1*8269e767SBrooks Davis.\" Copyright (c) 1980, 1991, 1993, 1994 2*8269e767SBrooks Davis.\" The Regents of the University of California. All rights reserved. 3*8269e767SBrooks Davis.\" 4*8269e767SBrooks Davis.\" Redistribution and use in source and binary forms, with or without 5*8269e767SBrooks Davis.\" modification, are permitted provided that the following conditions 6*8269e767SBrooks Davis.\" are met: 7*8269e767SBrooks Davis.\" 1. Redistributions of source code must retain the above copyright 8*8269e767SBrooks Davis.\" notice, this list of conditions and the following disclaimer. 9*8269e767SBrooks Davis.\" 2. Redistributions in binary form must reproduce the above copyright 10*8269e767SBrooks Davis.\" notice, this list of conditions and the following disclaimer in the 11*8269e767SBrooks Davis.\" documentation and/or other materials provided with the distribution. 12*8269e767SBrooks Davis.\" 3. Neither the name of the University nor the names of its contributors 13*8269e767SBrooks Davis.\" may be used to endorse or promote products derived from this software 14*8269e767SBrooks Davis.\" without specific prior written permission. 15*8269e767SBrooks Davis.\" 16*8269e767SBrooks Davis.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17*8269e767SBrooks Davis.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18*8269e767SBrooks Davis.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19*8269e767SBrooks Davis.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20*8269e767SBrooks Davis.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21*8269e767SBrooks Davis.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22*8269e767SBrooks Davis.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23*8269e767SBrooks Davis.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24*8269e767SBrooks Davis.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25*8269e767SBrooks Davis.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26*8269e767SBrooks Davis.\" SUCH DAMAGE. 27*8269e767SBrooks Davis.\" 28*8269e767SBrooks Davis.Dd February 8, 2001 29*8269e767SBrooks Davis.Dt SETREUID 2 30*8269e767SBrooks Davis.Os 31*8269e767SBrooks Davis.Sh NAME 32*8269e767SBrooks Davis.Nm setreuid 33*8269e767SBrooks Davis.Nd set real and effective user ID's 34*8269e767SBrooks Davis.Sh LIBRARY 35*8269e767SBrooks Davis.Lb libc 36*8269e767SBrooks Davis.Sh SYNOPSIS 37*8269e767SBrooks Davis.In unistd.h 38*8269e767SBrooks Davis.Ft int 39*8269e767SBrooks Davis.Fn setreuid "uid_t ruid" "uid_t euid" 40*8269e767SBrooks Davis.Sh DESCRIPTION 41*8269e767SBrooks DavisThe real and effective user IDs of the 42*8269e767SBrooks Daviscurrent process are set according to the arguments. 43*8269e767SBrooks DavisIf 44*8269e767SBrooks Davis.Fa ruid 45*8269e767SBrooks Davisor 46*8269e767SBrooks Davis.Fa euid 47*8269e767SBrooks Davisis -1, the current uid is filled in by the system. 48*8269e767SBrooks DavisUnprivileged users may change the real user 49*8269e767SBrooks DavisID to the effective user ID and vice-versa; only the super-user may 50*8269e767SBrooks Davismake other changes. 51*8269e767SBrooks Davis.Pp 52*8269e767SBrooks DavisIf the real user ID is changed (i.e.\& 53*8269e767SBrooks Davis.Fa ruid 54*8269e767SBrooks Davisis not -1) or the effective user ID is changed to something other than 55*8269e767SBrooks Davisthe real user ID, then the saved user ID will be set to the effective user ID. 56*8269e767SBrooks Davis.Pp 57*8269e767SBrooks DavisThe 58*8269e767SBrooks Davis.Fn setreuid 59*8269e767SBrooks Davissystem call has been used to swap the real and effective user IDs 60*8269e767SBrooks Davisin set-user-ID programs to temporarily relinquish the set-user-ID value. 61*8269e767SBrooks DavisThis purpose is now better served by the use of the 62*8269e767SBrooks Davis.Xr seteuid 2 63*8269e767SBrooks Davissystem call. 64*8269e767SBrooks Davis.Pp 65*8269e767SBrooks DavisWhen setting the real and effective user IDs to the same value, 66*8269e767SBrooks Davisthe standard 67*8269e767SBrooks Davis.Fn setuid 68*8269e767SBrooks Davissystem call is preferred. 69*8269e767SBrooks Davis.Sh RETURN VALUES 70*8269e767SBrooks Davis.Rv -std setreuid 71*8269e767SBrooks Davis.Sh ERRORS 72*8269e767SBrooks Davis.Bl -tag -width Er 73*8269e767SBrooks Davis.It Bq Er EPERM 74*8269e767SBrooks DavisThe current process is not the super-user and a change 75*8269e767SBrooks Davisother than changing the effective user-id to the real user-id 76*8269e767SBrooks Daviswas specified. 77*8269e767SBrooks Davis.El 78*8269e767SBrooks Davis.Sh SEE ALSO 79*8269e767SBrooks Davis.Xr getuid 2 , 80*8269e767SBrooks Davis.Xr issetugid 2 , 81*8269e767SBrooks Davis.Xr seteuid 2 , 82*8269e767SBrooks Davis.Xr setuid 2 83*8269e767SBrooks Davis.Sh HISTORY 84*8269e767SBrooks DavisThe 85*8269e767SBrooks Davis.Fn setreuid 86*8269e767SBrooks Davissystem call appeared in 87*8269e767SBrooks Davis.Bx 4.2 . 88