Linux_ Add a regular user

• Useradd User Name

• passwd Password

• SU user name can switch user

• Exit returns the user who was logged in before

• sodu User--"Do not tell the password of the normal user root to see all system files including root

  • visodu Direct open Find root all= (all) all

    • three all means: User can Execute any command on any machine in any form

      • let the Hadoop user execute the Kill

  • when a normal user wants to view the root user's file, precede the Sodu command and enter their own password to view the

    • sudo ls/root

Note: YYP copy a line of DD delete a row shift+zz save and exit

Linux_ Add a regular user