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 parameter 56.Fa gidsetlen 57indicates the number of entries that may be placed in 58.Fa gidset . 59The 60.Fn getgroups 61system call 62returns the actual number of groups returned in 63.Fa gidset . 64No more than 65.Dv NGROUPS_MAX 66will ever 67be returned. 68If 69.Fa gidsetlen 70is zero, 71.Fn getgroups 72returns the number of supplementary group IDs associated with 73the calling process without modifying the array pointed to by 74.Fa gidset . 75.Sh RETURN VALUES 76A successful call returns the number of groups in the group set. 77A value of -1 indicates that an error occurred, and the error 78code is stored in the global variable 79.Va errno . 80.Sh ERRORS 81The possible errors for 82.Fn getgroups 83are: 84.Bl -tag -width Er 85.It Bq Er EINVAL 86The argument 87.Fa gidsetlen 88is smaller than the number of groups in the group set. 89.It Bq Er EFAULT 90The argument 91.Fa gidset 92specifies 93an invalid address. 94.El 95.Sh SEE ALSO 96.Xr setgroups 2 , 97.Xr initgroups 3 98.Sh HISTORY 99The 100.Fn getgroups 101system call appeared in 102.Bx 4.2 . 103