From owner-freebsd-questions@FreeBSD.ORG Sat Jun 19 09:01:43 2004 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 A91A416A4CE for ; Sat, 19 Jun 2004 09:01:43 +0000 (GMT) Received: from ns3.tele-kom.ru (ns3.tele-kom.ru [217.107.251.251]) by mx1.FreeBSD.org (Postfix) with SMTP id 63DA443D2D for ; Sat, 19 Jun 2004 09:01:42 +0000 (GMT) (envelope-from doublef@tele-kom.ru) Received: (qmail 27280 invoked from network); 19 Jun 2004 07:58:41 -0000 Received: from mx.tele-kom.ru (213.80.148.6) by ns.tele-kom.ru with SMTP; 19 Jun 2004 07:58:41 -0000 Received: (qmail 9634 invoked by uid 555); 19 Jun 2004 09:01:15 -0000 Received: from shark (213.80.148.204) by t-k.ru with TeleMail/2 id 1087635675-9624 for freebsd-questions@freebsd.org; Sat, 19 Jun 13:01:15 2004 +0400 (MSD) Received: by shark (Postfix, from userid 1000) id DB3871A9; Sat, 19 Jun 2004 12:59:18 +0400 (MSD) Date: Sat, 19 Jun 2004 12:59:17 +0400 From: Sergey Zaharchenko To: Thomas Farrell Message-ID: <20040619085917.GA1820@Shark.localdomain> Mail-Followup-To: Sergey Zaharchenko , Thomas Farrell , freebsd-questions@freebsd.org References: <002001c455ae$8d16ab00$0b0a0a0a@neonduron> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ZGiS0Q5IWpPtfppv" Content-Disposition: inline In-Reply-To: <002001c455ae$8d16ab00$0b0a0a0a@neonduron> User-Agent: Mutt/1.4.2.1i cc: freebsd-questions@freebsd.org Subject: Re: how to extract 512 bytes from a file 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: Sat, 19 Jun 2004 09:01:43 -0000 --ZGiS0Q5IWpPtfppv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jun 18, 2004 at 11:36:04PM -0400, Thomas Farrell probably wrote: > I was thinking I could take a working avi and extract the first 512 > bytes and insert it into the beginning of a bogus file. Does anyone > think this may work? Given the number of compression formats actually hiding under the '.avi' extension, and that the most sensitive information is usually in the header, I doubt that. Unless you know for sure what should be there, this won't work. > Any idea how I can accomplish this? dd(1). Especially `seek=3D...', `skip=3D...' and `conv=3Dnotrunc'. > Do I smoke too much weed? Only if you think you're going to guess 512 bytes of the header from scratch:) --=20 DoubleF Any excuse will serve a tyrant. -- Aesop --ZGiS0Q5IWpPtfppv Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFA1ABjwo7hT/9lVdwRAl4XAJ9tmnwnctX+rpd/QvUY852xRGFZaQCfVxaQ auNuYCCoej6VaVBgVhCFjmU= =5mgY -----END PGP SIGNATURE----- --ZGiS0Q5IWpPtfppv--