/*
 * tminit.c - initializer and main part of termios emulation.
 *   designed for DJGPP by Daisuke Aoyama <jack@st.rim.or.jp>
 *   special thanks to Ryo Shimizu
 */

#if defined (__DJGPP__)

#include <libc/stubs.h>
#include <conio.h>
#include <fcntl.h>
#include <go32.h>
#include <io.h>
#include <limits.h>
#include <signal.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <sys/farptr.h>
#include <sys/fsext.h>
#include <libc/bss.h>
#include <libc/file.h>
#include <libc/dosio.h>
#include <libc/ttyprvt.h>
#include <sys/version.h>

#if __DJGPP_MINOR__ < 4
# define _DEV_STDIN  0x0001
# define _DEV_STDOUT 0x0002
# define _DEV_NUL    0x0004
# define _DEV_CLOCK  0x0008
# define _DEV_RAW    0x0020
# define _DEV_CDEV   0x0080
# define _DEV_IOCTRL 0x4000
#else
# include <libc/getdinfo.h>
#endif

#define CPMEOF 0x1a /* Ctrl+Z */

#define _REG_STATUS_CF 0x01
#define _REG_STATUS_ZF 0x40
#define _KEY_INS  0x80
#define _KEY_CAPS 0x40
#define _KEY_NUM  0x20
#define _KEY_SCRL 0x10
#define _KEY_ALT  0x08
#define _KEY_CTRL 0x04
#define _KEY_LSFT 0x02
#define _KEY_RSFT 0x01
#define _KEYE_SYSRQ 0x80
#define _KEYE_CAPS  0x40
#define _KEYE_NUM   0x20
#define _KEYE_SCRL  0x10
#define _KEYE_RALT  0x08
#define _KEYE_RCTRL 0x04
#define _KEYE_LALT  0x02
#define _KEYE_LCTRL 0x01

#define CHECKBYTES 32

/* tty buffers */
unsigned char __libc_tty_queue_buffer[_TTY_QUEUE_SIZE];
struct tty __libc_tty_internal = TTYDEFAULT;
struct tty *__libc_tty_p = &__libc_tty_internal;
struct tty_editline __libc_tty_editline = { 0, { 0 }, { 0 }, };

/* global only in the termios functions */
int __libc_termios_hook_common_count = -1;

/* static variables */
static int __libc_use_function_and_arrow_keys = 0;
static int __libc_has_enhanced_keyboard = 0;
static int __libc_has_extended_keystroke = 0;
static unsigned char __libc_extended_keystroke[16] = { 0, };
static ssize_t __libc_termios_check_bytes = CHECKBYTES;

/* static functions */
static void __libc_termios_fflushall (void);
static void __libc_termios_init_direct_functions (void);
static ssize_t __libc_termios_read (int handle, void *buffer, size_t count, ssize_t *rv);
static ssize_t __libc_termios_read_cooked_tty (int handle, void *buffer, size_t count);
static ssize_t __libc_termios_read_raw_tty (int handle, void *buffer, size_t count);
static ssize_t __libc_termios_write (int handle, const void *buffer, size_t count, ssize_t *rv);
static ssize_t __libc_termios_write_cooked_tty (int handle, const void *buffer, size_t count);
static ssize_t __libc_termios_write_raw_tty (int handle, const void *buffer, size_t count);
static int __libc_termios_fsext (__FSEXT_Fnumber n, int *rv, va_list ap);
static void __libc_termios_echo_ctrl (unsigned char ch);
static void __libc_termios_maybe_echo_ctrl (unsigned char ch);
static void __libc_termios_maybe_echo (unsigned char ch);
static void __libc_termios_maybe_erase1 (void);
static void __libc_termios_erase_editline (void);
static void __libc_termios_kill_editline (void);
static void __libc_termios_insert_editline (unsigned char ch);
#if __DJGPP_MINOR__ < 4
static int __libc_termios_exist_queue (void);
#endif
static void __libc_termios_clear_queue (void);
static int __libc_termios_get_queue (void);
static int __libc_termios_put_queue (unsigned char ch);
static void __libc_termios_raise_signal (unsigned char ch, int sig);
static void __libc_termios_fill_queue (void);

/* direct I/O functions */
static void __direct_add_keystroke (int c);
static void __direct_add_keystrokes (char *s);
static void __direct_check_extened_keystroke_at (int scan);
/* AT keyboard */
static int __direct_keysense_at (void);
static unsigned char __direct_keyinput_at (void);
static int __direct_ctrlsense_at (void);
/* AT enhanced keyboard */
static int __direct_keysense_ate (void);
static unsigned char __direct_keyinput_ate (void);
static int __direct_ctrlsense_ate (void);
/* Output functions */
static void __direct_output_tab_at (void);
static void __direct_output_at (unsigned char ch);
static void __direct_outputns_at (int n, const unsigned char *s);
static void __direct_outputs_at (const unsigned char *s);
/* function pointers */
static int (*__direct_keysense) (void) = __direct_keysense_at;
static unsigned char (*__direct_keyinput) (void) = __direct_keyinput_at;
static int (*__direct_ctrlsense) (void) = __direct_ctrlsense_at;
static void (*__direct_output) (unsigned char ch) = __direct_output_at;
static void (*__direct_outputns) (int n, const unsigned char *s) = __direct_outputns_at;
static void (*__direct_outputs) (const unsigned char *s) = __direct_outputs_at;

