1.\" Copyright (c) 1983, 1991 The Regents of the University of California. 2.\" 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. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" from: @(#)getgroups.2 6.7 (Berkeley) 3/10/91 33.\" $Id: getgroups.2,v 1.7 1994/04/19 00:09:04 jtc Exp $ 34.\" 35.Dd March 10, 1991 36.Dt GETGROUPS 2 37.Os BSD 4.2 38.Sh NAME 39.Nm getgroups 40.Nd get group access list 41.Sh SYNOPSIS 42.Fd #include <sys/param.h> 43.Fd #include <sys/types.h> 44.Fd #include <unistd.h> 45.Ft int 46.Fn getgroups "int gidsetlen" "gid_t *gidset" 47.Sh DESCRIPTION 48.Fn Getgroups 49gets the current group access list of the current user process 50and stores it in the array 51.Fa gidset . 52The parameter 53.Fa gidsetlen 54indicates the number of entries that may be placed in 55.Fa gidset . 56.Fn Getgroups 57returns the actual number of groups returned in 58.Fa gidset . 59No more than 60.Dv {NGROUPS_MAX} 61will ever 62be returned. 63If 64.Fa gidsetlen 65is 0, 66.Fn getgroups 67returns the number of groups without modifying the 68.Fa gidset 69array. 70.Sh RETURN VALUES 71A successful call returns the number of groups in the group set. 72A value of -1 indicates that an error occurred, and the error 73code is stored in the global variable 74.Va errno . 75.Sh ERRORS 76The possible errors for 77.Fn getgroups 78are: 79.Bl -tag -width Er 80.It Bq Er EINVAL 81The argument 82.Fa gidsetlen 83is smaller than the number of groups in the group set. 84.It Bq Er EFAULT 85The argument 86.Fa gidset 87specifies 88an 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