is eager to try it, he will always ask a few questions: What is it (What)? Why use it (Why)? How to learn it (How)? As a major component of the open source movement, Linux is used more and more widely, from our daily entertainment and learning to business, government offices, and large-scale computing applications. In order to meet people's needs, various Linux-based application software have emerged in an endless stream. As long as you have the basic skills of Linux and the ability to self-study, you can master the specialized content through long-term learning.

2. Start with commands and start with the basics

Often, some friends want to build a website as soon as they get in touch with Linux, without even thinking about understanding the basics of Linux first. This is quite difficult. Although Linux desktop applications are developing rapidly, commands still have a strong vitality in Linux. Linux is an operating system composed of command lines, and the essence is in the command line. No matter how the graphical interface develops, this principle will not change. Linux commands have many powerful functions: from simple disk operations and file access to complex multimedia image and streaming media file production. Here the author divides the more important and frequently used commands into several parts according to their roles in the system and introduces them to you. Through the study of these basic commands, we can further understand the Linux system:
●Installation and login commands: login, shutdown, halt, reboot, mount, umount, chsh
●File processing commands: file, mkdir, grep, dd, find, mv, ls, diff, cat, ln
●System management related commands: df, top, free, quota, at, lp, adduser, groupadd kill, crontab, tar, unzip, gunzip, last
●Network operation commands: ifconfig, ip, ping, netstat, telnet, ftp, route, rlogin rcp, finger, mail, nslookup
●System security related commands: passwd, su, umask, chgrp, chmod, chown, chattr, sudo, pswho

3. Choose a good Linux book

In some Linux forums, the most common questions we see are often from a novice who starts asking questions when he encounters a problem during the installation or use of Linux. Many of them are repetitive questions, and many people don’t even have a clear description of the basic problem. This shows that many people who are new to Linux have not yet mastered the basic skills. How can we quickly improve our basic skills in Linux? The most effective way is to study authoritative Linux reference books, which are very important for learners. A reference book with wrong concepts can lead novices astray. There are many books about Linux in China, but there are not many high-quality ones. It is best for novices to buy a paper book to study carefully and take notes carefully.

4. Develop the habit of working on the command line

You must develop the habit of working in the command line. You must know that X-window is just an application running in command line mode. Although the progress of learning in the command line is slow at first, once you are familiar with it, your future learning will increase exponentially. For network administrators, the command line is actually a rule, it is always valid and also

Flexible. Even through a slow modem line, it can operate remote systems thousands of kilometers away.

5. Think about Linux with Unix thinking

Since Linux is designed with reference to the ideas of Unix, to understand and master it, one must think in Unix terms, not in Windows terms. It is undeniable that a large part of Windows' success in the market lies in the uniqueness of its technical ideas. However, this innovation was carried out under the premise of facing individual users, and it is still somewhat powerless in the face of enterprise-level service applications. For many years in the field of computer operating systems, there have always been two dominant players: Unix in the server field, and Windows in the field of individual users. It can be seen that user needs determine the operating system used. No matter what the reason, if you want to learn Linux, you must first drag your thinking out of the "little river" of Windows and put it into the ocean of Unix.

6. Learn shell

People who are used to Windows must be very unfamiliar with Shell (Chinese name Shell), because Windows has only one "Shell" (if it can be called Shell), that is Windows itself. The easy-to-understand explanation in one sentence is that Shell is the intermediary between the user input command and the system interpretation of the command. The most intuitive way to say it is that a Shell has its own set of commands. To give an easy-to-understand example, the standard Shell of Linux is Bash Shell; the shell of Solaris is B shell; the Shell of Linux is expressed in the form of command line. Readers may not understand that Windows has "evolved" from the command line to the graphical interface, so isn't it a step backward for Linux to still use the command line?

I had this idea when I first came into contact with Linux. But later I found that if the graphical interface is used, then the resources allocated to the application software will be less. On an expensive server, it is very important to be able to achieve the same function with a lower hardware configuration. The

following example shows that a server has 1GB of memory, assuming that 512MB of it is used to process the graphical interface. If you want to install a database software that requires 784MB of memory, the only way is to expand the memory. But if the command line is used, the system may only need 64MB of memory, and the rest of the memory can be used by the database software. Using the command line not only saves memory, but also saves a lot of CPU and hard disk resources. Therefore, using the command line as a server is an advantage rather than a disadvantage. Since Shell has so many advantages, you must learn it.