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.\" @(#)group.5 8.3 (Berkeley) 4/19/94 33.\" 34.Dd April 19, 1994 35.Dt GROUP 5 36.Os 37.Sh NAME 38.Nm group 39.Nd format of the group permissions file 40.Sh DESCRIPTION 41The file 42.Aq Pa /etc/group 43consists of newline separated 44.Tn ASCII 45records, one per group, containing four colon 46.Ql \&: 47separated fields. These fields are as follows: 48.Bl -tag -width password -offset indent -compact 49.It group 50Name of the group. 51.It passwd 52Group's 53.Em encrypted 54password. 55.It gid 56The group's decimal ID. 57.It member 58Group members. 59.El 60.Pp 61The 62.Ar group 63field is the group name used for granting file access to users 64who are members of the group. 65The 66.Ar gid 67field is the number associated with the group name. 68They should both be unique across the system (and often 69across a group of systems) since they control file access. 70The 71.Ar passwd 72field 73is an optional 74.Em encrypted 75password. 76This field is rarely used 77and an asterisk is normally placed in it rather than leaving it blank. 78The 79.Ar member 80field contains the names of users granted the privileges of 81.Ar group . 82The member names are separated by commas without spaces or newlines. 83A user is automatically in a group if that group was specified 84in their 85.Pa /etc/passwd 86entry and does not need to be added to that group in the 87.Pa /etc/group file. 88.\" .Pp 89.\" When the system reads the file 90.\" .Pa /etc/group 91.\" the fields are read into the structure 92.\" .Fa group 93.\" declared in 94.\" .Aq Pa grp.h : 95.\" .Bd -literal -offset indent 96.\" struct group { 97.\" char *gr_name; /* group name */ 98.\" char *gr_passwd; /* group password */ 99.\" int gr_gid; /* group id */ 100.\" char **gr_mem; /* group members */ 101.\" }; 102.\" .Ed 103.Sh FILES 104.Bl -tag -width /etc/group -compact 105.It Pa /etc/group 106.El 107.Sh SEE ALSO 108.Xr setgroups 2 , 109.Xr initgroups 3 , 110.Xr crypt 3 , 111.Xr passwd 1 , 112.Xr passwd 5 113.Sh BUGS 114The 115.Xr passwd 1 116command does not change the 117.Nm group 118passwords. 119.Sh HISTORY 120A 121.Nm 122file format appeared in 123.At v6 . 124