1 .\" Copyright (c) 1980, 1991, 1993, 1994
2 .\" The Regents of the University of California. All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
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.
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
32 .\" @(#)setreuid.2 8.2 (Berkeley) 4/16/94
39 .Nd set real and effective user ID's
41 .Fd #include <unistd.h>
43 .Fn setreuid "uid_t ruid" "uid_t euid"
45 The real and effective user IDs of the
46 current process are set according to the arguments.
51 is -1, the current uid is filled in by the system.
52 Unprivileged users may change the real user
53 ID to the effective user ID and vice-versa; only the super-user may
58 function has been used to swap the real and effective user IDs
59 in set-user-ID programs to temporarily relinquish the set-user-ID value.
60 This purpose is now better served by the use of the
65 When setting the real and effective user IDs to the same value,
68 function is preferred.
70 Upon successful completion, a value of 0 is returned. Otherwise,
71 a value of -1 is returned and
73 is set to indicate the error.
75 .Bl -tag -width [EPERM]
77 The current process is not the super-user and a change
78 other than changing the effective user-id to the real user-id
89 system call appeared in