Re: API Calls in C++

[Mike Wahler]

"Lars Uffmann" <aral@nurfuerspam.de> wrote in message 
6bvfsvF3ejs7iU1@mid.dfncis.de">news:6bvfsvF3ejs7iU1@mid.dfncis.de...
> X-Posted to gnu.g++.help, F'Up set also
>
> Mike Wahler wrote:
>> Usually an API (aka 'library') is provided with headers to include
>> in your source, along with a library file containing compiled code
>> that you link with your executable.
>
> Well - the headers are there, the library file is a *.lib, apparently 
> compiled in Visual C++. Are such library-files compiler-independant 
> formatted?

They can be.  They are certainly platform-specific.

>> Somewhere there needs to be a file (either source or compiled)
>> that contains the implementation of the function 'UplinkUserCommand()'.
>
> Yes of course - I was expecting that this was the dll-files in 
> %WINDIR%\system32 - however I have no idea how to tell the linker to look 
> for the function in a dll

That's really getting further outside the scope of this group.
Find a place where your compiler/linker package is discussed.

> (Only now occured to me, because I have used dlls before, but those abode 
> by a name schema so that I could use -lxerces for example). Guess I will 
> have to ask in a gnu newsgroup?

If you're using a gnu compiler, then yes.

>
>> This is usually a file called an 'object file' or 'library file'
>> (compiled code).  Include it in the list of files submitted to your
>> linker.  If the source is provided, then of course it must first be
>> compiled as well.
>
> I have the *.lib from Visual C++ (I suppose thats VC++'s *incompatible* 
> equivalent of gnu's .a object files?) and the *.dll files. Can I use the 
> dll-files for linking? From what I know it should be possible... Now if I 
> only knew how to tell that to my linker...

See your documentation, or it's vendors forums if there are any, or
a newsgroup about your compiler/linker.

If you're using a MS compiler, msdn.microsoft.com has a plethora
of support info.

-Mike