Linux command format

 1. Command Prompt

   [root@localhost~]#

   in:

          root : the currently logged in user

          localhost: hostname

          ~: current directory

          #: Prompt for superuser

                A normal user's prompt uses $

2. Command format

  command [options] [parameters]

  Note: Individual command usage does not follow this format

             When there are multiple options, they can be written together

            Simplified and full options -a is equal to --all