1.\" $OpenBSD: getgroups.2,v 1.11 2008/08/04 07:08:23 jmc 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. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)getgroups.2 8.2 (Berkeley) 4/16/94 32.\" 33.Dd $Mdocdate: August 4 2008 $ 34.Dt GETGROUPS 2 35.Os 36.Sh NAME 37.Nm getgroups 38.Nd get group access list 39.Sh SYNOPSIS 40.Fd #include <sys/types.h> 41.Fd #include <unistd.h> 42.Ft int 43.Fn getgroups "int gidsetlen" "gid_t *gidset" 44.Sh DESCRIPTION 45.Fn getgroups 46gets the current group access list of the current user process 47and stores it in the array 48.Fa gidset . 49The parameter 50.Fa gidsetlen 51indicates the number of entries that may be placed in 52.Fa gidset . 53.Fn getgroups 54returns the actual number of groups returned in 55.Fa gidset . 56No more than 57.Dv {NGROUPS_MAX} 58will ever 59be returned. 60If 61.Fa gidsetlen 62is 0, 63.Fn getgroups 64returns the number of groups without modifying the 65.Fa gidset 66array. 67.Sh RETURN VALUES 68A successful call returns the number of groups in the group set. 69A value of \-1 indicates that an error occurred, and the error 70code is stored in the global variable 71.Va errno . 72.Sh ERRORS 73The possible errors for 74.Fn getgroups 75are: 76.Bl -tag -width Er 77.It Bq Er EINVAL 78The argument 79.Fa gidsetlen 80is smaller than the number of groups in the group set. 81.It Bq Er EFAULT 82The argument 83.Fa gidset 84specifies an invalid address. 85.El 86.Sh SEE ALSO 87.Xr getgid 2 , 88.Xr setgid 2 , 89.Xr setgroups 2 , 90.Xr initgroups 3 91.Sh HISTORY 92The 93.Fn getgroups 94function call appeared in 95.Bx 4.2 . 96