'\" t
.\"     dnsutl - utilities to make DNS easier to configure
.\"     Copyright (C) 1995, 1999, 2007 Peter Miller
.\"
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.\"     but WITHOUT ANY WARRANTY; without even the implied warranty of
.\"     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
.\"     GNU General Public License for more details.
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.\"
.ds n) dns-ethers
.TH dns-ethers 1 dnsutl "Reference Manual"
.SH NAME
dns-ethers \- generate /etc/ethers entries from DNS tables
.XX "dns-ethers(1)" "generate /etc/ethers entries from DNS tables"
.SH SYNOPSIS
.B \*(n)
[
.IR option ...
][
.I infile
[
.I outfile
]]
.br
.B \*(n)
.B -Help
.br
.B \*(n)
.B -VERSion
.SH DESCRIPTION
The
.I \*(n)
program is used to generate the
.I /etc/ethers
entries from DNS tables.
.PP
If the input file is not named,
or the name '-' is used,
the standard input is read.
.PP
If the output file is not named,
or the name '-' is used,
the startdard output is written.
.PP
A fake DNS type of ``ether'' is used, instead of the
usual ``in'' type,
to enable the use of the ``a'' to store the addresses.
.SH OPTIONS
The following options are understood:
.TP 8n
.B -Verbose
.br
This option may be used to see what
.I \*(n)
deciphers each resource record as.
.TP 8n
.B -Help
.br
This option may be used to get more information about
how to used th
.I \*(n)
program.
.TP 8n
.B -VERSion
.br
This option may be used to see what version of the
.I \*(n)
program is running.
.TP 8n
\fB-I\fP\fIdirectory\fP
.br
This option may be used to set the search path for include files.
.so arglex.so
.so exit.so
.SH EXAMPLE
The idea is that you have all of the information concerning each computer
in the one file.  This makes it less likely that something will be
omitted, and simpler to change if the name or IP address changes.
.PP
Given a database file called ``\fIexample.com\fP'' and which contains
the following text
.RS
.nf
.ft CW
.ta 8n 16n 24n 32n 40n
.so example.so
.ft R
.fi
.RE
You can generate the \fI/etc/ethers\fP file using the following command
.RS
.nf
.ft CW
% \f(CBdns-ethers example.com /etc/ethers\fP
%
.ft R
.fi
.RE
Here is what you would see as the output
.RS
.nf
.ft CW
.ta 8n 16n 24n 32n 40n
.so example.ethers.so
.ft R
.fi
.RE
Note that the output uses relative names.
.SS Makefile
All of this can be automated using the following makefile fragment:
.RS
.nf
.ft CW
.ta 8n 16n 24n 32n 40n
/etc/ethers: example.com
        dns-ethers example.com $@
.ft R
.fi
.RE
By doing this, all you need to do is edit the \fIexample.com\fP file,
and the use the \fImake\fP(1) command to bring everything up-to-date.
.PP
If you were using NIS, NIS+ or LDAP you would update them, rather than
the static file.
.so copyright.so
.so author.so