From owner-freebsd-hackers@FreeBSD.ORG Thu Nov 17 17:55:22 2011 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D8E641065670 for ; Thu, 17 Nov 2011 17:55:22 +0000 (UTC) (envelope-from dieterbsd@engineer.com) Received: from mailout-us.mail.com (mailout-us.gmx.com [74.208.5.67]) by mx1.freebsd.org (Postfix) with SMTP id 818F48FC14 for ; Thu, 17 Nov 2011 17:55:22 +0000 (UTC) Received: (qmail 3292 invoked by uid 0); 17 Nov 2011 17:55:16 -0000 Received: from 67.206.187.41 by rms-us001.v300.gmx.net with HTTP Content-Type: text/plain; charset="utf-8" Date: Thu, 17 Nov 2011 12:55:02 -0500 From: "Dieter BSD" Message-ID: <20111117175514.274040@gmx.com> MIME-Version: 1.0 To: freebsd-hackers@freebsd.org X-Authenticated: #74169980 X-Flags: 0001 X-Mailer: GMX.com Web Mailer x-registered: 0 Content-Transfer-Encoding: 8bit X-GMX-UID: 7T+sfUEl33erJQ7YAmtnpDsjL0tsZg08 Subject: Re: easy way to determine if a stream or fd is seekable X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 Nov 2011 17:55:22 -0000 > lseek() on a tape drive does not return an error, nor does it > actually do anything. IIRC some tape drives can seek, while others cannot. Vague memories that it is supposed to be possible to put a filesystem on a DECtape and mount the filesystem. It might be that FreeBSD doesn't currently support seeking on a tape, but we shouldn't paint ourselves into a corner by assuming that it is fundimentally impossible.