Check if file actually exists

mcopy.cpp

@@ -157,11 +157,19 @@ int main(int argc, char **argv) {
         exit(1);
     }
 
+    int set{0};
+
     for (int i{1}; i < ac; i++) {
         std::ifstream f(av[i]);
 
         if (static_cast<bool>(f.good())) {
+            set = 1;
             getMetadataFromFile(format, av[i]);
         }
     }
+
+    if (!set) {
+        std::cout << "mcopy: File not found.\n";
+        exit(1);
+    }
 }