The chgrp utility will set the group ID of the file named by each file operand to the group ID specified by the group operand.

For each file operand, it will perform actions equivalent to the chown(2) function, called with the following arguments:

• The file operand will be used as the path argument.
• The user ID of the file will be used as the owner argument.
• The specified group ID will be used as the group argument.

Unless chgrp is invoked by a process with appropriate privileges, the set-user-ID and set-group-ID bits of a regular file will be cleared upon successful completion; the set-user-ID and set-group-ID bits of other file types may be cleared.

The operating system has a configuration option _POSIX_CHOWN_RESTRICTED, to restrict ownership changes. When this option is in effect, the owner of the file may change the group of the file only to a group to which the owner belongs. Only the super-user can arbitrarily change owner IDs, whether or not this option is in effect. To set this configuration option, include the following line in /etc/system:

set rstchown = 1

To disable this option, include the following line in /etc/system:

set rstchown = 0

_POSIX_CHOWN_RESTRICTED is enabled by default. See system(4) and fpathconf(2).

-f

Force. Do not report errors.

-h

If the file is a symbolic link, change the group of the symbolic link. Without this option, the group of the file referenced by the symbolic link is changed.

-R

Recursive. chgrp descends through the directory, and any subdirectories, setting the specified group ID as it proceeds. When a symbolic link is encountered, the group of the target file is changed (unless the -h option is specified), but no recursion takes place.

The following operands are supported:

group

A group name from the group database or a numeric group ID. Either specifies a group ID to be given to each file named by one of the file operands. If a numeric group operand exists in the group database as a group name, the group ID number associated with that group name is used as the group ID.

file

A path name of a file whose group ID is to be modified.

See largefile(5) for the description of the behavior of chgrp when encountering files greater than or equal to 2 Gbyte (2³¹ bytes).

See environ(5) for descriptions of the following environment variables that affect the execution of chgrp: LC_CTYPE, LC_MESSAGES, and NLSPATH.

The following exit values are returned:

0

The utility executed successfully and all requested changes were made.

>0

An error occurred.

/etc/group

group file

See attributes(5) for descriptions of the following attributes:

chmod(1), chown(1), id(1M), chown(2), fpathconf(2), group(4), passwd(4), system(4), attributes(5), environ(5), largefile(5)

chgrp is CSI-enabled except for the group name.