`chgrp`

Change file group ownership (POSIX)

Syntax:

chgrp [-Rv] group file...

Options:

-R: Recursively change group ownership of files. For each file that names a directory, chgrp changes the group of the directory and of all files in the file hierarchy below it.
-v: Verbose. Display to standard output the operations which are being performed.
group: A group name from the group database, or a numeric group ID.
file: The pathname of a file whose group ID is to be modified.

Description:

The chgrp utility lets you change the group ownership of one or more files. For each file you name, chgrp sets the file's group ID to that specified by the group operand.

If you invoke chgrp with the -R option, and chgrp attempts but fails to change the group ID of a particular file in a specified file hierarchy, it continues to process the remaining files in the hierarchy. The chgrp utility can fail to change the group ID of a file if you don't have appropriate permissions.

You must be root to change the group ownership from one group to another.

Normal users can change the ownership of a group to themselves, but they can't change the ownership of a group to which they don't belong.

Examples:

Change file group of myfile to 27:

chgrp 27 myfile

Change file group of myfile to technical:

chgrp technical myfile

Files:

/etc/groups

This file defines the known group IDs for the system. It associates each group name with a numerical group ID and a list of usernames who are members of the group.

Entries in this file appear in the following format:

groupname::groupid:user[,user]...

Exit status:

0: The utility executed successfully and all requested changes were made.
>0: An error occurred.