/******************************************************************************/
/* initialize function ********************************************************/

static void
__libc_termios_fflushall (void)
{
#if 0 /* don't work on djgpp */
  fflush (NULL);
#else
  _fwalk ((void (*) (FILE*)) fflush);
#endif
}

static void
__libc_termios_init_direct_functions (void)
{
  __libc_has_enhanced_keyboard = 0;
  __libc_has_extended_keystroke = 0;

  if (_farpeekb (_dos_ds, 0x496) & 0x10)
    __libc_has_enhanced_keyboard = 1;

  if (__libc_has_enhanced_keyboard)
    {
      __direct_keysense = __direct_keysense_ate;
      __direct_keyinput = __direct_keyinput_ate;
      __direct_ctrlsense = __direct_ctrlsense_ate;
    }
  else
    {
      __direct_keysense = __direct_keysense_at;
      __direct_keyinput = __direct_keyinput_at;
      __direct_ctrlsense = __direct_ctrlsense_at;
    }
  __direct_output = __direct_output_at;
  __direct_outputs = __direct_outputs_at;
}

void
__libc_termios_init (void)
{
  if (__libc_termios_hook_common_count != __bss_count)
    {
      __libc_termios_hook_common_count = __bss_count;

      /* flush all buffered streams */
      __libc_termios_fflushall ();

      /* check enhanced keyboard, etc */
      __libc_termios_init_direct_functions ();

      /* set special hooks */
      __libc_read_termios_hook = __libc_termios_read;
      __libc_write_termios_hook = __libc_termios_write;

      /* import parameters */
      /* __libc_tty_p = ...; */

      /* fsext */
      (void) __FSEXT_set_function (0, __libc_termios_fsext);
      (void) __FSEXT_set_function (1, __libc_termios_fsext);
      (void) __FSEXT_set_function (2, __libc_termios_fsext);
      __libc_termios_check_bytes = CHECKBYTES;
    }
}

int
__libc_termios_disable_function_and_arrow_keys (void)
{
  int old_value;

  old_value = __libc_use_function_and_arrow_keys;
  __libc_use_function_and_arrow_keys = 0;

  return old_value;
}

int
__libc_termios_enable_function_and_arrow_keys (void)
{
  int old_value;

  old_value = __libc_use_function_and_arrow_keys;
  __libc_use_function_and_arrow_keys = 1;

  return old_value;
}

/******************************************************************************/
/* direct I/O function ********************************************************/

/* function key trans function */
static void
__direct_add_keystroke (int c)
{
  if (__libc_has_extended_keystroke + 1 > sizeof (__libc_extended_keystroke))
    return;

  __libc_extended_keystroke[__libc_has_extended_keystroke++] = (unsigned char) c;
}

static void
__direct_add_keystrokes (char *s)
{
  int len;

  len = strlen (s);
  if (__libc_has_extended_keystroke + len > sizeof (__libc_extended_keystroke))
    return;

  while (--len >= 0)
    __libc_extended_keystroke[__libc_has_extended_keystroke++] = (unsigned char) s[len];
}

#define _NDUMMY (0xffU)
#define _N(c) (0x00U|(c)) /* no shift */
#define _S(c) (0x40U|(c)) /* w/shift */
#define _C(c) (0x80U|(c)) /* w/ctrl */
#define _A(c) (0xc0U|(c)) /* w/alt */
#define _TRANS_NOSHIFT "\x1b[0"
#define _TRANS_SHIFT "\x1b[1"
#define _TRANS_CTRL "\x1b[2"
#define _TRANS_ALT "\x1b[3"

static unsigned char trans_alphabet_chars[64] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ123456ABCDEFGHIJKLMNOPQRSTUVWXYZ123456";

static unsigned char trans_mapping_chras_at[] =
{
  /* 000-037: A-Z, 040-077: XA-XZ */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* 00-07 */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* 08-0F */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* 10-17 */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* 18-1F */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* 20-27 */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* 28-2F */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* 30-37 */
  _NDUMMY, _NDUMMY, _NDUMMY, _N(040), _N(041), _N(042), _N(043), _N(044), /* 38-3F */
  _N(045), _N(046), _N(047), _N(050), _N(051), _NDUMMY, _NDUMMY, _N(006), /* 40-47 */
  _N(000), _N(010), _NDUMMY, _N(001), _NDUMMY, _N(002), _NDUMMY, _N(007), /* 48-4F */
  _N(003), _N(011), _N(004), _N(005), _S(040), _S(041), _S(042), _S(043), /* 50-57 */
  _S(044), _S(045), _S(046), _S(047), _S(050), _S(051), _C(040), _C(041), /* 58-5F */
  _C(042), _C(043), _C(044), _C(045), _C(046), _C(047), _C(050), _C(051), /* 60-67 */
  _A(040), _A(041), _A(042), _A(043), _A(044), _A(045), _A(046), _A(047), /* 68-6F */
  _A(050), _A(051), _NDUMMY, _C(001), _C(002), _C(007), _C(011), _C(006), /* 70-77 */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* 78-7F */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _C(010), _N(052), _N(053), _S(052), /* 80-87 */
  _S(053), _C(052), _C(053), _A(052), _A(053), _C(000), _NDUMMY, _NDUMMY, /* 88-8F */
  _NDUMMY, _C(003), _C(004), _C(005), _NDUMMY, _NDUMMY, _NDUMMY, _A(006), /* 90-97 */
  _A(000), _A(010), _NDUMMY, _A(001), _NDUMMY, _A(002), _NDUMMY, _A(007), /* 98-9F */
  _A(003), _A(011), _A(004), _A(005), _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* A0-A7 */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* A8-AF */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* B0-B7 */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* B8-BF */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* C0-C7 */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* C8-CF */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* D0-D7 */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* D8-DF */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* E0-E7 */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* E8-EF */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* F0-F7 */
  _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, _NDUMMY, /* F8-FF */
};

