chgrp
Command English original intent: change file group ownership
Path where the command: / bin / chgrp
Execute permissions: All users
Syntax: chgrp [user] [file or directory]
Description: owning group to change the file or directory
Add Group
$groupadd
When you create a file, the default default owner is the creator of this group, your group is the creator
example:
$groupadd css
$chgrp css markdown.md