Shulou(Shulou.com)06/02 Report--

Today's presentation is about the use of commands in Linux systems. Unlike Windows systems, Linux systems are more managed and configured at the command line.

I. Introduction:

Linux operating system consists of Linux kernel and various peripheral programs. The kernel is used to implement core operations such as CPU, memory allocation, process scheduling, device drivers, etc., and is hardware-oriented; peripheral programs include interpreters for analyzing user instructions, network service programs, graphic desktop programs, etc., and are user-oriented.

There are three Linux distributions:

1. Red Hat Series

2. Debian series

3. Ubuntu series

The name and version of the distribution are determined by the publisher.

GPL and LGPL

1.GPL

(1) the GNU Free Software General License;

(2) Allow users to copy, transfer, modify and republish at will;

(3) Software redistributed based on free software modifications is still subject to the GPL.

2.LGPL

(1) Relatively loose relative to the GPL, allowing not to disclose all source code;

(2) More space for commercial software development based on Linux platform.

Linux uses basic commands

1. Internal commands do not have separate files, accompany the kernel, in the kernel (minimal installation);

2. External commands have files on the system and do not accompany the kernel: create files, folders;

3. PATH : Specifies the range of command file locations recognized by the system.

Command application:

1. command to go to other files: cd /(file directory);(this command is detailed later in this article.)

First enter the xshell interface, the configuration interface in the bin/bash interface, enter the move command cd /bin/enter, and then enter ls (English letters l and s) to view, you will find:

[root@localhost bin]#Meaning of each part in Shell interface: root: stands for login user of current system @: separator, which plays a role of separation Localhost: host name Bin: current directory location #: administrator identity $: ordinary user identity

2. Command to change logged-in user: su (space)(username).

3. After changing the user, the #character becomes the $character, that is,$is the ordinary user identity, and then enter the init 0 shutdown command, prompting the shutdown failure. The reason is that ordinary users have small permissions and no shutdown permissions, while administrators have great permissions.

4. (1) After changing the directory with cd, enter ls to view the current directory (l is the letter), at this time it is home, that is, the ordinary user ming in home appears (everyone is different).

(2) Return to upper level: cd../../ Enter, as shown below, from the network-scripts directory back to the previous etc directory:

(3) Return to the previous level: cd.. Enter, as shown below, from the network-scripts directory back to the previous sysconfig directory:

(4) Display current layer: cd . (or cd ./) Enter:

(5) Return to the directory location of the cd command on the previous level: cd -

5. Displays the user's current working directory location: pwd.

6. Go back to the home directory (that is, the directory displayed when you first entered xshell): cd ~, cd, or cd /root.

7. The switch displays: \, backslash immediately after the command, no spaces allowed. When the command is too long to write a line available\command to switch.

The backslash links sys with the second config/network-scripts line.

8. Delete commands to the beginning of the line: ctrl+u (delete the command before the green cursor, the characters on the cursor will not be deleted).

9. Delete commands to the end line: ctrl+k (including cursor and all commands after delete).

10. Clear screen: ctrl+L (no difference between letter case, clear screen does not mean delete).

Click Ctrl+L to clear the screen as follows:

11. Interrupt command: ctrl+c, when connected to a server, it will always carry out data transmission, click ctrl+c to stop it.

12. See details: ls -l (l is a letter, do not think of it as a number 1, do not repeat it later).

13. Show hidden files: ls -a. Hidden files can be displayed.

14. Recursive display data: ls -R.

15. Help command: --help, you can view the format and specific analysis that can be connected.

16. Use the man command to read the manual (this command is written directly at the beginning, similar to help, but better than help). When the mouse wheel cannot read the manual up and down, use the up and down arrow keys to scroll the text, use the Page Up and Page Down keys to turn pages, press Q(upper and lower case can be used) to exit the reading environment, and press the "/" key to find the content.

Thank you for appearing in my life!

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