SU(1M-SysV)         RISC/os Reference Manual          SU(1M-SysV)



NAME
     su, ssu - substitute user id temporarily

SYNOPSIS
     su [ -f ] [ - ] [ -e ] [ -c ] [ userid [ command [ args... ]
     ] ]

DESCRIPTION
     su demands the password of the specified userid, and if it
     is given, changes to that userid and invokes the shell
     (unless -c is given, see below) without changing the current
     directory.  Unless the -e option is given (see below), the
     user environment is unchanged except for HOME and SHELL,
     which are taken from the password file for the user being
     substituted (see environ(5)).  The new user ID stays in
     force until the shell exits.

     If no userid is specified, ``root'' is assumed.  Only users
     in the ``root'' group (group 0) or in the file
     /etc/su_people (described below) can su to ``root'', even
     with the root password (this can be overridden by changing
     su to have group ``root'' and turning on the set-group-id
     permission).  To remind the super-user of his responsibili-
     ties, the shell substitutes `#' for its usual prompt.

     The command ssu is a link to su. Executing ssu is the same
     as executing the command `su -c root'.

     If the user tries to su to "root" and the root account has a
     password (as is the preferable case), the file
     /etc/su_people is read to see if that username is allowed to
     become root without a password.  Since this can be
     dangerous, the file must have owner 0 (root), group root
     (0), and mode 0600 (read and write by owner only), or it
     will be silently ignored.  See the manual page for
     su_people(4) for details on this file.

OPTIONS
     -f   Prevents csh(1) from executing the .cshrc file, thus
          making su start up faster.

     -    Simulates a full login by executing the shell with name
          `-sh'.

     -e   Do not overwrite any of the environment.  This means
          that the variables HOME and SHELL are retained from the
          original user and that shell is executed.  For csh(1)
          users, this means that the aliases are taken from the
          original user's .cshrc file, which is very convenient.

     -c   If any arguments are given after the username, they are
          executed as a command instead of the shell.  For



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SU(1M-SysV)         RISC/os Reference Manual          SU(1M-SysV)



          example, `su -c root ls' will execute the command ls(1)
          as root, whereas `su root ls' will execute the command
          `csh ls' as root (this is not the same thing).

FILES
     /etc/su_people           Special permission database

SEE ALSO
     sh(1), csh(1) in the User's Reference Manual.
     su_people(4) in the Programmer's Reference Manual.













































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