#include <stdlib.h> /* C standard library */
#include <unistd.h> /* unix standard library */
#include <stdio.h> /* standard I/O library */
-#include <string.h> /* string functions */
-#include <fcntl.h> /* string functions */
+#include <string.h> /* C strings library */
+#include <fcntl.h> /* file control functions */
+
+
/* user defined header */
#include "macros.h" /* some useful macros */