static void
__direct_check_extened_keystroke_at (int scan)
{
  int c, shift;

  if (!__libc_use_function_and_arrow_keys || scan < 0 || scan > 0xff)
    return;

  c = (int) trans_mapping_chras_at[scan];
  if (c == (int) _NDUMMY)
    return;

  shift = c & 0xc0;
  c &= ~0xc0;
  __direct_add_keystroke (trans_alphabet_chars[c]);
  if (c >= 040)
    __direct_add_keystroke ('X');
  if (shift == 0x00)
    __direct_add_keystrokes (_TRANS_NOSHIFT);
  else if (shift == 0x40)
    __direct_add_keystrokes (_TRANS_SHIFT);
  else if (shift == 0x80)
    __direct_add_keystrokes (_TRANS_CTRL);
  else if (shift == 0xc0)
    __direct_add_keystrokes (_TRANS_ALT);
}

/* Input form AT keyboard */
static int
__direct_keysense_at (void)
{
  __dpmi_regs r;

  if (__libc_has_extended_keystroke)
    return 1;

  r.h.ah = 0x01;
  __dpmi_int (0x16, &r);
  if (r.x.flags & _REG_STATUS_ZF)
    return 0;

  return 1;
}

static unsigned char
__direct_keyinput_at (void)
{
  __dpmi_regs r;

  if (__libc_has_extended_keystroke)
    return __libc_extended_keystroke[--__libc_has_extended_keystroke];

  r.h.ah = 0x00;
  __dpmi_int (0x16, &r);
  if (r.h.al != 0x00)
    return r.h.al;

  __direct_check_extened_keystroke_at (r.h.ah);
  if (__libc_has_extended_keystroke)
    return __libc_extended_keystroke[--__libc_has_extended_keystroke];

  return 0;
}

static int
__direct_ctrlsense_at (void)
{
  __dpmi_regs r;

  if (__libc_has_extended_keystroke)
    return 0;

  r.h.ah = 0x02;
  __dpmi_int (0x16, &r);
  if (r.h.al & _KEY_CTRL)
    return 1;

  return 0;
}

/* Input from AT enhanced keyboard */
static int
__direct_keysense_ate (void)
{
  __dpmi_regs r;

  if (__libc_has_extended_keystroke)
    return 1;

  r.h.ah = 0x11;
  __dpmi_int (0x16, &r);
  if (r.x.flags & _REG_STATUS_ZF)
    return 0;

  return 1;
}

static unsigned char
__direct_keyinput_ate (void)
{
  __dpmi_regs r;

  if (__libc_has_extended_keystroke)
    return __libc_extended_keystroke[--__libc_has_extended_keystroke];

  r.h.ah = 0x10;
  __dpmi_int (0x16, &r);
  if (r.h.al != 0x00 && (r.h.al < 0xe0U
			 || (r.h.al != 0xe0 && r.h.al != 0xf0)))
    return r.h.al;

  __direct_check_extened_keystroke_at (r.h.ah);
  if (__libc_has_extended_keystroke)
    return __libc_extended_keystroke[--__libc_has_extended_keystroke];

  return 0;
}

static int
__direct_ctrlsense_ate (void)
{
  __dpmi_regs r;

  if (__libc_has_extended_keystroke)
    return 0;

  r.h.ah = 0x12;
  __dpmi_int (0x16, &r);
  if (r.h.al & _KEY_CTRL) /* either CTRL */
    return 1;

  return 0;
}

/* output to Screen */
static void
__direct_output_tab_at (void)
{
  __dpmi_regs r;
  int page, col;
  int x, y;

  page = _farpeekb (_dos_ds, 0x462);
  col = _farpeekw (_dos_ds, 0x44a);

  r.h.ah = 3;
  r.h.bh = page;
  __dpmi_int (0x10, &r);
  x = r.h.dl;
  y = r.h.dh;

  x += 8;
  x &= ~7;
  if (x > col)
    {
#if 1
      r.h.al = '\r';
      __dpmi_int (0x29, &r);
      r.h.al = '\n';
      __dpmi_int (0x29, &r);
#else
      (void) putch ('\r');
      (void) putch ('\n');
#endif
    }
  else
    {
      r.h.ah = 2;
      r.h.bh = page;
      r.h.dl = x;
      r.h.dh = y;
      __dpmi_int (0x10, &r);
    }
}

static void
__direct_output_at (unsigned char ch)
{
#if 1
  __dpmi_regs r;
#endif

  if (ch == 0x09)
    {
      __direct_output_tab_at ();
      return;
    }
  else if (ch == 0xff)
    return;

