-f

This option forces the removal of the user account, even if the user is still logged in. It also forcesuserdel to remove the user's home directory and mail spool, even if another user uses the same homedirectory or if the mail spool is not owned by the specified user. If USERGROUPS_ENAB is defined to yes in/etc/login.defs and if a group exists with the same name as the deleted user, then this group will beremoved, even if it is still the primary group of another user.Note: This option is dangerous and may leave your system in an inconsistent state.

-h

Display help message and exit.

-r

Files in the user's home directory will be removed along with the home directory itself and the user'smail spool. Files located in other file systems will have to be searched for and deleted manually.The mail spool is defined by the MAIL_DIR variable in the login.defs file.

-R

Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory.

-Z

Remove any SELinux user mapping for the user's login.CONFIGURATIONThe 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 ismodified or deleted. If not specified, a compile-time default is used.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 theuser'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 makesure 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 usethis 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. ownedby 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 ]; thenecho "Usage: $0 username"exit 1fi# 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/atjobsfind $AT_SPOOL_DIR -name "[^.]*" -type f -user $1 -delete \;# Remove print jobs.lprm $1# All done.exit 0USERGROUPS_ENAB (boolean)If set to yes, userdel will remove the user's group if it contains no more members, and useradd willcreate by default a group with the name of the user.FILES/etc/groupGroup account information./etc/login.defsShadow password suite configuration./etc/passwdUser account information./etc/shadowSecure user account information./etc/subgidPer user subordinate group IDs./etc/subuidPer user subordinate user IDs.EXIT VALUESThe userdel command exits with the following values:0success1can't update password file2invalid command syntax6specified user doesn't exist8user currently logged in10can't update group file12can't remove home directoryCAVEATSuserdel 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 theaccount later. The -f option can force the deletion of this account.You should manually check all file systems to ensure that no files remain owned by this user.You may not remove any NIS attributes on a NIS client. This must be performed on the NIS server.If USERGROUPS_ENAB is defined to yes in /etc/login.defs, userdel will delete the group with the same name asthe user. To avoid inconsistencies in the passwd and group databases, userdel will check that this group isnot used as a primary group for another user, and will just warn without deleting the group otherwise. The -foption can force the deletion of this group.