Please help me understand how programs are layered

[Dariusz J. Garbowski]

On 10/03/2006 11:01 PM, Dotan Cohen wrote:
> On 03/10/06, Dariusz J. Garbowski <thuforuk at yahoo.co.uk> wrote:
>> On 10/03/2006 08:00 PM, Dotan Cohen wrote:
>>
>>> Thanks for the info. Nothing I've been able to google has explained
>>> this very well, for non-developers like myself.
>> Hope this helps :-)
>>
> 
> That does help, thanks. I now understand that a program like F-Spot,
> which is a "gnome app" must have gnome installed and will not run on a
> KDE-only system. So, if I want to lean out my system, I must find a
> KDE replacement for F-Spot.
> 
> Tell me, does having Gnome stuff running in the background slow down
> KDE?

Yes and no. Not by itself, but yes by resource consumption, e.g. memory 
(like you mention below).


> For instance, if I fire up F-Spot, will it use considerably most
> system resources than, say, DigiKam, because it must load the gnome
> libraries? Am I essentially, then, running two desktops at once and
> therefore killing the computer?

Not exactly two desktops, e.g you will run only one window manager, 
panel(s) from one desktop only, etc. But Gnome application running in 
KDE will load a bunch of Gnome libs (and vice versa).


> I'm on a 1.2 gHz Duron processor with
> 512MB ram, and I feel that the system is extremly slow. Would I be
> best off eliminating the Gnome apps?

That would help, especially due to memory limit.


> How can I know, before starting a
> program, what libraries it will load, and therefore how much resouces
> it will take?

You can get some indication of that using ldd command, for example try:

$ ldd /usr/bin/top
...
$ ldd /usr/bin/k3b
...

This works for dynamically linked applications (which are usually in 
majority on Linux systems) by printing shared library dependencies.

You can also use command line "top" or KDE's KSysGuard to monitor how 
much memory an application uses. There is however important thing to 
remember -- dynamically linked executables share libraries, i.e. if you 
run 5 Gnome apps they will definitely share Gnome libraries rather than 
each of the apps loading libs separately.

There's also more advanced "strace"...

Regards,
Dariusz


		
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