gcc에서 기본 include 디렉토리 변경하기

--sysroot=dir     Use dir as the logical root directory for headers and libraries. For example, if the compiler would normally search for headers in /usr/include and libraries in /usr/lib, it will instead search dir/usr/include and dir/usr/lib.     If you use both this option and the -isysroot option, then the --sysroot option will apply to libraries, but the -isysroot option will apply to header files.     The GNU linker (beginning with version 2.16) has the necessary support for this option. If your linker does not support this option, the header file aspect of --sysroot will still work, but the library aspect will not. -isysroot dir     This option is like the --sysroot option, but applies only to header files.  See the --sysroot option for     more information. [링크 : http://linux.die.net/man/1/gcc]

기본값은 /usr/include 인데, -sysroot로 기본 디렉토리를 변경 시키면
<stdio.h> 와 같은 파일도 찾지 못해 link 에러를 발생시키며 컴파일이 실패된다.

$ more test.c #include <stdio.h> int main(int argc, char **argv) {         printf("hello world\n");         return 0; }

$ gcc --sysroot=/ test.c /usr/bin/ld: this linker was not configured to use sysroots collect2: ld returned 1 exit status

아무튼, 크로스컴파일과 같이 특정 include 디렉토리를 사용해야 할 경우,
--sysroot 를 이용해서 변경하면 될 듯 하다