Add lab 2

Assignment2/main.c

@@ -77,6 +77,12 @@ int main() {
                 printf("The total is %d\n", total);
             }
         }
+        if (strcmp(input, "exec\n")) {
+            char *args[2];
+            args[0] = "/bin/ls";
+            args[1] = NULL;
+            execv(args[0], args);
+        }
     }
 }