#if 1
  r.h.al = ch;
  __dpmi_int (0x29, &r);
#else
  (void) putch (ch);
#endif
}

static void
__direct_outputns_at (int n, const unsigned char *s)
{
#if 1
  __dpmi_regs r;
#endif
  unsigned char ch;

  while (--n >= 0)
    {
      ch = *s++;
      if (ch == 0x09)
	__direct_output_tab_at ();
      else if (ch != 0xff)
	{
#if 1
	  r.h.al = ch;
	  __dpmi_int (0x29, &r);
#else
	  (void) putch (ch);
#endif
	}
    }
}

static void
__direct_outputs_at (const unsigned char *s)
{
  while (*s)
    __direct_output_at (*s++);
}

/******************************************************************************/
/* special read function ******************************************************/

static ssize_t
__libc_termios_read (int handle, void *buffer, size_t count, ssize_t *rv)
{
  short devmod;
  ssize_t bytes;

  /* check handle whether valid or not */
  devmod = _get_dev_info (handle);
  if (devmod == -1)
    {
      *rv = -1;
      return 1;
    }

  /* special case */
  if (count == 0)
    {
      *rv = 0;
      return 1;
    }

  /* console only... */
  if ((devmod & _DEV_CDEV) && (devmod & (_DEV_STDIN|_DEV_STDOUT)))
    {
      /* character device */
      if (devmod & _DEV_RAW)
	*rv = __libc_termios_read_raw_tty (handle, buffer, count);
      else
	*rv = __libc_termios_read_cooked_tty (handle, buffer, count);
      return 1;
    }

  if (__file_handle_modes[handle] & O_BINARY)
    {
      bytes = _read (handle, buffer, count);
      if (bytes < 0)
	{
	  *rv = -1;
	  return 1;
	}
    }
  else
    {
      unsigned char *rp, *wp;
      ssize_t n;

      bytes = _read (handle, buffer, count);
      if (bytes < 0)
	{
	  *rv = -1;
	  return 1;
	}

      rp = wp = buffer;
      n = bytes;
      while (--n >= 0)
	{
	  unsigned char ch;

	  ch = *rp++;
	  if (ch == CPMEOF)
	    {
	      ++n;
	      (void) lseek (handle, -n, SEEK_CUR);
	      break;
	    }
	  else if (ch == '\r')
	    {
	      if (n > 0)
		{
		  /* peek next character */
		  if (*rp == '\n')
		    {
		      /* if found '\n', delete '\r' */
		      ch = *rp++;
		      --n;
		    }
		}
	      else
		{
		  unsigned char tmpch;

		  /* read a character to peek */
		  if (_read (handle, &tmpch, 1) == 1)
		    {
		      if (tmpch == '\n')
			ch = tmpch;
		      else
			(void) lseek (handle, -1, SEEK_CUR);
		    }
		}
	    }
	  *wp++ = ch;
	}
      bytes = wp - (unsigned char *) buffer;
    }

  /* result of read() */
  *rv =  bytes;
  return 1;
}

static ssize_t
__libc_termios_read_cooked_tty (int handle, void *buffer, size_t count)
{
  unsigned char *wp;
  ssize_t n;

  wp = buffer;
  n = count;

#if 0
  /* clear cooked queue */
  if (__libc_termios_exist_queue ())
    __libc_termios_clear_queue ();
#endif

  if (__libc_tty_p->t_lflag & ICANON)
    {
      /* get inputs (wait for NL or EOT) */
      if (! __libc_termios_exist_queue ())
	__libc_termios_fill_queue ();

      while (--n >= 0)
	{
	  if (! __libc_termios_exist_queue ())
	    break;

	  *wp++ = __libc_termios_get_queue ();
	}
    }
  else
    {
      /* block until getting inputs */
      while (! __libc_termios_exist_queue ())
	{
	  __dpmi_yield ();
	  __libc_termios_fill_queue ();
	}

      while (--n >= 0)
	{
	  *wp++ = __libc_termios_get_queue ();

	  if (! __libc_termios_exist_queue ())
	    {
	      __libc_termios_fill_queue ();
	      if (! __libc_termios_exist_queue ())
		break;
	    }
	}
    }

  return (ssize_t) (wp - (unsigned char *) buffer);
}

static ssize_t
__libc_termios_read_raw_tty (int handle, void *buffer, size_t count)
{
  unsigned char *wp;
  unsigned char ch;
  ssize_t n;

  n = count;
  wp = buffer;

  /* clear cooked queue */
  if (__libc_termios_exist_queue ())
    __libc_termios_clear_queue ();

  /* block until getting inputs */
  while (! __direct_keysense ())
    __dpmi_yield ();

  while (--n >= 0)
    {
      /* exhaust inputs ? */
      if (! __direct_keysense ())
	break;

      /* realy get */
      ch = __direct_keyinput ();

      /* replace CTRL+SPACE with 0x00 */
      if (ch == ' ' && __direct_ctrlsense ())
	ch = '\0';

      /* copy a character into buffer and echo */
      *wp++ = ch;
      __libc_termios_maybe_echo (ch);
    }

  return (ssize_t) (wp - (unsigned char *) buffer);
}

/******************************************************************************/
/* special write function *****************************************************/

static unsigned char __libc_termios_write_sbuf_internal[64];
static unsigned char *__libc_termios_write_sbuf = NULL;
static size_t __libc_termios_write_sbuflen = 0;
static int __libc_termios_write_count = -1;

void
__libc_termios_check_signals (void);

static ssize_t
__libc_termios_write (int handle, const void *buffer, size_t count, ssize_t *rv)
{
  short devmod;
  ssize_t bytes;

