Question

To further explain my situation. I know that when you’re using dynamic libraries, you need to export the library paths to LD_LIBRARY_PATH, so that the executable will find the libraries when they’re run. If I don’t do this, an error will come up, that the shared library could not be found.

Now if I add the following linker flag “-L/path/to/library/ -lthelibrary.so”, I can run my executable without exporting the library path to LD_LIBRARY_PATH.

Why is this?

Answer 1

First of all, you do not generally need to set LD_LIBRARY_PATH to run a binary. This environment variable is used by the loader to find additional places to look for .so files to load when the binary is to be executed.

You need to set LD_LIBRARY_PATH if your binary references one or more .so files that are not available in the same location as when it was compiled. It is also needed if any of the directly referenced .so files depend on something that is not available in the same as when the .so file was created.

Use the ldd command to inspect the dependency information in your binary to get a clearer picture of what is saved by the linker when the binary is created.