1 files changed, 7 insertions, 1 deletions

diff --git a/tools/idevicename.c b/tools/idevicename.c
index 013becc..ef226f7 100644
--- a/tools/idevicename.c
+++ b/tools/idevicename.c
@@ -38,7 +38,7 @@ static void print_usage(void)
         printf("Display the device name or set it to NAME if specified.\n");
         printf("\n");
         printf("  -d, --debug\t\tenable communication debugging\n");
-        printf("  -u, --udid UDID\tuse UDID to target a specific device\n");
+        printf("  -u, --udid UDID\ttarget specific device by UDID\n");
         printf("  -h, --help\t\tprint usage information\n");
         printf("\n");
         printf("Homepage: <" PACKAGE_URL ">\n");
@@ -60,6 +60,12 @@ int main(int argc, char** argv)
         while ((c = getopt_long(argc, argv, "du:h", longopts, &optidx)) != -1) {
                 switch (c) {
                 case 'u':
+                        if (!*optarg) {
+                                fprintf(stderr, "ERROR: UDID must not be empty!\n");
+                                print_usage();
+                                exit(2);
+                        }
+                        free(udid);
                         udid = strdup(optarg);
                         break;
                 case 'h':