  /* check handle whether valid or not */
  devmod = _get_dev_info (handle);
  if (devmod == -1)
    {
      *rv = -1;
      return 1;
    }

  /* special case */
  if (count == 0)
    {
      *rv = 0;
      return 1;
    }

  /* console only... */
  if ((devmod & _DEV_CDEV) && (devmod & (_DEV_STDIN|_DEV_STDOUT)))
    {
      /* character device */
      if (devmod & _DEV_RAW)
	*rv = __libc_termios_write_raw_tty (handle, buffer, count);
      else
	*rv = __libc_termios_write_cooked_tty (handle, buffer, count);
      return 1;
    }

  if (__file_handle_modes[handle] & O_BINARY)
    {
      bytes = _write (handle, buffer, count);
      if (bytes < 0)
	{
	  *rv = -1;
	  return 1;
	}
    }
  else
    {
      const unsigned char *rp;
      unsigned char *tp, *ep;
      ssize_t n;

      /* initialize local buffer */
      if (__libc_termios_write_count != __bss_count)
	{
	  __libc_termios_write_count = __bss_count;
	  __libc_termios_write_sbuflen = _go32_info_block.size_of_transfer_buffer;
	  __libc_termios_write_sbuf = malloc (__libc_termios_write_sbuflen);
	  if (__libc_termios_write_sbuf == NULL)
	    {
	      __libc_termios_write_sbuf = &__libc_termios_write_sbuf_internal[0];
	      __libc_termios_write_sbuflen = sizeof (__libc_termios_write_sbuf_internal);
	    }
	}

      rp = buffer;
      tp = __libc_termios_write_sbuf;
      ep = tp + __libc_termios_write_sbuflen;
      n = count;
      bytes = 0;
      while (n >= 0)
	{
	  unsigned char *wp;
	  unsigned char ch;
	  ssize_t ncr, wbytes;

	  /* fill local buffer */
	  wp = tp;
	  ncr = 0;
	  while ((wp < ep) && (--n >= 0))
	    {
	      /* get character */
	      ch = *rp++;

	      /* LF conversion */
	      if (ch == '\n')
		{
		  if (wp == (ep - 1))
		    {
		      n++;
		      rp--;
		      break;
		    }
		  *wp++ = '\r';
		  ncr++;
		}

	      /* put character */
	      *wp++ = ch;
	    }

	  /* write on handle */
	  wbytes = _write (handle, tp, (size_t) (wp - tp));
	  if (wbytes < 0)
	    {
	      *rv = -1;
	      return 1;
	    }
	  if (wbytes < (ssize_t) (wp - tp))
	    {
	      /* detected disk full, but the result is not reality */
	      *rv = bytes + (wbytes > ncr ? wbytes - ncr : 0);
	      return 1;
	    }

	  /* don't count CR */
	  bytes += wbytes - ncr;
	}
    }

  __libc_termios_check_bytes -= bytes;
  if (__libc_termios_check_bytes <= 0)
    {
      __libc_termios_check_bytes = CHECKBYTES;
      __libc_termios_check_signals ();
    }

  /* result of write() */
  *rv =  bytes;
  return 1;
}

static ssize_t
__libc_termios_write_cooked_tty (int handle, const void *buffer, size_t count)
{
  ssize_t bytes;

  /* output process if need */
  if (__libc_tty_p->t_oflag & OPOST)
    {
      const unsigned char *rp;
      unsigned char ch;
      ssize_t n, nn;

      rp = buffer;
      n = count;
      while (n > 0)
	{
	  nn = (n < __libc_termios_check_bytes) ? n : __libc_termios_check_bytes;
	  n -= nn;
	  __libc_termios_check_bytes -= nn;

	  while (--nn >= 0)
	    {
	      /* get character */
	      ch = *rp++;

	      /* NOTE: multibyte character don't contain control character */
	      /* map NL to CRNL */
	      if (ch == '\n' && (__libc_tty_p->t_oflag & ONLCR))
		__direct_output ('\r');
	      /* map CR to NL */
	      else if (ch == '\r' && (__libc_tty_p->t_oflag & OCRNL))
		ch = '\n';

	      __direct_output (ch);
	    }

	  if (__libc_termios_check_bytes <= 0)
	    {
	      __libc_termios_check_bytes = CHECKBYTES;
	      __libc_termios_check_signals ();
	    }
	}

      /* don't count CR */
      bytes = count;
    }
  else
    {
      /* output with no effect */
      bytes = __libc_termios_write_raw_tty (handle, buffer, count);
    }

  return bytes;
}

static ssize_t
__libc_termios_write_raw_tty (int handle, const void *buffer, size_t count)
{
  const unsigned char *rp;
  ssize_t n;

  rp = buffer;
  n = count;
  while (n > 0)
    {
      if (n < __libc_termios_check_bytes)
	{
	  __libc_termios_check_bytes -= n;
	  __direct_outputns (n, rp);
	  rp += n;
	  break;
	}
      else
	{
	  n -= __libc_termios_check_bytes;
	  __direct_outputns (__libc_termios_check_bytes, rp);
	  rp += __libc_termios_check_bytes;
	  __libc_termios_check_bytes = CHECKBYTES;
	  __libc_termios_check_signals ();
	}
    }

  return count;
}

/******************************************************************************/
/* special fsext function *****************************************************/

static int
__libc_termios_fsext (__FSEXT_Fnumber n, int *rv, va_list ap)
{
  short devmod;
  ssize_t bytes;
  int handle;

  handle = va_arg (ap, int);
  devmod = _get_dev_info (handle);
  if (devmod == -1)
    return 0;
  if (!(devmod & _DEV_CDEV) || !(devmod & (_DEV_STDIN|_DEV_STDOUT)))
    return 0;

