new file mode 100644
--- /dev/null
+++ b/src/ls-mat4.cc
@@ -0,0 +1,490 @@
+/*
+
+Copyright (C) 1996, 1997 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.
+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <cfloat>
+#include <cstring>
+#include <cctype>
+
+#include <fstream>
+#include <iomanip>
+#include <iostream>
+#include <memory>
+#include <string>
+
+#include "byte-swap.h"
+#include "data-conv.h"
+#include "file-ops.h"
+#include "glob-match.h"
+#include "lo-mappers.h"
+#include "lo-sstream.h"
+#include "mach-info.h"
+#include "oct-env.h"
+#include "oct-time.h"
+#include "quit.h"
+#include "str-vec.h"
+
+#include "Cell.h"
+#include "defun.h"
+#include "error.h"
+#include "gripes.h"
+#include "load-save.h"
+#include "oct-obj.h"
+#include "oct-map.h"
+#include "ov-cell.h"
+#include "pager.h"
+#include "pt-exp.h"
+#include "symtab.h"
+#include "sysdep.h"
+#include "unwind-prot.h"
+#include "utils.h"
+#include "variables.h"
+#include "version.h"
+#include "dMatrix.h"
+
+#include "ls-mat4.h"
+
+// Read LEN elements of data from IS in the format specified by
+// PRECISION, placing the result in DATA.  If SWAP is TRUE, swap
+// the bytes of each element before copying to DATA.  FLT_FMT
+// specifies the format of the data if we are reading floating point
+// numbers.
+
+static void
+read_mat_binary_data (std::istream& is, double *data, int precision,
+		      int len, bool swap,
+		      oct_mach_info::float_format flt_fmt)
+{
+  switch (precision)
+    {
+    case 0:
+      read_doubles (is, data, LS_DOUBLE, len, swap, flt_fmt);
+      break;
+
+    case 1:
+      read_doubles (is, data, LS_FLOAT, len, swap, flt_fmt);
+      break;
+
+    case 2:
+      read_doubles (is, data, LS_INT, len, swap, flt_fmt);
+      break;
+
+    case 3:
+      read_doubles (is, data, LS_SHORT, len, swap, flt_fmt);
+      break;
+
+    case 4:
+      read_doubles (is, data, LS_U_SHORT, len, swap, flt_fmt);
+      break;
+
+    case 5:
+      read_doubles (is, data, LS_U_CHAR, len, swap, flt_fmt);
+      break;
+
+    default:
+      break;
+    }
+}
+
+int
+read_mat_file_header (std::istream& is, bool& swap, FOUR_BYTE_INT& mopt, 
+		      FOUR_BYTE_INT& nr, FOUR_BYTE_INT& nc,
+		      FOUR_BYTE_INT& imag, FOUR_BYTE_INT& len,
+		      int quiet)
+{
+  swap = false;
+
+  // We expect to fail here, at the beginning of a record, so not
+  // being able to read another mopt value should not result in an
+  // error.
+
+  is.read (X_CAST (char *, &mopt), 4);
+  if (! is)
+    return 1;
+
+  if (! is.read (X_CAST (char *, &nr), 4))
+    goto data_read_error;
+
+  if (! is.read (X_CAST (char *, &nc), 4))
+    goto data_read_error;
+
+  if (! is.read (X_CAST (char *, &imag), 4))
+    goto data_read_error;
+
+  if (! is.read (X_CAST (char *, &len), 4))
+    goto data_read_error;
+
+// If mopt is nonzero and the byte order is swapped, mopt will be
+// bigger than we expect, so we swap bytes.
+//
+// If mopt is zero, it means the file was written on a little endian
+// machine, and we only need to swap if we are running on a big endian
+// machine.
+//
+// Gag me.
+
+  if (oct_mach_info::words_big_endian () && mopt == 0)
+    swap = true;
+
+  // mopt is signed, therefore byte swap may result in negative value.
+
+  if (mopt > 9999 || mopt < 0)
+    swap = true;
+
+  if (swap)
+    {
+      swap_4_bytes (X_CAST (char *, &mopt));
+      swap_4_bytes (X_CAST (char *, &nr));
+      swap_4_bytes (X_CAST (char *, &nc));
+      swap_4_bytes (X_CAST (char *, &imag));
+      swap_4_bytes (X_CAST (char *, &len));
+    }
+
+  if (mopt > 9999 || mopt < 0 || imag > 1 || imag < 0)
+    {
+      if (! quiet)
+	error ("load: can't read binary file");
+      return -1;
+    }
+
+  return 0;
+
+ data_read_error:
+  return -1;
+}
+
+// We don't just use a cast here, because we need to be able to detect
+// possible errors.
