The C Preprocessor The C preprocessor is a 'macro processor' which is used automatically by the C compiler to transform your program before actual compilation. It is called a macro processor because it allows you to define 'macros,' which are abbreviations for longer constructs. The C preprocessor provides four separate facilities that you can use as you see fit: * Inclusion of header files. These are files of declarations that can be substituted into your program. * Macro expansion. You can define 'macros,' which are abbreviations for arbitrary fragments of C code, and then the C preprocessor will replace the macros with their definitions throughout the program. * Conditional compilation. Using special preprocessing directives, you can include or exclude parts of the program according to various conditions. * Line control. If you use a program to combine or rearrange source files into an intermediate file which is then compiled, you can use line control to inform the compiler about where each source line originated. You should install this package if you are a programmer who is searching for such a macro processor.