From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolae Mihalache Subject: Re: tcpdump equivalent for the serial port Date: Fri, 12 Sep 2003 16:01:50 +0200 Sender: linux-c-programming-owner@vger.kernel.org Message-ID: <3F61D1CE.7080404@abcpages.com> References: <000101c37934$dcd34740$0b04a8c0@aca.org.ar> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <000101c37934$dcd34740$0b04a8c0@aca.org.ar> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: mariano_moreyra@aca.org.ar, linux-c-programming@vger.kernel.org Mariano Moreyra wrote: >Hi Nicolae, > Hi Mariano! >I think that what you want to do is not posible just with a software. >You have to build a special cable to do that (somebody tell me if I'm wrong, >or if knows another option) >In my job we have one of those cables because we needed to see what was >going on between two applications that talk to each other via serial port. >The bad thing is that you need a third computer that would be the sniffer. > The problem is that opening the cable and connecting it to a third port may introduce some variations in the signals going over the serial cable. This is something that I want to avoid as much as possible. The other end of the serial cable is not another computer but a device that is itself the subject of development and test so it can not be assumed as working nor it can be developed with a non-nominal serial cable connected to it. Even worse, my serial link is not RS232 but RS422 which has a higher speed and it's more difficult to have break-out capability without interferences. This is why I'm looking for a software solution, i.e. something that communicates with the serial driver and gets all the messages that pass through it. Nicolae