+
+oct_mach_info::float_format
+mopt_digit_to_float_format (int mach)
+{
+  oct_mach_info::float_format flt_fmt = oct_mach_info::flt_fmt_unknown;
+
+  switch (mach)
+    {
+    case 0:
+      flt_fmt = oct_mach_info::flt_fmt_ieee_little_endian;
+      break;
+
+    case 1:
+      flt_fmt = oct_mach_info::flt_fmt_ieee_big_endian;
+      break;
+
+    case 2:
+      flt_fmt = oct_mach_info::flt_fmt_vax_d;
+      break;
+
+    case 3:
+      flt_fmt = oct_mach_info::flt_fmt_vax_g;
+      break;
+
+    case 4:
+      flt_fmt = oct_mach_info::flt_fmt_cray;
+      break;
+
+    default:
+      flt_fmt = oct_mach_info::flt_fmt_unknown;
+      break;
+    }
+
+  return flt_fmt;
+}
+
+int
+float_format_to_mopt_digit (oct_mach_info::float_format flt_fmt)
+{
+  int retval = -1;
+
+  switch (flt_fmt)
+    {
+    case oct_mach_info::flt_fmt_ieee_little_endian:
+      retval = 0;
+      break;
+
+    case oct_mach_info::flt_fmt_ieee_big_endian:
+      retval = 1;
+      break;
+
+    case oct_mach_info::flt_fmt_vax_d:
+      retval = 2;
+      break;
+
+    case oct_mach_info::flt_fmt_vax_g:
+      retval = 3;
+      break;
+
+    case oct_mach_info::flt_fmt_cray:
+      retval = 4;
+      break;
+
+    default:
+      break;
+    }
+
+  return retval;
+}
+
+// Extract one value (scalar, matrix, string, etc.) from stream IS and
+// place it in TC, returning the name of the variable.
+//
+// The data is expected to be in Matlab version 4 .mat format, though
+// not all the features of that format are supported.
+//
+// FILENAME is used for error messages.
+//
+// This format provides no way to tag the data as global.
+
+std::string
+read_mat_binary_data (std::istream& is, const std::string& filename,
+		      octave_value& tc)
+{
+  std::string retval;
+
+  // These are initialized here instead of closer to where they are
+  // first used to avoid errors from gcc about goto crossing
+  // initialization of variable.
+
+  Matrix re;
+  oct_mach_info::float_format flt_fmt = oct_mach_info::flt_fmt_unknown;
+  bool swap = false;
+  int type = 0;
+  int prec = 0;
+  int order = 0;
+  int mach = 0;
+  int dlen = 0;
+
+  FOUR_BYTE_INT mopt, nr, nc, imag, len;
+
+  int err = read_mat_file_header (is, swap, mopt, nr, nc, imag, len);
+  if (err)
+    {
+      if (err < 0)
+	goto data_read_error;
+      else
+	return retval;
+    }
+
+  type = mopt % 10;  // Full, sparse, etc.
+  mopt /= 10;        // Eliminate first digit.
+  prec = mopt % 10;  // double, float, int, etc.
+  mopt /= 10;        // Eliminate second digit.
+  order = mopt % 10; // Row or column major ordering.
+  mopt /= 10;        // Eliminate third digit.
+  mach = mopt % 10;  // IEEE, VAX, etc.
+
+  flt_fmt = mopt_digit_to_float_format (mach);
+
+  if (flt_fmt == oct_mach_info::flt_fmt_unknown)
+    {
+      error ("load: unrecognized binary format!");
+      return retval;
+    }
+
+  if (type != 0 && type != 1)
+    {
+      error ("load: can't read sparse matrices");
+      return retval;
+    }
+
+  if (imag && type == 1)
+    {
+      error ("load: encountered complex matrix with string flag set!");
+      return retval;
+    }
+
+  // LEN includes the terminating character, and the file is also
+  // supposed to include it, but apparently not all files do.  Either
+  // way, I think this should work.
