RHEL笔记__USER＆GROUP

1. su 与su - 的区别
su user 切换到user的使用者
su - user 切换到user，并重新启动user的login shell，载入user的环境变数
2。
find out who you are:
whoami
find out what groups you belong to:
groups , id
find out who is logged in
users,who,w
login/reboot history:
last