--- main.c.orig	2019-12-21 09:02:41.000000000 -0800
+++ main.c	2020-03-09 17:31:39.946323585 -0700
@@ -9,6 +9,7 @@
  */
 
 #include <sys/types.h>
+#include <sys/select.h>
 #include <stdio.h>
 #include <dirent.h>
 #include <stdlib.h>