1.\" Copyright 1980, 1991 The Regents of the University of California. 2.\" 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 6.2 (Berkeley) 4/29/91 33.\" $Id: group.5,v 1.2 1993/08/01 07:35:29 mycroft Exp $ 34.\" 35.Dd April 29, 1991 36.Dt GROUP 5 37.Os 38.Sh NAME 39.Nm group 40.Nd format of the group permissions file 41.Sh DESCRIPTION 42The file 43.Aq Pa /etc/group 44consists of newline separated 45.Tn ASCII 46records, one per group, containing four colon 47.Ql \&: 48separated fields. These fields are as follows: 49.Bl -tag -width password -offset indent -compact 50.It group 51Name of the group. 52.It passwd 53Group's 54.Em encrypted 55password. 56.It gid 57The group's decimal ID. 58.It member 59Group members. 60.El 61.Pp 62The 63.Ar group 64field is the group name used for granting file access to users 65who are members of the group. 66The 67.Ar gid 68field is the number associated with the group name. 69They should both be unique across the system (and often 70across a group of systems) since they control file access. 71The 72.Ar passwd 73field 74is an optional 75.Em encrypted 76password. 77This field is rarely used 78and an asterisk is normally placed in it rather than leaving it blank. 79The 80.Ar member 81field contains the names of users granted the priviledges of 82.Ar group . 83The member names are separated by commas with out spaces or newlines. 84A user is automatically in a group if that group was specified 85in their 86.Pa /etc/passwd 87entry and does not need to be added to that group in the 88.Pa /etc/group file. 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 FILES 105.Bl -tag -width /etc/group -compact 106.It Pa /etc/group 107.El 108.Sh SEE ALSO 109.Xr setgroups 2 , 110.Xr initgroups 3 , 111.Xr crypt 3 , 112.Xr passwd 1 , 113.Xr passwd 5 114.Sh BUGS 115The 116.Xr passwd 1 117command does not change the 118.Nm group 119passwords. 120.Sh HISTORY 121A 122.Nm 123file format appeared in 124.At v6 . 125