tminit.c

UNIX下SH的实现源码

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

static int
__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 ("");
		    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);
    }
}

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