holiday12

holiday12--linux basis

super user(root)

• In linux, account root usually use for system maintain and managerment ,it has all access permission for all resources of system
• In most linux system version,not recommended use root account log in system directly

sudo

• su is abbreviation of substitute user , repersent use another user
• sudo command used to execute commands in othter user , default identity is root

group managerment command

tips:add/delete group must execute as root

add/delete group

command	action
groupadd [group name]	add group
groupdel [group name]	delete group
cat /etc/group	make sure group information
chgrp -R [group name] [file/directory]	recursive modify the group of file directory

user managerment command

tips:add/delete user or modify other users password must execute as root

add/delete user and change password

command	action	description
useradd -m -g [grup] [new user]	add new user	-m automatically create home directory, -g appoint the user's group, otherwise will create a group which has same name with user
passwd user	set user's password	if you are normal user, you can use passwd command to change password directly
userdel -r [user name]	delete user	-r option will delete home directory automatically

cat /etc/passwd | grep [user name] #make sure user's information