From owner-freebsd-chat@FreeBSD.ORG Mon Aug 20 09:54:29 2007 Return-Path: Delivered-To: freebsd-chat@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3287616A41B for ; Mon, 20 Aug 2007 09:54:29 +0000 (UTC) (envelope-from keramida@ceid.upatras.gr) Received: from igloo.linux.gr (igloo.linux.gr [62.1.205.36]) by mx1.freebsd.org (Postfix) with ESMTP id 7855C13C45D for ; Mon, 20 Aug 2007 09:54:28 +0000 (UTC) (envelope-from keramida@ceid.upatras.gr) Received: from kobe.laptop (vader.bytemobile.ondsl.gr [83.235.244.135]) (authenticated bits=128) by igloo.linux.gr (8.14.1/8.14.1/Debian-8) with ESMTP id l7K9asnp013748 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Mon, 20 Aug 2007 12:37:06 +0300 Received: from kobe.laptop (kobe.laptop [127.0.0.1]) by kobe.laptop (8.14.1/8.14.1) with ESMTP id l7K9aVwZ001718; Mon, 20 Aug 2007 12:36:48 +0300 (EEST) (envelope-from keramida@ceid.upatras.gr) Received: (from keramida@localhost) by kobe.laptop (8.14.1/8.14.1/Submit) id l7JKbMmN010307; Sun, 19 Aug 2007 23:37:22 +0300 (EEST) (envelope-from keramida@ceid.upatras.gr) Date: Sun, 19 Aug 2007 23:37:22 +0300 From: Giorgos Keramidas To: deeptech71@gmail.com Message-ID: <20070819203721.GA10057@kobe.laptop> References: <46C863A6.5010404@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46C863A6.5010404@gmail.com> X-Hellug-MailScanner: Found to be clean X-Hellug-MailScanner-SpamCheck: not spam, SpamAssassin (not cached, score=-3.431, required 5, ALL_TRUSTED -1.80, AWL -0.02, BAYES_00 -2.60, DATE_IN_PAST_12_24 0.99) X-Hellug-MailScanner-From: keramida@ceid.upatras.gr X-Spam-Status: No Cc: freebsd-chat@freebsd.org Subject: Re: filesystem timestamps and their usage X-BeenThere: freebsd-chat@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Non technical items related to the community List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 20 Aug 2007 09:54:29 -0000 On 2007-08-19 17:37, deeptech71@gmail.com wrote: > Let's talk about file system timestamps. What kind of timestamps are > there currently, and what are they used for? (or what new timestamps > would be needed/beneficial, or whatever.) > > Currently I can think of only two: > 1. data_time: The last time the file was written to. > 2. file_time: The last time the file was moved or written to. > > [snip discussion about fictitious timestamp values] It would be more interesting, educating and useful to discuss the usefulness of the current 'ctime', 'mtime' and 'atime' attributes implemented by most UNIX file systems (as opposed to, say, a discussion of the usefulness and merits of a pair of imaginary timestamp attributes). Try searching for 'ctime', 'mtime' and 'atime' in the source tree of FreeBSD. The most interesting place (but the most 'technical' too) is, naturally, the implementation of the UFS file system itself: /usr/src/sys/ufs/ufs/dinode.h If you go through this header file, looking for 'time', you will see many useful bits and pieces of information. - Giorgos