[Mono-devel-list] How to use shared library with C# on linux

[Gonzalo Paniagua Javier]

El mié, 19-11-2003 a las 18:23, Daniel Schalk escribió:
> Hi,
> 
> I'm trying to code a C# app, which calls a C-function out of a shared
> library (e.g. testlib.so).
> In the testlib.cc i placed the following code:
> 
> #include <stdio.h>
> 
> void fktTest(void)
> {
> 	printf("called fktTest");
> }
> 
> I compiled it with: gcc -c -fpic testlib.cc
> then: gcc -shared -fpic -o testlib.so testlib.o
> 
> Now I created LibTest.cs:
> 
> using System;
> using System.Runtime.InteropServices;
> 
> namespace LibTest
> {
>  class LibraryTest
>  {
>   [DllImport("testlib", EntryPoint="fktTest")]
>   public static extern void fktTest();
> 
>   static void Main(string[] args)
>   {
>    fktTest();
>   }
>  }
> }
> 
> I compiled it with : mcs LibTest.cs
> So far, there were no errors. Because I'm novice on linux (and mono :-)),
> was it right, what I did so far? Are there any faults within my code/doing?

No, except for the .cc already pointed out.

> Further questions:
> How do I have to go on to get running my application?
> Where to place the .so file?
> 
> Because if I run the app with the .so in the same directory, I get error
> "unhandeled exception: System.MissingMethodException ...").
> What is wrong? After one day of "googling", I didn't find a solution.

I generated the .so as you did and used your test program. It worked
right away.

IF it still doesn't work for you, try this command when linking:

gcc -shared -fpic -o libtestlib.so testlib.o

and that will probably work.

-Gonzalo