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

Just look at the actual gcc documentation. It's all explained there.

To summarize:

• LIBRARY_PATH is for the linker, not for header files (used when looking for libraries requested by a -l option)
• CPATH specifies directories to look for header files in (like the -I option)
• C_INCLUDE_PATH and CPLUS_INCLUDE_PATH are like CPATH, but for C/C++ respectively.