From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.help Subject: Re: Best way to check file modification time? Date: Fri, 20 Nov 2015 09:50:19 -0500 Message-ID: References: NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1448031158 18830 80.91.229.3 (20 Nov 2015 14:52:38 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 20 Nov 2015 14:52:38 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Nov 20 15:52:29 2015 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Zzn2t-00046Q-CZ for geh-help-gnu-emacs@m.gmane.org; Fri, 20 Nov 2015 15:52:15 +0100 Original-Received: from localhost ([::1]:47805 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zzn2o-0006B3-1L for geh-help-gnu-emacs@m.gmane.org; Fri, 20 Nov 2015 09:52:10 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:33132) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zzn2Z-00068I-UO for help-gnu-emacs@gnu.org; Fri, 20 Nov 2015 09:51:56 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zzn2U-00082M-UR for help-gnu-emacs@gnu.org; Fri, 20 Nov 2015 09:51:55 -0500 Original-Received: from plane.gmane.org ([80.91.229.3]:41179) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zzn2U-00082G-OE for help-gnu-emacs@gnu.org; Fri, 20 Nov 2015 09:51:50 -0500 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1Zzn1Y-0002Og-Ll for help-gnu-emacs@gnu.org; Fri, 20 Nov 2015 15:50:52 +0100 Original-Received: from 23-91-153-239.cpe.pppoe.ca ([23.91.153.239]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 20 Nov 2015 15:50:52 +0100 Original-Received: from monnier by 23-91-153-239.cpe.pppoe.ca with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 20 Nov 2015 15:50:52 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 12 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 23-91-153-239.cpe.pppoe.ca User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1.50 (gnu/linux) Cancel-Lock: sha1:zNQ7u5aC1buuslyzLaAFNiyPREU= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:108166 Archived-At: > Yes, I figured that. I was just wondering if there were a standard way > of dealing with such cases, since AFAIU it is possible to put a lock on > a file on the OS level. But Emacs doesn't do that, right? Locking in general is difficult, and on top of that locking in POSIX is a big mess. So you have to restrict the problem by considering which other programs might interfere (and what kind of locking they might use), as well how much effort you're willing to expend and what amount of breakage you're willing to live with. Stefan