check argc and show usage if no args

diff --git a/main.c b/main.c
index ea7622a..b4c514f 100644 (file)
--- a/main.c
+++ b/main.c
@@ -494,6 +494,11 @@ int main(int argc,char *argv[])
        starttime = time(NULL);
        am_root = (getuid() == 0);
 
+       if (argc < 2) {
+               usage(FERROR);
+               exit(1);
+       }
+
        /* we set a 0 umask so that correct file permissions can be
           carried across */
        orig_umask = (int)umask(0);