/*

Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
              2005, 2006, 2007, 2008, 2009 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 3 of the License, 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, see
<http://www.gnu.org/licenses/>.

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <cassert>
#include <cctype>
#include <cstring>

#include <iomanip>
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>

#include <Array.h>

#include "byte-swap.h"
#include "lo-ieee.h"
#include "lo-mappers.h"
#include "lo-utils.h"
#include "str-vec.h"
#include "quit.h"

#include "error.h"
#include "gripes.h"
#include "input.h"
#include "oct-stdstrm.h"
#include "oct-stream.h"
#include "oct-obj.h"
#include "utils.h"

// Possible values for conv_err:
//
//   1 : not a real scalar
//   2 : value is NaN
//   3 : value is not an integer

static int
convert_to_valid_int (const octave_value& tc, int& conv_err)
{
  int retval = 0;

  conv_err = 0;

  double dval = tc.double_value ();

  if (! error_state)
    {
      if (! lo_ieee_isnan (dval))
        {
          int ival = NINT (dval);

          if (ival == dval)
            retval = ival;
          else
            conv_err = 3;
        }
      else
        conv_err = 2;
    }
  else
    conv_err = 1;

  return retval;
}

static int
get_size (double d, const std::string& who)
{
  int retval = -1;

  if (! lo_ieee_isnan (d))
    {
      if (! xisinf (d))
        {
          if (d >= 0.0)
            retval = NINT (d);
          else
            ::error ("%s: negative value invalid as size specification",
                     who.c_str ());
        }
      else
        retval = -1;
    }
  else
    ::error ("%s: NaN is invalid as size specification", who.c_str ());

  return retval;
}

static void
get_size (const Array<double>& size, octave_idx_type& nr, octave_idx_type& nc, bool& one_elt_size_spec,
          const std::string& who)
{
  nr = -1;
  nc = -1;

  one_elt_size_spec = false;

  double dnr = -1.0;
  double dnc = -1.0;

  octave_idx_type sz_len = size.length ();

  if (sz_len == 1)
    {
      one_elt_size_spec = true;

      dnr = size (0);

      dnc = (dnr == 0.0) ? 0.0 : 1.0;
    }
  else if (sz_len == 2)
    {
      dnr = size (0);

      if (! xisinf (dnr))
        dnc = size (1);
      else
        ::error ("%s: invalid size specification", who.c_str ());
    }
  else
    ::error ("%s: invalid size specification", who.c_str ());

  if (! error_state)
    {
      nr = get_size (dnr, who);

      if (! error_state && dnc >= 0.0)
        nc = get_size (dnc, who);
    }
}

scanf_format_list::scanf_format_list (const std::string& s)
  : nconv (0), curr_idx (0), list (16, 1), buf (0)
{
  octave_idx_type num_elts = 0;

  size_t n = s.length ();

  size_t i = 0;

  int width = 0;
  bool discard = false;
  char modifier = '\0';
  char type = '\0';

  bool have_more = true;

  while (i < n)
    {
      have_more = true;

      if (! buf)
        buf = new std::ostringstream ();

      if (s[i] == '%')
        {
          // Process percent-escape conversion type.

          process_conversion (s, i, n, width, discard, type, modifier,
                              num_elts);

          have_more = (buf != 0);
        }
      else if (isspace (s[i]))
        {
          type = scanf_format_elt::whitespace_conversion;

          width = 0;
          discard = false;
          modifier = '\0';
          *buf << " ";

          while (++i < n && isspace (s[i]))
            /* skip whitespace */;

          add_elt_to_list (width, discard, type, modifier, num_elts);

          have_more = false;
        }
      else
        {
          type = scanf_format_elt::literal_conversion;

          width = 0;
          discard = false;
          modifier = '\0';

          while (i < n && ! isspace (s[i]) && s[i] != '%')
            *buf << s[i++];

          add_elt_to_list (width, discard, type, modifier, num_elts);

          have_more = false;
        }

      if (nconv < 0)
        {
          have_more = false;
          break;
        }
    }

  if (have_more)
    add_elt_to_list (width, discard, type, modifier, num_elts);

  list.resize (num_elts, 1);

  delete buf;
}

scanf_format_list::~scanf_format_list (void)
{
  octave_idx_type n = list.length ();

  for (octave_idx_type i = 0; i < n; i++)
    {
      scanf_format_elt *elt = list(i);
      delete elt;
    }   
}

void
scanf_format_list::add_elt_to_list (int width, bool discard, char type,
                                    char modifier, octave_idx_type& num_elts,
                                    const std::string& char_class)
{
  if (buf)
    {
      std::string text = buf->str ();

      if (! text.empty ())
        {
          scanf_format_elt *elt
            = new scanf_format_elt (text.c_str (), width, discard, type,
                                    modifier, char_class);

          if (num_elts == list.length ())
            list.resize (2 * num_elts, 1);

          list(num_elts++) = elt;
        }

      delete buf;
      buf = 0;
    }
}

static std::string
expand_char_class (const std::string& s)
{
  std::string retval;

  size_t len = s.length ();

  size_t i = 0;

  while (i < len)
    {
      unsigned char c = s[i++];

      if (c == '-' && i > 1 && i < len
          && static_cast<unsigned char> (s[i-2]) <= static_cast<unsigned char> (s[i]))
        {
          // Add all characters from the range except the first (we
          // already added it below).

          for (c = s[i-2]+1; c < s[i]; c++)
            retval += c;
        }
      else
        {
          // Add the character to the class.  Only add '-' if it is
          // the last character in the class.

          if (c != '-' || i == len)
            retval += c;
        }
    }

  return retval;
}

void
scanf_format_list::process_conversion (const std::string& s, size_t& i,
                                       size_t n, int& width, bool& discard,
                                       char& type, char& modifier,
                                       octave_idx_type& num_elts)
{
  width = 0;
  discard = false;
  modifier = '\0';
  type = '\0';

  *buf << s[i++];

  bool have_width = false;

  while (i < n)
    {
      switch (s[i])
        {
        case '*':
          if (discard)
            nconv = -1;
          else
            {
              discard = true;
              *buf << s[i++];
            }
          break;

        case '0': case '1': case '2': case '3': case '4':
        case '5': case '6': case '7': case '8': case '9':
          if (have_width)
            nconv = -1;
          else
            {
              char c = s[i++];
              width = width * 10 + c - '0';
              have_width = true;
              *buf << c;
              while (i < n && isdigit (s[i]))
                {
                  c = s[i++];
                  width = width * 10 + c - '0';
                  *buf << c;
                }
            }
          break;

        case 'h': case 'l': case 'L':
          if (modifier != '\0')
            nconv = -1;
          else
            modifier = s[i++];
          break;

        case 'd': case 'i': case 'o': case 'u': case 'x':
          if (modifier == 'L')
            {
              nconv = -1;
              break;
            }
          goto fini;

        case 'e': case 'f': case 'g':
          if (modifier == 'h')
            {
              nconv = -1;
              break;
            }

          // No float or long double conversions, thanks.
          *buf << 'l';

          goto fini;

        case 'c': case 's': case 'p': case '%': case '[':
          if (modifier != '\0')
            {
              nconv = -1;
              break;
            }
          goto fini;

        fini:
          {
            if (finish_conversion (s, i, n, width, discard, type,
                                   modifier, num_elts) == 0)
              return;
          }
          break;

        default:
          nconv = -1;
          break;
        }

      if (nconv < 0)
        break;
    }

  nconv = -1;
}

int
scanf_format_list::finish_conversion (const std::string& s, size_t& i,
                                      size_t n, int& width, bool discard,
                                      char& type, char modifier,
                                      octave_idx_type& num_elts)
{
  int retval = 0;

  std::string char_class;

  size_t beg_idx = std::string::npos;
  size_t end_idx = std::string::npos;

  if (s[i] == '%')
    {
      type = '%';
      *buf << s[i++];
    }
  else
    {
      type = s[i];

      if (s[i] == '[')
        {
          *buf << s[i++];

          if (i < n)
            {
              beg_idx = i;

              if (s[i] == '^')
                {
                  type = '^';
                  *buf << s[i++];

                  if (i < n)
                    {
                      beg_idx = i;

                      if (s[i] == ']')
                        *buf << s[i++];
                    }
                }
              else if (s[i] == ']')
                *buf << s[i++];
            }

          while (i < n && s[i] != ']')
            *buf << s[i++];

          if (i < n && s[i] == ']')
            {
              end_idx = i-1;
              *buf << s[i++];
            }

          if (s[i-1] != ']')
            retval = nconv = -1;
        }
      else
        *buf << s[i++];

      nconv++;
    }

  if (nconv >= 0)
    {
      if (beg_idx != std::string::npos && end_idx != std::string::npos)
        char_class = expand_char_class (s.substr (beg_idx,
                                                  end_idx - beg_idx + 1));

      add_elt_to_list (width, discard, type, modifier, num_elts, char_class);
    }

  return retval;
}

void
scanf_format_list::printme (void) const
{
  octave_idx_type n = list.length ();

  for (octave_idx_type i = 0; i < n; i++)
    {
      scanf_format_elt *elt = list(i);

      std::cerr
        << "width:      " << elt->width << "\n"
        << "discard:    " << elt->discard << "\n"
        << "type:       ";

      if (elt->type == scanf_format_elt::literal_conversion)
        std::cerr << "literal text\n";
      else if (elt->type == scanf_format_elt::whitespace_conversion)
        std::cerr << "whitespace\n";
      else
        std::cerr << elt->type << "\n";

      std::cerr
        << "modifier:   " << elt->modifier << "\n"
        << "char_class: `" << undo_string_escapes (elt->char_class) << "'\n"
        << "text:       `" << undo_string_escapes (elt->text) << "'\n\n";
    }
}

bool
scanf_format_list::all_character_conversions (void)
{
  octave_idx_type n = list.length ();

  if (n > 0)
    {
      for (octave_idx_type i = 0; i < n; i++)
        {
          scanf_format_elt *elt = list(i);

          switch (elt->type)
            {
            case 'c': case 's': case '%': case '[': case '^':
            case scanf_format_elt::literal_conversion:
            case scanf_format_elt::whitespace_conversion:
              break;

            default:
              return false;
              break;
            }
        }

      return true;
    }
  else
    return false;
}

bool
scanf_format_list::all_numeric_conversions (void)
{
  octave_idx_type n = list.length ();

  if (n > 0)
    {
      for (octave_idx_type i = 0; i < n; i++)
        {
          scanf_format_elt *elt = list(i);

          switch (elt->type)
            {
            case 'd': case 'i': case 'o': case 'u': case 'x':
            case 'e': case 'f': case 'g':
              break;

            default:
              return false;
              break;
            }
        }

      return true;
    }
  else
    return false;
}

// Ugh again.

printf_format_list::printf_format_list (const std::string& s)
  : nconv (0), curr_idx (0), list (16, 1), buf (0)
{
  octave_idx_type num_elts = 0;

  size_t n = s.length ();

  size_t i = 0;

  int args = 0;
  std::string flags;
  int fw = 0;
  int prec = 0;
  char modifier = '\0';
  char type = '\0';

  bool have_more = true;
  bool empty_buf = true;

  if (n == 0)
    {
      printf_format_elt *elt
        = new printf_format_elt ("", args, fw, prec, flags, type, modifier);

      list(num_elts++) = elt;

      list.resize (num_elts, 1);
    }
  else
    {
      while (i < n)
        {
          have_more = true;

          if (! buf)
            {
              buf = new std::ostringstream ();
              empty_buf = true;
            }

          switch (s[i])
            {
            case '%':
              {
                if (empty_buf)
                  {
                    process_conversion (s, i, n, args, flags, fw, prec,
                                        type, modifier, num_elts);

                    have_more = (buf != 0);
                  }
                else
                  add_elt_to_list (args, flags, fw, prec, type, modifier,
                                   num_elts);
              }
              break;

            default:
              {
                args = 0;
                flags = "";
                fw = 0;
                prec = 0;
                modifier = '\0';
                type = '\0';
                *buf << s[i++];
                empty_buf = false;
              }
              break;
            }

          if (nconv < 0)
            {
              have_more = false;
              break;
            }
        }

      if (have_more)
        add_elt_to_list (args, flags, fw, prec, type, modifier, num_elts);

      list.resize (num_elts, 1);

      delete buf;
    }
}

printf_format_list::~printf_format_list (void)
{
  octave_idx_type n = list.length ();

  for (octave_idx_type i = 0; i < n; i++)
    {
      printf_format_elt *elt = list(i);
      delete elt;
    }   
}

void
printf_format_list::add_elt_to_list (int args, const std::string& flags,
                                     int fw, int prec, char type,
                                     char modifier, octave_idx_type& num_elts)
{
  if (buf)
    {
      std::string text = buf->str ();

      if (! text.empty ())
        {
          printf_format_elt *elt
            = new printf_format_elt (text.c_str (), args, fw, prec, flags,
                                     type, modifier);

          if (num_elts == list.length ())
            list.resize (2 * num_elts, 1);

          list(num_elts++) = elt;
        }

      delete buf;
      buf = 0;
    }
}

void
printf_format_list::process_conversion
  (const std::string& s, size_t& i, size_t n, int& args, std::string& flags,
   int& fw, int& prec, char& modifier, char& type, octave_idx_type& num_elts)
{
  args = 0;
  flags = "";
  fw = 0;
  prec = 0;
  modifier = '\0';
  type = '\0';

