dev_disconnect: support '*N' syntax for disconnecting on the N'th occurance.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

lightningd/dev_disconnect.c

@@ -12,10 +12,12 @@
 /* We move the fd IFF we do a disconnect. */
 static int dev_disconnect_fd = -1;
 static char dev_disconnect_line[200];
+static int dev_disconnect_count, dev_disconnect_len;
 
 void dev_disconnect_init(int fd)
 {
 	int r;
+	char *asterisk;
 
 	r = read(fd, dev_disconnect_line, sizeof(dev_disconnect_line)-1);
 	if (r < 0)
@@ -24,7 +26,17 @@ void dev_disconnect_init(int fd)
 
 	/* Get first line */
 	dev_disconnect_line[r] = '\n';
-	*strchr(dev_disconnect_line, '\n') = '\0';
+	dev_disconnect_len = strcspn(dev_disconnect_line, "\n");
+	dev_disconnect_line[dev_disconnect_len] = '\0';
+	asterisk = strchr(dev_disconnect_line, '*');
+	if (asterisk) {
+		dev_disconnect_count = atoi(asterisk+1);
+		if (dev_disconnect_count < 1)
+			errx(1, "dev_disconnect invalid count: %s",
+			     dev_disconnect_line);
+		*asterisk = '\0';
+	} else
+		dev_disconnect_count = 1;
 
 	/* So we can move forward if we do use the line. */
 	dev_disconnect_fd = fd;
@@ -35,8 +47,13 @@ char dev_disconnect(int pkt_type)
 	if (!streq(wire_type_name(pkt_type), dev_disconnect_line+1))
 		return DEV_DISCONNECT_NORMAL;
 
+	if (dev_disconnect_count != 1) {
+		dev_disconnect_count--;
+		return DEV_DISCONNECT_NORMAL;
+	}
+
 	assert(dev_disconnect_fd != -1);
-	lseek(dev_disconnect_fd, strlen(dev_disconnect_line)+1, SEEK_CUR);
+	lseek(dev_disconnect_fd, dev_disconnect_len+1, SEEK_CUR);
 
 	status_trace("dev_disconnect: %s", dev_disconnect_line);
 	return dev_disconnect_line[0];