make all header files self-contained and include it in the source file

Including the header in the source file guarantees matching signatures,
thus preventing subtle errors.

Self-contained headers document the required headers and makes using it
easier to use the header in new source files.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/os.h b/src/os.h
index 1a9402d..9ebd938 100644
--- a/src/os.h
+++ b/src/os.h
@@ -27,9 +27,12 @@
  * $Id$ GNU
  */
 
+#include "config.h"
+
 #include <stdio.h>
 #include <errno.h>
 #include <sys/param.h>
+#include <fcntl.h>
 
 #include <limits.h>