Summary of Common commands in Linux

The previous sections briefly explain the permissions of Linux Files. Now let's take a look at common commands, starting from a simple:

1. Switch the Directory

CD

To the/tmp directory: CD/tmp

To the upper Directory: CD ..

2. view the current directory

PWD

3. Create a new folder:

Mkdir

Create a directory:

Create a multi-level directory:

4. delete a directory:

Rmdir [-p] If you need to delete directories at a level, you need to add P (only empty directories can be deleted)

5. query environment variables

Echo $ path or $ path

 

6. Switch users:

Su User Name

7. Move files

 

 

Bytes

 

8. view files and directories

Ls

Ls-a directory name: list all files in the directory

Ls-Al directory name: List long strings, including some details about the file

If the directory name is not specified, it is the current directory.

 

9. File Replication:

CP [-adfilprsu] source file target file // copy the source file to the target file

CP src1, src2,... des // copy multiple source files to the destination folder

 

The CP command is very important. Executing different identities has different effects on commands, especially the-A and-P parameters. for different identities, the difference is very large.

Example 1:

Run the following command with root:

If we want to copy all the attributes of the file, we need to add the parameter-

 

Copy a directory to another directory CP-r/src/DESC

 

 

10. Remove files or directories

Rm [-fir] file or directory

-F indicates that the file does not exist and no warning is reported.

-I Interactive Mode: before deletion, you will be asked whether to delete

-R: recursive Deletion

 

I will not demonstrate it here. Do you remember the previous rmdir? Only empty directories can be deleted. Therefore, only Rm-R can be used to delete non-empty directories.

11. File category Query

Cat

-B: List row numbers.

-N: List row numbers, including blank rows.

 

Cat displays data on the screen at a time. What if I want to view the data one page at a time?

Use the more command

When running more, you can press the following buttons:

Space key: Indicates turning one page down

Enter: Indicates rolling down a row

Q: leave more

B: turning back

 

 

12. Create a file

Touch

Touch a.txt will be created under the current directory a.txt

 

13. file search commands

Whereis, find

Whereis [-bmsu] file or directory name

-B: Binary File

-M: Only search for the information in the manual path of the instruction file.

-S: only find the source file

-U: Find other special files that are not in the preceding three options.

 

Whereis ifconfig

 

Next let's take a look at the find command

 

Find [path] [Option] [actioin]

Find the Gavin file under/home

Find/home-user Gavin

Search for files that do not belong to anyone in the system

Find/-nouser

Find the file named passwd.

Find/-name passwd

Search for files with socket type

Find/-type S

 

14. Disk and directory capacity

DF: list the total disk usage of the file system

Du: Evaluate the disk usage of the file system

15. Create a link file

Ln [-SF] source file target file

 

-S: Creates a soft connection. If it is not added, it is a hard connection.

-F: if the target file exists, the file is deleted and then created.

 

[Root @ localhost Test2] # echo 'good'> a.txt
[Root @ localhost Test2] # ls
A.txt
[Root @ localhost Test2] # ln-s a.txt B
[Root @ localhost Test2] # ls
A.txt B
[Root @ localhost Test2] # ll
Total 12
-RW-r -- 1 Root 5 Aug 8 0:09 a.txt
Lrwxrwxrwx 1 Root 5 Aug 8 0:09 B-> a.txt
[Root @ localhost Test2] # echo 'hello'> B
[Root @ localhost Test2] # Cat B
Good
Hello
[Root @ localhost Test2] # Cat a.txt
Good
Hello
[Root @ localhost Test2] # ln a.txt C
[Root @ localhost Test2] # ll
Total 20
-RW-r -- 2 root Root 11 Aug 8 0:09 a.txt
Lrwxrwxrwx 1 Root 5 Aug 8 0:09 B-> a.txt
-RW-r -- 2 root Root 11 Aug 8 0:09 C
[Root @ localhost Test2] # echo 'bad'> C
[Root @ localhost Test2] # Cat C
Good
Hello
Bad
[Root @ localhost Test2] # Cat a.txt
Good
Hello
Bad
[Root @ localhost Test2] # Cat B
Good
Hello
Bad
[Root @ localhost Test2] # rm a.txt
RM: Remove regular file 'a.txt '? Y
[Root @ localhost Test2] # Cat B
Cat: B: No such file or directory
[Root @ localhost Test2] # Cat C
Good
Hello
Bad
[Root @ localhost Test2] #

 

Run the preceding command line. I believe your use of LN will be very clear.

 

15. Attach a cd

16. File compression

Tar

-C: Create a compressed file

-V: displays the compression process.

-F: indicates the compressed file name.

-X: Decompress the file

-T: view the files in the compressed package.