1.\" Copyright (c) 1980, 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.\" From: @(#)group.5 8.3 (Berkeley) 4/19/94 33.\" $FreeBSD: src/share/man/man5/group.5,v 1.29 2006/02/18 16:48:56 brueffer Exp $ 34.\" $DragonFly: src/share/man/man5/group.5,v 1.6 2007/04/07 19:29:52 swildner Exp $ 35.\" 36.Dd September 29, 1994 37.Dt GROUP 5 38.Os 39.Sh NAME 40.Nm group 41.Nd format of the group permissions file 42.Sh DESCRIPTION 43The 44.Nm 45file is the local source of group information. 46It can be used in conjunction with the Hesiod domain 47`group', and the NIS maps `group.byname' and `group.bygid', 48as controlled by 49.Xr nsswitch.conf 5 . 50.Pp 51The file 52.Nm 53consists of newline separated 54.Tn ASCII 55records, one per group, containing four colon 56.Ql \&: 57separated fields. 58These fields are as follows: 59.Bl -tag -width password -offset indent -compact 60.It group 61Name of the group. 62.It passwd 63Group's 64.Em encrypted 65password. 66.It gid 67The group's decimal ID. 68.It member 69Group members. 70.El 71.Pp 72Lines whose first non-whitespace character is a pound-sign (#) 73are comments, and are ignored. 74Blank lines that consist 75only of spaces, tabs or newlines are also ignored. 76.Pp 77The 78.Ar group 79field is the group name used for granting file access to users 80who are members of the group. 81The 82.Ar gid 83field is the number associated with the group name. 84They should both be unique across the system (and often 85across a group of systems) since they control file access. 86The 87.Ar passwd 88field 89is an optional 90.Em encrypted 91password. 92This field is rarely used 93and an asterisk is normally placed in it rather than leaving it blank. 94The 95.Ar member 96field contains the names of users granted the privileges of 97.Ar group . 98The member names are separated by commas without spaces or newlines. 99A user is automatically in a group if that group was specified 100in their 101.Pa /etc/passwd 102entry and does not need to be added to that group in the 103.Nm 104file. 105.\" .Pp 106.\" When the system reads the file 107.\" .Pa /etc/group 108.\" the fields are read into the structure 109.\" .Fa group 110.\" declared in 111.\" .In grp.h : 112.\" .Bd -literal -offset indent 113.\" struct group { 114.\" char *gr_name; /* group name */ 115.\" char *gr_passwd; /* group password */ 116.\" int gr_gid; /* group id */ 117.\" char **gr_mem; /* group members */ 118.\" }; 119.\" .Ed 120.Sh LIMITS 121There are various limitations which are explained in 122the function where they occur; see section 123.Sx SEE ALSO . 124.Pp 125In older implementations, 126a group cannot have more than 200 members. 127The maximum line length of 128.Pa /etc/group 129is 1024 characters. 130Longer lines will be skipped. 131This limitation disappeared in 132.Fx 3.0 . 133Older binaries that are statically linked, depend on old 134shared libraries, or 135.No non- Ns Dx 136binaries in compatibility mode 137may still have this limit. 138.Sh FILES 139.Bl -tag -width /etc/group -compact 140.It Pa /etc/group 141.El 142.Sh SEE ALSO 143.Xr passwd 1 , 144.Xr setgroups 2 , 145.Xr crypt 3 , 146.Xr getgrent 3 , 147.Xr initgroups 3 , 148.Xr nsswitch.conf 5 , 149.Xr passwd 5 , 150.Xr chkgrp 8 , 151.Xr pw 8 , 152.Xr yp 8 153.Sh HISTORY 154A 155.Nm 156file format appeared in 157.At v6 . 158Support for comments first appeared in 159.Fx 3.0 . 160.Sh BUGS 161The 162.Xr passwd 1 163command does not change the 164.Nm 165passwords. 166