int i;
static int loop_send(void *handle, char *buf, int len) {    struct loop_state *st = handle;    int i;    fprintf(stderr, "%d chars: ", len);    for (i = 0; i < len; i++)	fprintf(stderr, " 0x%x", buf[i]);    fprintf(stderr, "\n");    return from_backend(st->term, 0, buf, len);}