From owner-freebsd-hackers@FreeBSD.ORG Wed Jun 24 10:31:41 2009 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 499B81065673 for ; Wed, 24 Jun 2009 10:31:41 +0000 (UTC) (envelope-from m.seaman@infracaninophile.co.uk) Received: from smtp.infracaninophile.co.uk (gate6.infracaninophile.co.uk [IPv6:2001:8b0:151:1::1]) by mx1.freebsd.org (Postfix) with ESMTP id B98838FC0A for ; Wed, 24 Jun 2009 10:31:40 +0000 (UTC) (envelope-from m.seaman@infracaninophile.co.uk) Received: from significant-gravitas-shortfall.thebunker.net (gateway.ash.thebunker.net [213.129.64.4]) (authenticated bits=0) by smtp.infracaninophile.co.uk (8.14.3/8.14.3) with ESMTP id n5OAVMP7017884 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 24 Jun 2009 11:31:27 +0100 (BST) (envelope-from m.seaman@infracaninophile.co.uk) X-DKIM: Sendmail DKIM Filter v2.8.3 smtp.infracaninophile.co.uk n5OAVMP7017884 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infracaninophile.co.uk; s=200708; t=1245839488; bh=Fb9BVItfYRmhlggWq36krOBmrwzNPp6w5tY6Y7BNya8=; h=Message-ID:Date:From:MIME-Version:To:CC:Subject:References: In-Reply-To:Content-Type:Cc:Content-Type:Date:From:In-Reply-To: Message-ID:Mime-Version:References:To; z=Message-ID:=20<4A420073.6060405@infracaninophile.co.uk>|Date:=20W ed,=2024=20Jun=202009=2011:31:15=20+0100|From:=20Matthew=20Seaman= 20|Organization:=20Infracaninophi le|User-Agent:=20Thunderbird=202.0.0.22=20(X11/20090624)|MIME-Vers ion:=201.0|To:=20Alexander=20Best=20|CC:=20Wojciech=20Puchar=20,=20 =0D=0A=20Julian=20Elischer=20,=0D=0A=20freebs d-hackers@freebsd.org|Subject:=20Re:=20small=20usr.bin/find=20patc h|References:=20|In-Reply-To:=20|X-Enigmail-Ve rsion:=200.95.7|OpenPGP:=20id=3D60AE908C|Content-Type:=20multipart /signed=3B=20micalg=3Dpgp-sha1=3B=0D=0A=20protocol=3D"application/ pgp-signature"=3B=0D=0A=20boundary=3D"------------enig2E256E8A5CC0 367E058D39F3"; b=tD2gqTyuNEfZcH2Qp1P7EOqtFguFOCRWFGOmdtzJ46MyiQro45coBl8yclFcrpESL eMnlks29xR6UCEj/OHltZmqydr0YXmlMmWnCaNcxse/QlrrITPK1aoXEbQLabEY5oJ jc1RTA40qvA8+Vr9QZ1pwgkZ+cj6KxGrMDCdyXcI= X-Authentication-Warning: happy-idiot-talk.infracaninophile.co.uk: Host gateway.ash.thebunker.net [213.129.64.4] claimed to be significant-gravitas-shortfall.thebunker.net Message-ID: <4A420073.6060405@infracaninophile.co.uk> Date: Wed, 24 Jun 2009 11:31:15 +0100 From: Matthew Seaman Organization: Infracaninophile User-Agent: Thunderbird 2.0.0.22 (X11/20090624) MIME-Version: 1.0 To: Alexander Best References: In-Reply-To: X-Enigmail-Version: 0.95.7 OpenPGP: id=60AE908C Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig2E256E8A5CC0367E058D39F3" X-Virus-Scanned: clamav-milter 0.95.2 at happy-idiot-talk.infracaninophile.co.uk X-Virus-Status: Clean X-Spam-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VERIFIED,SPF_FAIL autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on happy-idiot-talk.infracaninophile.co.uk Cc: Wojciech Puchar , Julian Elischer , freebsd-hackers@freebsd.org Subject: Re: small usr.bin/find patch 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: Wed, 24 Jun 2009 10:31:41 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig2E256E8A5CC0367E058D39F3 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Alexander Best wrote: > hmmm...but dd e.g. uses lowercase instead of upercase letters to indica= te > kilobyte, megabyte and so on. isn't there some unix/posix/whatever stan= dard > telling app developers what to use? Sure. The standard for scale-prefixes is defined by the Systeme Internationale as part of the definition of SI units: http://www.npl.co.uk/reference/measurement-units/si-prefixes/ Note that these are strictly powers-of-10^3 multipliers, and explicitly not the computing style powers-of-2^10 commonly used for file sizes or hard drive capacities, which should instead use the somewhat clunky Ki, Mi, Gi etc. forms: http://physics.nist.gov/cuu/Units/binary.html These binary prefixes are mandated by the IEC and approved by the IEEE amongst others. Not that many people use the binary prefixes appropriately, relying on context to disambiguate 1 MB =3D 1024 KB =3D 1,048,576 Bytes etc. Except= that (confusingly) as a measure of network bandwidth 10 Mb/s always was 10,000,000 b/s and never 10,485,760 b/s; a fact that has caught me out more than a few times. Making find(1) / dd(1) / etc. operate pedantically correctly with these scale-factor symbols would cause a certain degree of pain for little practical gain. Unless there was a broad consensus amongst all Unixoid OS providers, I can't see that change ever happening. Cheers, Matthew --=20 Dr Matthew J Seaman MA, D.Phil. Flat 3 7 Priory Courtyard PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate Kent, CT11 9PW, UK --------------enig2E256E8A5CC0367E058D39F3 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.12 (FreeBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkpCAHkACgkQ3jDkPpsZ+Vbk2QCfTy+bY7J+xLQqPLPuS13EyGqJ U/0AnicsyrN5dYfq6XqtKJJWpYOJWmmt =0BN+ -----END PGP SIGNATURE----- --------------enig2E256E8A5CC0367E058D39F3--