在linux下创建了用户，发现有问题，想删除重建，结果就遇到了这个问题，网上找解决方法，发现有如下两种方法：
感觉都比较麻烦，既然提示是该用户已经登录，那么将该用户退出登录不就可以了么，测试了一下，果然可以，具体过程如下：
[root@linuxserver ~]# useradd stone
[root@linuxserver ~]# passwd stone
Changing password for user stone.
New password:
BAD PASSWORD: it is too simplistic/systematic
BAD PASSWORD: is too simple
Retype new password:
passwd: all authentication tokens updated successfully.
[root@linuxserver ~]# su - stone
[stone@linuxserver ~]$ su -
Password:
[root@linuxserver ~]# userdel -r stone
userdel: user stone is currently logged in
[root@linuxserver ~]# logout
[stone@linuxserver ~]$ logout
[root@linuxserver ~]# userdel -r stone
[root@linuxserver ~]# passwd stone
Changing password for user stone.
New password:
BAD PASSWORD: it is too simplistic/systematic
BAD PASSWORD: is too simple
Retype new password:
passwd: all authentication tokens updated successfully.
[root@linuxserver ~]# su - stone
[stone@linuxserver ~]$ su -
Password:
[root@linuxserver ~]# userdel -r stone
userdel: user stone is currently logged in
[root@linuxserver ~]# logout
[stone@linuxserver ~]$ logout
[root@linuxserver ~]# userdel -r stone
大功告成！