bsd man page for su

SU(1)							      General Commands Manual							     SU(1)

NAME
       su - substitute user id temporarily

SYNOPSIS
       su [ -f ] [ - ] [ userid ]

DESCRIPTION
       Su  demands  the password of the specified userid, and if it is given, changes to that userid and invokes the Shell sh(1) or csh(1) without
       changing the current directory.	The user environment is unchanged except for HOME and SHELL, which are taken from the  password  file  for
       the user being substituted (see environ(7)).  The new user ID stays in force until the Shell exits.

       If  no  userid is specified, ``root'' is assumed.  Only users in the ``wheel'' group (group 0) can su to ``root'', even with the root pass-
       word.  To remind the super-user of his responsibilities, the Shell substitutes `#' for its usual prompt.

       The -f option prevents csh(1) from executing the .cshrc file; thus making su start up faster.

       The - option simulates a full login.

SEE ALSO
       sh(1), csh(1)

3rd Berkeley Distribution					    May 5, 1986 							     SU(1)