  *buf << s[i++];

  bool nxt = false;

  while (i < n)
    {
      switch (s[i])
        {
        case '-': case '+': case ' ': case '0': case '#':
          flags += s[i];
          *buf << s[i++];
          break;

        default:
          nxt = true;
          break;
        }

      if (nxt)
        break;
    }

  if (i < n)
    {
      if (s[i] == '*')
        {
          fw = -1;
          args++;
          *buf << s[i++];
        }
      else
        {
          if (isdigit (s[i]))
            {
              int nn = 0;
              std::string tmp = s.substr (i);
              sscanf (tmp.c_str (), "%d%n", &fw, &nn);
            }

          while (i < n && isdigit (s[i]))
            *buf << s[i++];
        }
    }

  if (i < n && s[i] == '.')
    {
      *buf << s[i++];

      if (i < n)
        {
          if (s[i] == '*')
            {
              prec = -1;
              args++;
              *buf << s[i++];
            }
          else
            {
              if (isdigit (s[i]))
                {
                  int nn = 0;
                  std::string tmp = s.substr (i);
                  sscanf (tmp.c_str (), "%d%n", &prec, &nn);
                }

              while (i < n && isdigit (s[i]))
                *buf << s[i++];
            }
        }
    }

  if (i < n)
    {
      switch (s[i])
        {
        case 'h': case 'l': case 'L':
          modifier = s[i];
          *buf << s[i++];
          break;

        default:
          break;
        }
    }

  if (i < n)
    finish_conversion (s, i, args, flags, fw, prec, modifier, type, num_elts);
  else
    nconv = -1;
}

void
printf_format_list::finish_conversion
  (const std::string& s, size_t& i, int args, const std::string& flags,
   int fw, int prec, char modifier, char& type, octave_idx_type& num_elts)

{
  switch (s[i])
    {
    case 'd': case 'i': case 'o': case 'x': case 'X':
    case 'u': case 'c':
      if (modifier == 'L')
        {
          nconv = -1;
          break;
        }
      goto fini;

    case 'f': case 'e': case 'E': case 'g': case 'G':
      if (modifier == 'h' || modifier == 'l')
        {
          nconv = -1;
          break;
        }
      goto fini;

    case 's': case 'p': case '%':
      if (modifier != '\0')
        {
          nconv = -1;
          break;
        }
      goto fini;

    fini:

      type = s[i];

      *buf << s[i++];

      if (type != '%' || args != 0)
        nconv++;

      if (type != '%')
        args++;

      add_elt_to_list (args, flags, fw, prec, type, modifier, num_elts);

      break;

    default:
      nconv = -1;
      break;
    }
}

void
printf_format_list::printme (void) const
{
  int n = list.length ();

  for (int i = 0; i < n; i++)
    {
      printf_format_elt *elt = list(i);

      std::cerr
        << "args:     " << elt->args << "\n"
        << "flags:    `" << elt->flags << "'\n"
        << "width:    " << elt->fw << "\n"
        << "prec:     " << elt->prec << "\n"
        << "type:     `" << elt->type << "'\n"
        << "modifier: `" << elt->modifier << "'\n"
        << "text:     `" << undo_string_escapes (elt->text) << "'\n\n";
    }
}

int
octave_base_stream::file_number (void)
{
  // Kluge alert!

  if (name () == "stdin")
    return 0;

  if (name () == "stdout")
    return 1;

  if (name () == "stderr")
    return 2;

  int retval = -1;

  std::istream *is = input_stream ();
  std::ostream *os = output_stream ();

  // There is no standard way to get the underlying file descriptor from 
  // std::filebuf (nor in the GNU libstdc++-v3 implementation). We cache
  // the descriptor in c_file_ptr_buf, and then extract it here.

  c_file_ptr_buf *ibuf
    = is ? dynamic_cast<c_file_ptr_buf *> (is->rdbuf ()) : 0;

  c_file_ptr_buf *obuf
    = os ? dynamic_cast<c_file_ptr_buf *> (os->rdbuf ()) : 0;

  int i_fid = ibuf ? ibuf->file_number () : -1;
  int o_fid = obuf ? obuf->file_number () : -1;

  if (i_fid >= 0)
    {
      if (o_fid >= 0)
        retval = (i_fid == o_fid) ? i_fid : -1;
      else
        retval = i_fid;
    }
  else if (o_fid >= 0)
    retval = o_fid;

  return retval;
}

void
octave_base_stream::error (const std::string& msg)
{
  fail = true;
  errmsg = msg;
}

void
octave_base_stream::error (const std::string& who, const std::string& msg)
{
  fail = true;
  errmsg = who + ": " + msg;
}

void
octave_base_stream::clear (void)
{
  fail = false;
  errmsg = "";
}

void
octave_base_stream::clearerr (void)
{
  std::istream *is = input_stream ();
  std::ostream *os = output_stream ();

  if (is)
    is->clear ();

  if (os)
    os->clear ();
}

// Functions that are defined for all input streams (input streams
// are those that define is).

std::string
octave_base_stream::do_gets (octave_idx_type max_len, bool& err,
                             bool strip_newline, const std::string& who)
{
  std::string retval;

  if ((interactive || forced_interactive) && file_number () == 0)
    {
      ::error ("%s: unable to read from stdin while running interactively",
               who.c_str ());
             
      return retval;
    }

  err = false;

  std::istream *isp = input_stream ();

  if (isp)
    {
      std::istream& is = *isp;

      std::ostringstream buf;

      int c = 0;
      int char_count = 0;

      if (max_len != 0)
        {
          while (is && (c = is.get ()) != EOF)
            {
              char_count++;

              // Handle CRLF, CR, or LF as line ending.

              if (c == '\r')
                {
                  if (! strip_newline)
                    buf << static_cast<char> (c);

                  c = is.get ();

                  if (c != EOF)
                    {
                      if (c == '\n')
                        {
                          char_count++;

                          if (! strip_newline)
                            buf << static_cast<char> (c);
                        }
                      else
                        is.putback (c);
                    }

                  break;
                }
              else if (c == '\n')
                {
                  if (! strip_newline)
                    buf << static_cast<char> (c);

                  break;
                }
              else
                buf << static_cast<char> (c);

              if (max_len > 0 && char_count == max_len)
                break;
            }
        }

      if (! is.eof () && char_count > 0)
        {
          // GAGME.  Matlab seems to check for EOF even if the last
          // character in a file is a newline character.  This is NOT
          // what the corresponding C-library functions do.
          int disgusting_compatibility_hack = is.get ();
          if (! is.eof ())
            is.putback (disgusting_compatibility_hack);
        }

      if (is.good () || (is.eof () && char_count > 0))
        retval = buf.str ();
      else
        {
          err = true;

          if (is.eof () && char_count == 0)
            error (who, "at end of file");
          else
            error (who, "read error");
        }
    }
  else
    {
      err = true;
      invalid_operation (who, "reading");
    }

  return retval;
}

std::string
octave_base_stream::getl (octave_idx_type max_len, bool& err, const std::string& who)
{
  return do_gets (max_len, err, true, who);
}

std::string
octave_base_stream::gets (octave_idx_type max_len, bool& err, const std::string& who)
{
  return do_gets (max_len, err, false, who);
}

long
octave_base_stream::skipl (long num, bool& err, const std::string& who)
{
  long cnt = -1;

  if ((interactive || forced_interactive) && file_number () == 0)
    {
      ::error ("%s: unable to read from stdin while running interactively",
               who.c_str ());
             
      return count;
    }

  err = false;

  std::istream *isp = input_stream ();

  if (isp)
    {
      std::istream& is = *isp;

      int c = 0, lastc = -1;
      cnt = 0;

      while (is && (c = is.get ()) != EOF)
        {
          // Handle CRLF, CR, or LF as line ending.

          if (c == '\r' || (c == '\n' && lastc != '\r'))
            {
              if (++cnt == num)
                break;
            }

          lastc = c;
        }

      // Maybe eat the following \n if \r was just met.
      if (c == '\r' && is.peek () == '\n')
       is.get ();

      if (is.bad ())
        {
          err = true;
          error (who, "read error");
        }

      if (err)
        cnt = -1;
    }
  else
    {
      err = true;
      invalid_operation (who, "reading");
    }

  return cnt;
}

#define OCTAVE_SCAN(is, fmt, arg) octave_scan (is, fmt, arg)

template <class T>
std::istream&
octave_scan_1 (std::istream& is, const scanf_format_elt& fmt, T* valptr)
{
  T& ref = *valptr;

  switch (fmt.type)
    {
    case 'o':
      is >> std::oct >> ref >> std::dec;
      break;

    case 'x':
      is >> std::hex >> ref >> std::dec;
      break;

    case 'i':
      {
        int c1 = is.get ();

        if (! is.eof ())
          {
            if (c1 == '0')
              {
                int c2 = is.peek ();

                if (c2 == 'x' || c2 == 'X')
                  {
                    is.ignore ();
                    if (std::isxdigit (is.peek ()))
                      is >> std::hex >> ref >> std::dec;
                    else
                      ref = 0;
                  }
                else
                  {
                    if (c2 == '0' || c2 == '1' || c2 == '2'
                        || c2 == '3' || c2 == '4' || c2 == '5'
                        || c2 == '6' || c2 == '7')
                      is >> std::oct >> ref >> std::dec;
                    else
                      ref = 0;
                  }
              }
            else
              {
                is.putback (c1);

                is >> ref;
              }
          }
      }
      break;

    default:
      is >> ref;
      break;
    }

  return is;
}

template <class T>
std::istream&
octave_scan (std::istream& is, const scanf_format_elt& fmt, T* valptr)
{
  if (fmt.width)
    {
      // Limit input to fmt.width characters by reading into a
      // temporary stringstream buffer.

      std::string tmp;

      is.width (fmt.width);
      is >> tmp;

      std::istringstream ss (tmp);

      octave_scan_1 (ss, fmt, valptr);
    }
  else
    octave_scan_1 (is, fmt, valptr);

  return is;
}

// Note that this specialization is only used for reading characters, not 
// character strings. See BEGIN_S_CONVERSION for details.

template<>
std::istream&
octave_scan<> (std::istream& is, const scanf_format_elt& /* fmt */,
               char* valptr)
{
  return is >> valptr;
}

template std::istream&
octave_scan (std::istream&, const scanf_format_elt&, int*);

template std::istream&
octave_scan (std::istream&, const scanf_format_elt&, long int*);

template std::istream&
octave_scan (std::istream&, const scanf_format_elt&, short int*);

template std::istream&
octave_scan (std::istream&, const scanf_format_elt&, unsigned int*);

template std::istream&
octave_scan (std::istream&, const scanf_format_elt&, unsigned long int*);

template std::istream&
octave_scan (std::istream&, const scanf_format_elt&, unsigned short int*);

