I don't understand, do you want to compile your library using FFI or do you want to bind a library compiled your way with FFI ?
If you want to compile your library using FFI, then use OSProcess to run the compilation line you showed. If you want to bind a library compiled your way with FFI, the easiest way is to compile the C files as a dylib with something like: *gcc -shared -m32 -Wall helloworld.c -o helloworld.dylib $(pkg-config --cflags --libs gstreamer-1.0)* (replace .dylib by .so or .dll if you're on windows or on Mac). Then you can bind the dynamic library generated with FFI. I am not sure about the FFI syntax but with NativeBoost it would look like: Integer>>fib4NB <primitive: #primitiveNativeCall module: #NativeBoostPlugin error: errorCode> ^ self nbCall: #( int functionToCall (int self) ) module: '/Users/myName/Desktop/helloWorld.dylib' Regards, Clement 2014-08-13 11:55 GMT+02:00 Annick Fron <i...@afceurope.com>: > Hi, > > I would like to compile a FFI program but the compiling implies compile > flags like in the following : > > *gcc -Wall helloworld.c -o helloworld $(pkg-config --cflags --libs > gstreamer-1.0)* > > *How do I do this with FFI ?* > > *Annick* >