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.Fd #include <sys/types.h> 45.Fd #include <unistd.h> 46.Ft int 47.Fn getgroups "int gidsetlen" "gid_t *gidset" 48.Sh DESCRIPTION 49.Fn Getgroups 50gets the current group access list of the user process 51and stores it in the array 52.Fa gidset . 53The parameter 54.Fa gidsetlen 55indicates the number of entries that may be placed in 56.Fa gidset . 57.Fn Getgroups 58returns the actual number of groups returned in 59.Fa gidset . 60No more than 61.Dv NGROUPS_MAX 62will ever 63be returned. 64If 65.Fa gidsetlen 66is zero, 67.Fn getgroups 68returns the number of supplementary group IDs associated with 69the calling process without modifying the array pointed to by 70.Fa gidset . 71.Sh RETURN VALUES 72A successful call returns the number of groups in the group set. 73A value of -1 indicates that an error occurred, and the error 74code is stored in the global variable 75.Va errno . 76.Sh ERRORS 77The possible errors for 78.Fn getgroups 79are: 80.Bl -tag -width Er 81.It Bq Er EINVAL 82The argument 83.Fa gidsetlen 84is smaller than the number of groups in the group set. 85.It Bq Er EFAULT 86The argument 87.Fa gidset 88specifies 89an invalid address. 90.El 91.Sh SEE ALSO 92.Xr setgroups 2 , 93.Xr initgroups 3 94.Sh HISTORY 95The 96.Fn getgroups 97function call appeared in 98.Bx 4.2 . 99