1.\" $OpenBSD: group.5,v 1.7 2000/10/26 00:37:04 aaron Exp $ 2.\" $NetBSD: group.5,v 1.4 1995/07/28 06:41:39 phil Exp $ 3.\" 4.\" Copyright (c) 1980, 1991, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" Portions Copyright(c) 1994, Jason Downs. All rights reserved. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" @(#)group.5 8.3 (Berkeley) 4/19/94 37.\" 38.Dd July 18, 1995 39.Dt GROUP 5 40.Os 41.Sh NAME 42.Nm group 43.Nd format of the group permissions file 44.Sh DESCRIPTION 45The file 46.Pa /etc/group 47consists of newline separated 48.Tn ASCII 49records, one per group, containing four colon 50.Pq Ql \&: 51separated fields. 52These fields are as follows: 53.Pp 54.Bl -tag -width password -offset indent -compact 55.It group 56Name of the group. 57.It passwd 58Group's encrypted password. 59.It gid 60The group's decimal ID. 61.It member 62Group members. 63.El 64.Pp 65The 66.Ar group 67field is the group name used for granting file access to users 68who are members of the group. 69The 70.Ar gid 71field is the number associated with the group name. 72They should both be unique across the system (and often 73across a group of systems) since they control file access. 74The 75.Ar passwd 76field is an optional encrypted password. 77This field is rarely used and an asterisk is normally placed in it 78rather than leaving it blank. 79The 80.Ar member 81field contains the names of users granted the privileges of 82.Ar group . 83The member names are separated by commas without spaces or newlines. 84A user is automatically in a group if that group was specified in their 85.Pa /etc/passwd 86entry and does not need to be added to that group in the 87.Pa /etc/group 88file. 89.\" .Pp 90.\" When the system reads the file 91.\" .Pa /etc/group 92.\" the fields are read into the structure 93.\" .Fa group 94.\" declared in 95.\" .Aq Pa grp.h : 96.\" .Bd -literal -offset indent 97.\" struct group { 98.\" char *gr_name; /* group name */ 99.\" char *gr_passwd; /* group password */ 100.\" int gr_gid; /* group id */ 101.\" char **gr_mem; /* group members */ 102.\" }; 103.\" .Ed 104.Sh YP SUPPORT 105If YP is active, the 106.Nm 107file may also contain lines of the format 108.Pp 109.Bd -literal -offset indent 110+name:*:: 111.Ed 112.Pp 113which causes the specified group to be included from the 114.Pa group.byname 115YP map. 116If no group name is specified, or the 117.Ql + 118(plus sign) appears alone on a line, all groups are included from the YP map. 119.Pp 120YP references may appear anywhere in the file, but the single 121.Ql + 122form should be on the last line, for historical reasons. 123Only the first group with a specific name encountered, whether in the 124.Nm 125file itself, or included via YP, will be used. 126.Sh FILES 127.Bl -tag -width /etc/group -compact 128.It Pa /etc/group 129.El 130.Sh SEE ALSO 131.Xr passwd 1 , 132.Xr setgroups 2 , 133.Xr crypt 3 , 134.Xr initgroups 3 , 135.Xr passwd 5 , 136.Xr yp 8 137.Sh BUGS 138The 139.Xr passwd 1 140command does not change the 141.Nm 142passwords. 143.Sh HISTORY 144A 145.Nm 146file format appeared in 147.At v6 . 148.Pp 149The YP file format first appeared in SunOS. 150