In a C function declaration, what does “…” as the last parameter do?

Question

Often I see a function declared like this:

void Feeder(char *buff, ...)

what does \"...\" mean?

Answer 1

Variadic functions

Variadic functions are functions which may take a variable number of arguments and are declared with an ellipsis in place of the last parameter. An example of such a function is printf.

A typical declaration is

    int check(int a, double b, ...);

Variadic functions must have at least one named parameter, so, for instance,

    char *wrong(...);  

is not allowed in C.