GROUPMOD(8) Maintenance Commands and Procedures GROUPMOD(8)

groupmod - modify a group definition on the system

/usr/sbin/groupmod [-g gid [-o]] [-n name] group

The groupmod command modifies the definition of the specified group by modifying the appropriate entry in the /etc/group file.

The following options are supported:

-g gid

Specify the new group ID for the group. This group ID must be a non-negative decimal integer less than MAXUID, as defined in <sys/param.h>. The group ID defaults to the next available (unique) number above 99. (Group IDs from 0-99 are reserved for future applications.)

-n name

Specify the new name for the group. The name argument is a string of no more than eight bytes consisting of characters from the set of lower case alphabetic characters and numeric characters. A warning message will be written if these restrictions are not met. A future release may refuse to accept group fields that do not meet these requirements. The name argument must contain at least one character and must not include a colon (:) or NEWLINE (\n).


Allow the gid to be duplicated (non-unique).

The following operands are supported:


An existing group name to be modified.

The groupmod utility exits with one of the following values:




Invalid command syntax. A usage message for the groupmod command is displayed.


An invalid argument was provided to an option.


gid is not unique (when the -o option is not used).


group does not exist.


name already exists as a group name.


Cannot update the /etc/group file.


group file

group(5), attributes(7), groupadd(8), groupdel(8), logins(8), useradd(8), userdel(8), usermod(8)

The groupmod utility only modifies group definitions in the /etc/group file. If a network name service is being used to supplement the local /etc/group file with additional entries, groupmod cannot change information supplied by the network name service. The groupmod utility will, however, verify the uniqueness of group name and group ID against the external name service.

groupmod fails if a group entry (a single line in /etc/group) exceeds 2047 characters.

January 7, 2018 OmniOS