+
+  {
+    OCTAVE_LOCAL_BUFFER (char, name, len+1);
+    name[len] = '\0';
+    if (! is.read (X_CAST (char *, name), len))
+      goto data_read_error;
+    retval = name;
+
+    dlen = nr * nc;
+    if (dlen < 0)
+      goto data_read_error;
+
+    if (order)
+      {
+	int tmp = nr;
+	nr = nc;
+	nc = tmp;
+      }
+
+      re.resize (nr, nc);
+
+      read_mat_binary_data (is, re.fortran_vec (), prec, dlen, swap, flt_fmt);
+
+      if (! is || error_state)
+	{
+	  error ("load: reading matrix data for `%s'", name);
+	  goto data_read_error;
+	}
+
+      if (imag)
+	{
+	  Matrix im (nr, nc);
+
+	  read_mat_binary_data (is, im.fortran_vec (), prec, dlen, swap,
+				flt_fmt);
+
+	  if (! is || error_state)
+	    {
+	      error ("load: reading imaginary matrix data for `%s'", name);
+	      goto data_read_error;
+	    }
+
+	  ComplexMatrix ctmp (nr, nc);
+
+	  for (int j = 0; j < nc; j++)
+	    for (int i = 0; i < nr; i++)
+	      ctmp (i, j) = Complex (re (i, j), im (i, j));
+
+	  tc = order ? ctmp.transpose () : ctmp;
+	}
+      else
+	tc = order ? re.transpose () : re;
+
+      if (type == 1)
+	tc = tc.convert_to_str ();
+
+      return retval;
+    }
+
+ data_read_error:
+  error ("load: trouble reading binary file `%s'", filename.c_str ());
+  return retval;
+}
+
+// Save the data from TC along with the corresponding NAME on stream OS 
+// in the MatLab version 4 binary format.
+
+bool
+save_mat_binary_data (std::ostream& os, const octave_value& tc,
+		      const std::string& name) 
+{
+  FOUR_BYTE_INT mopt = 0;
+
+  mopt += tc.is_string () ? 1 : 0;
+
+  oct_mach_info::float_format flt_fmt =
+    oct_mach_info::native_float_format ();;
+
+  mopt += 1000 * float_format_to_mopt_digit (flt_fmt);
+
+  os.write (X_CAST (char *, &mopt), 4);
+  
+  FOUR_BYTE_INT nr = tc.rows ();
+  os.write (X_CAST (char *, &nr), 4);
+
+  FOUR_BYTE_INT nc = tc.columns ();
+  os.write (X_CAST (char *, &nc), 4);
+
+  int len = nr * nc;
+
+  FOUR_BYTE_INT imag = tc.is_complex_type () ? 1 : 0;
+  os.write (X_CAST (char *, &imag), 4);
+
+  // LEN includes the terminating character, and the file is also
+  // supposed to include it.
+
+  FOUR_BYTE_INT name_len = name.length () + 1;
+
+  os.write (X_CAST (char *, &name_len), 4);
+  os << name << '\0';
+
+  if (tc.is_string ())
+    {
+      unwind_protect::begin_frame ("save_mat_binary_data");
+
+      charMatrix chm = tc.char_matrix_value ();
+
+      int nrow = chm.rows ();
+      int ncol = chm.cols ();
+	
+      OCTAVE_LOCAL_BUFFER (double, buf, ncol*nrow);
+	
+      for (int i = 0; i < nrow; i++)
+      	{
+	  std::string tstr = chm.row_as_string (i);
+	  const char *s = tstr.data ();
+	  
+	  for (int j = 0; j < ncol; j++)
+	    buf[j*nrow+i] = static_cast<double> (*s++ & 0x00FF);
+       	}
+      os.write ((char *)buf, nrow*ncol*sizeof(double));
+      
+      unwind_protect::run_frame ("save_mat_binary_data");
+    }
+  else if (tc.is_range ())
+    {
+      Range r = tc.range_value ();
+      double base = r.base ();
+      double inc = r.inc ();
+      int nel = r.nelem ();
+      for (int i = 0; i < nel; i++)
+	{
+	  double x = base + i * inc;
+	  os.write (X_CAST (char *, &x), 8);
+	}
+    }
+  else if (tc.is_real_scalar ())
+    {
+      double tmp = tc.double_value ();
+      os.write (X_CAST (char *, &tmp), 8);
+    }
+  else if (tc.is_real_matrix ())
+    {
+      Matrix m = tc.matrix_value ();
+      os.write (X_CAST (char *, m.data ()), 8 * len);
+    }
+  else if (tc.is_complex_scalar ())
+    {
+      Complex tmp = tc.complex_value ();
+      os.write (X_CAST (char *, &tmp), 16);
+    }
+  else if (tc.is_complex_matrix ())
+    {
+      ComplexMatrix m_cmplx = tc.complex_matrix_value ();
+      Matrix m = ::real (m_cmplx);
+      os.write (X_CAST (char *, m.data ()), 8 * len);
+      m = ::imag (m_cmplx);
+      os.write (X_CAST (char *, m.data ()), 8 * len);
+    }
+  else
+    gripe_wrong_type_arg ("save", tc, false);
+
+  return os;
+}
+
+/*
+;;; Local Variables: ***
+;;; mode: C++ ***
+;;; End: ***
+*/