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

just a note: CPLUS_INCLUDE_PATH and C_INCLUDE_PATH are not the equivalent of LD_LIBRARY_PATH. LD_LIBRARY_PATH serves the ld (the dynamic linker at runtime) whereas the equivalent of the former two that serves your C/C++ compiler with the location of libraries is LIBRARY_PATH.

Answer 2

Create an alias for gcc with your favorite includes.

alias mygcc='gcc -I /whatever/'

Answer 3

A gcc spec file can do the job, however all users on the machine will be affected.

See here

Answer 4

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++.

More details here.

Answer 5

Here is link to GCC 4.8.1 manual where C_INCLUDE_PATH and CPLUS_INCLUDE_PATH environment variables are documented.