Function bprintf

tools/ipfw/ipfw2.c:474–496

* Print message specified by @format and args. * Automatically manage buffer space and transparently handle * buffer overruns. * * Returns number of bytes that should have been printed. */

 * Returns number of bytes that should have been printed.
 */
int
bprintf(struct buf_pr *b, const char *format, ...)
{
	va_list args;
	int i;

	va_start(args, format);

	i = vsnprintf(b->ptr, b->avail, format, args);
	va_end(args);

	if (i < 0 || (size_t)i > b->avail) {
		/* Overflow or print error */
		b->avail = 0;
	} else {
		b->ptr += i;
		b->avail -= i;
	} 

	b->needed += i;

	return (i);
}

/*
 * Special values printer for tablearg-aware opcodes.