Add users and groups to centos

I have never been very familiar with this. Now let's summarize it.

Create two groups and specify the GID:

Groupadd-G 1200 postdropgroupadd-G 1000 Postfix

Create a user without a home directory. Specify the group as Postfix and the additional group as postdrop. You cannot log on to the system:

Useradd-m-u 1000-G postfix-G postdrop-S/sbin/nologin Postfix

When you delete a user, the following message is displayed:

Userdel: User newname is currently logged in

This user can be deleted brute force: userdel-r-F xxxx

Tip:Userdel:Warning: Can't remove/var/mail/git: no such file or directory

Userdel:Git home directory (/home/GIT) not found

It doesn't matter. The user has been deleted successfully.

Add users and groups to centos