15.1 I heard that you have to #include <stdio.h> before calling printf. Why?
15.2 How can %f be used for both float and double arguments in printf?
15.3 Why don't function prototypes guard against mismatches in printf's arguments?
15.4 How can I write a function that takes a variable number of arguments?
15.5 How can I write a function that takes a format string and a variable number of arguments, like printf, and passes them to printf to do most of the work?
15.6 How can I write a function analogous to scanf, that calls scanf to do most of the work?
15.7 I have a pre-ANSI compiler, without <stdarg.h>. What can I do?
15.8 How can I discover how many arguments a function was actually called with?
15.9 My compiler isn't letting me declare a function that accepts only variable arguments.
15.11 I can't get va_arg to pull in an argument of type pointer-to-function.
15.12 How can I write a function which takes a variable number of arguments and passes them to some other function ?
15.13 How can I call a function with an argument list built up at run time?