chgrp - change the group ownership of files


chgrp [ options ] [[owner:]group] file ...


chgrp changes the group ownership of each file to group, which can be either a group name or a numeric group id. The user ownership of each file may also be changed to user by prepending user: to the group name.


-b, --before=file

Only change files with ctime before (less than) the mtime of file.
-c, --changes

Describe only files whose ownership actually changes.
-f, --quiet|silent

Do not report files whose ownership fails to change.
-h|l, --symlink

Change the ownership of symbolic links on systems that support lchown(2). Implies --physical.
-m, --map

The first operand is interpreted as a file that contains a map of space separated from_uid:from_gid to_uid:to_gid pairs. The uid or gid part of each pair may be omitted to mean any uid or gid. Ownership of files matching the from part of any pair is changed to the corresponding to part of the pair. The matching for each file operand is in the order uid:gid, uid:, :gid. For a given file, once a uid or gid mapping is determined it is not overridden by any subsequent match. Unmatched files are silently ignored.
-n, --show

Show actions but don't execute.
-N, --numeric

By default numeric user and group id operands are first interpreted as names; if no name exists then they are interpreted as explicit numeric ids. --numeric interprets numeric id operands as numeric ids.
-r, --reference=file

Omit the explicit ownership operand and use the ownership of file instead.
-u, --unmapped

Print a diagnostic for each file for which either the uid or gid or both were not mapped.
-v, --verbose

Describe changed permissions of all files.
-H, --metaphysical

Follow symbolic links for command arguments; otherwise don't follow symbolic links when traversing directories.
-L, --logical|follow

Follow symbolic links when traversing directories.
-P, --physical|nofollow

Don't follow symbolic links when traversing directories.
-R, --recursive

Recursively change ownership of directories and their contents.
-X, --test

Canonicalize output for testing.


All files changed successfully.

Unable to change ownership of one or more files.


chmod(1), chown(2), tw(1), getconf(1), ls(1)



chgrp (AT&T Research) 2012-04-20

Glenn Fowler <>

David Korn <>

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