-#include <string.h> /* string functions */
-#include <fcntl.h> /* fcntl function */
-#include <sys/ioctl.h> /* ioctl function */
+#include <string.h> /* C strings library */
+#include <fcntl.h> /* file control functions */
+#include <sys/ioctl.h> /* ioctl syscall and constants */