Variable-length Argument Lists in C

[merkava]

Hi guys.
When we want to use variable-length argument lists we use these three functions:
va_start()
va_arg()
va_end()
I didn't list the arguments.

But how do we know that the one returned by va_arg() is the last one? if we don't want to implement Variable-length arguments like printf() or scanf().

[RaBones]

As I recall, va_arg yields NULL when you try to get passed the final argument.

char *arg;
while ((arg = va_arg()) != NULL) {
...

It's been a while, but that seems about right.

Oh, now I remember. I always passed a list of arguments in the function call ending with NULL.

myfunc (arg1, arg2, arg3, NULL);

So I would know.

[merkava]

Thank you very much.