[apple/libc.git] / sys / setreuid.2

.\" Copyright (c) 1980, 1991, 1993, 1994
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
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.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
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.\"     @(#)setreuid.2	8.2 (Berkeley) 4/16/94
.\" $FreeBSD: src/lib/libc/sys/setreuid.2,v 1.6.2.6 2001/12/14 18:34:01 ru Exp $
.\"
.Dd February 8, 2001
.Dt SETREUID 2
.Os
.Sh NAME
.Nm setreuid
.Nd set real and effective user ID's
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In unistd.h
.Ft int
.Fn setreuid "uid_t ruid" "uid_t euid"
.Sh DESCRIPTION
The real and effective user IDs of the
current process are set according to the arguments.
If
.Fa ruid
or
.Fa euid
is -1, the current uid is filled in by the system.
Unprivileged users may change the real user
ID to the effective user ID and vice-versa; only the super-user may
make other changes.
.Pp
The
.Fn setreuid
function has been used to swap the real and effective user IDs
in set-user-ID programs to temporarily relinquish the set-user-ID value.
This purpose is now better served by the use of the
.Fn seteuid
function (see
.Xr setuid 2 ) .
.Pp
When setting the real and effective user IDs to the same value,
the standard
.Fn setuid
function is preferred.
.Sh RETURN VALUES
.Rv -std setreuid
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er EPERM
The current process is not the super-user and a change
other than changing the effective user-id to the real user-id
was specified.
.El
.Sh SEE ALSO
.Xr getuid 2 ,
.Xr issetugid 2 ,
.Xr seteuid 2 ,
.Xr setuid 2
.Sh HISTORY
The
.Fn setreuid
system call appeared in
.Bx 4.2 .
Commit	Line	Data
5b2abdfb	1	.\" Copyright (c) 1980, 1991, 1993, 1994
e9ce8d39 A	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	.\"
5b2abdfb A	32	.\" @(#)setreuid.2 8.2 (Berkeley) 4/16/94
5b2abdfb A	33	.\" $FreeBSD: src/lib/libc/sys/setreuid.2,v 1.6.2.6 2001/12/14 18:34:01 ru Exp $
e9ce8d39	34	.\"
5b2abdfb A	35	.Dd February 8, 2001
5b2abdfb A	36	.Dt SETREUID 2
e9ce8d39 A	37	.Os
e9ce8d39 A	38	.Sh NAME
5b2abdfb A	39	.Nm setreuid
5b2abdfb A	40	.Nd set real and effective user ID's
e9ce8d39 A	41	.Sh LIBRARY
	42	.Lb libc
	43	.Sh SYNOPSIS
5b2abdfb	44	.In unistd.h
e9ce8d39	45	.Ft int
5b2abdfb	46	.Fn setreuid "uid_t ruid" "uid_t euid"
e9ce8d39	47	.Sh DESCRIPTION
5b2abdfb A	48	The real and effective user IDs of the
5b2abdfb A	49	current process are set according to the arguments.
e9ce8d39	50	If
5b2abdfb A	51	.Fa ruid
	52	or
	53	.Fa euid
	54	is -1, the current uid is filled in by the system.
	55	Unprivileged users may change the real user
	56	ID to the effective user ID and vice-versa; only the super-user may
	57	make other changes.
	58	.Pp
e9ce8d39	59	The
5b2abdfb A	60	.Fn setreuid
	61	function has been used to swap the real and effective user IDs
	62	in set-user-ID programs to temporarily relinquish the set-user-ID value.
	63	This purpose is now better served by the use of the
	64	.Fn seteuid
	65	function (see
	66	.Xr setuid 2 ) .
	67	.Pp
	68	When setting the real and effective user IDs to the same value,
	69	the standard
	70	.Fn setuid
	71	function is preferred.
e9ce8d39	72	.Sh RETURN VALUES
5b2abdfb	73	.Rv -std setreuid
e9ce8d39	74	.Sh ERRORS
e9ce8d39	75	.Bl -tag -width Er
5b2abdfb A	76	.It Bq Er 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
	79	was specified.
	80	.El
e9ce8d39	81	.Sh SEE ALSO
5b2abdfb A	82	.Xr getuid 2 ,
	83	.Xr issetugid 2 ,
	84	.Xr seteuid 2 ,
	85	.Xr setuid 2
e9ce8d39 A	86	.Sh HISTORY
e9ce8d39 A	87	The
5b2abdfb A	88	.Fn setreuid
	89	system call appeared in
	90	.Bx 4.2 .