diff -Naur ctl-1.4.1.orig/IlmCtl/CtlInterpreter.cpp ctl-1.4.1/IlmCtl/CtlInterpreter.cpp
--- ctl-1.4.1.orig/IlmCtl/CtlInterpreter.cpp	2006-12-14 23:43:55.000000000 +0100
+++ ctl-1.4.1/IlmCtl/CtlInterpreter.cpp	2012-01-19 04:49:14.150570152 +0100
@@ -65,6 +65,8 @@
 #include <algorithm>
 #include <cassert>
 
+#include <unistd.h>
+
 #ifdef WIN32
     #include <io.h>
     #include <stdio.h>