1.\" Copyright (c) 1983, 1991, 1993 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. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)getgroups.2 8.2 (Berkeley) 4/16/94 29.\" $FreeBSD: src/lib/libc/sys/getgroups.2,v 1.6.2.4 2001/12/14 18:34:00 ru Exp $ 30.\" $DragonFly: src/lib/libc/sys/getgroups.2,v 1.2 2003/06/17 04:26:47 dillon Exp $ 31.\" 32.Dd March 5, 1999 33.Dt GETGROUPS 2 34.Os 35.Sh NAME 36.Nm getgroups 37.Nd get group access list 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In sys/types.h 42.In unistd.h 43.Ft int 44.Fn getgroups "int gidsetlen" "gid_t *gidset" 45.Sh DESCRIPTION 46.Fn Getgroups 47gets the current group access list of the user process 48and stores it in the array 49.Fa gidset . 50The parameter 51.Fa gidsetlen 52indicates the number of entries that may be placed in 53.Fa gidset . 54.Fn Getgroups 55returns the actual number of groups returned in 56.Fa gidset . 57No more than 58.Dv NGROUPS_MAX 59will ever 60be returned. 61If 62.Fa gidsetlen 63is zero, 64.Fn getgroups 65returns the number of supplementary group IDs associated with 66the calling process without modifying the array pointed to by 67.Fa gidset . 68.Sh RETURN VALUES 69A successful call returns the number of groups in the group set. 70A value of -1 indicates that an error occurred, and the error 71code is stored in the global variable 72.Va errno . 73.Sh ERRORS 74The possible errors for 75.Fn getgroups 76are: 77.Bl -tag -width Er 78.It Bq Er EINVAL 79The argument 80.Fa gidsetlen 81is smaller than the number of groups in the group set. 82.It Bq Er EFAULT 83The argument 84.Fa gidset 85specifies 86an invalid address. 87.El 88.Sh SEE ALSO 89.Xr setgroups 2 , 90.Xr initgroups 3 91.Sh HISTORY 92The 93.Fn getgroups 94function call appeared in 95.Bx 4.2 . 96