1.\" $OpenBSD: initgroups.3,v 1.9 2000/04/15 11:46:02 aaron 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. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.Dd June 4, 1993 35.Dt INITGROUPS 3 36.Os 37.Sh NAME 38.Nm initgroups 39.Nd initialize supplementary group IDs 40.Sh SYNOPSIS 41.Fd #include <unistd.h> 42.Ft int 43.Fn initgroups "const char *name" "gid_t basegid" 44.Sh DESCRIPTION 45The 46.Fn initgroups 47function 48uses the 49.Xr getgrouplist 3 50function to calculate the supplementary group IDs for the user 51specified in 52.Fa name . 53This group list then set up for the current process using 54.Xr setgroups 2 . 55The 56.Fa basegid 57is automatically included in the group list. 58Typically this value is given as 59the group number from the password file. 60.Pp 61If the groups database lists more than 62.Ev NGROUPS 63groups for 64.Fa name 65(including one for 66.Fa basegid ) , 67the later groups are ignored. 68.Sh RETURN VALUES 69The 70.Fn initgroups 71function 72returns \-1 if it was not invoked by the superuser. 73.Sh SEE ALSO 74.Xr setgroups 2 , 75.Xr getgrouplist 3 76.Sh HISTORY 77The 78.Fn initgroups 79function appeared in 80.Bx 4.2 . 81.Sh BUGS 82The 83.Xr getgrouplist 3 84function called by 85.Fn initgroups 86uses the routines based on 87.Xr getgrent 3 . 88If the invoking program uses any of these routines, 89the group structure will 90be overwritten in the call to 91.Fn initgroups . 92