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:
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
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
group does not exist.
name already exists as a group name.
Cannot update the /etc/group file.
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.