The Regents of the University of California. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this software
must display the following acknowledgement:
This product includes software developed by the University of
California, Berkeley and its contributors.
4. Neither the name of the University nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
From: @(#)group.5 8.3 (Berkeley) 4/19/94
$Id$
.Dd September 29, 1994 .Dt GROUP 5 .Os .Sh NAME .Nm group .Nd format of the group permissions file .Sh DESCRIPTION The file .Aq Pa /etc/group consists of newline separated .Tn ASCII records, one per group, containing four colon .Ql : separated fields. These fields are as follows: l -tag -width password -offset indent -compact t group Name of the group. t passwd Group's .Em encrypted password. t gid The group's decimal ID. t member Group members. .El
p The .Ar group field is the group name used for granting file access to users who are members of the group. The .Ar gid field is the number associated with the group name. They should both be unique across the system (and often across a group of systems) since they control file access. The .Ar passwd field is an optional .Em encrypted password. This field is rarely used and an asterisk is normally placed in it rather than leaving it blank. The .Ar member field contains the names of users granted the privileges of .Ar group . The member names are separated by commas without spaces or newlines. A user is automatically in a group if that group was specified in their
a /etc/passwd entry and does not need to be added to that group in the
a /etc/group file.
.Pp
When the system reads the file
.Pa /etc/group
the fields are read into the structure
.Fa group
declared in
.Aq Pa grp.h :
.Bd -literal -offset indent
struct group {
char *gr_name; /* group name */
char *gr_passwd; /* group password */
int gr_gid; /* group id */
char **gr_mem; /* group members */
};
.Ed
.Sh YP/NIS INTERACTION
The
a /etc/group file can be configured to enable the YP/NIS group database. An entry whose .Ar name field consists of a plus sign (`+') followed by a group name, will be replaced internally to the C library with the YP/NIS group entry for the named group. An entry whose .Ar name field consists of a single plus sign with no group name following, will be replaced with the entire YP/NIS .Dq Li group.byname map.
p If the YP/NIS group database is enabled for any reason, all reverse lookups (i.e., .Fn getgrgid ) will use the entire database, even if only a few groups are enabled. Thus, the group name returned by .Fn getgrgid is not guaranteed to have a valid forward mapping. .Sh FILES l -tag -width /etc/group -compact t Pa /etc/group .El .Sh SEE ALSO .Xr crypt 3 , .Xr getgrent 3 , .Xr initgroups 3 , .Xr passwd 1 , .Xr passwd 5 , .Xr setgroups 2 , .Xr yp 4 .Sh BUGS The .Xr passwd 1 command does not change the .Nm group passwords. .Sh HISTORY A .Nm file format appeared in .At v6 . The YP/NIS functionality is modeled after .Tn SunOS and first appeared in .Tn FreeBSD 1.1.