deluser

Remove a user

$ sudo deluser [username]

$ sudo deluser --remove-home [username]

$ sudo deluser --backup-to [path/to/backup_directory] --remove-home [username]

$ sudo deluser --remove-all-files [username]

deluser [options] login
deluser --group [options] groupname
deluser [options] login group

--help
    Display help message and exit

--quiet
    Suppress informational output

--remove-home
    Remove user's home directory and mail spool

--remove-all-files
    Remove all files owned by user on the system

--backup
    Create backup of home directory before removal

--backup-to

deluser is a user-friendly command-line utility from the Debian adduser package, serving as a safe frontend to the lower-level userdel(8). It removes specified user accounts from the system's user and group databases (/etc/passwd, /etc/shadow, /etc/group), optionally deleting the user's home directory, mail spool, and all files owned by the user. Unlike userdel, deluser performs sanity checks: it refuses to delete users who are currently logged in (unless forced), verifies username validity, and handles backups to prevent data loss.

Primarily used on Debian-based distributions like Ubuntu, it supports both regular and system users. For groups, it integrates with delgroup functionality via options like --group. It automatically removes the user from secondary groups and can overwrite group memberships. The command is a Perl script, making it portable and extensible.

Key advantages include interactive prompts for confirmation (unless --quiet), safe file removal with exclusion lists, and integration with PAM for authentication. It's essential for system administration tasks like cleaning up test accounts or decommissioning services.

Refuses to delete logged-in users; kill processes first or use --remove-all-files. Does not remove crontabs, at jobs, or print queues automatically. System users may require --system. Backups exclude dotfiles unless specified.

To remove a user from a group: deluser login group. To delete a group: deluser --group groupname.

Settings customizable in /etc/deluser.conf, including removal options and exclusions.

Introduced in Debian 1.1 (1996) as part of Ian Jackson's adduser suite, replacing ad-hoc scripts. Evolved through Debian releases with Perl enhancements for safety and PAM support; widely adopted in Ubuntu and derivatives.

userdel(8), adduser(8), delgroup(1), groupdel(8), useradd(8)