How Variadic Functions are Defined and Used
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Defining and using a variadic function involves three steps:
* _Define_ the function as variadic, using an ellipsis (`...') in
the argument list, and using special macros to access the variable
arguments. Note:Receiving Arguments.
* _Declare_ the function as variadic, using a prototype with an
ellipsis (`...'), in all the files which call it. Note:Variadic
Prototypes.
* _Call_ the function by writing the fixed arguments followed by the
additional variable arguments. Note:Calling Variadics.