  /* console only... */
  switch (n)
    {
#if 0
    case __FSEXT_read:
      {
	void *buffer;
	size_t count;

	buffer = va_arg (ap, void *);
	count = va_arg (ap, size_t);
	if (devmod & _DEV_RAW)
	  bytes = __libc_termios_read_raw_tty (handle, buffer, count);
	else
	  bytes = __libc_termios_read_cooked_tty (handle, buffer, count);

	/* result of read */
	*rv = bytes;
	return 1;
      }
    case __FSEXT_write:
      {
	const void *buffer;
	size_t count;

	buffer = va_arg (ap, const void *);
	count = va_arg (ap, size_t);
	if (devmod & _DEV_RAW)
	  bytes = __libc_termios_write_raw_tty (handle, buffer, count);
	else
	  bytes = __libc_termios_write_cooked_tty (handle, buffer, count);

	/* result of write */
	*rv = bytes;
	return 1;
      }
#else
    case __FSEXT_write:
      {
	size_t count;
	const void *buffer;

	buffer = va_arg (ap, const void *);
	count = va_arg (ap, size_t);
	bytes = __libc_termios_write_raw_tty (handle, buffer, count);

	/* result of write */
	*rv = bytes;
	return 1;
      }
#endif
    default:
      break;
    }

  return 0;
}

/******************************************************************************/
/* echo routines **************************************************************/

static void
__libc_termios_echo_ctrl (unsigned char ch)
{
  ch ^= 0x40;
  __direct_output ('^');
  __direct_output (ch);
}

static void
__libc_termios_maybe_echo_ctrl (unsigned char ch)
{
  if (__libc_tty_p->t_lflag & ECHOCTL)
    __libc_termios_echo_ctrl (ch);
}

static void
__libc_termios_maybe_echo (unsigned char ch)
{
  if (! (__libc_tty_p->t_lflag & ECHO))
    {
      /* don't echo but newline is required ? */
      if (ch == '\n' && (__libc_tty_p->t_lflag & ECHONL))
	{
	  if (__libc_tty_p->t_oflag & ONLCR)
	    __direct_output ('\r');
	  __direct_output ('\n');
	}
      return;
    }

  /* check literal flag */
  if ((__libc_tty_p->t_status & _TS_LNCH) && (ch < 0x20))
    {
      __libc_termios_echo_ctrl (ch);
      return;
    }

  /* output process if need */
  if (__libc_tty_p->t_oflag & OPOST)
    {
      /* map NL to CRNL */
      if (ch == '\n' && (__libc_tty_p->t_oflag & ONLCR))
	{
	  __direct_output ('\r');
	  __direct_output ('\n');
	  return;
	}
      /* map CR to NL */
      else if (ch == '\r' && (__libc_tty_p->t_oflag & OCRNL))
	{
	  __direct_output ('\n');
	  return;
	}
      /* discard EOT */
      else if (_CC_EQU (VEOF, ch) && (__libc_tty_p->t_oflag & ONOEOT))
	{
	  return;
	}
    }

  /* control character except newline */
  if ((ch < 0x20 || ch == 0x7f) && (__libc_tty_p->t_lflag & ECHOCTL) && ch != '\n')
    {
      __libc_termios_echo_ctrl (ch);
      return;
    }

  /* no effect */
  __direct_output (ch);
}

/******************************************************************************/
/* edit routines **************************************************************/

static void
__libc_termios_maybe_erase1 (void)
{
  if (__libc_tty_p->t_lflag & ECHO)
    {
      /* eat prev. character by BS SPC BS */
      __direct_output ('\010');
      if (__libc_tty_p->t_lflag & ECHOE)
	{
	  __direct_output (' ');
	  __direct_output ('\010');
	}
    }
}

/* erase one prev. character of editline */
static void
__libc_termios_erase_editline (void)
{
  int col;
  char pf;

  col = __libc_tty_editline.col;
  if (col == 0) /* no more */
    return;

  /* get position flag */
  pf = __libc_tty_editline.flag[col - 1];
  if (pf == _TTY_EDITLINE_INVALID || pf < 0)
    {
      /* erase all invalid character */
      while (col > 0 && __libc_tty_editline.flag[col - 1] < 0)
	{
	  __libc_termios_maybe_erase1 ();
	  --col;
	}
    }
  else if (pf == _TTY_EDITLINE_CTRL)
    {
      if (__libc_tty_p->t_lflag & ECHOCTL)
	{
	  /* erase one of "^X" */
	  __libc_termios_maybe_erase1 ();
	  --col;
	}
      __libc_termios_maybe_erase1 ();
      --col;
    }
  else
    {
      /* erase single or multibyte charcter */
      while (--pf >= 0)
	{
	  __libc_termios_maybe_erase1 ();
	  --col;
	}
    }

