Path: utzoo!attcan!uunet!lll-winken!casey@gauss.llnl.gov
From: casey@gauss.llnl.gov (Casey Leedom)
Newsgroups: comp.windows.x
Subject: Re: connections to numeric host names
Message-ID: <65391@lll-winken.LLNL.GOV>
Date: 26 Jul 90 18:20:24 GMT
References: <8340@b11.ingr.com>
Sender: usenet@lll-winken.LLNL.GOV
Reply-To: casey@gauss.llnl.gov (Casey Leedom)
Organization: Lawrence Livermore National Laboratory
Lines: 37

| From: dwig@b11.ingr.com (David Wiggins)
| 
| We have a problem making X connections to hosts whose names are pure
| numbers, e.g.  2020.  MakeTCPConnection (XConnDis.c) tries to use this
| as an IP address instead of a host name.
| 
| What we'd like to do is change Xlib to interpret the hostname string as
| a hostname first, and if there's no such host, interpret it as an IP
| address ... I balk at changing the order because the following comment...
| 
|     /*
|      * if numeric host name then try to parse it as such; do the number
|      * first because some systems return garbage instead of INVALID_INETADDR
|      */
| 
| ...indicates that there was a good reason for the current order.

  From RFC-952, page 1 discussing the format of host names (among others):

	1. A "name" (Net, Host, Gateway, or Domain name) is a text string up
	to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus
	sign (-), and period (.).  Note that periods are only allowed when
	they serve to delimit components of "domain style names".  (See
	RFC-921, "Domain Name System Implementation Schedule", for
	background).  No blank or space characters are permitted as part of a
	name.  No disinction is made between  upper and lower case.  The first
	character must be an alpha character.  The last character must not be
	a minus sign or a period. ...

(Note that RFC-1122 or RFC-1123 probably has something to say about this also
but I *still* haven't had time to read through them. (sigh))

  Thus, if a name begins with a non-alpha, it's not a ``host name''.  It must
be some other method of naming a host.  If it begins with a numeric digit,
it's a good guess that the host is being named via its IP address.

Casey