#if 0
template std::istream&
octave_scan (std::istream&, const scanf_format_elt&, float*);
#endif

template<>
std::istream&
octave_scan<> (std::istream& is, const scanf_format_elt& fmt, double* valptr)
{
  double& ref = *valptr;

  switch (fmt.type)
    {
    case 'e':
    case 'f':
    case 'g':
      {
        int c1 = EOF;

        while (is && (c1 = is.get ()) != EOF && isspace (c1))
          /* skip whitespace */;

        if (c1 != EOF)
          {
            if (c1 == 'N')
              {
                int c2 = is.get ();

                if (c2 != EOF)
                  {
                    if (c2 == 'A')
                      {
                        int c3 = is.get ();

                        if (c3 != EOF)
                          {
                            is.putback (c3);

                            if (isspace (c3) || ispunct (c3))
                              ref = octave_NA;
                            else
                              {
                                is.putback (c2);
                                is.putback (c1);

                                is >> ref;
                              }
                          }
                        else
                          {
                            is.clear ();

                            ref = octave_NA;
                          }
                      }
                    else if (c2 == 'a')
                      {
                        int c3 = is.get ();

                        if (c3 != EOF)
                          {
                            if (c3 == 'N')
                              {
                                int c4 = is.get ();

                                if (c4 != EOF)
                                  {
                                    is.putback (c4);

                                    if (isspace (c4) || ispunct (c4))
                                      ref = octave_NaN;
                                    else
                                      {
                                        is.putback (c3);
                                        is.putback (c2);
                                        is.putback (c1);

                                        is >> ref;
                                      }
                                  }
                                else
                                  {
                                    is.clear ();

                                    ref = octave_NaN;
                                  }
                              }
                            else
                              {
                                is.putback (c3);
                                is.putback (c2);
                                is.putback (c1);

                                is >> ref;
                              }
                          }
                      }
                    else
                      {
                        is.putback (c2);
                        is.putback (c1);

                        is >> ref;
                      }
                  }
              }
            else if (c1 == 'I')
              {
                int c2 = is.get ();

                if (c2 != EOF)
                  {
                    if (c2 == 'n')
                      {
                        int c3 = is.get ();

                        if (c3 != EOF)
                          {
                            if (c3 == 'f')
                              {
                                int c4 = is.get ();

                                if (c4 != EOF)
                                  {
                                    is.putback (c4);

                                    if (isspace (c4) || ispunct (c4))
                                      ref = octave_Inf;
                                    else
                                      {
                                        is.putback (c3);
                                        is.putback (c2);
                                        is.putback (c1);

                                        is >> ref;
                                      }
                                  }
                                else
                                  {
                                    is.clear ();

                                    ref = octave_Inf;
                                  }
                              }
                            else
                              {
                                is.putback (c3);
                                is.putback (c2);
                                is.putback (c1);

                                is >> ref;
                              }
                        }
                      else
                        {
                          is.putback (c2);
                          is.putback (c1);

                          is >> ref;
                        }
                      }
                  }
              }
            else
              {
                is.putback (c1);

                is >> ref;
              }
          }
      }
      break;

    default:
      panic_impossible ();
      break;
    }

  return is;
}

template <class T>
void
do_scanf_conv (std::istream& is, const scanf_format_elt& fmt,
               T valptr, Matrix& mval, double *data, octave_idx_type& idx,
               octave_idx_type& conversion_count, octave_idx_type nr, octave_idx_type max_size,
               bool discard) 
{
  OCTAVE_SCAN (is, fmt, valptr);

  if (is)
    {
      if (idx == max_size && ! discard)
        {
          max_size *= 2;

          if (nr > 0)
            mval.resize (nr, max_size / nr, 0.0);
          else
            mval.resize (max_size, 1, 0.0);

          data = mval.fortran_vec ();
        }

      if (! discard)
        {
          conversion_count++;
          data[idx++] = *(valptr);
        }
    }
}

template void
do_scanf_conv (std::istream&, const scanf_format_elt&, int*,
               Matrix&, double*, octave_idx_type&, octave_idx_type&, octave_idx_type, octave_idx_type, bool);

template void
do_scanf_conv (std::istream&, const scanf_format_elt&, long int*,
               Matrix&, double*, octave_idx_type&, octave_idx_type&, octave_idx_type, octave_idx_type, bool);

template void
do_scanf_conv (std::istream&, const scanf_format_elt&, short int*,
               Matrix&, double*, octave_idx_type&, octave_idx_type&, octave_idx_type, octave_idx_type, bool);

template void
do_scanf_conv (std::istream&, const scanf_format_elt&, unsigned int*,
               Matrix&, double*, octave_idx_type&, octave_idx_type&, octave_idx_type, octave_idx_type, bool);

template void
do_scanf_conv (std::istream&, const scanf_format_elt&, unsigned long int*,
               Matrix&, double*, octave_idx_type&, octave_idx_type&, octave_idx_type, octave_idx_type, bool);

template void
do_scanf_conv (std::istream&, const scanf_format_elt&, unsigned short int*,
               Matrix&, double*, octave_idx_type&, octave_idx_type&, octave_idx_type, octave_idx_type, bool);

#if 0
template void
do_scanf_conv (std::istream&, const scanf_format_elt&, float*,
               Matrix&, double*, octave_idx_type&, octave_idx_type&, octave_idx_type, octave_idx_type, bool);
#endif

template void
do_scanf_conv (std::istream&, const scanf_format_elt&, double*,
               Matrix&, double*, octave_idx_type&, octave_idx_type&, octave_idx_type, octave_idx_type, bool);

#define DO_WHITESPACE_CONVERSION() \
  do \
    { \
      int c = EOF; \
 \
      while (is && (c = is.get ()) != EOF && isspace (c)) \
        /* skip whitespace */; \
 \
      if (c != EOF) \
        is.putback (c); \
    } \
  while (0)

#define DO_LITERAL_CONVERSION() \
  do \
    { \
      int c = EOF; \
 \
      int n = strlen (fmt); \
      int i = 0; \
 \
      while (i < n && is && (c = is.get ()) != EOF) \
        { \
          if (c == static_cast<unsigned char> (fmt[i])) \
            { \
              i++; \
              continue; \
            } \
          else \
            { \
              is.putback (c); \
              break; \
            } \
        } \
 \
      if (i != n) \
        is.setstate (std::ios::failbit); \
    } \
  while (0)

#define DO_PCT_CONVERSION() \
  do \
    { \
      int c = is.get (); \
 \
      if (c != EOF) \
        { \
          if (c != '%') \
            { \
              is.putback (c); \
              is.setstate (std::ios::failbit); \
            } \
        } \
      else \
        is.setstate (std::ios::failbit); \
    } \
  while (0)

#define BEGIN_C_CONVERSION() \
  is.unsetf (std::ios::skipws); \
 \
  int width = elt->width ? elt->width : 1; \
 \
  std::string tmp (width, '\0'); \
 \
  int c = EOF; \
  int n = 0; \
 \
  while (is && n < width && (c = is.get ()) != EOF) \
    tmp[n++] = static_cast<char> (c); \
 \
  if (n > 0 && c == EOF) \
    is.clear ()

// For a `%s' format, skip initial whitespace and then read until the
// next whitespace character or until WIDTH characters have been read.
#define BEGIN_S_CONVERSION() \
  int width = elt->width; \
 \
  std::string tmp; \
 \
  do \
    { \
      if (width) \
        { \
          tmp = std::string (width, '\0'); \
 \
          int c = EOF; \
 \
          int n = 0; \
 \
          while (is && (c = is.get ()) != EOF) \
            { \
              if (! isspace (c)) \
                { \
                  tmp[n++] = static_cast<char> (c); \
                  break; \
                } \
            } \
 \
          while (is && n < width && (c = is.get ()) != EOF) \
            { \
              if (isspace (c)) \
                { \
                  is.putback (c); \
                  break; \
                } \
              else \
                tmp[n++] = static_cast<char> (c); \
            } \
 \
          if (n > 0 && c == EOF) \
            is.clear (); \
 \
          tmp.resize (n); \
        } \
      else \
        { \
          is >> std::ws >> tmp; \
        } \
    } \
  while (0)

// This format must match a nonempty sequence of characters.
#define BEGIN_CHAR_CLASS_CONVERSION() \
  int width = elt->width; \
 \
  std::string tmp; \
 \
  do \
    { \
      if (! width) \
        width = INT_MAX; \
 \
      std::ostringstream buf; \
 \
      std::string char_class = elt->char_class; \
 \
      int c = EOF; \
 \
      if (elt->type == '[') \
        { \
          int chars_read = 0; \
          while (is && chars_read++ < width && (c = is.get ()) != EOF \
                 && char_class.find (c) != std::string::npos) \
            buf << static_cast<char> (c); \
        } \
      else \
        { \
          int chars_read = 0; \
          while (is && chars_read++ < width && (c = is.get ()) != EOF \
                 && char_class.find (c) == std::string::npos) \
            buf << static_cast<char> (c); \
        } \
 \
      if (width == INT_MAX && c != EOF) \
        is.putback (c); \
 \
      tmp = buf.str (); \
 \
      if (tmp.empty ()) \
        is.setstate (std::ios::failbit); \
    } \
  while (0)

#define FINISH_CHARACTER_CONVERSION() \
  do \
    { \
      width = tmp.length (); \
 \
      if (is) \
        { \
          int i = 0; \
 \
          if (! discard) \
            { \
              conversion_count++; \
 \
              while (i < width) \
                { \
                  if (data_index == max_size) \
                    { \
                      max_size *= 2; \
 \
                      if (all_char_conv) \
                        { \
                          if (one_elt_size_spec) \
                            mval.resize (1, max_size, 0.0); \
                          else if (nr > 0) \
                            mval.resize (nr, max_size / nr, 0.0); \
                          else \
                            panic_impossible (); \
                        } \
                      else if (nr > 0) \
                        mval.resize (nr, max_size / nr, 0.0); \
                      else \
                        mval.resize (max_size, 1, 0.0); \
 \
                      data = mval.fortran_vec (); \
                    } \
 \
                  data[data_index++] = tmp[i++]; \
                } \
            } \
        } \
    } \
  while (0)

octave_value
octave_base_stream::do_scanf (scanf_format_list& fmt_list,
                              octave_idx_type nr, octave_idx_type nc, bool one_elt_size_spec,
                              octave_idx_type& conversion_count, const std::string& who)
{
  octave_value retval = Matrix ();

  if ((interactive || forced_interactive) && file_number () == 0)
    {
      ::error ("%s: unable to read from stdin while running interactively",
               who.c_str ());
             
      return retval;
    }

  conversion_count = 0;

  octave_idx_type nconv = fmt_list.num_conversions ();

  octave_idx_type data_index = 0;

  if (nr == 0 || nc == 0)
    {
      if (one_elt_size_spec)
        nc = 0;

      return Matrix (nr, nc, 0.0);
    }

  std::istream *isp = input_stream ();

  bool all_char_conv = fmt_list.all_character_conversions ();

  Matrix mval;
  double *data = 0;
  octave_idx_type max_size = 0;
  octave_idx_type max_conv = 0;

  octave_idx_type final_nr = 0;
  octave_idx_type final_nc = 0;

  if (all_char_conv)
    {
      // Any of these could be resized later (if we have %s
      // conversions, we may read more than one element for each
      // conversion).