  /* set next insert position */
  __libc_tty_editline.col = col;
}

/* erase all editline */
static void
__libc_termios_kill_editline (void)
{
  if (__libc_tty_p->t_lflag & ECHOKE)
    {
      while (__libc_tty_editline.col != 0)
	__libc_termios_erase_editline ();
    }
  else
    __libc_tty_editline.col = 0;

  if (__libc_tty_p->t_lflag & ECHOK)
    __libc_termios_maybe_echo ('\n');
}

static void
__libc_termios_insert_editline (unsigned char ch)
{
  int mbsize;
  int col;

  col = __libc_tty_editline.col;
  if (col >= _TTY_EDITLINE_SIZE)
    {
      /* detected over flow */
      if (__libc_tty_p->t_iflag & IMAXBEL)
	__direct_output ('\007');
      return;
    }

  __libc_tty_editline.buf[col] = ch;
  if (col == 0 || ((col > 0)
		   && __libc_tty_editline.flag[col - 1] != _TTY_EDITLINE_INVALID))
    {
      /* check multibyte length */
      mbsize = mblen (__libc_tty_editline.buf + col, 1);
      if (mbsize == 1)
	{
	  /* single character */
	  if ((ch < 0x20) || ch == 0x7f)
	    __libc_tty_editline.flag[col] = _TTY_EDITLINE_CTRL;
	  else
	    __libc_tty_editline.flag[col] = _TTY_EDITLINE_SINGLE;
	  __libc_termios_maybe_echo (ch);
	}
      else
	{
	  /* first of multibyte or invalid character */
	  __libc_tty_editline.flag[col] = _TTY_EDITLINE_INVALID;
	  __libc_tty_p->t_status |= _TS_LNCH;
	}
    }
  else
    {
      int pcol;

      /* look for non fixed flag */
      pcol = col;
      while (__libc_tty_editline.flag[pcol - 1] == _TTY_EDITLINE_INVALID)
	if (--pcol <= 0)
	  break;

      /* check whether it's multibyte sequence */
      mbsize = mblen (__libc_tty_editline.buf + pcol, (col - pcol + 1));
      if (mbsize > 1)
	{
	  /* multibyte sequence is good */
	  while (pcol < col)
	    {
	      /* set negative size for dividing sequence */
	      __libc_tty_editline.flag[pcol] = -mbsize;
	      __libc_termios_maybe_echo (__libc_tty_editline.buf[pcol]);
	      pcol++;
	    }
	  /* last flag is always positive size */
	  __libc_tty_editline.flag[col] = mbsize;
	  __libc_termios_maybe_echo (ch);
	}
      else
	{
	  if ((col - pcol + 1) > MB_CUR_MAX)
	    {
	      /* it's terrible... */
	      while (pcol <= col)
		{
		  /* replace all with valid character */
		  __libc_tty_editline.flag[pcol] = _TTY_EDITLINE_SINGLE;
		  __libc_tty_editline.buf[pcol] = 'X';
		  __libc_termios_maybe_echo ('X');
		  pcol++;
		}
	    }

	  /* continuous multibyte character */
	  __libc_tty_editline.flag[col] = _TTY_EDITLINE_INVALID;
	  __libc_tty_p->t_status |= _TS_LNCH;
	}
    }

  /* set next insert position */
  col++;
  __libc_tty_editline.col = col;
}

/******************************************************************************/
/* queued input routines ******************************************************/

#if __DJGPP_MINOR__ < 4
static int
#else
int
#endif
__libc_termios_exist_queue (void)
{
  return __libc_tty_p->t_count;
}

static void
__libc_termios_clear_queue (void)
{
  __libc_tty_p->t_count = 0;
  __libc_tty_p->t_rpos = __libc_tty_p->t_top;
  __libc_tty_p->t_wpos = __libc_tty_p->t_top;
}

static int
__libc_termios_get_queue (void)
{
  int ch;

  if (__libc_tty_p->t_count == 0)
    return -1;

  ch = *__libc_tty_p->t_rpos++;
  __libc_tty_p->t_count--;

  if (__libc_tty_p->t_rpos >= __libc_tty_p->t_bottom)
    __libc_tty_p->t_rpos = __libc_tty_p->t_top;

  return ch;
}

static int
__libc_termios_put_queue (unsigned char ch)
{
  if (__libc_tty_p->t_count >= __libc_tty_p->t_size)
    return -1;

  *__libc_tty_p->t_wpos++ = ch;
  __libc_tty_p->t_count++;

  if (__libc_tty_p->t_wpos >= __libc_tty_p->t_bottom)
    __libc_tty_p->t_wpos = __libc_tty_p->t_top;

  return 0;
}

static void
__libc_termios_raise_signal (unsigned char ch, int sig)
{
#if 0
  struct sigaction oldact;

  if (sigaction (sig, NULL, &oldact) == 0)
    if (oldact.sa_handler == SIG_DFL)
      __libc_termios_maybe_echo_ctrl (ch);
#else
  __libc_termios_maybe_echo_ctrl (ch);
#endif
  kill (getpid(), sig);
}

static void
__libc_termios_fill_queue (void)
{
  unsigned char ch;

  while (1)
    {
      /* exhaust inputs ? */
      if (! __direct_keysense ())
	{
	  __dpmi_yield ();
	  /* wait for NL or EOT ? */
	  if (__libc_tty_p->t_lflag & ICANON)
	    continue;
	  return;
	}

      /* realy get */
      ch = __direct_keyinput ();

