| |
| This directory is intended for project header files. |
| |
| A header file is a file containing C declarations and macro definitions |
| to be shared between several project source files. You request the use of a |
| header file in your project source file (C, C++, etc) located in `src` folder |
| by including it, with the C preprocessing directive `#include'. |
| |
| ```src/main.c |
| |
| #include "header.h" |
| |
| int main (void) |
| { |
| ... |
| } |
| ``` |
| |
| Including a header file produces the same results as copying the header file |
| into each source file that needs it. Such copying would be time-consuming |
| and error-prone. With a header file, the related declarations appear |
| in only one place. If they need to be changed, they can be changed in one |
| place, and programs that include the header file will automatically use the |
| new version when next recompiled. The header file eliminates the labor of |
| finding and changing all the copies as well as the risk that a failure to |
| find one copy will result in inconsistencies within a program. |
| |
| In C, the usual convention is to give header files names that end with `.h'. |
| It is most portable to use only letters, digits, dashes, and underscores in |
| header file names, and at most one dot. |
| |
| Read more about using header files in official GCC documentation: |
| |
| * Include Syntax |
| * Include Operation |
| * Once-Only Headers |
| * Computed Includes |
| |
| https://gcc.gnu.org/onlinedocs/cpp/Header-Files.html |
