With the SDL libraries for example, one would have to point to the headers at the beginning of their code, like so:
#include <SDL/SDL.h>
And, when compiling with GCC for example the library would then have to be included with:
gcc project.cpp -o project -l/path/to/library/SDL
So, when you are developing a program with a specific library to include, where should the header files and the library be located so that GCC can recognize where to pull that information from? Do they have to be stored in the usr directory or can you tell GCC to point to whatever location you want?
This is specific to development on Ubuntu as that is the platform I am developing for but any *nix platform would likely be similar.