- slave = XOpenDevice(dpy, atoi(argv[0]));
- master = XOpenDevice(dpy, atoi(argv[1]));
+ info_sd = find_device_info(dpy, argv[0], True);
+ info_md = find_device_info(dpy, argv[1], False);
+
+ if (!info_sd) {
+ fprintf(stderr, "unable to find device %s\n", argv[0]);
+ return EXIT_FAILURE;
+ }
+
+ if (!info_md) {
+ fprintf(stderr, "unable to find device %s\n", argv[1]);
+ return EXIT_FAILURE;
+ }
+
+ slave = XOpenDevice(dpy, info_sd->id);
+ master = XOpenDevice(dpy, info_md->id);