      if (one_elt_size_spec)
        {
          max_size = 512;
          mval.resize (1, max_size, 0.0);

          if (nr > 0)
            max_conv = nr;
        }
      else if (nr > 0)
        {
          if (nc > 0)
            {
              mval.resize (nr, nc, 0.0);
              max_size = max_conv = nr * nc;
            }
          else
            {
              mval.resize (nr, 32, 0.0);
              max_size = nr * 32;
            }
        }
      else
        panic_impossible ();
    }
  else if (nr > 0)
    {
      if (nc > 0)
        {
          // Will not resize later.
          mval.resize (nr, nc, 0.0);
          max_size = nr * nc;
          max_conv = max_size;
        }
      else
        {
          // Maybe resize later.
          mval.resize (nr, 32, 0.0);
          max_size = nr * 32;
        }
    }
  else
    {
      // Maybe resize later.
      mval.resize (32, 1, 0.0);
      max_size = 32;
    }

  data = mval.fortran_vec ();

  if (isp)
    {
      std::istream& is = *isp;

      const scanf_format_elt *elt = fmt_list.first ();

      std::ios::fmtflags flags = is.flags ();

      octave_idx_type trips = 0;

      octave_idx_type num_fmt_elts = fmt_list.length ();

      for (;;)
        {
          octave_quit ();

          if (elt)
            {
              if (! (elt->type == scanf_format_elt::whitespace_conversion
                     || elt->type == scanf_format_elt::literal_conversion
                     || elt->type == '%')
                  && max_conv > 0 && conversion_count == max_conv)
                {
                  if (all_char_conv && one_elt_size_spec)
                    {
                      final_nr = 1;
                      final_nc = data_index;
                    }
                  else
                    {
                      final_nr = nr;
                      final_nc = (data_index - 1) / nr + 1;
                    }

                  break;
                }
              else if (data_index == max_size)
                {
                  max_size *= 2;

                  if (all_char_conv)
                    {
                      if (one_elt_size_spec)
                        mval.resize (1, max_size, 0.0);
                      else if (nr > 0)
                        mval.resize (nr, max_size / nr, 0.0);
                      else
                        panic_impossible ();
                    }
                  else if (nr > 0)
                    mval.resize (nr, max_size / nr, 0.0);
                  else
                    mval.resize (max_size, 1, 0.0);

                  data = mval.fortran_vec ();
                }

              const char *fmt = elt->text;

              bool discard = elt->discard;

              switch (elt->type)
                {
                case scanf_format_elt::whitespace_conversion:
                  DO_WHITESPACE_CONVERSION ();
                  break;

                case scanf_format_elt::literal_conversion:
                  DO_LITERAL_CONVERSION ();
                  break;

                case '%':
                  DO_PCT_CONVERSION ();
                  break;

                case 'd': case 'i':
                  {
                    switch (elt->modifier)
                      {
                      case 'h':
                        {
                          short int tmp;
                          do_scanf_conv (is, *elt, &tmp, mval, data,
                                         data_index, conversion_count,
                                         nr, max_size, discard);
                        }
                        break;

                      case 'l':
                        {
                          long int tmp;
                          do_scanf_conv (is, *elt, &tmp, mval, data,
                                         data_index, conversion_count,
                                         nr, max_size, discard);
                        }
                        break;

                      default:
                        {
                          int tmp;
                          do_scanf_conv (is, *elt, &tmp, mval, data,
                                         data_index, conversion_count,
                                         nr, max_size, discard);
                        }
                        break;
                      }
                  }
                  break;

                case 'o': case 'u': case 'x':
                  {
                    switch (elt->modifier)
                      {
                      case 'h':
                        {
                          unsigned short int tmp;
                          do_scanf_conv (is, *elt, &tmp, mval, data,
                                         data_index, conversion_count,
                                         nr, max_size, discard);
                        }
                        break;

                      case 'l':
                        {
                          unsigned long int tmp;
                          do_scanf_conv (is, *elt, &tmp, mval, data,
                                         data_index, conversion_count,
                                         nr, max_size, discard);
                        }
                        break;

                      default:
                        {
                          unsigned int tmp;
                          do_scanf_conv (is, *elt, &tmp, mval, data,
                                         data_index, conversion_count,
                                         nr, max_size, discard);
                        }
                        break;
                      }
                  }
                  break;

                case 'e': case 'f': case 'g':
                  {
                    double tmp;

                    do_scanf_conv (is, *elt, &tmp, mval, data,
                                   data_index, conversion_count,
                                   nr, max_size, discard);
                  }
                  break;

                case 'c':
                  {
                    BEGIN_C_CONVERSION ();

                    FINISH_CHARACTER_CONVERSION ();

                    is.setf (flags);
                  }
                  break;

                case 's':
                  {
                    BEGIN_S_CONVERSION ();

                    FINISH_CHARACTER_CONVERSION ();
                  }
                  break;

                case '[': case '^':
                  {
                    BEGIN_CHAR_CLASS_CONVERSION ();

                    FINISH_CHARACTER_CONVERSION ();
                  }
                  break;

                case 'p':
                  error ("%s: unsupported format specifier", who.c_str ());
                  break;

                default:
                  error ("%s: internal format error", who.c_str ());
                  break;
                }

              if (! ok ())
                {
                  break;
                }
              else if (! is)
                {
                  if (all_char_conv)
                    {
                      if (one_elt_size_spec)
                        {
                          final_nr = 1;
                          final_nc = data_index;
                        }
                      else if (data_index > nr)
                        {
                          final_nr = nr;
                          final_nc = (data_index - 1) / nr + 1;
                        }
                      else
                        {
                          final_nr = data_index;
                          final_nc = 1;
                        }
                    }
                  else if (nr > 0)
                    {
                      if (data_index > nr)
                        {
                          final_nr = nr;
                          final_nc = (data_index - 1) / nr + 1;
                        }
                      else
                        {
                          final_nr = data_index;
                          final_nc = 1;
                        }
                    }
                  else
                    {
                      final_nr = data_index;
                      final_nc = 1;
                    }

                  // If it looks like we have a matching failure, then
                  // reset the failbit in the stream state.

                  if (is.rdstate () & std::ios::failbit)
                    is.clear (is.rdstate () & (~std::ios::failbit));

                  // FIXME -- is this the right thing to do?

                  if (interactive && name () == "stdin")
                    {
                      is.clear ();

                      // Skip to end of line.

                      bool err;
                      do_gets (-1, err, false, who);
                    }

                  break;
                }
            }
          else
            {
              error ("%s: internal format error", who.c_str ());
              break;
            }

          if (nconv == 0 && ++trips == num_fmt_elts)
            {
              if (all_char_conv && one_elt_size_spec)
                {
                  final_nr = 1;
                  final_nc = data_index;
                }
              else
                {
                  final_nr = nr;
                  final_nc = (data_index - 1) / nr + 1;
                }

              break;
            }
          else
            elt = fmt_list.next (nconv > 0);
        }
    }

  if (ok ())
    {
      mval.resize (final_nr, final_nc, 0.0);

      retval = mval;

      if (all_char_conv)
        retval = retval.convert_to_str (false, true);
    }

  return retval;
}

octave_value
octave_base_stream::scanf (const std::string& fmt, const Array<double>& size,
                           octave_idx_type& conversion_count, const std::string& who)
{
  octave_value retval = Matrix ();

  conversion_count = 0;

  std::istream *isp = input_stream ();

  if (isp)
    {
      scanf_format_list fmt_list (fmt);

      if (fmt_list.num_conversions () == -1)
        ::error ("%s: invalid format specified", who.c_str ());
      else
        {
        octave_idx_type nr = -1;
        octave_idx_type nc = -1;

        bool one_elt_size_spec;

        get_size (size, nr, nc, one_elt_size_spec, who);

        if (! error_state)
          retval = do_scanf (fmt_list, nr, nc, one_elt_size_spec,
                             conversion_count, who);
        }
    }
  else
    invalid_operation (who, "reading");

  return retval;
}

bool
octave_base_stream::do_oscanf (const scanf_format_elt *elt,
                               octave_value& retval, const std::string& who)
{
  bool quit = false;

  std::istream *isp = input_stream ();

  if (isp)
    {
      std::istream& is = *isp;

      std::ios::fmtflags flags = is.flags ();

      if (elt)
        {
          const char *fmt = elt->text;

          bool discard = elt->discard;

          switch (elt->type)
            {
            case scanf_format_elt::whitespace_conversion:
              DO_WHITESPACE_CONVERSION ();
              break;

            case scanf_format_elt::literal_conversion:
              DO_LITERAL_CONVERSION ();
              break;

            case '%':
              {
                DO_PCT_CONVERSION ();

                if (! is)
                  quit = true;

              }
              break;

            case 'd': case 'i':
              {
                int tmp;

                if (OCTAVE_SCAN (is, *elt, &tmp))
                  {
                    if (! discard)
                      retval = tmp;
                  }
                else
                  quit = true;
              }
              break;

            case 'o': case 'u': case 'x':
              {
                long int tmp;

                if (OCTAVE_SCAN (is, *elt, &tmp))
                  {
                    if (! discard)
                      retval = tmp;
                  }
                else
                  quit = true;
              }
              break;

            case 'e': case 'f': case 'g':
              {
                double tmp;

                if (OCTAVE_SCAN (is, *elt, &tmp))
                  {
                    if (! discard)
                      retval = tmp;
                  }
                else
                  quit = true;
              }
              break;

            case 'c':
              {
                BEGIN_C_CONVERSION ();

                if (! discard)
                  retval = tmp;

                if (! is)
                  quit = true;

                is.setf (flags);
              }
              break;

            case 's':
              {
                BEGIN_S_CONVERSION ();

                if (! discard)
                  retval = tmp;

                if (! is)
                  quit = true;
              }
              break;

            case '[': case '^':
              {
                BEGIN_CHAR_CLASS_CONVERSION ();

                if (! discard)
                  retval = tmp;

                if (! is)
                  quit = true;
              }
              break;

            case 'p':
              error ("%s: unsupported format specifier", who.c_str ());
              break;

            default:
              error ("%s: internal format error", who.c_str ());
              break;
            }
        }

      if (ok () && is.fail ())
        {
          error ("%s: read error", who.c_str ());

          // FIXME -- is this the right thing to do?

          if (interactive && name () == "stdin")
            {
              // Skip to end of line.

              bool err;
              do_gets (-1, err, false, who);
            }
        }
    }

  return quit;
}

octave_value_list
octave_base_stream::oscanf (const std::string& fmt, const std::string& who)
{
  octave_value_list retval;

  std::istream *isp = input_stream ();

  if (isp)
    {
      std::istream& is = *isp;

      scanf_format_list fmt_list (fmt);

      octave_idx_type nconv = fmt_list.num_conversions ();

      if (nconv == -1)
        ::error ("%s: invalid format specified", who.c_str ());
      else
        {
          is.clear ();

          octave_idx_type len = fmt_list.length ();

          retval.resize (nconv+1, Matrix ());

          const scanf_format_elt *elt = fmt_list.first ();

          int num_values = 0;

          bool quit = false;

          for (octave_idx_type i = 0; i < len; i++)
            {
              octave_value tmp;

              quit = do_oscanf (elt, tmp, who);

              if (quit)
                break;
              else
                {
                  if (tmp.is_defined ())
                    retval (num_values++) = tmp;

                  if (! ok ())
                    break;

                  elt = fmt_list.next (nconv > 0);
                }
            }

          retval(nconv) = num_values;

          if (! quit)
            {
              // Pick up any trailing stuff.
              if (ok () && len > nconv)
                {
                  octave_value tmp;

                  elt = fmt_list.next ();

                  do_oscanf (elt, tmp, who);
                }
            }
        }
    }
  else
    invalid_operation (who, "reading");

  return retval;
}

// Functions that are defined for all output streams (output streams
// are those that define os).

int
octave_base_stream::flush (void)
{
  int retval = -1;

  std::ostream *os = output_stream ();

  if (os)
    {
      os->flush ();

      if (os->good ())
        retval = 0;
    }
  else
    invalid_operation ("fflush", "writing");

  return retval;
}

class
printf_value_cache
{
public:

  enum state { ok, conversion_error };

  printf_value_cache (const octave_value_list& args, const std::string& who)
    : values (args), val_idx (0), elt_idx (0),
      n_vals (values.length ()), n_elts (0), data (0),
      curr_state (ok)
  {
    for (octave_idx_type i = 0; i < values.length (); i++)
      {
        octave_value val = values(i);

        if (val.is_map () || val.is_cell () || val.is_object ())
          {
            gripe_wrong_type_arg (who, val);
            break;
          }
      }
  }

  ~printf_value_cache (void) { }

  // Get the current value as a double and advance the internal pointer.
  double double_value (void);

  // Get the current value as an int and advance the internal pointer.
  int int_value (void);

