Cproto generates function prototypes and variable declarations from C code Cproto generates function prototypes and variable declarations from C source code. Cproto can also convert function definitions between the old style and the ANSI C style. This conversion will overwrite the original files, however, so be sure to make a backup copy of your original files in case something goes wrong. Since cproto uses a Yacc generated parser, it shouldn't be confused by complex function definitions as much as other prototype generators) because it uses a Yacc generated parser. Cproto will be useful for C programmers, so install cproto if you are going to do any C programming.