sudo useradd -m xx
sudo passwd xx
sudo usermod -aG sudo xx
sudo usermod -aG wheel xx
验证sudo权限： 切换到xx用户，并验证其sudo权限：
su - xx sudo whoami 如果命令返回root，则表示xx用户已正确配置为具有sudo权限。
[root@ll ~]# sudo useradd -m xx
[root@ll ~]# sudo passwd xx
Changing password for user xx.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.
[root@ll ~]# sudo usermod -aG sudo xx
usermod: group 'sudo' does not exist
[root@ll ~]# sudo usermod -aG wheel xx
[root@ll ~]# sudo usermod -aG sudo xx
usermod: group 'sudo' does not exist
[root@ll ~]# su - xx
[xx@ll ~]$ sudo whoami
We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:
#1) Respect the privacy of others.
#2) Think before you type.
#3) With great power comes great responsibility.
[sudo] password for xx:
root
