SYNOPSIS

       su [-] [username [arg ...]]

DESCRIPTION

       The  su command allows one user to get the credentials of another with-
       out logging on and off.  The default username is  root  (that  is,  the
       super-user).

       Unless  the  caller  is  the  super-user,  the  user's password must be
       entered (the exact authentication mechanism may depend on PAM  settings
       for su, see pam(8)).  If access is granted, the su command will execute
       the user's shell from the system's password file with  the  appropriate
       user  id,  group  id and supplementary group ids.  Any additional argu-
       ments will be passed to this shell.

       If the first argument is -, a login shell is  executed  in  the  user's
       home  directory  using default environment variables; only the settings
       of the DISPLAY and TERM variables are retained.  In any case, the  PATH
       environment variable is adjusted.

       The su command reads the configuration file /etc/default/su on startup.
       Lines containing the following strings are interpreted:

       CONSOLE=filename
              All attempts are logged to the specified file, usually /dev/con-
              sole.   If no such line is present, console logging is not done.

       PATH=path
              The  default  path  for  non-super-user  accounts.   If   unset,
              /usr/local/bin:/bin:/usr/bin: is assumed.

       SLEEPTIME=seconds
              If  authentication  fails,  su will wait the specified number of
              seconds before printing an error message and  exiting.   Default
              is 4, minimum is 0, maximum is 5 seconds.

       SULOG=filename
              All attempts are logged to the specified file, if present.

       SUPATH=path
              The default path for super-user accounts. If unset,
              /usr/local/sbin:/usr/local/bin:/sbin:/usr/sbin:/bin:/usr/bin is
              assumed.

       SYSLOG=value
              Log  attempts  to  the  syslog(3) LOG_AUTH facility. If value is
              YES, all attempts are  logged;  if  FAIL,  only  the  ones  that
              failed.  LOG_CRIT messages are generated for failed su attempts,
              LOG_NOTICE messages for successful  attempts  to  become  super-
              user, and LOG_INFO messages otherwise.

FILES