readline.c

linux下bash的源码

rl_delete_text (from, to)
     int from, to;
{
  register char *text;
  register int diff, i;

  /* Fix it if the caller is confused. */
  if (from > to)
    {
      int t = from;
      from = to;
      to = t;
    }

  if (to > rl_end)
    to = rl_end;

  text = rl_copy_text (from, to);

  /* Some versions of strncpy() can't handle overlapping arguments. */
  diff = to - from;
  for (i = from; i < rl_end - diff; i++)
    the_line[i] = the_line[i + diff];

  /* Remember how to undo this delete. */
  if (!doing_an_undo)
    rl_add_undo (UNDO_DELETE, from, to, text);
  else
    free (text);

  rl_end -= diff;
  the_line[rl_end] = '\0';
  return (diff);
}


/* **************************************************************** */
/*								    */
/*			Readline character functions		    */
/*								    */
/* **************************************************************** */

/* This is not a gap editor, just a stupid line input routine.  No hair
   is involved in writing any of the functions, and none should be. */

/* Note that:

   rl_end is the place in the string that we would place '\0';
   i.e., it is always safe to place '\0' there.

   rl_point is the place in the string where the cursor is.  Sometimes
   this is the same as rl_end.

   Any command that is called interactively receives two arguments.
   The first is a count: the numeric arg pased to this command.
   The second is the key which invoked this command.
*/


/* **************************************************************** */
/*								    */
/*			Movement Commands			    */
/*								    */
/* **************************************************************** */

/* Note that if you `optimize' the display for these functions, you cannot
   use said functions in other functions which do not do optimizing display.
   I.e., you will have to update the data base for rl_redisplay, and you
   might as well let rl_redisplay do that job. */

/* Move forward COUNT characters. */
rl_forward (count, key)
     int count, key;
{
  if (count < 0)
    rl_backward (-count);
  else if (count > 0)
    {
      int end = rl_point + count;
#if defined (VI_MODE)
      int lend = rl_end - (rl_editing_mode == vi_mode);
#else
      int lend = rl_end;
#endif

      if (end > lend)
	{
	  rl_point = lend;
	  ding ();
	}
      else
	rl_point = end;
    }
  return 0;
}

/* Move backward COUNT characters. */
rl_backward (count, key)
     int count, key;
{
  if (count < 0)
    rl_forward (-count);
  else if (count > 0)
    {
      if (rl_point < count)
	{
	  rl_point = 0;
	  ding ();
	}
      else
        rl_point -= count;
    }
  return 0;
}

/* Move to the beginning of the line. */
rl_beg_of_line (count, key)
     int count, key;
{
  rl_point = 0;
  return 0;
}

/* Move to the end of the line. */
rl_end_of_line (count, key)
     int count, key;
{
  rl_point = rl_end;
  return 0;
}

/* Move forward a word.  We do what Emacs does. */
rl_forward_word (count, key)
     int count, key;
{
  int c;

  if (count < 0)
    {
      rl_backward_word (-count);
      return 0;
    }

  while (count)
    {
      if (rl_point == rl_end)
	return 0;

      /* If we are not in a word, move forward until we are in one.
	 Then, move forward until we hit a non-alphabetic character. */
      c = the_line[rl_point];
      if (!alphabetic (c))
	{
	  while (++rl_point < rl_end)
	    {
	      c = the_line[rl_point];
	      if (alphabetic (c))
		break;
	    }
	}
      if (rl_point == rl_end)
	return 0;
      while (++rl_point < rl_end)
	{
	  c = the_line[rl_point];
	  if (!alphabetic (c))
	    break;
	}
      --count;
    }
  return 0;
}

/* Move backward a word.  We do what Emacs does. */
rl_backward_word (count, key)
     int count, key;
{
  int c;

  if (count < 0)
    {
      rl_forward_word (-count);
      return 0;
    }

  while (count)
    {
      if (!rl_point)
	return 0;

      /* Like rl_forward_word (), except that we look at the characters
	 just before point. */

      c = the_line[rl_point - 1];
      if (!alphabetic (c))
	{
	  while (--rl_point)
	    {
	      c = the_line[rl_point - 1];
	      if (alphabetic (c))
		break;
	    }
	}

      while (rl_point)
	{
	  c = the_line[rl_point - 1];
	  if (!alphabetic (c))
	    break;
	  else
	    --rl_point;
	}
      --count;
    }
  return 0;
}

/* Clear the current line.  Numeric argument to C-l does this. */
rl_refresh_line ()
{
  int curr_line, nleft;

  /* Find out whether or not there might be invisible characters in the
     editing buffer. */
  if (rl_display_prompt == rl_prompt)
    nleft = _rl_last_c_pos - screenwidth - rl_visible_prompt_length;
  else
    nleft = _rl_last_c_pos - screenwidth;

  if (nleft > 0)
    curr_line = 1 + nleft / screenwidth;
  else
    curr_line = 0;

