C Programming Preprocessor

The C Preprocessor

Lines that begins  with a # are called preprocessing directives.

#define LIMIT 100
The identifier LIMIT is called the symbolic constant.

#include <stdio.h>
<> indicates that the file is to be found in the system path. The preprocessor looks for the file only in the system path and not in the current directory.

#include "my_file.h"
The quotes surrounding the name of the file are necessary. A search for the file is made first in the current directory and then in other system-dependent places.