  // Get the current value as a string and advance the internal pointer.
  std::string string_value (void);

  operator bool () const { return (curr_state == ok); }

  bool exhausted (void) { return (val_idx >= n_vals); }

private:

  const octave_value_list values;
  int val_idx;
  int elt_idx;
  int n_vals;
  int n_elts;
  const double *data;
  NDArray curr_val;
  state curr_state;

  // Must create value cache with values!

  printf_value_cache (void);

  // No copying!

  printf_value_cache (const printf_value_cache&);

  printf_value_cache& operator = (const printf_value_cache&);
};

double
printf_value_cache::double_value (void)
{
  double retval = 0.0;

  if (exhausted ())
    curr_state = conversion_error;

  while (! exhausted ())
    {
      if (! data)
        {
          octave_value tmp_val = values (val_idx);

          // Force string conversion here for compatibility.

          curr_val = tmp_val.array_value (true);

          if (! error_state)
            {
              elt_idx = 0;
              n_elts = curr_val.length ();
              data = curr_val.data ();
            }
          else
            {
              curr_state = conversion_error;
              break;
            }
        }

      if (elt_idx < n_elts)
        {
          retval = data[elt_idx++];

          if (elt_idx >= n_elts)
            {
              elt_idx = 0;
              val_idx++;
              data = 0;
            }

          break;
        }
      else
        {
          val_idx++;
          data = 0;

          if (n_elts == 0 && exhausted ())
            curr_state = conversion_error;

          continue;
        }
    }

  return retval;
}

int
printf_value_cache::int_value (void)
{
  int retval = 0;

  double dval = double_value ();

  if (! error_state)
    {
      if (D_NINT (dval) == dval)
        retval = NINT (dval);
      else
        curr_state = conversion_error;
    }

  return retval;
}

std::string
printf_value_cache::string_value (void)
{
  std::string retval;

  if (exhausted ())
    curr_state = conversion_error;
  else
    {
      octave_value tval = values (val_idx++);

      if (tval.rows () == 1)
        retval = tval.string_value ();
      else
        {
          // In the name of Matlab compatibility.

          charMatrix chm = tval.char_matrix_value ();

          octave_idx_type nr = chm.rows ();
          octave_idx_type nc = chm.columns ();

          int k = 0;

          retval.resize (nr * nc, '\0');

          for (octave_idx_type j = 0; j < nc; j++)
            for (octave_idx_type i = 0; i < nr; i++)
              retval[k++] = chm(i,j);
        }

      if (error_state)
        curr_state = conversion_error;
    }

  return retval;
}

// Ugh again and again.

template <class T>
int
do_printf_conv (std::ostream& os, const char *fmt, int nsa, int sa_1,
                int sa_2, T arg, const std::string& who)
{
  int retval = 0;

  switch (nsa)
    {
    case 2:
      retval = octave_format (os, fmt, sa_1, sa_2, arg);
      break;

    case 1:
      retval = octave_format (os, fmt, sa_1, arg);
      break;

    case 0:
      retval = octave_format (os, fmt, arg);
      break;

    default:
      ::error ("%s: internal error handling format", who.c_str ());
      break;
    }

  return retval;
}

template int
do_printf_conv (std::ostream&, const char*, int, int, int, int,
                const std::string&);

template int
do_printf_conv (std::ostream&, const char*, int, int, int, long,
                const std::string&);

template int
do_printf_conv (std::ostream&, const char*, int, int, int, unsigned int,
                const std::string&);

template int
do_printf_conv (std::ostream&, const char*, int, int, int, unsigned long,
                const std::string&);

template int
do_printf_conv (std::ostream&, const char*, int, int, int, double,
                const std::string&);

template int
do_printf_conv (std::ostream&, const char*, int, int, int, const char*,
                const std::string&);

#define DO_DOUBLE_CONV(TQUAL) \
  do \
    { \
      if (val > std::numeric_limits<TQUAL long>::max () \
          || val < std::numeric_limits<TQUAL long>::min ()) \
        { \
          std::string tfmt = fmt; \
 \
          tfmt.replace (tfmt.rfind (elt->type), 1, ".f"); \
 \
          if (elt->modifier == 'l') \
            tfmt.replace (tfmt.rfind (elt->modifier), 1, ""); \
 \
          retval += do_printf_conv (os, tfmt.c_str (), nsa, sa_1, sa_2, \
                                    val, who); \
        } \
      else \
        retval += do_printf_conv (os, fmt, nsa, sa_1, sa_2, \
                                  static_cast<TQUAL long> (val), who); \
    } \
  while (0)

int
octave_base_stream::do_printf (printf_format_list& fmt_list,
                               const octave_value_list& args,
                               const std::string& who)
{
  int retval = 0;

  octave_idx_type nconv = fmt_list.num_conversions ();

  std::ostream *osp = output_stream ();

  if (osp)
    {
      std::ostream& os = *osp;

      const printf_format_elt *elt = fmt_list.first ();

      printf_value_cache val_cache (args, who);

      if (error_state)
        return retval;

      for (;;)
        {
          octave_quit ();

          if (elt)
            {
              // NSA is the number of `star' args to convert.

              int nsa = (elt->fw < 0) + (elt->prec < 0);

              int sa_1 = 0;
              int sa_2 = 0; 

              if (nsa > 0)
                {
                  sa_1 = val_cache.int_value ();

                  if (! val_cache)
                    break;
                  else
                    {
                      if (nsa > 1)
                        {
                          sa_2 = val_cache.int_value ();

                          if (! val_cache)
                            break;
                        }
                    }
                }

              const char *fmt = elt->text;

              if (elt->type == '%')
                {
                  os << "%";
                  retval++;
                }
              else if (elt->args == 0 && elt->text)
                {
                  os << elt->text;
                  retval += strlen (elt->text);
                }             
              else if (elt->type == 's')
                {
                  std::string val = val_cache.string_value ();

                  if (val_cache)
                    retval += do_printf_conv (os, fmt, nsa, sa_1,
                                              sa_2, val.c_str (), who);
                  else
                    break;
                }
              else
                {
                  double val = val_cache.double_value ();

                  if (val_cache)
                    {
                      if (lo_ieee_isnan (val) || xisinf (val))
                        {
                          std::string tfmt = fmt;
                          std::string::size_type i1, i2;

                          tfmt.replace ((i1 = tfmt.rfind (elt->type)),
                                        1, 1, 's');

                          if ((i2 = tfmt.rfind ('.')) != std::string::npos && i2 < i1)
                            {
                              tfmt.erase (i2, i1-i2);
                              if (elt->prec < 0)
                                nsa--;
                            }

                          const char *tval = xisinf (val)
                            ? (val < 0 ? "-Inf" : "Inf")
                            : (lo_ieee_is_NA (val) ? "NA" : "NaN");

                          retval += do_printf_conv (os, tfmt.c_str (),
                                                    nsa, sa_1, sa_2,
                                                    tval, who);
                        }
                      else
                        {
                          char type = elt->type;

                          switch (type)
                            {
                            case 'd': case 'i': case 'c':
                              DO_DOUBLE_CONV (OCTAVE_EMPTY_CPP_ARG);
                              break;

                            case 'o': case 'x': case 'X': case 'u':
                              DO_DOUBLE_CONV (unsigned);
                              break;

                            case 'f': case 'e': case 'E':
                            case 'g': case 'G':
                              retval
                                += do_printf_conv (os, fmt, nsa, sa_1, sa_2,
                                                   val, who);
                              break;

                            default:
                              error ("%s: invalid format specifier",
                                     who.c_str ());
                              return -1;
                              break;
                            }
                        }
                    }
                  else
                    break;
                }

              if (! os)
                {
                  error ("%s: write error", who.c_str ());
                  break;
                }
            }
          else
            {
              ::error ("%s: internal error handling format", who.c_str ());
              retval = -1;
              break;
            }

          elt = fmt_list.next (nconv > 0 && ! val_cache.exhausted ());

          if (! elt || (val_cache.exhausted () && elt->args > 0))
            break;
        }             
    }
  else
    invalid_operation (who, "writing");

  return retval;
}

int
octave_base_stream::printf (const std::string& fmt,
                            const octave_value_list& args,
                            const std::string& who)
{
  int retval = 0;

  printf_format_list fmt_list (fmt);

  if (fmt_list.num_conversions () == -1)
    ::error ("%s: invalid format specified", who.c_str ());
  else
    retval = do_printf (fmt_list, args, who);

  return retval;
}

int
octave_base_stream::puts (const std::string& s, const std::string& who)
{
  int retval = -1;

  std::ostream *osp = output_stream ();

  if (osp)
    {
      std::ostream& os = *osp;

      os << s;

      if (os)
        {
          // FIXME -- why does this seem to be necessary?
          // Without it, output from a loop like
          //
          //   for i = 1:100, fputs (stdout, "foo\n"); endfor
          //
          // doesn't seem to go to the pager immediately.

          os.flush ();

          if (os)
            retval = 0;
          else
            error ("%s: write error", who.c_str ());
        }
      else
        error ("%s: write error", who.c_str ());
    }
  else
    invalid_operation (who, "writing");

  return retval;
}

// Return current error message for this stream.

std::string
octave_base_stream::error (bool clear_err, int& err_num)
{
  err_num = fail ? -1 : 0;

  std::string tmp = errmsg;

  if (clear_err)
    clear ();

  return tmp;
}

void
octave_base_stream::invalid_operation (const std::string& who, const char *rw)
{
  // Note that this is not ::error () !

  error (who, std::string ("stream not open for ") + rw);
}

octave_stream::octave_stream (octave_base_stream *bs)
  : rep (bs)
{
  if (rep)
    rep->count = 1;
}

octave_stream::~octave_stream (void)
{
  if (rep && --rep->count == 0)
    delete rep;
}

octave_stream::octave_stream (const octave_stream& s)
  : rep (s.rep)
{
  if (rep)
    rep->count++;
}

octave_stream&
octave_stream::operator = (const octave_stream& s)
{
  if (rep != s.rep)
    {
      if (rep && --rep->count == 0)
        delete rep;

      rep = s.rep;

      if (rep)
        rep->count++;
    }

  return *this;
}

int
octave_stream::flush (void)
{
  int retval = -1;

  if (stream_ok ())
    retval = rep->flush ();

  return retval;
}

std::string
octave_stream::getl (octave_idx_type max_len, bool& err, const std::string& who)
{
  std::string retval;

  if (stream_ok ())
    retval = rep->getl (max_len, err, who);

  return retval;
}

std::string
octave_stream::getl (const octave_value& tc_max_len, bool& err,
                     const std::string& who)
{
  std::string retval;

  err = false;

  int conv_err = 0;

  int max_len = -1;

  if (tc_max_len.is_defined ())
    {
      max_len = convert_to_valid_int (tc_max_len, conv_err);

      if (conv_err || max_len < 0)
        {
          err = true;
          ::error ("%s: invalid maximum length specified", who.c_str ());
        }
    }

  if (! error_state)
    retval = getl (max_len, err, who);

  return retval;
}

std::string
octave_stream::gets (octave_idx_type max_len, bool& err, const std::string& who)
{
  std::string retval;

  if (stream_ok ())
    retval = rep->gets (max_len, err, who);

  return retval;
}

std::string
octave_stream::gets (const octave_value& tc_max_len, bool& err,
                     const std::string& who)
{
  std::string retval;

  err = false;

  int conv_err = 0;

  int max_len = -1;

  if (tc_max_len.is_defined ())
    {
      max_len = convert_to_valid_int (tc_max_len, conv_err);

      if (conv_err || max_len < 0)
        {
          err = true;
          ::error ("%s: invalid maximum length specified", who.c_str ());
        }
    }

  if (! error_state)
    retval = gets (max_len, err, who);

  return retval;
}

long
octave_stream::skipl (long count, bool& err, const std::string& who)
{
  long retval = -1;

  if (stream_ok ())
    retval = rep->skipl (count, err, who);

  return retval;
}

long
octave_stream::skipl (const octave_value& tc_count, bool& err, const std::string& who)
{
  long retval = -1;

  err = false;

  int conv_err = 0;

  int count = 1;

  if (tc_count.is_defined ())
    {
      if (tc_count.is_scalar_type () && xisinf (tc_count.scalar_value ()))
        count = -1;
      else
        {
          count = convert_to_valid_int (tc_count, conv_err);

          if (conv_err || count < 0)
            {
              err = true;
              ::error ("%s: invalid number of lines specified", who.c_str ());
            }
        }
    }

  if (! error_state)
    retval = skipl (count, err, who);

  return retval;
}

int
octave_stream::seek (long offset, int origin)
{
  int status = -1;

  if (stream_ok ())
    {
      clearerr ();

      long orig_pos = rep->tell ();

      status = rep->seek (offset, origin);

      if (status == 0)
        {
          long save_pos = rep->tell ();

          rep->seek (0, SEEK_END);

          long pos_eof = rep->tell ();

