--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lisp/multicast.el	Mon Aug 13 10:23:51 2007 +0200
@@ -0,0 +1,81 @@
+;;; multicast.el --- lisp frontend for multicast connections in XEmacs
+
+;; Copyright (C) 1997-1998 Didier Verna.
+
+;; Author:          Didier Verna <verna@inf.enst.fr>
+;; Maintainer:      Didier Verna <verna@inf.enst.fr>
+;; Created:         Thu Dec  4 16:37:39 1997 
+;; Last Revision:   Mon Jan 19 19:10:50 1998
+;; Current Version: 0.4
+;; Keywords:        dumped comm processes
+
+;; This file is part of XEmacs.				 
+
+;; XEmacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2 of the License, or
+;; (at your option) any later version.			 
+
+;; XEmacs is distributed in the hope that it will be useful,
+;; 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.		 
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program; if not, write to the Free Software
+;; Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+
+;;; Commentary:
+
+;; This file just contains a lisp frontend to the internal function
+;; open-multicast-group-internal written in C and belonging to process.c
+;; Well, nothing much to say about it ... read the doc string.
+
+
+;;; Change Log:
+
+;; Rev. of Mon Jan 19 19:04:44 1998 : packaging cleanup
+;; Rev. of Thu Dec 11 13:54:26 1997 : updated the docstring
+;; Rev. of Mon Dec  8 15:28:47 1997 : Improved the doc string
+;; Rev. of Thu Dec  4 16:38:09 1997 : Initial Version.
+
+
+;;; Code:
+
+(defun open-multicast-group (name buffer address)
+  "Open a multicast connection on the specified address.
+Returns a subprocess-object to represent the connection.
+Input and output work as for subprocesses; `delete-process' closes it.
+Args are NAME BUFFER ADDRESS.
+NAME is a name for the process. It is modified if necessary to make it unique.
+BUFFER is the buffer (or buffer-name) to associate with the process.
+ Process output goes at the end of that buffer, unless you specify an output
+ stream or filter function to handle the output.
+ BUFFER may be also nil, meaning that this process is not associated with any
+ buffer
+ADDRESS specifies a standard multicast address \"dest/port/ttl\":
+ dest is an internet address between 224.0.0.0 and 239.255.255.255
+ port is a communication port like in traditional unicast
+ ttl is the time-to-live (15 for site, 63 for region and 127 for world).
+
+WARNING: it is *strongly* recommended to avoid using groups beginning with
+         224 or 239. Such groups are considered 'admin' groups, and may 
+         behave in a surprising way ..."
+  (let (dest port ttl)
+    ;; We check only the general form of the multicast address.
+    ;; The rest will be handled by the internal function.
+    (string-match "^\\([0-9\\.]+\\)/\\([0-9]+\\)/\\([0-9]+\\)$" address)
+    (and (not (and (= (match-beginning 0) 0)
+		   (= (match-end 0) (length address))))
+	 (error "malformed multicast address: %s" address))
+    (and (not (setq dest (match-string 1 address)))
+	 (error "invalid destination specification."))
+    (and (= 0 (setq port (string-to-int (match-string 2 address))))
+	 (error "invalid port specification."))
+    (and (= 0 (setq ttl (string-to-int (match-string 3 address))))
+	 (error "invalid ttl specification."))
+    (open-multicast-group-internal name buffer dest port ttl)
+    ))
+    
+;;; multicast.el ends here