From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Edwards Subject: Re: tty loop-back device Date: Sat, 28 Sep 2013 16:03:20 +0000 (UTC) Message-ID: References: Return-path: Received: from plane.gmane.org ([80.91.229.3]:39471 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754339Ab3I1QDk (ORCPT ); Sat, 28 Sep 2013 12:03:40 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1VPwza-0004nz-QM for linux-serial@vger.kernel.org; Sat, 28 Sep 2013 18:03:38 +0200 Received: from c-24-118-110-103.hsd1.mn.comcast.net ([24.118.110.103]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 28 Sep 2013 18:03:38 +0200 Received: from grant.b.edwards by c-24-118-110-103.hsd1.mn.comcast.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 28 Sep 2013 18:03:38 +0200 Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: linux-serial@vger.kernel.org On 2013-09-28, Matwey V. Kornilov wrote: > Not sure whether here is the right place to ask. Do the kernel already > has (or, would it be great to have) the tty loop-back support? At least > I've not found something appropriate. I mean, imagine kind of /dev/tty > device, supporting read/write and termios interface and transferring > your read/write/ioctl calls to another user-space application listening, > for instance, /dev/tty_loopback_master. Like a named pipe device. What you're talking about is pretty much the existing pty device. Unfortunately, Linux pty's only support a subset of the serial port API, so they can't be used for applications like network-connected serial ports. So people like me have to write kernel-mode drivers for such devices. I've suggested extending the Linux pty so that it _does_ support the rest of the serial port API. I even offered to work on it if the results would likely be accepted into the kernel tree, but my questions/offers have never gotten any response. -- Grant