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. 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.\" @(#)getgroups.2 8.2 (Berkeley) 4/16/94 33.\" $FreeBSD$ 34.\" 35.Dd March 5, 1999 36.Dt GETGROUPS 2 37.Os 38.Sh NAME 39.Nm getgroups 40.Nd get group access list 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In sys/types.h 45.In unistd.h 46.Ft int 47.Fn getgroups "int gidsetlen" "gid_t *gidset" 48.Sh DESCRIPTION 49The 50.Fn getgroups 51system call 52gets the current group access list of the user process 53and stores it in the array 54.Fa gidset . 55The 56.Fa gidsetlen 57argument 58indicates the number of entries that may be placed in 59.Fa gidset . 60The 61.Fn getgroups 62system call 63returns the actual number of groups returned in 64.Fa gidset . 65No more than 66.Dv NGROUPS_MAX 67will ever 68be returned. 69If 70.Fa gidsetlen 71is zero, 72.Fn getgroups 73returns the number of supplementary group IDs associated with 74the calling process without modifying the array pointed to by 75.Fa gidset . 76.Sh RETURN VALUES 77A successful call returns the number of groups in the group set. 78A value of -1 indicates that an error occurred, and the error 79code is stored in the global variable 80.Va errno . 81.Sh ERRORS 82The possible errors for 83.Fn getgroups 84are: 85.Bl -tag -width Er 86.It Bq Er EINVAL 87The argument 88.Fa gidsetlen 89is smaller than the number of groups in the group set. 90.It Bq Er EFAULT 91The argument 92.Fa gidset 93specifies 94an invalid address. 95.El 96.Sh SEE ALSO 97.Xr setgroups 2 , 98.Xr initgroups 3 99.Sh HISTORY 100The 101.Fn getgroups 102system call appeared in 103.Bx 4.2 . 104