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.\"     from: @(#)htable.8	6.6 (Berkeley) 3/16/91
.\"	$Id: htable.8,v 1.1 1995/10/18 08:47:36 deraadt Exp $
.\"
.Dd March 16, 1991
.Dt HTABLE 8
.Os BSD 4.2
.Sh NAME
.Nm htable
.Nd convert
.Tn NIC
standard format host tables
.Sh SYNOPSIS
.Nm htable
.Op Fl c Ar connected-nets
.Op Fl l Ar local-nets
.Ar file
.Sh DESCRIPTION
.Nm Htable
is used to convert host files in the format specified
in Internet
.Tn RFC
810 to the format used by the network
library routines.  Three files are created as a result
of running 
.Nm htable :
.Pa hosts ,
.Pa networks ,
and
.Pa gateways .
The 
.Xr hosts
file may be used by the 
.Xr gethostbyname 3
routines in mapping host names to addresses
if the nameserver,
.Xr named 8 ,
is not used.
The
.Pa networks
file is used by the
.Xr getnetent 3
routines in mapping network names to numbers.
The
.Pa gateways
file may be used by the routing daemon
in identifying
.Dq passive
Internet gateways;
see
.Xr routed 8
for an explanation.
.Pp
Options available for
.Nm htable :
.Bl -tag -width Ds
.It Fl c Ar connected-nets
If the gateways file is to be used,
.Ar connected-nets
is a list of networks to which the host is directly connected.
The networks, separated by commas,
may be given by name or in Internet-standard dot notation,
for example:
.Bd -literal -offset indent
\-c arpanet,128.32,local-ether-net.
.Ed
.Pp
.Nm Htable
only includes gateways
which are directly connected to one of the networks specified,
or which can be reached from another gateway on a connected net.
.It Fl l Ar local-nets
If the
.Fl l
option is given with a list of networks (in the same format as for
.Fl c ) ,
these networks will be treated as ``local,''
and information about hosts on local networks is
taken only from the localhosts file.
Entries for local hosts from the main database will be omitted.
This allows the localhosts file to completely override
any entries in the input file.
.El
.Pp
If any of the files
.Pa localhosts ,
.Pa localnetworks ,
or
.Pa localgateways
are present in the current directory,
the file's contents is prepended to the
output file.
Of these, only the gateways file is interpreted.
This allows sites to maintain local aliases and
entries which are not normally present in the
master database.
Only one gateway to each network will be placed in the gateways file;
a gateway listed in the localgateways file will override any in the
input file.
.Pp
.Nm Htable
is best used in conjunction with the
.Xr gettable 8
program which retrieves the
.Tn NIC
database from a host.
.Sh SEE ALSO
.Xr netintro 4 ,
.Xr gettable 8 ,
.Xr named 8
.Sh BUGS
If the name-domain system provided network name mapping well as host
name mapping,
.Nm htable
would no longer be needed.
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.2 .