usr/src/usr.bin/su/su.1

.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"     @(#)su.1        6.3 (Berkeley) %G%
.\"
.TH SU 1 ""
.UC
.SH NAME
su \- substitute user id temporarily
.SH SYNOPSIS
.B su
[ \-fl] [ login ]
.SH DESCRIPTION
.I Su
requests the password for the specified
.I login,
changes to that
.I userid
and invokes the login's shell 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
.IR environ (7)).
The new user ID stays in force until the shell exits.
.PP
If
.I login
is unspecified, the super-user, ``root'' is assumed.
Only users in the ``wheel'' group (group 0) can
.I su
to ``root'', even with the root password.
To remind the super-user of his responsibilities, by default,
the shell substitutes ``#'' for its usual prompt.
.PP
The
.B \-f
option prevents
.IR csh (1)
from executing the
.I .cshrc
file; thus making
.I su
start up faster.
.PP
The
.B \-l
option simulates a full login.
.SH "SEE ALSO"
sh(1), csh(1), environ(7)