          // I don't think save_pos can be less than zero, but we'll
          // check anyway...

          if (save_pos > pos_eof || save_pos < 0)
            {
              // Seek outside bounds of file.  Failure should leave
              // position unchanged.

              rep->seek (orig_pos, SEEK_SET);

              status = -1;
            }
          else
            {
              // Is it possible for this to fail?  We are just
              // returning to a position after the first successful
              // seek.

              rep->seek (save_pos, SEEK_SET);
            }
        }
    }

  return status;
}

int
octave_stream::seek (const octave_value& tc_offset,
                     const octave_value& tc_origin)
{
  int retval = -1;

  long xoffset = tc_offset.long_value (true);

  if (! error_state)
    {
      int conv_err = 0;

      int origin = SEEK_SET;

      if (tc_origin.is_string ())
        {
          std::string xorigin = tc_origin.string_value ();

          if (xorigin == "bof")
            origin = SEEK_SET;
          else if (xorigin == "cof")
            origin = SEEK_CUR;
          else if (xorigin == "eof")
            origin = SEEK_END;
          else
            conv_err = -1;
        }
      else
        {
          int xorigin = convert_to_valid_int (tc_origin, conv_err);

          if (! conv_err)
            {
              if (xorigin == -1)
                origin = SEEK_SET;
              else if (xorigin == 0)
                origin = SEEK_CUR;
              else if (xorigin == 1)
                origin = SEEK_END;
              else
                conv_err = -1;
            }
        }

      if (! conv_err)
        {
          retval = seek (xoffset, origin);

          if (retval != 0)
            error ("fseek: failed to seek to requested position");
        }
      else
        error ("fseek: invalid value for origin");
    }
  else
    error ("fseek: invalid value for offset");

  return retval;
}

long
octave_stream::tell (void)
{
  long retval = -1;

  if (stream_ok ())
    retval = rep->tell ();

  return retval;
}

int
octave_stream::rewind (void)
{
  return seek (0, SEEK_SET);
}

bool
octave_stream::is_open (void) const
{
  bool retval = false;

  if (stream_ok ())
    retval = rep->is_open ();

  return retval;
}

void
octave_stream::close (void)
{
  if (stream_ok ())
    rep->close ();
}

template <class RET_T, class READ_T>
octave_value
do_read (octave_stream& strm, octave_idx_type nr, octave_idx_type nc, octave_idx_type block_size,
         octave_idx_type skip, bool do_float_fmt_conv, bool do_NA_conv,
         oct_mach_info::float_format from_flt_fmt, octave_idx_type& count)
{
  octave_value retval;

  RET_T nda;

  count = 0;

  typedef typename RET_T::element_type ELMT;
  ELMT elt_zero = ELMT ();

  ELMT *dat = 0;

  octave_idx_type max_size = 0;

  octave_idx_type final_nr = 0;
  octave_idx_type final_nc = 1;

  if (nr > 0)
    {
      if (nc > 0)
        {
          nda.resize (dim_vector (nr, nc), elt_zero);
          dat = nda.fortran_vec ();
          max_size = nr * nc;
        }
      else
        {
          nda.resize (dim_vector (nr, 32), elt_zero);
          dat = nda.fortran_vec ();
          max_size = nr * 32;
        }
    }
  else
    {
      nda.resize (dim_vector (32, 1), elt_zero);
      dat = nda.fortran_vec ();
      max_size = 32;
    }

  // FIXME -- byte order for Cray?

  bool swap = false;

  if (oct_mach_info::words_big_endian ())
    swap = (from_flt_fmt == oct_mach_info::flt_fmt_ieee_little_endian
            || from_flt_fmt == oct_mach_info::flt_fmt_vax_g
            || from_flt_fmt == oct_mach_info::flt_fmt_vax_g);
  else
    swap = (from_flt_fmt == oct_mach_info::flt_fmt_ieee_big_endian);

  union
  {
    char buf[sizeof (typename strip_template_param<octave_int, READ_T>::type)];
    typename strip_template_param<octave_int, READ_T>::type val;
  } u;

  std::istream *isp = strm.input_stream ();

  if (isp)
    {
      std::istream& is = *isp;

      octave_idx_type elts_read = 0;

      for (;;)
        {
          // FIXME -- maybe there should be a special case for
          // skip == 0.

          if (is)
            {
              if (nr > 0 && nc > 0 && count == max_size)
                {
                  final_nr = nr;
                  final_nc = nc;

                  break;
                }

              is.read (u.buf, sizeof (typename strip_template_param<octave_int, READ_T>::type));

              // We only swap bytes for integer types.  For float
              // types, the format conversion will also handle byte
              // swapping.

              if (swap)
                swap_bytes<sizeof (typename strip_template_param<octave_int, READ_T>::type)> (u.buf);
              else if (do_float_fmt_conv)
                do_float_format_conversion
                  (u.buf,
                   sizeof (typename strip_template_param<octave_int, READ_T>::type),
                   1, from_flt_fmt, oct_mach_info::float_format ());

              typename RET_T::element_type tmp
                = static_cast <typename RET_T::element_type> (u.val);

              if (is)
                {
                  if (count == max_size)
                    {
                      max_size *= 2;

                      if (nr > 0)
                        nda.resize (dim_vector (nr, max_size / nr),
                                    elt_zero);
                      else
                        nda.resize (dim_vector (max_size, 1), elt_zero);

                      dat = nda.fortran_vec ();
                    }

                  if (do_NA_conv && __lo_ieee_is_old_NA (tmp))
                    tmp = __lo_ieee_replace_old_NA (tmp);

                  dat[count++] = tmp;

                  elts_read++;
                }

              int seek_status = 0;

              if (skip != 0 && elts_read == block_size)
                {
                  seek_status = strm.seek (skip, SEEK_CUR);
                  elts_read = 0;
                }

              if (is.eof () || seek_status < 0)
                {
                  if (nr > 0)
                    {
                      if (count > nr)
                        {
                          final_nr = nr;
                          final_nc = (count - 1) / nr + 1;
                        }
                      else
                        {
                          final_nr = count;
                          final_nc = 1;
                        }
                    }
                  else
                    {
                      final_nr = count;
                      final_nc = 1;
                    }

                  break;
                }
            }
          else if (is.eof ())
            break;
        }
    }

  nda.resize (dim_vector (final_nr, final_nc), elt_zero);

  retval = nda;

  return retval;
}

#define DO_READ_VAL_TEMPLATE(RET_T, READ_T) \
  template octave_value \
  do_read<RET_T, READ_T> (octave_stream&, octave_idx_type, octave_idx_type, octave_idx_type, octave_idx_type, bool, bool, \
                          oct_mach_info::float_format, octave_idx_type&)

// FIXME -- should we only have float if it is a different
// size from double?

#define INSTANTIATE_DO_READ(VAL_T) \
  DO_READ_VAL_TEMPLATE (VAL_T, octave_int8); \
  DO_READ_VAL_TEMPLATE (VAL_T, octave_uint8); \
  DO_READ_VAL_TEMPLATE (VAL_T, octave_int16); \
  DO_READ_VAL_TEMPLATE (VAL_T, octave_uint16); \
  DO_READ_VAL_TEMPLATE (VAL_T, octave_int32); \
  DO_READ_VAL_TEMPLATE (VAL_T, octave_uint32); \
  DO_READ_VAL_TEMPLATE (VAL_T, octave_int64); \
  DO_READ_VAL_TEMPLATE (VAL_T, octave_uint64); \
  DO_READ_VAL_TEMPLATE (VAL_T, float); \
  DO_READ_VAL_TEMPLATE (VAL_T, double); \
  DO_READ_VAL_TEMPLATE (VAL_T, char); \
  DO_READ_VAL_TEMPLATE (VAL_T, signed char); \
  DO_READ_VAL_TEMPLATE (VAL_T, unsigned char)

INSTANTIATE_DO_READ (int8NDArray);
INSTANTIATE_DO_READ (uint8NDArray);
INSTANTIATE_DO_READ (int16NDArray);
INSTANTIATE_DO_READ (uint16NDArray);
INSTANTIATE_DO_READ (int32NDArray);
INSTANTIATE_DO_READ (uint32NDArray);
INSTANTIATE_DO_READ (int64NDArray);
INSTANTIATE_DO_READ (uint64NDArray);
INSTANTIATE_DO_READ (FloatNDArray);
INSTANTIATE_DO_READ (NDArray);
INSTANTIATE_DO_READ (charNDArray);
INSTANTIATE_DO_READ (boolNDArray);

typedef octave_value (*read_fptr) (octave_stream&, octave_idx_type, octave_idx_type, octave_idx_type, octave_idx_type, bool, bool,
                                   oct_mach_info::float_format ffmt, octave_idx_type&);

#define FILL_TABLE_ROW(R, VAL_T) \
  read_fptr_table[R][oct_data_conv::dt_int8] = do_read<VAL_T, octave_int8>; \
  read_fptr_table[R][oct_data_conv::dt_uint8] = do_read<VAL_T, octave_uint8>; \
  read_fptr_table[R][oct_data_conv::dt_int16] = do_read<VAL_T, octave_int16>; \
  read_fptr_table[R][oct_data_conv::dt_uint16] = do_read<VAL_T, octave_uint16>; \
  read_fptr_table[R][oct_data_conv::dt_int32] = do_read<VAL_T, octave_int32>; \
  read_fptr_table[R][oct_data_conv::dt_uint32] = do_read<VAL_T, octave_uint32>; \
  read_fptr_table[R][oct_data_conv::dt_int64] = do_read<VAL_T, octave_int64>; \
  read_fptr_table[R][oct_data_conv::dt_uint64] = do_read<VAL_T, octave_uint64>; \
  read_fptr_table[R][oct_data_conv::dt_single] = do_read<VAL_T, float>; \
  read_fptr_table[R][oct_data_conv::dt_double] = do_read<VAL_T, double>; \
  read_fptr_table[R][oct_data_conv::dt_char] = do_read<VAL_T, char>; \
  read_fptr_table[R][oct_data_conv::dt_schar] = do_read<VAL_T, signed char>; \
  read_fptr_table[R][oct_data_conv::dt_uchar] = do_read<VAL_T, unsigned char>; \
  read_fptr_table[R][oct_data_conv::dt_logical] = do_read<VAL_T, unsigned char>

octave_value
octave_stream::read (const Array<double>& size, octave_idx_type block_size,
                     oct_data_conv::data_type input_type,
                     oct_data_conv::data_type output_type,
                     octave_idx_type skip, oct_mach_info::float_format ffmt,
                     octave_idx_type& char_count)
{
  static bool initialized = false;

  // Table function pointers for return types x read types.

  static read_fptr read_fptr_table[oct_data_conv::dt_unknown][14];

  if (! initialized)
    {
      for (int i = 0; i < oct_data_conv::dt_unknown; i++)
        for (int j = 0; j < 14; j++)
          read_fptr_table[i][j] = 0;

      FILL_TABLE_ROW (oct_data_conv::dt_int8, int8NDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_uint8, uint8NDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_int16, int16NDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_uint16, uint16NDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_int32, int32NDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_uint32, uint32NDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_int64, int64NDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_uint64, uint64NDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_single, FloatNDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_double, NDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_char, charNDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_schar, charNDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_uchar, charNDArray);
      FILL_TABLE_ROW (oct_data_conv::dt_logical, boolNDArray);

      initialized = true;
    }

  octave_value retval;

  if (stream_ok ())
    {
      // FIXME -- we may eventually want to make this extensible.

