How to add a default include path for GCC in Linux?

Question

I'd like gcc to include files from $HOME/include in addition to the usual include directories, but there doesn't seem to be an analogue to $LD_LIBRARY_PATH.

I know I can just add the include directory at command line when compiling (or in the makefile), but I'd really like a universal approach here, as in the library case.

Answer 1

Try setting C_INCLUDE_PATH (for C header files) or CPLUS_INCLUDE_PATH (for C++ header files).

As Ciro mentioned, CPATH will set the path for both C and C++ (and any other language).

More details in GCC's documentation.