Linux Learning Note 2 chgrp chmod chown

chgrp Change Group changes the user group that the file belongs to eg. Chgrp-r User 1.txt

[[email protected] test]# ll   Query the files and properties under the test directory total 0                   is now empty, no files [[email protected ] test]# touch 1.txt   established 1.txt[[email protected] test]# touch 2. txt[[email protected] test]# touch 3.txt[[email protected] test]#  ll query the files and properties under the test directory Total 0-rw-r--r--.  1 root root 0 Jan 25 11:44  1.txt   file Property-rw-r--r--.  1 root root 0 jan 25 11:44 2. Txt-rw-r--r--.  1 root root 0 jan 25 11:44 3.txt[[email protected]  test]# chgrp srd 1.txt   change 1.txt to SRD-owned group [[email protected] test]#  Ll   total 0-rw-r--r--.  1 root srd  0 jan 25 11:44 The  1.txt 1.txt file belongs to a group that has been converted to SRd The-rw-r--r--.  1 root root 0 jan 25 11:44 2.txt-rw-r--r--.  1  Root root 0 jan 25 11:44 3.txt

chmod Change Mode changes the file properties, and the file attributes are set in two ways: numbers and tags.

The pattern is as follows: [Ugoa ...] [[+-=][RWXX] ...] [,...], in which u represents the owner of the file, G represents the group to which the owner of the file belongs, and O represents the other person, and a means that all three are. + means add permission,-means dismiss permission, = indicates only set permission. R means readable, w means writable,x table implies executable

eg. Set file 1.txt to be readable by everyone: chmod ugo+r 1.txt or chmod a+r file1.txt

The files 1.txt and 2.txt are set to the owner of the file, and the person to whom it belongs can be written to, but not others: chmod ug+w,o-w 1.txt 2.txt

Set 3.txt to only the owner of the file can be implemented: chmod u+x 3.txt

Set all files in the current directory to be readable by anyone: chmod-r A+r *

[email protected] test]# LL

Total 0

-rw-r--r--. 1 root SRD 0 Jan 11:44 1.txt

-rw-r--r--. 1 root root 0 Jan 11:44 2.txt

-rw-r--r--. 1 root root 0 Jan 11:44 3.txt

[Email protected] test]# chmod a+w 1.txt

[email protected] test]# LL

Total 0

-rw-rw-rw-. 1 root SRD 0 Jan 11:44 1.txt

-rw-r--r--. 1 root root 0 Jan 11:44 2.txt

-rw-r--r--. 1 root root 0 Jan 11:44 3.txt

Chmod can also use numbers to represent permissions such as chmod 777 file

The syntax is: chmod ABC file

This a,b,c is a number that represents the permissions of the user, Group, and other respectively.

R=4,w=2,x=1

The Rwx property is 4+2+1=7, the Rw-property is 4+2=6, and the R-x property is 4+1=5.

eg. chmod a=rwx file and chmod 777 file result

chmod ug=rwx,o=x file and chmod 771 file result

[email protected] test]# LL

Total 0

-rw-rw-rw-. 1 root SRD 0 Jan 11:44 1.txt

-rw-r--r--. 1 root root 0 Jan 11:44 2.txt

-rw-r--r--. 1 root root 0 Jan 11:44 3.txt

[Email protected] test]# chmod 777 2.txt

[email protected] test]# LL

Total 0

-rw-rw-rw-. 1 root SRD 0 Jan 11:44 1.txt

-rwxrwxrwx. 1 root root 0 Jan 11:44 2.txt

-rw-r--r--. 1 root root 0 Jan 11:44 3.txt

chown Change owner changes file owner

Chown-r-H User name file/directory,-r option means that all subdirectories under the same operation,- The h option means that the target file that the link points to is not affected when the owner of the symbolic link file is changed. NOTE: Once ownership of the file is given to another user, it can no longer be re-owned and can only be resorted to by the system administrator.

Chown User name: User group: File/directory, if the entire directory is changed, then the plus-r parameter is used for recursion.

Chown-r root/etc/config.cfg

Chown-r Root:root/home

[[email protected] test]# ll change pre-query

Total 0

-rw-rw-rw-. 1 root SRD 0 Jan 11:44 1.txt

-rwxrwxrwx. 1 root root 0 Jan 11:44 2.txt

-rw-r--r--. 1 root root 0 Jan 11:44 3.txt

[[email protected] test]# chown SRD 1.txt Modified

[[email protected] test]# ll change pre-query

Total 0

-rw-rw-rw-. 1 SRD SRD 0 Jan 11:44 1.txt File The owner has changed

-rwxrwxrwx. 1 root root 0 Jan 11:44 2.txt

-rw-r--r--. 1 root root 0 Jan 11:44 3.txt

Linux Learning Note 2 chgrp chmod chown