著者: Jaromil 日付: To: dng 題目: Re: [DNG] with or without libsystemd0
On Wed, 20 Jul 2016, fsmithred wrote:
> On 07/19/2016 06:10 PM, Rick Moen wrote:
> > Saying libsystemd0 'does something' merely because higher-layer GNOME
> > code probed it for a function and then decided to do or not do something
> > based on what it found (my high-confidence surmise about your gvfs
> > anecdote) entails very peculiar construing of the verb 'to do' -- and
> > I'm pretty sure hardly anyone else uses the verb quite that way.
>
>
> Oh, you must have missed my last report. Surely, you would agree that
> executing an executable file is doing something.
technically speaking, one doesn't even need to "run an executable" to
execute code. Either by shared-lib linking or by dynamic loading
(dlopen), a program linking a library can execute code provided by the
library in its own stack. Such code will run with the exact same
access than the calling code (access to file descriptors, processes
etc.).
>
> For the past two years, people have been saying that libsystemd0 is just a
> library, and it does nothing if systemd is not installed or not running.
> I've been skeptical of such claims, but until yesterday, I wasn't sure.
> Neither one of those claims is accurate. Among the files that the
> libsystemd0 package provides, at least two of them are executable files.
> There may be more that aren't located in /lib/systemd/.
[...]
> To summarize: libsystemd0 runs its program(s) even when systemd is not
> installed.
This may be incorrect, as I don't see any execve() in libsystemd.
What we can say is that libsystemd0 runs its code, called by other
programs, even when systemd is not installed.