1.\" $OpenBSD: getgroups.2,v 1.15 2019/07/08 18:48:30 anton 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: July 8 2019 $ 34.Dt GETGROUPS 2 35.Os 36.Sh NAME 37.Nm getgroups 38.Nd get group access list 39.Sh SYNOPSIS 40.In unistd.h 41.Ft int 42.Fn getgroups "int gidsetlen" "gid_t *gidset" 43.Sh DESCRIPTION 44.Fn getgroups 45gets the current group access list of the current user process 46and stores it in the array 47.Fa gidset . 48The parameter 49.Fa gidsetlen 50indicates the number of entries that may be placed in 51.Fa gidset . 52.Fn getgroups 53returns the actual number of groups returned in 54.Fa gidset . 55No more than 56.Dv NGROUPS_MAX 57will ever 58be returned. 59If 60.Fa gidsetlen 61is 0, 62.Fn getgroups 63returns the number of groups without modifying the 64.Fa gidset 65array. 66.Sh RETURN VALUES 67A successful call returns the number of groups in the group set. 68A value of \-1 indicates that an error occurred, and the error 69code is stored in the global variable 70.Va errno . 71.Sh ERRORS 72The possible errors for 73.Fn getgroups 74are: 75.Bl -tag -width Er 76.It Bq Er EINVAL 77The argument 78.Fa gidsetlen 79is smaller than the number of groups in the group set. 80.It Bq Er EFAULT 81The argument 82.Fa gidset 83specifies an invalid address. 84.El 85.Sh SEE ALSO 86.Xr getgid 2 , 87.Xr setgid 2 , 88.Xr setgroups 2 , 89.Xr initgroups 3 90.Sh STANDARDS 91The 92.Fn getgroups 93function conforms to 94.St -p1003.1-2008 . 95.Sh HISTORY 96The 97.Fn getgroups 98system call first appeared in 99.Bx 4.1c . 100