To change the group ownership of a file in Linux, you can use the chgrp command followed by the name of the group and the file you want to modify. Here is the basic syntax:
sudo chgrp group_name file_name
For example, to change the group ownership of a file called “example.txt” to the group “admin”, you could use the following command:
sudo chgrp admin example.txt
Note that you need to have root privileges (or be a member of the sudo group) to use the chgrp command.