vsprintf
(void)vsprintf(next, format, va);
len = vsprintf(next, format, va);
int vsprintf(char * __restrict, const char * __restrict,
rv = vsprintf(buf, fmt, ap);
rv = vsprintf(buf, fmt, ap);
ret = vsprintf(str, fmt, ap);
n = vsprintf(stackbuf, format, args);
n = vsprintf(buf, format, args);
(void)vsprintf(b, fmt, ap);
ret2 = vsprintf (tmp, format, args);
ret2 = vsprintf (tmp, format, args);
ret2 = vsprintf (tmp, format, args);
vsprintf(buf, fmt, ap);
vsprintf(error_string, fmt, ap);