4. Linux Basics

Introduction to a computer operating system

1 Introduction to Computer operating systems
1) Master the definition of the operating system: the operating system is a system program that coordinates, manages, and controls the hardware and software resources of the computer, located between the hardware and the application. 、
2) Master the definition of the kernel of the operating system: the kernel of the operating system is a management and control program that is responsible for managing all the physical resources of the computer, including. File system, memory management, device management, and process management.
3 Learn about the two operating system user interfaces: graphical interface, command line interface.
2 Understanding Linux Major distributions: CENTOS, RHEL, FEDORA, UBUNTU, SUSE

Two Unix and Linux operating systems overview

1. What is UNIX
1) Mastering the definition of Unix: UNIX is a computer operating system, a control program used to coordinate, manage and control computer hardware and software resources.
2) Understand the features of the UNIX operating system: multiuser and multi-tasking
a) Multi-user indicates that at the same time multiple users can use UNIX operating system simultaneously and they do not interfere with each other;
b) Multitasking means that any user can run multiple programs on the UNIX operating system at the same time.
2. Learn about the brief History of Unix
(see Bird's p40-p52 or Linux system Management P13)
3.GNU projects and free software
1) The idea of the gun program was publicly launched by Richard Stallman on September 27, 1983, and its goal was to create a completely free operating system.
2) Understand the GPL terms
The GPL clause is to ensure that GNU software is free to use, reproduce, modify and distribute, and that all GNU software has an agreement to grant all rights to any person without limiting any restrictions to others.
3) Understanding free software means:
a) You have the freedom to run the program for any purpose.
b) You have the freedom to modify the program to suit your needs.
c) You have the right to republish the copy, either in white or at a charge.
d) You have the right to publish the modified version of the program so that others benefit from your improvements.
4.Linux Introduction
1) Mastering the definition of Linux: Linux is a free-to-use and free-spread UNIX-like operating system, a POSIX and Unix-based multiuser, multitasking, multi-threaded and multi-CPU operating system.
2) Master The main purpose of Linux operating system: Mainly used for servers, especially network servers.
3) Master Two common desktop environments: KDE and GNOME.
5. Log in and out of Linux
1) command to shut down the Linux system: Init 0
2) Mastering what Linux terminals are: Linux endpoints are also known as virtual consoles. The Linux terminal uses the character command line method to work, the user through the keyboard input command, through the Linux terminal to control the system.
3) Master the method of switching virtual Terminal: Ctrl+alt+f[1~6], if you want to switch to the second virtual terminal, press CTRL+ALT+F2 at the same time
4) Master user login After the system prompt: $
5) Master the system prompt after the root user login: #
6) Master Exit command: Exit

Three commonly used command functions

Date Query Current time

Cat Query Calendar Cat Year of the Sun: Cat 2 9 1991 equals query September 2, 1991 calendar

CD (chage directory) command function

CD/Return root directory CD: Return to previous directory CD-previous directory cd~ switch to the current user's home directory ls command functionLS View all files under current directory Ls-l list current directory detail file information ls-a view hidden file Ls-lh h = Human View user-friendly Display file list MV Command functionMV FileName File directory move files to file directory mkdir Command Functionmkdir file name Create files directory mkdir-p recursively create multiple directories

RM Command Function

RM Delete File (Cannot delete directory), there is a hint whether to delete rm-r Delete files and files directory, if prompted to delete

RM-RF Delete files and files directory, directly delete without prompting　

　

Touch Command function

Touch Xxx.txt New File

help query how to useWhich LS find command path echo repeat action | Indicates that the drum password changes repeatedly put | The front of the move to the back, that is, change the password into ' 123456 ' repeat 2 times Cat file name view file contents

Tree Directory name Displays the directory trees chart

More filenames start from the beginning to view the contents of the file

PWD View your current directory

Vim. Test creates a hidden file

edit ModeVim file name Press I enter insert mode save exit ESC press SHIFT and: Build, enter Wq, knock return

4. Linux Basics