Before a c program is compiled in a compiler, source code is processed by a program called preprocessor. The c preprocessor, often known as cpp, is a macro processor that is used. Below is the list of preprocessor directives that c programming language offers. These lines are not program statements but directives for the preprocessor. The preprocessor examines the code before actual compilation of code begins and resolves all these directives before any code is actually generated by regular statements. The c preprocessor, often known as cpp, is a macro processor that is used automatically by. Preprocessing and macros c preprocessor preprocessor directives. This directive includes a copy of the specified file or library. Preprocessing directives are lines in your program that start with. In simplistic terms, a c preprocessor is just a text substitution tool and they instruct compiler to do required preprocessing before actual compilation. The c preprocessor gcc, the gnu compiler collection. Preprocessor directives in c language, macro substitution. The preprocessor is executed before the actual compilation of code begins.
The c preprocessor is a macro processor that is used automatically by the c compiler to transform your program before actual compilation proprocessor direcives are executed before compilation. A preprocessor directive must be the only instruction on a line. The c preprocessor is not part of the compiler, but is a separate step in the compilation process. The preprocessing language consists of directives to be executed and macros to. Preprocessor directives preprocessor directives are lines included in the code of our programs that are not program statements but directives for the preprocessor. The c preprocessor is a languageindependent tool for lightweight metaprogramming that provides no percep tible form of modularity 44. It is called a macro processor because it allows you to define macros, which are brief abbreviations for longer constructs.
The c preprocessor, often known as cpp, is a macro processor that is used automatically by the c compiler to transform your program before compilation. Programs cannot define new preprocessing directives. Only defined at the top of the program definition and only white space and comments may appear before preprocessor directive line. It is called a macro processor because it allows you to definemacros, which are brief abbreviations for longer constructs. Postscript or pdf produced by some word processors for output purposes only. The result of preprocessor is expanded source, which will be input to the compiler. Ce marking is currently required for many products sold in europe, yet many u.