1.\" $OpenBSD: initgroups.3,v 1.14 2013/06/05 03:39:22 tedu Exp $ 2.\" 3.\" Copyright (c) 1983, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.Dd $Mdocdate: June 5 2013 $ 31.Dt INITGROUPS 3 32.Os 33.Sh NAME 34.Nm initgroups 35.Nd initialize supplementary group IDs 36.Sh SYNOPSIS 37.In unistd.h 38.Ft int 39.Fn initgroups "const char *name" "gid_t basegid" 40.Sh DESCRIPTION 41The 42.Fn initgroups 43function uses the 44.Xr getgrouplist 3 45function to calculate the supplementary group IDs for the user specified in 46.Fa name . 47This group list is then set up for the current process using 48.Xr setgroups 2 . 49The 50.Fa basegid 51is automatically included in the group list. 52Typically this value is given as the group number from the password file. 53.Pp 54If the groups database lists more than 55.Ev NGROUPS 56groups for 57.Fa name 58(including one for 59.Fa basegid ) , 60the later groups are ignored. 61.Sh RETURN VALUES 62The 63.Fn initgroups 64function returns \-1 if it was not invoked by the superuser. 65.Sh SEE ALSO 66.Xr setgroups 2 , 67.Xr getgrouplist 3 68.Sh HISTORY 69The 70.Fn initgroups 71function appeared in 72.Bx 4.2 . 73.Sh BUGS 74The 75.Xr getgrouplist 3 76function called by 77.Fn initgroups 78uses the routines based on 79.Xr getgrent 3 . 80If the invoking program uses any of these routines, the group structure 81will be overwritten in the call to 82.Fn initgroups . 83