From owner-freebsd-questions@FreeBSD.ORG Wed Nov 19 12:24:06 2003 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1F94E16A4CE for ; Wed, 19 Nov 2003 12:24:06 -0800 (PST) Received: from www6.web2010.com (www6.web2010.com [216.157.5.254]) by mx1.FreeBSD.org (Postfix) with ESMTP id CD9E843FDF for ; Wed, 19 Nov 2003 12:24:04 -0800 (PST) (envelope-from MLandman@face2interface.com) Received: from delliver.face2interface.com (dialup-wash-129-203.thebiz.net [64.30.129.203] (may be forged)) by www6.web2010.com (8.12.10/8.9.0) with ESMTP id hAJKNhp6014504; Wed, 19 Nov 2003 15:23:44 -0500 (EST) Message-Id: <6.0.0.22.0.20031119151727.03c40620@pop.face2interface.com> X-Sender: face@pop.face2interface.com X-Mailer: QUALCOMM Windows Eudora Version 6.0.0.22 Date: Wed, 19 Nov 2003 15:23:59 -0500 To: "Feltis, Ralph C." , "'freebsd-questions@freebsd.org'" From: Marty Landman In-Reply-To: <496C6CA6ABA8DD4AB652EA39C9E5540D2938B7@dshs-exch1> References: <496C6CA6ABA8DD4AB652EA39C9E5540D2938B7@dshs-exch1> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Subject: Re: Network messaging X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Nov 2003 20:24:06 -0000 X-List-Received-Date: Wed, 19 Nov 2003 20:24:06 -0000 At 02:51 PM 11/19/2003, Feltis, Ralph C. wrote: >Is it possible to set some type of simple messaging system between networked >FreeBSD machines? For example, client A pings client B, and then client B >sends some prespecified text reply to client A. Ralph, it's certainly possible to setup something a bit more sophisticated using ftp and cron to store and routinely check for the presence of a file, or in an intranet situation, e.g. if Apache is installed and both boxes have http access you could use a CGI script. The details of the implementation would/should be based on the detailed need which you haven't given. This raises a question I'm curious about which is in this scenario you could easily run into the need for semaphores. I've run into this problem running MS-DOS execs on networked windoz boxes (stop that snickering plz) and could clearly see the updates stepping on each other's toes. What is available on fbsd by way of protecting e.g. file writes? FWIW I understand the standard flock mechanism I've used with Perl on nix servers isn't foolproof, but surely something in the system is....? Marty Landman Face 2 Interface Inc 845-679-9387 Sign On Required: Web membership software for your site Make a Website: http://face2interface.com/Home/Demo.shtml