From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp1 ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms11 with LMTPS id 5KI1DrxdrV47CgAA0tVLHw (envelope-from ) for ; Sat, 02 May 2020 11:47:08 +0000 Received: from aspmx1.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp1 with LMTPS id 8JDUHcZdrV4ydwAAbx9fmQ (envelope-from ) for ; Sat, 02 May 2020 11:47:18 +0000 Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:470:142::17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by aspmx1.migadu.com (Postfix) with ESMTPS id D86EA941C5C for ; Sat, 2 May 2020 11:47:15 +0000 (UTC) Received: from localhost ([::1]:42744 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jUqby-00086L-ML for larch@yhetil.org; Sat, 02 May 2020 07:47:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48756) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jUqbZ-00082j-P7 for emacs-orgmode@gnu.org; Sat, 02 May 2020 07:46:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.90_1) (envelope-from ) id 1jUqbV-0006Hb-3M for emacs-orgmode@gnu.org; Sat, 02 May 2020 07:46:48 -0400 Received: from mail.mojserwer.eu ([195.110.48.8]:49324) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jUqbU-00061U-Ji for emacs-orgmode@gnu.org; Sat, 02 May 2020 07:46:44 -0400 Received: from localhost (localhost [127.0.0.1]) by mail.mojserwer.eu (Postfix) with ESMTP id E0084E65AD; Sat, 2 May 2020 13:46:35 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at mail.mojserwer.eu Received: from mail.mojserwer.eu ([127.0.0.1]) by localhost (mail.mojserwer.eu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id PlviIQHA86Dq; Sat, 2 May 2020 13:46:33 +0200 (CEST) Received: from localhost (jeden09-dwa27.echostar.pl [213.156.109.227]) by mail.mojserwer.eu (Postfix) with ESMTPSA id C914BE64A6; Sat, 2 May 2020 13:46:32 +0200 (CEST) References: <87imhh4lc7.fsf@kyleam.com> <87y2qaokhn.fsf@mbork.pl> <20200502081244.GC7696@tuxteam.de> User-agent: mu4e 1.1.0; emacs 27.0.50 From: Marcin Borkowski To: tomas@tuxteam.de Subject: Re: How to properly set up reminders for paying cellphone fees in org? In-reply-to: <20200502081244.GC7696@tuxteam.de> Date: Sat, 02 May 2020 13:46:28 +0200 Message-ID: <87v9leo8yz.fsf@mbork.pl> MIME-Version: 1.0 Content-Type: text/plain Received-SPF: pass client-ip=195.110.48.8; envelope-from=mbork@mbork.pl; helo=mail.mojserwer.eu X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/02 07:46:38 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] X-Received-From: 195.110.48.8 X-BeenThere: emacs-orgmode@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "General discussions about Org-mode." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: emacs-orgmode@gnu.org Errors-To: emacs-orgmode-bounces+larch=yhetil.org@gnu.org Sender: "Emacs-orgmode" X-Scanner: scn0 X-Spam-Score: -0.01 Authentication-Results: aspmx1.migadu.com; dkim=none; dmarc=none; spf=pass (aspmx1.migadu.com: domain of emacs-orgmode-bounces@gnu.org designates 2001:470:142::17 as permitted sender) smtp.mailfrom=emacs-orgmode-bounces@gnu.org X-Scan-Result: default: False [-0.01 / 13.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; GENERIC_REPUTATION(0.00)[-0.49492468068171]; DWL_DNSWL_FAIL(0.00)[2001:470:142::17:server fail]; R_SPF_ALLOW(-0.20)[+ip6:2001:470:142::/48:c]; IP_REPUTATION_HAM(0.00)[asn: 22989(0.15), country: US(-0.00), ip: 2001:470:142::17(-0.49)]; TO_DN_NONE(0.00)[]; MX_GOOD(-0.50)[cached: eggs.gnu.org]; RCPT_COUNT_TWO(0.00)[2]; MAILLIST(-0.20)[mailman]; FORGED_RECIPIENTS_MAILLIST(0.00)[]; RCVD_IN_DNSWL_FAIL(0.00)[2001:470:142::17:server fail]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:22989, ipnet:2001:470:142::/48, country:US]; FROM_NEQ_ENVFROM(0.00)[mbork@mbork.pl,emacs-orgmode-bounces@gnu.org]; MID_RHS_MATCH_FROM(0.00)[]; ARC_NA(0.00)[]; TAGGED_FROM(0.00)[larch=yhetil.org]; SUBJECT_ENDS_QUESTION(1.00)[]; FROM_HAS_DN(0.00)[]; URIBL_BLOCKED(0.00)[tuxteam.de:email,kyleam.com:email,mbork.pl:url]; MIME_GOOD(-0.10)[text/plain]; RCVD_TLS_LAST(0.00)[]; DMARC_NA(0.00)[mbork.pl: no valid DMARC record]; HAS_LIST_UNSUB(-0.01)[]; RECEIVED_SPAMHAUS_PBL(0.00)[213.156.109.227:received]; RCVD_COUNT_SEVEN(0.00)[8]; FORGED_SENDER_MAILLIST(0.00)[] X-TUID: D6NqbpSDyAVA On 2020-05-02, at 10:12, tomas@tuxteam.de wrote: > On Sat, May 02, 2020 at 09:37:40AM +0200, Marcin Borkowski wrote: >> >> On 2020-04-30, at 07:02, Kyle Meyer wrote: >> >> > And note that a utility like datefudge or libfaketime is useful for >> > testing these sorts of things out. For example: >> > >> > $ datefudge "2020-02-18" emacs [...] >> >> Shameless plug: I wrote about this use-case of datefudge sime time ago: >> http://mbork.pl/2019-08-05_datefudge_and_agenda_testing >> >> (I don't know libfaketime). > > It just plays games with LD_PRELOAD to trick the application (which is > supposed to use the usual libs when asking for time, but most do that). > > Infinitely more lightweight than a container or a VM. On Debian: > > tomas@trotzki:~$ apt show libfaketime > Package: libfaketime > [...] > Download-Size: 31.2 kB > APT-Sources: http://ftp.de.debian.org/debian buster/main amd64 Packages > Description: Report faked system time to programs (preload library) > The Fake Time Preload Library (FTPL, a.k.a. libfaketime) intercepts > various system calls which programs use to retrieve the current date > and time [...] FTPL allows you to specify both absolute dates (e.g., > 2004-01-01) and relative dates (e.g., 10 days ago). > > You might need a VM for an app which bypasses the "usual libraries", > but then, I don't know whether I would like to have such a thing on > my box. Probably not without a good reason :-) One use-case when this might be reasonable is an application which talks to a database, when you have to convince both the application and the database server that the time is different than in reality. Best, -- Marcin Borkowski http://mbork.pl