The third day of rhcsa summer vacation

It's not finished , Make up tomorrow afternoon

1. Soft link and hard link drawing , And the code
2. Explanation of the first level catalogue ( Store what , english )
3. Redirect ：
>
>>
2>
2>>
&>
>&
take 1 Redirect to file , take 2 Redirect to 1
take 2 Redirect to file , take 1 Redirect to 2
Redirect files to 0
cat Read content from standard input , Then output to a file
Optional:
cmd >&n Send the output to the file descriptor n
cmd m>&n Output to file symbol m To the file descriptor n
cmd >&- Turn off standard output
cmd <&n Input from file descriptor n
cmd m<&n m From the file descriptor n
cmd <&- Turn off standard input
cmd <&n- Move the input file descriptor n Instead of copying it
cmd >&n- Move the output file descriptor n Instead of copying it
4. create a file , Delete file , Create directory , Delete directory
5.cp command ：
Copy file paste rename
Copy files to directory rename
Copy directory to directory
Copy the file to the directory without changing the file properties
mv Use of commands

1. Soft link and hard link drawing , And the code

2. Explanation of the first level catalogue ( Store what , english )

In the root directory bin and sbin,usr In the catalog bin and sbin, All four directories are used to hold system commands . difference ：bin All users of the directory can use ,sbin Only root Only users can use .

proc and sys The directory cannot be manipulated directly , These two directories store the mount points of memory

It is not recommended to place customized data in the root directory

3. Redirect ：
>
>>
2>
2>>
&>
>&
take 1 Redirect to file , take 2 Redirect to 1
take 2 Redirect to file , take 1 Redirect to 2
Redirect files to 0
cat Read content from standard input , Then output to a file
Optional:
cmd >&n Send the output to the file descriptor n
cmd m>&n Output to file symbol m To the file descriptor n
cmd >&- Turn off standard output
cmd <&n Input from file descriptor n
cmd m<&n m From the file descriptor n
cmd <&- Turn off standard input
cmd <&n- Move the input file descriptor n Instead of copying it
cmd >&n- Move the output file descriptor n Instead of copying it

4. create a file , Delete file , Create directory , Delete directory

---

create a file

  Delete file

Create directory  

Delete directory  

 

5.cp command ：
Copy file paste rename
Copy files to directory rename
Copy directory to directory
Copy the file to the directory without changing the file properties
mv Use of commands