      // FIXME -- we need a better way to ensure that this
      // numbering stays consistent with the order of the elements in the
      // data_type enum in the oct_data_conv class.

      char_count = 0;

      octave_idx_type nr = -1;
      octave_idx_type nc = -1;

      bool ignore;

      get_size (size, nr, nc, ignore, "fread");

      if (! error_state)
        {
          if (nr == 0 || nc == 0)
            retval = Matrix (nr, nc);
          else
            {
              if (ffmt == oct_mach_info::flt_fmt_unknown)
                ffmt = float_format ();

              read_fptr fcn = read_fptr_table[output_type][input_type];

              bool do_float_fmt_conv = ((input_type == oct_data_conv::dt_double
                                         || input_type == oct_data_conv::dt_single)
                                        && ffmt != float_format ());

              bool do_NA_conv = (output_type == oct_data_conv::dt_double);

              if (fcn)
                {
                  retval = (*fcn) (*this, nr, nc, block_size, skip,
                                   do_float_fmt_conv, do_NA_conv,
                                   ffmt, char_count);

                  // FIXME -- kluge!

                  if (! error_state
                      && (output_type == oct_data_conv::dt_char
                          || output_type == oct_data_conv::dt_schar
                          || output_type == oct_data_conv::dt_uchar))
                    retval = retval.char_matrix_value ();
                }
              else
                error ("fread: unable to read and convert requested types");
            }
        }
      else
        invalid_operation ("fread", "reading");
    }

  return retval;
}

octave_idx_type
octave_stream::write (const octave_value& data, octave_idx_type block_size,
                      oct_data_conv::data_type output_type, octave_idx_type skip,
                      oct_mach_info::float_format flt_fmt)
{
  octave_idx_type retval = -1;

  if (stream_ok ())
    {
      if (! error_state)
        {
          if (flt_fmt == oct_mach_info::flt_fmt_unknown)
            flt_fmt = float_format ();

          octave_idx_type status = data.write (*this, block_size, output_type,
                                   skip, flt_fmt);

          if (status < 0)
            error ("fwrite: write error");
          else
            retval = status;
        }
      else
        invalid_operation ("fwrite", "writing");
    }

  return retval;
}

template <class T>
void
write_int (std::ostream& os, bool swap, const T& val)
{
  typename T::val_type tmp = val.value ();

  if (swap)
    swap_bytes<sizeof (typename T::val_type)> (&tmp);

  os.write (reinterpret_cast<const char *> (&tmp),
            sizeof (typename T::val_type));
}

template void write_int (std::ostream&, bool, const octave_int8&);
template void write_int (std::ostream&, bool, const octave_uint8&);
template void write_int (std::ostream&, bool, const octave_int16&);
template void write_int (std::ostream&, bool, const octave_uint16&);
template void write_int (std::ostream&, bool, const octave_int32&);
template void write_int (std::ostream&, bool, const octave_uint32&);
template void write_int (std::ostream&, bool, const octave_int64&);
template void write_int (std::ostream&, bool, const octave_uint64&);

template <class T>
static inline bool
do_write (std::ostream& os, const T& val, oct_data_conv::data_type output_type,
          oct_mach_info::float_format flt_fmt, bool swap,
          bool do_float_conversion)
{
  bool retval = true;

  // For compatibility, Octave converts to the output type, then
  // writes.  This means that truncation happens on the conversion.
  // For example, the following program prints 0:
  //
  //   x = int8 (-1)
  //   f = fopen ("foo.dat", "w");
  //   fwrite (f, x, "unsigned char");
  //   fclose (f);
  //   f = fopen ("foo.dat", "r");
  //   y = fread (f, 1, "unsigned char");
  //   printf ("%d\n", y);

  switch (output_type)
    {
    case oct_data_conv::dt_char:
    case oct_data_conv::dt_schar:
    case oct_data_conv::dt_int8:
      write_int (os, swap, octave_int8 (val));
      break;

    case oct_data_conv::dt_uchar:
    case oct_data_conv::dt_uint8:
      write_int (os, swap, octave_uint8 (val));
      break;

    case oct_data_conv::dt_int16:
      write_int (os, swap, octave_int16 (val));
      break;

    case oct_data_conv::dt_uint16:
      write_int (os, swap, octave_uint16 (val));
      break;

    case oct_data_conv::dt_int32:
      write_int (os, swap, octave_int32 (val));
      break;

    case oct_data_conv::dt_uint32:
      write_int (os, swap, octave_uint32 (val));
      break;

    case oct_data_conv::dt_int64:
      write_int (os, swap, octave_int64 (val));
      break;

    case oct_data_conv::dt_uint64:
      write_int (os, swap, octave_uint64 (val));
      break;

    case oct_data_conv::dt_single:
      {
        float f = static_cast<float> (val);

        if (do_float_conversion)
          do_float_format_conversion (&f, 1, flt_fmt);

        os.write (reinterpret_cast<const char *> (&f), sizeof (float));
      }
      break;

    case oct_data_conv::dt_double:
      {
        double d = static_cast<double> (val);
        if (do_float_conversion)
          do_double_format_conversion (&d, 1, flt_fmt);

        os.write (reinterpret_cast<const char *> (&d), sizeof (double));
      }
      break;

    default:
      retval = false;
      (*current_liboctave_error_handler)
        ("write: invalid type specification");
      break;
    }

  return retval;
}

template bool
do_write (std::ostream&, const octave_int8&, oct_data_conv::data_type,
          oct_mach_info::float_format, bool, bool);

template bool
do_write (std::ostream&, const octave_uint8&, oct_data_conv::data_type,
          oct_mach_info::float_format, bool, bool);

template bool
do_write (std::ostream&, const octave_int16&, oct_data_conv::data_type,
          oct_mach_info::float_format, bool, bool);

template bool
do_write (std::ostream&, const octave_uint16&, oct_data_conv::data_type,
          oct_mach_info::float_format, bool, bool);

template bool
do_write (std::ostream&, const octave_int32&, oct_data_conv::data_type,
          oct_mach_info::float_format, bool, bool);

template bool
do_write (std::ostream&, const octave_uint32&, oct_data_conv::data_type,
          oct_mach_info::float_format, bool, bool);

template bool
do_write (std::ostream&, const octave_int64&, oct_data_conv::data_type,
          oct_mach_info::float_format, bool, bool);

template bool
do_write (std::ostream&, const octave_uint64&, oct_data_conv::data_type,
          oct_mach_info::float_format, bool, bool);

template <class T>
octave_idx_type
octave_stream::write (const Array<T>& data, octave_idx_type block_size,
                      oct_data_conv::data_type output_type,
                      octave_idx_type skip, oct_mach_info::float_format flt_fmt)
{
  octave_idx_type retval = -1;

  bool status = true;

  octave_idx_type count = 0;

  const T *d = data.data ();

  octave_idx_type n = data.length ();

  oct_mach_info::float_format native_flt_fmt
    = oct_mach_info::float_format ();

  bool do_float_conversion = (flt_fmt != native_flt_fmt);

  // FIXME -- byte order for Cray?

  bool swap = false;

  if (oct_mach_info::words_big_endian ())
    swap = (flt_fmt == oct_mach_info::flt_fmt_ieee_little_endian
            || flt_fmt == oct_mach_info::flt_fmt_vax_g
            || flt_fmt == oct_mach_info::flt_fmt_vax_g);
  else
    swap = (flt_fmt == oct_mach_info::flt_fmt_ieee_big_endian);

  for (octave_idx_type i = 0; i < n; i++)
    {
      std::ostream *osp = output_stream ();

      if (osp)
        {
          std::ostream& os = *osp;

          if (skip != 0 && (i % block_size) == 0)
            {
              // Seek to skip when inside bounds of existing file.
              // Otherwise, write NUL to skip.

              long orig_pos = tell ();

              seek (0, SEEK_END);

              long eof_pos = tell ();

              // Is it possible for this to fail to return us to the
              // original position?
              seek (orig_pos, SEEK_SET);

              long remaining = eof_pos - orig_pos;

              if (remaining < skip)
                {
                  seek (0, SEEK_END);

                  // FIXME -- probably should try to write larger
                  // blocks...

                  unsigned char zero = 0;
                  for (octave_idx_type j = 0; j < skip - remaining; j++)
                    os.write (reinterpret_cast<const char *> (&zero), 1);
                }
              else
                seek (skip, SEEK_CUR);
            }

          if (os)
            {
              status = do_write (os, d[i], output_type, flt_fmt, swap,
                                 do_float_conversion);

              if (os && status)
                count++;
              else
                break;
            }
          else
            {
              status = false;
              break;
            }
        }
      else
        {
          status = false;
          break;
        }
    }

  if (status)
    retval = count;

  return retval;
}

template octave_idx_type
octave_stream::write (const Array<char>&, octave_idx_type,
                      oct_data_conv::data_type,
                      octave_idx_type, oct_mach_info::float_format);

template octave_idx_type
octave_stream::write (const Array<bool>&, octave_idx_type,
                      oct_data_conv::data_type,
                      octave_idx_type, oct_mach_info::float_format);

template octave_idx_type
octave_stream::write (const Array<double>&, octave_idx_type,
                      oct_data_conv::data_type,
                      octave_idx_type, oct_mach_info::float_format);

template octave_idx_type
octave_stream::write (const Array<float>&, octave_idx_type,
                      oct_data_conv::data_type,
                      octave_idx_type, oct_mach_info::float_format);

template octave_idx_type
octave_stream::write (const Array<octave_int8>&, octave_idx_type,
                      oct_data_conv::data_type,
                      octave_idx_type, oct_mach_info::float_format);

template octave_idx_type
octave_stream::write (const Array<octave_uint8>&, octave_idx_type,
                      oct_data_conv::data_type,
                      octave_idx_type, oct_mach_info::float_format);

template octave_idx_type
octave_stream::write (const Array<octave_int16>&, octave_idx_type,
                      oct_data_conv::data_type,
                      octave_idx_type, oct_mach_info::float_format);

template octave_idx_type
octave_stream::write (const Array<octave_uint16>&, octave_idx_type,
                      oct_data_conv::data_type,
                      octave_idx_type, oct_mach_info::float_format);

template octave_idx_type
octave_stream::write (const Array<octave_int32>&, octave_idx_type,
                      oct_data_conv::data_type,
                      octave_idx_type, oct_mach_info::float_format);

template octave_idx_type
octave_stream::write (const Array<octave_uint32>&, octave_idx_type,
                      oct_data_conv::data_type,
                      octave_idx_type, oct_mach_info::float_format);

template octave_idx_type
octave_stream::write (const Array<octave_int64>&, octave_idx_type,
                      oct_data_conv::data_type,
                      octave_idx_type, oct_mach_info::float_format);

template octave_idx_type
octave_stream::write (const Array<octave_uint64>&, octave_idx_type,
                      oct_data_conv::data_type,
                      octave_idx_type, oct_mach_info::float_format);

octave_value
octave_stream::scanf (const std::string& fmt, const Array<double>& size,
                      octave_idx_type& count, const std::string& who)
{
  octave_value retval;

  if (stream_ok ())
    retval = rep->scanf (fmt, size, count, who);

  return retval;
}

octave_value
octave_stream::scanf (const octave_value& fmt, const Array<double>& size,
                      octave_idx_type& count, const std::string& who)
{
  octave_value retval = Matrix ();

  if (fmt.is_string ())
    {
      std::string sfmt = fmt.string_value ();

      if (fmt.is_sq_string ())
        sfmt = do_string_escapes (sfmt);

      retval = scanf (sfmt, size, count, who);
    }
  else
    {
      // Note that this is not ::error () !

      error (who + ": format must be a string");
    }

  return retval;
}

octave_value_list
octave_stream::oscanf (const std::string& fmt, const std::string& who)
{
  octave_value_list retval;

  if (stream_ok ())
    retval = rep->oscanf (fmt, who);

  return retval;
}

octave_value_list
octave_stream::oscanf (const octave_value& fmt, const std::string& who)
{
  octave_value_list retval;

  if (fmt.is_string ())
    {
      std::string sfmt = fmt.string_value ();

      if (fmt.is_sq_string ())
        sfmt = do_string_escapes (sfmt);

      retval = oscanf (sfmt, who);
    }
  else
    {
      // Note that this is not ::error () !

