# su(1)

    NAME
         su - temporarily log in as superuser or another user

    SYNOPSIS
         su [name]

    EXAMPLES

         su                  # Become superuser

         su ast              # Become ast

    DESCRIPTION

         Su can be used to temporarily login as another user.  It prompts for  the
         superuser  password.   If  the  correct password is entered, su creates a
         shell with the desired uid.  If no name is specified,  root  is  assumed.
         To  exit  the  temporary shell, type CTRL-D.  When memory is tight, it is
         better to become superuser by logging out and then logging  in  again  as
         root,  rather  than  using  su since the latter creates an extra shell in
         memory.  Any user with a zero group id need not type  a  password.   This
         makes life easier for the system administrator.

    SEE ALSO
         login(1).