名称

       userdel - 删除用户账户和相关文件

大纲

       userdel [options] LOGIN

描述

       userdel is a low level utility for removing users. On Debian, administrators should usually use
       deluser(8) instead.

       The userdel command modifies the system account files, deleting all entries that refer to the user name
       LOGIN. The named user must exist.

选项

       The options which apply to the userdel command are:

       -f, --force
           This option forces the removal of the user account and any other requested actions, skipping any
           safety checks.

           Note: This option is dangerous and may leave your system in an inconsistent state.

       -h, --help
           显示帮助信息并退出。

       -r, --remove
           用户主目录中的文件将随用户主目录和用户邮箱一起删除。在其它文件系统中的文件必须手动搜索并删除。

           The mail spool is defined by the MAIL_DIR variable in the login.defs file.

       -R, --root CHROOT_DIR
           Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR
           directory. Only absolute paths are supported.

       -P, --prefix PREFIX_DIR
           Apply changes in the PREFIX_DIR directory and use the configuration files from the PREFIX_DIR
           directory. This option does not chroot and is intended for preparing a cross-compilation target. Some
           limitations: NIS and LDAP users/groups are not verified. PAM authentication is using the host files.
           No SELINUX support.

       -Z, --selinux-user
           移除用户登录的所有 SELinux 用户映射。

配置文件

       The following configuration variables in /etc/login.defs change the behavior of this tool:

       MAIL_DIR (string)
           The mail spool directory. This is needed to manipulate the mailbox when its corresponding user
           account is modified or deleted. If not specified, a compile-time default is used. The parameter
           CREATE_MAIL_SPOOL in /etc/default/useradd determines whether the mail spool should be created.

       MAIL_FILE (string)
           Defines the location of the users mail spool files relatively to their home directory.

       The MAIL_DIR and MAIL_FILE variables are used by useradd, usermod, and userdel to create, move, or delete
       the user's mail spool.

       MAX_MEMBERS_PER_GROUP (number)
           Maximum members per group entry. When the maximum is reached, a new group entry (line) is started in
           /etc/group (with the same name, same password, and same GID).

           The default value is 0, meaning that there are no limits in the number of members in a group.

           This feature (split group) permits to limit the length of lines in the group file. This is useful to
           make sure that lines for NIS groups are not larger than 1024 characters.

           If you need to enforce such limit, you can use 25.

           Note: split groups may not be supported by all tools (even in the Shadow toolsuite). You should not
           use this variable unless you really need it.

       USERDEL_CMD (string)
           If defined, this command is run when removing a user. It should remove any at/cron/print jobs etc.
           owned by the user to be removed (passed as the first argument).

           The return code of the script is not taken into account.

           Here is an example script, which removes the user's cron, at and print jobs:

               #! /bin/sh

               # Check for the required argument.
               if [ $# != 1 ]; then
                    echo "Usage: $0 username"
                    exit 1
               fi

               # Remove cron jobs.
               crontab -r -u $1

               # Remove at jobs.
               # Note that it will remove any jobs owned by the same UID,
               # even if it was shared by a different username.
               AT_SPOOL_DIR=/var/spool/cron/atjobs
               find $AT_SPOOL_DIR -name "[^.]*" -type f -user $1 -delete \;

               # Remove print jobs.
               lprm $1

               # All done.
               exit 0

       USERGROUPS_ENAB (boolean)
           If set to yes, userdel will remove the user's group if it contains no more members, and useradd will
           create by default a group with the name of the user.

文件

       /etc/group
           组账户信息。

       /etc/login.defs
           Shadow 密码套件配置。

       /etc/passwd
           用户账户信息。

       /etc/shadow
           安全用户账户信息。

       /etc/shadow-maint/userdel-pre.d/*, /etc/shadow-maint/userdel-post.d/*
           Run-part files to execute during user deletion. The environment variable ACTION will be populated
           with userdel and SUBJECT with the username.  userdel-pre.d will be executed prior to any user
           deletion.  userdel-post.d will execute after user deletion. If a script exits non-zero then execution
           will terminate.

       /etc/subgid
           Per user subordinate group IDs.

       /etc/subuid
           Per user subordinate user IDs.

退出值

       The userdel command exits with the following values:

       0
           success

       1
           can't update password file

       2
           invalid command syntax

       6
           specified user doesn't exist

       8
           user currently logged in

       10
           can't update group file

       12
           can't remove home directory

CAVEATS

       userdel will not allow you to remove an account if there are running processes which belong to this
       account. In that case, you may have to kill those processes or lock the user's password or account and
       remove the account later. The -f option can force the deletion of this account.

       您应该手动检查所以文件系统，以确保没有遗留此用户的文件。

       您不能在 NIS 客户端上移除任何 NIS 属性。这必须在 NIS 服务器上执行。

       If USERGROUPS_ENAB is defined to yes in /etc/login.defs, userdel will delete the group with the same name
       as the user. To avoid inconsistencies in the passwd and group databases, userdel will check that this
       group is not used as a primary group for another user, and will just warn without deleting the group
       otherwise. The -f option can force the deletion of this group.

参见

       chfn(1), chsh(1), passwd(1), login.defs(5), gpasswd(8), groupadd(8), groupdel(8), groupmod(8), subgid(5),
       subuid(5), useradd(8), usermod(8).

shadow-utils 4.17.4                                2025-09-06                                         USERDEL(8)