Syntax Form | Action |
---|---|
Quoted form | The preprocessor searches for include files in this order: 1) In the same directory as the file that contains the #include statement. 2) In the directories of the currently opened include files, in the reverse order in which they were opened. The search begins in the directory of the parent include file and continues upward through the directories of any grandparent include files. 3) Along the path that's specified by each /I compiler option. 4) Along the paths that are specified by the INCLUDE environment variable. |
Angle-bracket form | The preprocessor searches for include files in this order: 1) Along the path that's specified by each /I compiler option. 2) When compiling occurs on the command line, along the paths that are specified by the INCLUDE environment variable. |
' '
), the preprocessor searches only that path specification and ignores the standard directories.#include 'path-spec'
, directory searching begins with the directory of the parent file and then proceeds through the directories of any grandparent files. That is, searching begins relative to the directory that contains the source file that contains the #include directive that's being processed. If there is no grandparent file and the file has not been found, the search continues as if the file name were enclosed in angle brackets.