27. 講個笑話:userdel -rf hal
●
-f, --force: This option forces the removal of the
user account, even if the user is still logged in.
●
-r, --remove: Files in the user's home directory
will be removed along with the home directory
itself and the user's mail spool.
●
hal 的 home directory 是 '/'
●
→ 我不知不覺間使出了 rm -rf / 自爆必殺技!