Re: How to properly set up reminders for paying cellphone fees in org?

[Marcin Borkowski]

On 2020-05-02, at 10:12, address@hidden wrote:

> On Sat, May 02, 2020 at 09:37:40AM +0200, Marcin Borkowski wrote:
>>
>> On 2020-04-30, at 07:02, Kyle Meyer <address@hidden> 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