xref: /openbsd-src/lib/libc/sys/getgroups.2 (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1.\"	$OpenBSD: getgroups.2,v 1.7 2000/10/18 05:12:09 aaron Exp $
2.\"	$NetBSD: getgroups.2,v 1.8 1995/02/27 12:32:57 cgd Exp $
3.\"
4.\" Copyright (c) 1983, 1991, 1993
5.\"	The Regents of the University of California.  All rights reserved.
6.\"
7.\" Redistribution and use in source and binary forms, with or without
8.\" modification, are permitted provided that the following conditions
9.\" are met:
10.\" 1. Redistributions of source code must retain the above copyright
11.\"    notice, this list of conditions and the following disclaimer.
12.\" 2. Redistributions in binary form must reproduce the above copyright
13.\"    notice, this list of conditions and the following disclaimer in the
14.\"    documentation and/or other materials provided with the distribution.
15.\" 3. All advertising materials mentioning features or use of this software
16.\"    must display the following acknowledgement:
17.\"	This product includes software developed by the University of
18.\"	California, Berkeley and its contributors.
19.\" 4. Neither the name of the University nor the names of its contributors
20.\"    may be used to endorse or promote products derived from this software
21.\"    without specific prior written permission.
22.\"
23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33.\" SUCH DAMAGE.
34.\"
35.\"     @(#)getgroups.2	8.2 (Berkeley) 4/16/94
36.\"
37.Dd April 16, 1994
38.Dt GETGROUPS 2
39.Os
40.Sh NAME
41.Nm getgroups
42.Nd get group access list
43.Sh SYNOPSIS
44.Fd #include <sys/types.h>
45.Fd #include <unistd.h>
46.Ft int
47.Fn getgroups "int gidsetlen" "gid_t *gidset"
48.Sh DESCRIPTION
49.Fn getgroups
50gets the current group access list of the current user process
51and stores it in the array
52.Fa gidset .
53The parameter
54.Fa gidsetlen
55indicates the number of entries that may be placed in
56.Fa gidset .
57.Fn getgroups
58returns the actual number of groups returned in
59.Fa gidset .
60No more than
61.Dv {NGROUPS_MAX}
62will ever
63be returned.
64If
65.Fa gidsetlen
66is 0,
67.Fn getgroups
68returns the number of groups without modifying the
69.Fa gidset
70array.
71.Sh RETURN VALUES
72A successful call returns the number of groups in the group set.
73A value of \-1 indicates that an error occurred, and the error
74code is stored in the global variable
75.Va errno .
76.Sh ERRORS
77The possible errors for
78.Fn getgroups
79are:
80.Bl -tag -width Er
81.It Bq Er EINVAL
82The argument
83.Fa gidsetlen
84is smaller than the number of groups in the group set.
85.It Bq Er EFAULT
86The argument
87.Fa gidset
88specifies an invalid address.
89.El
90.Sh SEE ALSO
91.Xr setgroups 2 ,
92.Xr initgroups 3
93.Sh HISTORY
94The
95.Fn getgroups
96function call appeared in
97.Bx 4.2 .
98