--- file_not_specified_in_diff	
+++ file_not_specified_in_diff	
@@ -, +, @@ 
--- src/freedoko.cpp
+++ src/freedoko.cpp
@@ -37,6 +37,7 @@ 
 
 #include "constants.h"
 #include <time.h>
+#include <unistd.h>
 #ifdef WINDOWS
 // for 'mkdir'
 #include <io.h>