addgroup

Addgroup is a command-line utility used on many Linux systems, particularly Debian-based distributions, to create new groups in the system. It updates the group database, typically /etc/group, and is often part of the adduser package.

Usage typically involves invoking addgroup with a group name and optional members or options. A common form is addgroup [options] groupname [member ...], which creates the specified group and may assign initial members or a specific GID. Common options include --system to create a system group with a GID in the system range and --gid to specify a particular group ID. The command updates relevant system files such as /etc/group and related authentication databases.

Relation to other tools: In Debian-based systems, addgroup serves as a friendly front-end to the underlying group management utilities and is commonly paired with adduser. It focuses on modifying the group database rather than creating user accounts. In other distributions, the standard tool is groupadd, which performs a similar function as part of the shadow-utils package.

Privileges and examples: Running addgroup typically requires root privileges. Examples include: sudo addgroup developers to create a new group named developers; sudo addgroup --gid 1001 developers to create the group with a specific GID; and sudo addgroup --system tftp to create a system group used by services. These operations influence file access and permissions by defining group ownership and membership.

See also: delgroup, adduser, groupadd, /etc/group.