+# undef HAVE_MMAP
+#endif
+
+#ifdef HISTORY_USE_MMAP
+# include <sys/mman.h>
+
+# ifdef MAP_FILE
+# define MAP_RFLAGS (MAP_FILE|MAP_PRIVATE)
+# define MAP_WFLAGS (MAP_FILE|MAP_SHARED)
+# else
+# define MAP_RFLAGS MAP_PRIVATE
+# define MAP_WFLAGS MAP_SHARED
+# endif
+
+# ifndef MAP_FAILED
+# define MAP_FAILED ((void *)-1)
+# endif
+
+#endif /* HISTORY_USE_MMAP */
+
+/* If we're compiling for __EMX__ (OS/2) or __CYGWIN__ (cygwin32 environment
+ on win 95/98/nt), we want to open files with O_BINARY mode so that there
+ is no \n -> \r\n conversion performed. On other systems, we don't want to
+ mess around with O_BINARY at all, so we ensure that it's defined to 0. */
+#if defined (__EMX__) || defined (__CYGWIN__)