What does ... mean in an argument list in C?

Question

I came across the following function signature and I wondered if this (the ellipsis, or "...") is some kind of polymorphism?

#include <fcntl.h>
int fcntl(int fd, int cmd, ... );

Thanks in advance.

question from:https://stackoverflow.com/questions/1124265/what-does-mean-in-an-argument-list-in-c

Answer 1

It's a variable argument list.