groupdel

Delete an existing group

$ sudo groupdel [group_name]

groupdel GROUP

GROUP
    The name of the group to be removed from the system. This argument is mandatory.

The groupdel command is used to remove a group definition from the local system’s account files, typically /etc/group and /etc/gshadow. This operation is critical for maintaining a clean and accurate user and group database. For the command to succeed, it is imperative that no user currently has the group being deleted as their primary group. If any user's primary group is the one being deleted, the command will fail, and such users must first be assigned a different primary group using tools like usermod. Users who are secondary (supplementary) members of the deleted group will automatically have that group removed from their supplementary group list, ensuring consistency. This command is a fundamental tool for system administrators to efficiently manage and maintain group accounts on a Linux or Unix-like system, contributing to proper access control and security.

Primary Group Conflict: groupdel will fail if the specified group is the primary group for any user. All such users must be re-assigned a different primary group before the group can be deleted.
File Ownership: Deleting a group does not change the group ownership of existing files. Files previously owned by the deleted group will display the numeric Group ID (GID) instead of a group name. Manual intervention (e.g., using chgrp) is required to re-assign ownership.
System Groups: Deleting system-level groups (typically GIDs below 1000, though this can vary by distribution) can have unintended consequences and is generally not recommended unless absolutely necessary.

When a group is deleted, its Group ID (GID) becomes available for reuse. If a new group is subsequently created with the same GID, it could potentially inherit ownership of files or directories that were previously owned by the old group, leading to unexpected permissions or security issues if not properly managed. It is important to audit file ownership after group deletions, especially if GIDs are reused.

groupdel is part of the shadow-utils package, which provides a comprehensive set of tools for managing user and group accounts, including support for shadow passwords. This command has been a staple in Linux and Unix-like environments for many years, offering a standardized and reliable way to remove group entries from the system’s configuration files. Its core functionality has remained largely consistent across different distributions and versions.

groupadd(8), groupmod(8), useradd(8), usermod(8), userdel(8), gpasswd(1)