      error (who + ": format must be a string");
    }

  return retval;
}

int
octave_stream::printf (const std::string& fmt, const octave_value_list& args,
                       const std::string& who)
{
  int retval = -1;

  if (stream_ok ())
    retval = rep->printf (fmt, args, who);

  return retval;
}

int
octave_stream::printf (const octave_value& fmt, const octave_value_list& args,
                       const std::string& who)
{
  int retval = 0;

  if (fmt.is_string ())
    {
      std::string sfmt = fmt.string_value ();

      if (fmt.is_sq_string ())
        sfmt = do_string_escapes (sfmt);

      retval = printf (sfmt, args, who);
    }
  else
    {
      // Note that this is not ::error () !

      error (who + ": format must be a string");
    }

  return retval;
}

int
octave_stream::puts (const std::string& s, const std::string& who)
{
  int retval = -1;

  if (stream_ok ())
    retval = rep->puts (s, who);

  return retval;
}

// FIXME -- maybe this should work for string arrays too.

int
octave_stream::puts (const octave_value& tc_s, const std::string& who)
{
  int retval = -1;

  if (tc_s.is_string ())
    {
      std::string s = tc_s.string_value ();      
      retval = puts (s, who);
    }
  else
    {
      // Note that this is not ::error () !

      error (who + ": argument must be a string");
    }

  return retval;
}

bool
octave_stream::eof (void) const
{
  int retval = -1;

  if (stream_ok ())
    retval = rep->eof ();

  return retval;
}

std::string
octave_stream::error (bool clear, int& err_num)
{
  std::string retval = "invalid stream object";

  if (stream_ok (false))
    retval = rep->error (clear, err_num);

  return retval;
}

std::string
octave_stream::name (void) const
{
  std::string retval;

  if (stream_ok ())
    retval = rep->name ();

  return retval;
}

int
octave_stream::mode (void) const
{
  int retval = 0;

  if (stream_ok ())
    retval = rep->mode ();

  return retval;
}

oct_mach_info::float_format
octave_stream::float_format (void) const
{
  oct_mach_info::float_format retval = oct_mach_info::flt_fmt_unknown;

  if (stream_ok ())
    retval = rep->float_format ();

  return retval;
}

std::string
octave_stream::mode_as_string (int mode)
{
  std::string retval = "???";
  std::ios::openmode in_mode = static_cast<std::ios::openmode> (mode);

  if (in_mode == std::ios::in)
    retval = "r";
  else if (in_mode == std::ios::out 
           || in_mode == (std::ios::out | std::ios::trunc))
    retval = "w";
  else if (in_mode == (std::ios::out | std::ios::app))
    retval = "a";
  else if (in_mode == (std::ios::in | std::ios::out))
    retval = "r+";
  else if (in_mode == (std::ios::in | std::ios::out | std::ios::trunc))
    retval = "w+";
  else if (in_mode == (std::ios::in | std::ios::out | std::ios::ate))
    retval = "a+";
  else if (in_mode == (std::ios::in | std::ios::binary))
    retval = "rb";
  else if (in_mode == (std::ios::out | std::ios::binary)
           || in_mode == (std::ios::out | std::ios::trunc | std::ios::binary))
    retval = "wb";
  else if (in_mode == (std::ios::out | std::ios::app | std::ios::binary))
    retval = "ab";
  else if (in_mode == (std::ios::in | std::ios::out | std::ios::binary))
    retval = "r+b";
  else if (in_mode == (std::ios::in | std::ios::out | std::ios::trunc 
                       | std::ios::binary))
    retval = "w+b";
  else if (in_mode == (std::ios::in | std::ios::out | std::ios::ate
                       | std::ios::binary))
    retval = "a+b";

  return retval;
}

octave_stream_list *octave_stream_list::instance = 0;

bool
octave_stream_list::instance_ok (void)
{
  bool retval = true;

  if (! instance)
    instance = new octave_stream_list ();

  if (! instance)
    {
      ::error ("unable to create stream list object!");

      retval = false;
    }

  return retval;
}

int
octave_stream_list::insert (octave_stream& os)
{
  return (instance_ok ()) ? instance->do_insert (os) : -1;
}

octave_stream
octave_stream_list::lookup (int fid, const std::string& who)
{
  return (instance_ok ()) ? instance->do_lookup (fid, who) : octave_stream ();
}

octave_stream
octave_stream_list::lookup (const octave_value& fid, const std::string& who)
{
  return (instance_ok ()) ? instance->do_lookup (fid, who) : octave_stream ();
}

int
octave_stream_list::remove (int fid, const std::string& who)
{
  return (instance_ok ()) ? instance->do_remove (fid, who) : -1;
}

int
octave_stream_list::remove (const octave_value& fid, const std::string& who)
{
  return (instance_ok ()) ? instance->do_remove (fid, who) : -1;
}

void
octave_stream_list::clear (bool flush)
{
  if (instance)
    instance->do_clear (flush);
}

string_vector
octave_stream_list::get_info (int fid)
{
  return (instance_ok ()) ? instance->do_get_info (fid) : string_vector ();
}

string_vector
octave_stream_list::get_info (const octave_value& fid)
{
  return (instance_ok ()) ? instance->do_get_info (fid) : string_vector ();
}

std::string
octave_stream_list::list_open_files (void)
{
  return (instance_ok ()) ? instance->do_list_open_files () : std::string ();
}

octave_value
octave_stream_list::open_file_numbers (void)
{
  return (instance_ok ())
    ? instance->do_open_file_numbers () : octave_value ();
}

int
octave_stream_list::get_file_number (const octave_value& fid)
{
  return (instance_ok ()) ? instance->do_get_file_number (fid) : -1;
}

int
octave_stream_list::do_insert (octave_stream& os)
{
  // Insert item with key corresponding to file-descriptor.

  int stream_number;

  if ((stream_number = os.file_number ()) == -1)
    return stream_number;

  // Should we test for "(list.find (stream_number) != list.end ()) &&
  // list[stream_number].is_open ()" and respond with "error
  // ("internal error: ...")"? It should not happen except for some
  // bug or if the user has opened a stream with an interpreted
  // command, but closed it directly with a system call in an
  // oct-file; then the kernel knows the fd is free, but Octave does
  // not know. If it happens, it should not do harm here to simply
  // overwrite this entry, although the wrong entry might have done
  // harm before.

  if (list.size () < list.max_size ())
    list[stream_number] = os;
  else
    {
      stream_number = -1;
      error ("could not create file id");
    }

  return stream_number;

}

static void
gripe_invalid_file_id (int fid, const std::string& who)
{
  if (who.empty ())
    ::error ("invalid stream number = %d", fid);
  else
    ::error ("%s: invalid stream number = %d", who.c_str (), fid);
}

octave_stream
octave_stream_list::do_lookup (int fid, const std::string& who) const
{
  octave_stream retval;

  if (fid >= 0)
    {
      if (lookup_cache != list.end () && lookup_cache->first == fid)
        retval = lookup_cache->second;
      else
        {
          ostrl_map::const_iterator iter = list.find (fid);

          if (iter != list.end ())
            {
              retval = iter->second;
              lookup_cache = iter;
            }
          else
            gripe_invalid_file_id (fid, who);
        }
    }
  else
    gripe_invalid_file_id (fid, who);

  return retval;
}

octave_stream
octave_stream_list::do_lookup (const octave_value& fid,
                               const std::string& who) const
{
  octave_stream retval;

  int i = get_file_number (fid);

  if (! error_state)
    retval = do_lookup (i, who);

  return retval;
}

int
octave_stream_list::do_remove (int fid, const std::string& who)
{
  int retval = -1;

  // Can't remove stdin (std::cin), stdout (std::cout), or stderr
  // (std::cerr).

  if (fid > 2)
    {
      ostrl_map::iterator iter = list.find (fid);

      if (iter != list.end ())
        {
          octave_stream os = iter->second;
          list.erase (iter);
          lookup_cache = list.end ();

          // FIXME: is this check redundant?
          if (os.is_valid ())
            {
              os.close ();
              retval = 0;
            }
          else
            gripe_invalid_file_id (fid, who);
        }
      else
        gripe_invalid_file_id (fid, who);
    }
  else
    gripe_invalid_file_id (fid, who);

  return retval;
}

int
octave_stream_list::do_remove (const octave_value& fid, const std::string& who)
{
  int retval = -1;

  if (fid.is_string () && fid.string_value () == "all")
    {
      do_clear (false);

      retval = 0;
    }
  else
    {
      int i = get_file_number (fid);

      if (! error_state)
        retval = do_remove (i, who);
    }

  return retval;
}

void
octave_stream_list::do_clear (bool flush)
{
  if (flush)
    {
      // Do flush stdout and stderr.

      list[0].flush ();
      list[1].flush ();
    }

  octave_stream saved_os[3];
  // But don't delete them or stdin.
  for (ostrl_map::iterator iter = list.begin (); iter != list.end (); iter++)
    {
      int fid = iter->first;
      octave_stream os = iter->second;
      if (fid < 3)
        saved_os[fid] = os;
      else if (os.is_valid ())
        os.close ();
    }
  list.clear ();
  for (int fid = 0; fid < 3; fid++) list[fid] = saved_os[fid];
  lookup_cache = list.end ();
}

string_vector
octave_stream_list::do_get_info (int fid) const
{
  string_vector retval;

  octave_stream os = do_lookup (fid);

  if (os.is_valid ())
    {
      retval.resize (3);

      retval(0) = os.name ();
      retval(1) = octave_stream::mode_as_string (os.mode ());
      retval(2) = oct_mach_info::float_format_as_string (os.float_format ());
    }
  else
    ::error ("invalid file id = %d", fid);

  return retval;
}

string_vector
octave_stream_list::do_get_info (const octave_value& fid) const
{
  string_vector retval;

  int conv_err = 0;

  int int_fid = convert_to_valid_int (fid, conv_err);

  if (! conv_err)
    retval = do_get_info (int_fid);
  else
    ::error ("file id must be a file object or integer value");

  return retval;
}

std::string
octave_stream_list::do_list_open_files (void) const
{
  std::string retval;

  std::ostringstream buf;

  buf << "\n"
      << "  number  mode  arch       name\n"
      << "  ------  ----  ----       ----\n";

  for (ostrl_map::const_iterator p = list.begin (); p != list.end (); p++)
    {
      octave_stream os = p->second;

      buf << "  "
          << std::setiosflags (std::ios::right)
          << std::setw (4) << p->first << "     "
          << std::setiosflags (std::ios::left)
          << std::setw (3)
          << octave_stream::mode_as_string (os.mode ())
          << "  "
          << std::setw (9)
          << oct_mach_info::float_format_as_string (os.float_format ())
          << "  "
          << os.name () << "\n";
    }

  buf << "\n";

  retval = buf.str ();

  return retval;
}

octave_value
octave_stream_list::do_open_file_numbers (void) const
{
  Matrix retval (1, list.size (), 0.0);

  int num_open = 0;

  for (ostrl_map::const_iterator p = list.begin (); p != list.end (); p++)
    {
      // Skip stdin, stdout, and stderr.

      if (p->first > 2 && p->second)
        retval(0,num_open++) = p->first;
    }

  retval.resize ((num_open > 0), num_open);

  return retval;
}

int
octave_stream_list::do_get_file_number (const octave_value& fid) const
{
  int retval = -1;

  if (fid.is_string ())
    {
      std::string nm = fid.string_value ();

      for (ostrl_map::const_iterator p = list.begin (); p != list.end (); p++)
        {
          // stdin (std::cin), stdout (std::cout), and stderr (std::cerr)
          // are unnamed.

          if (p->first > 2)
            {
              octave_stream os = p->second;

              if (os && os.name () == nm)
                {
                  retval = p->first;
                  break;
                }
            }
        }
    }
  else
    {
      int conv_err = 0;

      int int_fid = convert_to_valid_int (fid, conv_err);

      if (conv_err)
        ::error ("file id must be a file object, std::string, or integer value");
      else
        retval = int_fid;
    }

  return retval;
}