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.\"     @(#)netgroup.5	8.2 (Berkeley) 12/11/93
.\"
.Dd $Mdocdate: January 25 2020 $
.Dt NETGROUP 5
.Os
.Sh NAME
.Nm netgroup
.Nd defines network groups
.Sh DESCRIPTION
The
.Nm
file specifies
.Dq netgroups ,
which are sets of
.Sy (host, user, domain)
tuples that are to be given similar network access.
.Pp
Each line in the file consists of a netgroup name followed by a list of
the members of the netgroup.
Each member can be either the name of another netgroup or a specification
of a tuple as follows:
.Bd -literal -offset indent
(host, user, domain)
.Ed
.Pp
where the
.Ar host ,
.Ar user ,
and
.Ar domain
are character string names for the corresponding component.
Any of the comma separated fields may be empty to specify a
.Dq wildcard
value or may consist of the single character
.Dq \&-
to specify
.Dq no valid value .
The members of the list may be separated by whitespace; the
.Dq \e
character may be used at the end of a line to specify line continuation.
.Pp
Lines that begin with a
.Ql #
are treated as comments.
.Pp
After modification of
.Pa /etc/netgroup ,
.Xr netgroup_mkdb 8
should be run, as the
.Xr getnetgrent 3
functions only operate on the Berkeley DB file
.Pa /etc/netgroup.db .
.Pp
If that file is not present, and the system supports NIS, then the
.Nm
NIS maps are used.
The NIS maps are also used if the
.Nm
file contains a
.Dq +
entry.
.Sh FILES
.Bl -tag -width /etc/netgroup.db -compact
.It Pa /etc/netgroup
default netgroup list
.It Pa /etc/netgroup.db
netgroup database
.El
.Sh EXAMPLES
Define a group of three machines:
.Pp
.Dl friends (10.0.0.2,,) (10.0.0.3,,) (10.0.0.4,,)
.Pp
This group can be used in
.Xr exports 5
as follows:
.Pp
.Dl /home -maproot=nobody friends
.Sh SEE ALSO
.Xr dbopen 3 ,
.Xr getnetgrent 3 ,
.Xr exports 5 ,
.Xr netgroup_mkdb 8
.Sh STANDARDS
The file format is compatible with that of various vendors, although it
appears that not all vendors use an identical format.
.Sh BUGS
The interpretation of access restrictions based on the member tuples of a
netgroup is left up to the various network applications.