출처 : https://gcc.gnu.org/onlinedocs/cpp/Include-Syntax.html Both user and system header files are included using the preprocessing directive ‘#include’. It has two variants:사용자와 시스템 헤더 파일은 모두 사전 처리 지침 '#include'를 사용하여 포함된다. 두 가지 변형이 있다.#include This variant is used for system header files. It searches for a file named file in a standard list of system directories. You can prepend directories to ..