Intro To 'chgrp' Command In Linux

2023-05-03 - By Robert Elder

     I use the 'chgrp' command to change the group ownership of files and directories.  For example, here is a file that currently belongs to the group 'robert':

ls -l file1.txt

-rw-rw-r-- 1 robert robert 0 May  4 10:49 file1.txt

     This command will change the group ownership of file1.txt from 'robert' to 'dialout':

chgrp dialout file1.txt

     Below, you can see how the group has been updated to 'dialout':

ls -l file1.txt

-rw-rw-r-- 1 robert dialout 0 May  4 10:49 file1.txt

     You can see which groups the current user belongs to by running the 'groups' command:

groups

     and the output is as follows:

robert adm dialout cdrom sudo dip plugdev lpadmin lxd sambashare tomcat

     If the current user is not the owner of the file, but belongs to a group that owns the file, then the file permissions located at this position will apply:

     Using the 'ls' command, you can see that the read write, but not execute permissions are enabled for the dialout group:

ls -l file1.txt

-rw-rw-r-- 1 robert dialout 0 May  4 10:49 file1.txt

     Let's add the execute permission for the group now:

chmod g+x file1.txt

ls -l file1.txt

-rw-rwxr-- 1 robert dialout 0 May  4 10:49 file1.txt

     Now, let's take away all of the group permissions entirely:

chmod g-rwx file1.txt

ls -l file1.txt

-rw----r-- 1 robert dialout 0 May  4 10:49 file1.txt

     And that's why the 'chgrp' command is my favourite Linux command.