groupmod - Modifies a group definition on the system
/usr/sbin/groupmod [-g gid [-o]] [-n newgroup] [-x extended_option] group_name
/usr/sbin/groupmod -D [-x extended_option]
When used without arguments, this flag displays the system defaults for group information. If invoked with other flags, it sets the system defaults for the flag specified. Specifies a new group identification number (GID) for the group being modified. The GID must be a non-negative decimal integer. When the -o flag is used, the GID can be duplicated. Specifies a new name for the group. The group name can be any printable characters, except the colon (:) and newline (\n) characters. Lets a group identification (GID) number be duplicated (non-unique). This flag can be used only with the -g flag. The following extended_option attributes are available. If you use more than one extended_option attribute on the command line, you must precede each attribute with the -x flag or enclose the desired attributes in quotes. Specifies the largest numeric identifier, which may be associated with a group. This attribute can be used only with the -D flag. The value of the max_gid attribute must be a non-negative decimal number. Specifies the smallest numeric identifier, which may be associated with a group. This attribute can be used only with the -D flag. The value of the min_gid attribute must be a non-negative decimal number.
Specifies the next available group identifier number (GID) in the range of min_gid to max_gid. This attribute can be used only with the -D flag. The value of the next_gid attribute must be a non-negative decimal number. Indicates that the group is distributed. The value of the distributed=n attribute must be 0 or 1. If set to 0, the group is maintained on the local system. If set to 1, the group is maintained in the NIS master database on the running system. Indicates that the group is local. The value of the local=n attribute must be 0 or 1. If set to 1, the group is stored on a local database. If set to 0, the group information is not stored locally, but exists in the NIS master database. Specifies the name of the group to be modified. The groupname must exist.
The groupmod command lets the system administrator modify and rename groups on the system. In addition, the system administrator can use the -D and -x flags on the same command line to change the maximum, minimum, and/or next available group identifier numbers, as well as specify whether the group account is local or resides in the NIS master database. If the -x flag is not specified on the command line, the system modifies the group information in the appropriate database as specified by the system defaults.
The default behavior on the system for the groupmod command is distributed=0 and local=1. With these values, the system modifies the group information in the local database by default. Setting the distributed= and local= attributes to the same value (for example, distributed=0 and local=0) produces an error.
You must have superuser privilege to execute this command.
The following example changes the GID of the group, testgrp, to 451: % groupmod -g 451 testgrp
The following example changes the group name of the testgrp group to unxgrp: % groupmod -n unxgrp testgrp
The following example changes the maximum group ID (max_gid) to 300 and the next available group ID (next_gid) to 30: % groupmod -D -x max_gid=300 -x next_gid=30 or % groupmod -D -x"max_gid=300 next_gid=30"
The groupmod command exits with one of the following values: Success Invalid command syntax or insufficient privilege. A usage message for the groupmod command or an error message is displayed. An invalid argument was provided to an option. The GID is not unique. The group does not exist. The group name is not unique. Cannot update the group database.
The groupmod command operates on the appropriate files for the specific level of system security.
Commands: groupadd(8), groupdel(8), useradd(8), userdel(8), usermod(8)
Documents: System Administration, Security delim off