SU(1)                                BSD                                 SU(1)



NAME
     su - substitute user ID temporarily

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

DESCRIPTION
     su permits the temporary substitution of a new user ID.  Before allowing
     this change, however, it demands the password of the specified userid,
     and if it is given, su 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 you specify no userid, "root" is assumed.  To remind the super-user of
     his responsibilities, the shell substitutes a pound sign (#) for its
     usual prompt.

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

     -    Simulate a full login.

FILES
     /etc/passwd     System password file
     /etc/sulog      Log file for su use

BUGS
     Local administrative rules cause restrictions to be placed on who can su
     to "root", even with the relevant password. These rules vary from site to
     site. In particular, you must belong to the group "wheel".

SEE ALSO
     sh(1), csh(1)