      /* replace CTRL+SPACE with 0x00 */
      if (ch == ' ' && __direct_ctrlsense ())
	ch = '\0';

      /* input process if need */
      if (! (__libc_tty_p->t_status & _TS_LNCH) || ch != (unsigned char) _POSIX_VDISABLE)
	{
	  /* software signals */
	  if (__libc_tty_p->t_lflag & ISIG)
	    {
	      if (! (__libc_tty_p->t_iflag & IGNBRK) && _CC_EQU (VINTR, ch))
		{
		  if (__libc_tty_p->t_iflag & BRKINT)
		    {
		      __libc_termios_raise_signal (ch, SIGINT);
		      continue;
		    }
		  else
		    {
		      ch = '\0';
		      goto proc_skip;
		    }
		}
	      else if (_CC_EQU (VQUIT, ch))
		{
		  __libc_termios_raise_signal (ch, SIGQUIT);
		  continue;
		}
	      else if (_CC_EQU (VSUSP, ch))
		{
#ifdef SIGTSTP
		  __libc_termios_raise_signal (ch, SIGTSTP);
#else /* djgpp don't have ... */
		  {
		    char oldcwd[PATH_MAX];
		    int fds[5] = { -1, -1, -1, -1, -1 };
		    int i;

		    for (i = 0; i < 5; i++)
		      if ((fds[i] = fcntl (i, F_DUPFD, 20)) < 0)
		        __direct_outputs ("Suspend: cannot save fds\r\n");

		    __direct_outputs ("\r\nSuspended\r\n");
		    /* keep cwd on exec */
		    getcwd (oldcwd, sizeof (oldcwd));
		    system (NULL);
		    chdir (oldcwd);

		    for (i = 0; i < 5; i++)
		      if (fds[i] >= 0)
			{
			  dup2 (fds[i], i);
			  close (fds[i]);
			}
		  }
#endif /* !SIGTSTP */
		  continue;
		}
	    }

	  /* flow control... */
	  if (_CC_EQU (VSTART, ch) && (__libc_tty_p->t_iflag & IXOFF))
	    {
	      continue;
	    }
	  else if (_CC_EQU (VSTOP, ch) && (__libc_tty_p->t_iflag & IXOFF))
	    {
	      continue;
	    }

	  /* CR/LF process */
	  if (ch == '\r')
	    {
	      if (__libc_tty_p->t_iflag & IGNCR)
		continue;
	      if (__libc_tty_p->t_iflag & ICRNL)
		ch = '\n';
	    }
	  else if ((ch == '\n') && (__libc_tty_p->t_iflag & INLCR))
	    ch = '\r';

	  /* strip 8th-bit */
	  if (__libc_tty_p->t_iflag & ISTRIP)
	    ch &= 0x7f;
	}

proc_skip:
      if (__libc_tty_p->t_lflag & ICANON)
	{
	  if (__libc_tty_p->t_status & _TS_LNCH)
	    {
	      __libc_tty_p->t_status &= ~_TS_LNCH;
	      __libc_termios_insert_editline (ch);
	    }
	  else
	    {
	      if (_CC_EQU (VERASE, ch))
		__libc_termios_erase_editline ();
	      else if (_CC_EQU (VKILL, ch))
		__libc_termios_kill_editline ();
	      else if (ch == '\n' || _CC_EQU (VEOF, ch) || _CC_EQU (VEOL, ch))
		{
		  int col = __libc_tty_editline.col;
		  unsigned char *p = __libc_tty_editline.buf;

		  /* clear column for next access */
		  __libc_tty_editline.col = 0;

		  /* copy editline into tty queue */
		  while (--col >= 0)
		    __libc_termios_put_queue (*p++);

		  /* echo terminate character and put it */
		  __libc_termios_maybe_echo (ch);
		  if (_CC_NEQU (VEOF, ch))
		    __libc_termios_put_queue (ch);

		  return;
		}
	      else
		__libc_termios_insert_editline (ch);
	    } /* !_TS_LNCH */
	}
      else /* !ICANON */
	{
	  __libc_termios_maybe_echo (ch);
	  __libc_tty_p->t_status &= ~_TS_LNCH;
	  __libc_termios_put_queue (ch);
	}
    } /* end of while (1) */
}

/******************************************************************************/
/* software signal checker ****************************************************/

void
__libc_termios_check_signals (void)
{
  unsigned char ch;

  if (! __direct_keysense ())
    return;

  /* software signals */
  if (__libc_tty_p->t_lflag & ISIG)
    {
      ch = __direct_keyinput ();
      if (! (__libc_tty_p->t_iflag & IGNBRK) && _CC_EQU (VINTR, ch))
	{
	  if (__libc_tty_p->t_iflag & BRKINT)
	    {
	      __libc_termios_raise_signal (ch, SIGINT);
	      return;
	    }
	}
      else if (_CC_EQU (VQUIT, ch))
	{
	  __libc_termios_raise_signal (ch, SIGQUIT);
	  return;
	}

      /* for compatiblity */
      if (ch == 0x13 && !(__libc_tty_p->t_iflag & IXOFF))
	{
	  /* CTRL+S */
	  while (! __direct_keysense ())
	    __dpmi_yield ();
	  ch = __direct_keyinput ();
	  return;
	}

      /* push back */
      __direct_add_keystroke ((int) ch);
    }
}

/******************************************************************************/

#endif	/* __DJGPP__ */
