1.\" $NetBSD: getgrouplist.3,v 1.10 2003/08/07 16:42:49 agc Exp $ 2.\" 3.\" Copyright (c) 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.\" @(#)getgrouplist.3 8.1 (Berkeley) 6/9/93 31.\" 32.Dd April 25, 1999 33.Dt GETGROUPLIST 3 34.Os 35.Sh NAME 36.Nm getgrouplist 37.Nd calculate group access list 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In unistd.h 42.Ft int 43.Fn getgrouplist "const char *name" "gid_t basegid" "gid_t *groups" "int *ngroups" 44.Sh DESCRIPTION 45The 46.Fn getgrouplist 47function reads through the group database and calculates 48the group access list for the user specified in 49.Fa name . 50The 51.Fa basegid 52is automatically included in the groups list. 53Typically this value is given as 54the group number from the password database. 55.Pp 56The resulting group list is returned in the integer array pointed to by 57.Fa groups . 58The caller specifies the size of the 59.Fa groups 60array in the integer pointed to by 61.Fa ngroups ; 62the actual number of groups found is returned in 63.Fa ngroups . 64.Pp 65Duplicate group ids will be suppressed from the result. 66.Sh RETURN VALUES 67The 68.Fn getgrouplist 69function 70returns \-1 if the size of the group list is too small to 71hold all the user's groups. 72Here, the group array will be filled with as many groups as will fit. 73.Sh FILES 74.Bl -tag -width /etc/group -compact 75.It Pa /etc/group 76group membership list 77.El 78.Sh SEE ALSO 79.Xr setgroups 2 , 80.Xr initgroups 3 81.Sh HISTORY 82The 83.Fn getgrouplist 84function first appeared in 85.Bx 4.4 . 86.Sh BUGS 87The 88.Fn getgrouplist 89function 90uses the routines based on 91.Xr getgrent 3 . 92If the invoking program uses any of these routines, 93the group structure will 94be overwritten in the call to 95.Fn getgrouplist . 96.Pp 97In the case where the group array is too small and duplicate gids 98have been suppressed, the returned 99.Fa ngroups 100will be too large by a factor of the difference between the given 101size and the number of matches. 102This is not considered to be a major problem, since it's still going 103to be a smaller figure than when duplicates were not suppressed. 104