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.\" 4. 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.\" $FreeBSD$ 30.\" 31.Dd March 5, 1999 32.Dt GETGROUPS 2 33.Os 34.Sh NAME 35.Nm getgroups 36.Nd get group access list 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In sys/types.h 41.In unistd.h 42.Ft int 43.Fn getgroups "int gidsetlen" "gid_t *gidset" 44.Sh DESCRIPTION 45The 46.Fn getgroups 47system call 48gets the current group access list of the user process 49and stores it in the array 50.Fa gidset . 51The 52.Fa gidsetlen 53argument 54indicates the number of entries that may be placed in 55.Fa gidset . 56The 57.Fn getgroups 58system call 59returns the actual number of groups returned in 60.Fa gidset . 61At least one and as many as {NGROUPS_MAX}+1 values may be returned. 62If 63.Fa gidsetlen 64is zero, 65.Fn getgroups 66returns the number of supplementary group IDs associated with 67the calling process without modifying the array pointed to by 68.Fa gidset . 69.Sh RETURN VALUES 70A successful call returns the number of groups in the group set. 71A value of -1 indicates that an error occurred, and the error 72code is stored in the global variable 73.Va errno . 74.Sh ERRORS 75The possible errors for 76.Fn getgroups 77are: 78.Bl -tag -width Er 79.It Bq Er EINVAL 80The argument 81.Fa gidsetlen 82is smaller than the number of groups in the group set. 83.It Bq Er EFAULT 84The argument 85.Fa gidset 86specifies 87an invalid address. 88.El 89.Sh SEE ALSO 90.Xr setgroups 2 , 91.Xr initgroups 3 92.Sh STANDARDS 93The 94.Fn getgroups 95system call conforms to 96.St -p1003.1-2008 . 97.Sh HISTORY 98The 99.Fn getgroups 100system call appeared in 101.Bx 4.2 . 102