user and group

 

useradd
-d, --home HOME_DIR
   The new user will be created using HOME_DIR as the value for the user's login directory. The default is to append
the LOGIN name to BASE_DIR and use that as the login directory name. The directory HOME_DIR does not have to exist
but will not be created if it is missing.
-M
  Do no create the user's home directory, even if the system wide setting from /etc/login.defs (CREATE_HOME) is set to yes.


修改用户的密码
sudo passwd muhe221


查看所有用户和用户组：
cat /etc/passwd
cat /etc/group

删除一个用户
sudo userdel muhe221
sudo useradd muhe221

删除一个组
sudo groupadd ftpgroup
sudo groupdel ftpgroup


mutian@mutian:/etc$ wc -l group
68 group
mutian@mutian:/etc$ sudo groupadd sx221
[sudo] password for mutian: 
mutian@mutian:/etc$ wc -l group
69 group
mutian@mutian:/etc$ sudo groupdel sx221
mutian@mutian:/etc$ wc -l group
68 group