sbuf_printf_drain
sbuf_set_drain(sb, sbuf_printf_drain, NULL);
sbuf_set_drain(sb, sbuf_printf_drain, &cnt);
sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
sbuf_set_drain(sb, sbuf_printf_drain, NULL);
sbuf_set_drain(sb, sbuf_printf_drain, NULL);
sbuf_set_drain(sb, sbuf_printf_drain, NULL);
sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
sbuf_set_drain(&sb, sbuf_printf_drain, &retval);
sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
sbuf_set_drain(&s, &sbuf_printf_drain, NULL);
sbuf_set_drain(&s, &sbuf_printf_drain, NULL);
sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
sbuf_set_drain(&sb, sbuf_printf_drain, &retval);
sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
int sbuf_printf_drain(void *arg, const char *data, int len);