Handle UEV_HUP properly in examples and unit tests

If an I/O watcher callback fails to read(), returning zero, we check
events for UEV_HUP to detect EOF or socket remote end shutdown().

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

examples/joystick.c

@@ -43,16 +43,24 @@ struct js_event {
  */
 static void joystick_cb(uev_t *w, void *arg, int events)
 {
+	ssize_t len;
+
 	if (UEV_ERROR == events) {
 		warnx("Spurious problem with the joystick watcher, restarting.");
 		uev_io_start(w);
 	}
 
-	if (read(w->fd, &e, sizeof(e)) < 0) {
+	len = read(w->fd, &e, sizeof(e));
+	if (len < 0) {
 		warn("Failed reading joystick event");
 		return;
 	}
 
+	if (len == 0 || UEV_HUP == events) {
+		warn("Joystick disconnected");
+		return;
+	}
+
 	switch (e.type) {
 	case 1:
 		printf("Button %d %s\n", e.number, e.value ? "pressed" : "released");

examples/redirect.c

@@ -35,7 +35,7 @@ void process_stdin(uev_t *w, void *arg, int events)
 		return;
 	}
 
-	if (len == 0) {
+	if (len == 0 || UEV_HUP == events) {
 		warnx("Connection closed.");
 		return;
 	}

tests/complete.c

@@ -72,7 +72,7 @@ static void signal_cb(uev_t *w, void *UNUSED(arg), int events)
 
 static void pipe_read_cb(uev_t *w, void UNUSED(*arg), int events)
 {
-	int cnt;
+	int len;
 	char msg[50];
 
 	if (UEV_ERROR == events) {
@@ -87,13 +87,19 @@ static void pipe_read_cb(uev_t *w, void UNUSED(*arg), int events)
 		uev_timer_set(watchdog, 1000, 0);
 
 	/* Here we can read() from in or w->fd, either works. */
-	cnt = read(w->fd, msg, sizeof(msg));
-	if (cnt < 0) {
+	len = read(w->fd, msg, sizeof(msg));
+	if (len < 0) {
 		perror(__func__);
 		goto error;
 	}
-//	fprintf(stderr, "READ %.*s %d\n", cnt, msg, cnt);
-	fprintf(stderr, "%.*s.%d ", cnt, msg, cnt);
+
+	if (len == 0 || UEV_HUP == events) {
+		fprintf(stderr, "Other end of pipe closed, no more data\n");
+		return;
+	}
+
+//	fprintf(stderr, "READ %.*s %d\n", len, msg, len);
+	fprintf(stderr, "%.*s.%d ", len, msg, len);
 }
 
 static void pipe_write_cb(uev_t *w, void *arg, int UNUSED(events))