new file mode 100644
--- /dev/null
+++ b/liboctave/byte-swap.h
@@ -0,0 +1,97 @@
+// byte-swap.h                                            -*- C++ -*-
+/*
+
+Copyright (C) 1996 John W. Eaton
+
+This file is part of Octave.
+
+Octave is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 2, or (at your option) any
+later version.
+
+Octave is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with Octave; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+#if !defined (octave_byte_swap_h)
+#define octave_byte_swap_h 1
+
+static inline void
+swap_bytes (char *t, unsigned int i, unsigned int j)
+{
+  char tmp = t[i];
+  t[i] = t[j];
+  t[j] = tmp;
+}
+
+static inline void
+swap_2_bytes (char *t)
+{
+  swap_bytes (t, 0, 1);
+}
+
+static inline void
+swap_4_bytes (char *t)
+{
+  swap_bytes (t, 0, 3);
+  swap_bytes (t, 1, 2);
+}
+
+static inline void
+swap_8_bytes (char *t)
+{
+  swap_bytes (t, 0, 7);
+  swap_bytes (t, 1, 6);
+  swap_bytes (t, 2, 5);
+  swap_bytes (t, 3, 4);
+}
+
+static inline void
+swap_2_bytes (char *t, int len)
+{
+  char *ptr = t;
+  for (int i = 0; i < len; i++)
+    {
+      swap_2_bytes (ptr);
+      ptr += 2;
+    }
+}
+
+static inline void
+swap_4_bytes (char *t, int len)
+{
+  char *ptr = t;
+  for (int i = 0; i < len; i++)
+    {
+      swap_4_bytes (ptr);
+      ptr += 4;
+    }
+}
+
+static inline void
+swap_8_bytes (char *t, int len)
+{
+  char *ptr = t;
+  for (int i = 0; i < len; i++)
+    {
+      swap_8_bytes (ptr);
+      ptr += 8;
+    }
+}
+
+#endif
+
+/*
+;;; Local Variables: ***
+;;; mode: C++ ***
+;;; page-delimiter: "^/\\*" ***
+;;; End: ***
+*/