1.\" Copyright (c) 1988, 1990, 1993, 1994 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)su.1 8.2 (Berkeley) 4/18/94 33.\" $Id$ 34.\" 35.\" this is for hilit19's braindeadness: " 36.Dd April 18, 1994 37.Dt SU 1 38.Os 39.Sh NAME 40.Nm su 41.Nd substitute user identity 42.Sh SYNOPSIS 43.Nm su 44.Op Fl Kflm 45.Op Ar login Op Ar args 46.Sh DESCRIPTION 47.Nm Su 48requests the Kerberos password for 49.Ar login 50(or for 51.Dq Ar login Ns .root , 52if no login is provided), and switches to 53that user and group ID after obtaining a Kerberos ticket granting ticket. 54A shell is then executed. 55.Nm Su 56will resort to the local password file to find the password for 57.Ar login 58if there is a Kerberos error. 59If 60.Nm su 61is executed by root, no password is requested and a shell 62with the appropriate user ID is executed; no additional Kerberos tickets 63are obtained. 64.Pp 65By default, the environment is unmodified with the exception of 66.Ev USER , 67.Ev HOME , 68and 69.Ev SHELL . 70.Ev HOME 71and 72.Ev SHELL 73are set to the target login's default values. 74.Ev USER 75is set to the target login, unless the target login has a user ID of 0, 76in which case it is unmodified. 77The invoked shell is the target login's. 78This is the traditional behavior of 79.Nm su . 80.Pp 81The options are as follows: 82.Bl -tag -width Ds 83.It Fl K 84Do not attempt to use Kerberos to authenticate the user. 85.It Fl f 86If the invoked shell is 87.Xr csh 1 , 88this option prevents it from reading the 89.Dq Pa .cshrc 90file. 91.It Fl l 92Simulate a full login. 93The environment is discarded except for 94.Ev HOME , 95.Ev SHELL , 96.Ev PATH , 97.Ev TERM , 98and 99.Ev USER . 100.Ev HOME 101and 102.Ev SHELL 103are modified as above. 104.Ev USER 105is set to the target login. 106.Ev PATH 107is set to 108.Dq Pa /bin:/usr/bin . 109.Ev TERM 110is imported from your current environment. 111The invoked shell is the target login's, and 112.Nm su 113will change directory to the target login's home directory. 114.It Fl m 115Leave the environment unmodified. 116The invoked shell is your login shell, and no directory changes are made. 117As a security precaution, if the target user's shell is a non-standard 118shell (as defined by 119.Xr getusershell 3 ) 120and the caller's real uid is 121non-zero, 122.Nm su 123will fail. 124.El 125.Pp 126The 127.Fl l 128and 129.Fl m 130options are mutually exclusive; the last one specified 131overrides any previous ones. 132.Pp 133If the optional 134.Ar args 135are provided on the command line, they are passed to the login shell of 136the target login. This allows it to pass arbitrary commands via 137the 138.Fl c 139option as understood by most shells. Note that 140.Fl c 141usually expects a single argument only; you have to quote it when 142passing multiple words. 143.Pp 144Only users in group 0 (normally 145.Dq wheel ) 146can 147.Nm su 148to 149.Dq root . 150.Pp 151By default (unless the prompt is reset by a startup file) the super-user 152prompt is set to 153.Dq Sy \&# 154to remind one of its awesome power. 155.Sh SEE ALSO 156.Xr csh 1 , 157.Xr login 1 , 158.Xr sh 1 , 159.Xr kinit 1 , 160.Xr kerberos 1 , 161.Xr passwd 5 , 162.Xr group 5 , 163.Xr environ 7 164.Sh ENVIRONMENT 165Environment variables used by 166.Nm su : 167.Bl -tag -width HOME 168.It Ev HOME 169Default home directory of real user ID unless modified as 170specified above. 171.It Ev PATH 172Default search path of real user ID unless modified as specified above. 173.It Ev TERM 174Provides terminal type which may be retained for the substituted 175user ID. 176.It Ev USER 177The user ID is always the effective ID (the target user ID) after an 178.Nm su 179unless the user ID is 0 (root). 180.El 181.Sh EXAMPLES 182.Bl -tag -width 5n -compact 183.It Li "su man -c catman" 184Runs the command 185.Li catman 186as user 187.Li man . 188You will be asked for man's password unless your real UID is 0. 189.It Li "su man -c 'catman /usr/share/man /usr/local/man /usr/X11R6/man'" 190Same as above, but the target command constitutes of more than a 191single word. 192.It Li "su -l foo" 193Pretend a login for user 194.Li foo . 195.El 196.Sh HISTORY 197A 198.Nm 199command appeared in 200.At v1 . 201