[apple/xnu.git] / bsd / man / man2 / issetugid.2

.\"	$OpenBSD: issetugid.2,v 1.7 1997/02/18 00:16:09 deraadt Exp $
.\"
.\" Copyright (c) 1980, 1991, 1993
.\"	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
.\"    notice, this list of conditions and the following disclaimer.
.\" 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.
.\"
.Dd August, 25 1996
.Dt ISSETUGID 2
.Os OpenBSD 2.0
.Sh NAME
.Nm issetugid
.Nd is current executable running setuid or setgid
.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft int
.Fn issetugid void
.Sh DESCRIPTION
The
.Fn issetugid
function returns 1 if the process was made setuid or setgid as
the result of the last
.Fn execve
system call.
Otherwise it returns 0.
.Pp
This system call exists so that library routines (inside libc, libtermlib,
or other libraries) can gaurantee safe behavior when used inside
setuid or setgid programs.
Some library routines may not be passed sufficient information to know
if the current program was started setuid or setgid because higher level
calling code may have made changes to the uid or the euid.
In particular, it is wise to use this call to determine if a
pathname returned from a
.Fn getenv
call may safely be used to
.Fn open
the specified file.
.Pp
.Fn issetugid
is unaffected by calls to
.Fn setuid ,
.Fn fork ,
and other such calls.  It is only controlled by
.Fn execve .
.Sh ERRORS
The
.Fn issetugid
function is always successful, and no return value is reserved to
indicate an error.
.Sh SEE ALSO
.Xr execve 2 ,
.Xr setuid 2 ,
.Xr seteuid 2,
.Xr setgid 2 ,
.Xr setegid 2
.Sh HISTORY
A
.Fn lstat
function call appeared in
OpenBSD 2.0
Commit	Line	Data
9bccf70c A	1	.\" $OpenBSD: issetugid.2,v 1.7 1997/02/18 00:16:09 deraadt Exp $
	2	.\"
	3	.\" Copyright (c) 1980, 1991, 1993
	4	.\" The Regents of the University of California. All rights reserved.
	5	.\"
	6	.\" Redistribution and use in source and binary forms, with or without
	7	.\" modification, are permitted provided that the following conditions
	8	.\" are met:
	9	.\" 1. Redistributions of source code must retain the above copyright
	10	.\" notice, this list of conditions and the following disclaimer.
	11	.\" 2. Redistributions in binary form must reproduce the above copyright
	12	.\" notice, this list of conditions and the following disclaimer in the
	13	.\" documentation and/or other materials provided with the distribution.
	14	.\" 3. All advertising materials mentioning features or use of this software
	15	.\" must display the following acknowledgement:
	16	.\" This product includes software developed by the University of
	17	.\" California, Berkeley and its contributors.
	18	.\" 4. Neither the name of the University nor the names of its contributors
	19	.\" may be used to endorse or promote products derived from this software
	20	.\" without specific prior written permission.
	21	.\"
	22	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	23	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	24	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	25	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	26	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	27	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	28	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	29	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	30	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	31	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	32	.\" SUCH DAMAGE.
	33	.\"
	34	.Dd August, 25 1996
	35	.Dt ISSETUGID 2
	36	.Os OpenBSD 2.0
	37	.Sh NAME
	38	.Nm issetugid
	39	.Nd is current executable running setuid or setgid
	40	.Sh SYNOPSIS
	41	.Fd #include <unistd.h>
	42	.Ft int
	43	.Fn issetugid void
	44	.Sh DESCRIPTION
	45	The
	46	.Fn issetugid
	47	function returns 1 if the process was made setuid or setgid as
	48	the result of the last
	49	.Fn execve
	50	system call.
	51	Otherwise it returns 0.
	52	.Pp
	53	This system call exists so that library routines (inside libc, libtermlib,
	54	or other libraries) can gaurantee safe behavior when used inside
	55	setuid or setgid programs.
	56	Some library routines may not be passed sufficient information to know
	57	if the current program was started setuid or setgid because higher level
	58	calling code may have made changes to the uid or the euid.
	59	In particular, it is wise to use this call to determine if a
	60	pathname returned from a
	61	.Fn getenv
	62	call may safely be used to
	63	.Fn open
	64	the specified file.
65	.Pp
66	.Fn issetugid
67	is unaffected by calls to
68	.Fn setuid ,
69	.Fn fork ,
70	and other such calls. It is only controlled by
71	.Fn execve .
72	.Sh ERRORS
73	The
74	.Fn issetugid
75	function is always successful, and no return value is reserved to
76	indicate an error.
77	.Sh SEE ALSO
78	.Xr execve 2 ,
79	.Xr setuid 2 ,
80	.Xr seteuid 2,
81	.Xr setgid 2 ,
82	.Xr setegid 2
83	.Sh HISTORY
84	A
85	.Fn lstat
86	function call appeared in
87	OpenBSD 2.0