On Tue, Jun 20, 2017 at 07:33:30AM +0200, Arnt Karlsen wrote:

[cut]

> > depend on libsystemd0, but the dep is not harmful in Jessie, since
> > libsystemd0 does nothing if systemd is not running as pid1.
>
> ..how do we know libsystemd0 "does nothing", if we know?
>

Like "by reading the code"? The source is available at:

https://github.com/systemd/systemd/tree/master/src/libsystemd

If you go through the code (and I warmly invite anybody in this list
capable of reading C to do that) you will notice that most of
libsystemd actions are basically of three kinds:

- direct interactions (read/write) with the fs under /run/systemd/*

- calls to other functions which directly interact with the fs under
/run/systemd/*

- wrapped calls to dbus

The fs under /run/systemd is created and maintained by systemd. If
systemd is not running, there is nothing there. If there is nothing
there, libsystemd can't do either of the two things that it would like
to do. Hence, if systemd is not running, libsystemd0 is basically
*harmless*.

But this is just my poor understanding, due to a quick look at the
source code. It would be better if more and more people would like to
dive a bit into it.

Only unknown things can scare us. So the more we know, the less
fearful our lives will be.

HND

KatolaZ

-- 
[ ~.,_  Enzo Nicosia aka KatolaZ - GLUGCT -- Freaknet Medialab  ]  
[     "+.  katolaz [at] freaknet.org --- katolaz [at] yahoo.it  ]
[       @)   http://kalos.mine.nu ---  Devuan GNU + Linux User  ]
[     @@)  http://maths.qmul.ac.uk/~vnicosia --  GPG: 0B5F062F  ] 
[ (@@@)  Twitter: @KatolaZ - skype: katolaz -- github: KatolaZ  ]