What is the environment variable for GCC/G++ to look for .h files during compilation: LIBRARY_PATH, C_PATH, C_INCLUDE_PATH or CPLUS_PATH?

Question

Is there an environment variable for GCC/G++ to look for .h files during compilation?

I google my question, there are people say LIBRARY_PATH, C_PATH, C_INCLUDE_PATH, CP

Answer 1

Also, if you're not sure which paths are being checked on your system you can use

cpp -v

Which will tell you which paths are being checked for .h files, the output includes sections:

#include "..." search starts here:
#include <...> search starts here: