C++, multiple definition

Question

I need to define a constant containing an environment variable (Linux, g++). I would prefer to use string, but std::getenv needs *char

Answer 1

Use

extern const char* ENV_APPL_ROOT;

in the header file, and place

const char* ENV_APPL_ROOT = "APPL_ROOT";

in one particular translation unit (e.g. DataLocation.cpp).

This should fix it.