The #include directive inputs the contents of another file into the file being processed. The included file is also pre processed, so it can contain comments and directives. The #include directive operates in a similar to the #include directive for c and c++ compilers. The syntax of the #include directive is: #include <filename.ext> #include ``filename.ext"
The difference between the <filename.ext> and ``filename.ext" formats is the search algorithm used to find the include file. When #include ``filename.ext" is specified, the file is searched for first in the current directory. If the file is not found in the current directory, the directories listed in the environment variable DC_PATH are searched in order until the file is found. If the file is not found, an error message is produced. When #include <filename.ext> is specified, the file is searched for in the directories listed by the environment variable DC_PATH. If the file is not found in these directories, an error message is produced.
#include "file1.ext" /* searches for the file in the local directory,
then in the DC_PATH directory */
#include <file2.ext> /* searches for the file in the DC_PATH directory
stops searching when first match is found. */