How to force using local shared libraries over system libraries?

Question

How can I force using a local library over the system library in linux?

I linked my executable explicitly to some .so files in my project/lib directory e.g. (../lib

Answer 1

When you link, specify the directory of the library and also use an rpath:

-Wl,-rpath,/absolute/path/to/your/library -L/absolute/path/to/your/library -llibrary

-L tells the linker where to find your library at link time, and -rpath tells it where to search for the library at runtime.

Note that -L and -rpath need the directory that contains your .so file, not the actual path of the library file itself.

Answer 2

I have to question why you want to use your own version of a library over a system-provided version (having multiple different versions floating around is nothing but a recipe for trouble and user confusion).

However, you should be able to export LD_PRELOAD=<path_to_your_shared_obj> to force it to load your own version.

Note that no mechanism to override library versions will persist through any sort of privilege elevation (for example sudo).