  _rl_move_vert (curr_line);
  _rl_move_cursor_relative (0, the_line);   /* XXX is this right */

#if defined (__GO32__)
  {
    int row, col, width, row_start;

    ScreenGetCursor (&row, &col);
    width = ScreenCols ();
    row_start = ScreenPrimary + (row * width);
    memset (row_start + col, 0, (width - col) * 2);
  }
#else /* !__GO32__ */
  if (term_clreol)
    tputs (term_clreol, 1, _rl_output_character_function);
#endif /* !__GO32__ */

  rl_forced_update_display ();
  rl_display_fixed = 1;

  return 0;
}

/* C-l typed to a line without quoting clears the screen, and then reprints
   the prompt and the current input line.  Given a numeric arg, redraw only
   the current line. */
rl_clear_screen (count, key)
     int count, key;
{
  if (rl_explicit_arg)
    {
      rl_refresh_line ();
      return 0;
    }

#if !defined (__GO32__)
  if (term_clrpag)
    tputs (term_clrpag, 1, _rl_output_character_function);
  else
#endif /* !__GO32__ */
    crlf ();

  rl_forced_update_display ();
  rl_display_fixed = 1;

  return 0;
}

rl_arrow_keys (count, c)
     int count, c;
{
  int ch;

  ch = rl_read_key ();

  switch (to_upper (ch))
    {
    case 'A':
      rl_get_previous_history (count);
      break;

    case 'B':
      rl_get_next_history (count);
      break;

    case 'C':
      rl_forward (count);
      break;

    case 'D':
      rl_backward (count);
      break;

    default:
      ding ();
    }
  return 0;
}


/* **************************************************************** */
/*								    */
/*			Text commands				    */
/*								    */
/* **************************************************************** */

/* Insert the character C at the current location, moving point forward. */
rl_insert (count, c)
     int count, c;
{
  register int i;
  char *string;

  if (count <= 0)
    return 0;

  /* If we can optimize, then do it.  But don't let people crash
     readline because of extra large arguments. */
  if (count > 1 && count < 1024)
    {
      string = xmalloc (1 + count);

      for (i = 0; i < count; i++)
	string[i] = c;

      string[i] = '\0';
      rl_insert_text (string);
      free (string);

      return 0;
    }

  if (count > 1024)
    {
      int decreaser;
      char str[1024+1];

      for (i = 0; i < 1024; i++)
	str[i] = c;

      while (count)
	{
	  decreaser = (count > 1024 ? 1024 : count);
	  str[decreaser] = '\0';
	  rl_insert_text (str);
	  count -= decreaser;
	}

      return 0;
    }

  /* We are inserting a single character.
     If there is pending input, then make a string of all of the
     pending characters that are bound to rl_insert, and insert
     them all. */
  if (any_typein)
    {
      int key = 0, t;

      i = 0;
      string = xmalloc (ibuffer_len + 1);
      string[i++] = c;

      while ((t = rl_get_char (&key)) &&
	     (_rl_keymap[key].type == ISFUNC &&
	      _rl_keymap[key].function == rl_insert))
	string[i++] = key;

      if (t)
	rl_unget_char (key);

      string[i] = '\0';
      rl_insert_text (string);
      free (string);
    }
  else
    {
      /* Inserting a single character. */
      char str[2];

      str[1] = '\0';
      str[0] = c;
      rl_insert_text (str);
    }
  return 0;
}

/* Insert the next typed character verbatim. */
rl_quoted_insert (count, key)
     int count, key;
{
  int c;

  c = rl_read_key ();
  return (rl_insert (count, c));  
}

/* Insert a tab character. */
rl_tab_insert (count, key)
     int count, key;
{
  return (rl_insert (count, '\t'));
}

/* What to do when a NEWLINE is pressed.  We accept the whole line.
   KEY is the key that invoked this command.  I guess it could have
   meaning in the future. */
rl_newline (count, key)
     int count, key;
{
  rl_done = 1;

#if defined (VI_MODE)
  _rl_vi_done_inserting ();
  _rl_vi_reset_last ();

#endif /* VI_MODE */

  if (readline_echoing_p)
    _rl_update_final ();
  return 0;
}

rl_clean_up_for_exit ()
{
  if (readline_echoing_p)
    {
      _rl_move_vert (_rl_vis_botlin);
      _rl_vis_botlin = 0;
      fflush (out_stream);
      rl_restart_output ();
    }
  return 0;
}

/* What to do for some uppercase characters, like meta characters,
   and some characters appearing in emacs_ctlx_keymap.  This function
   is just a stub, you bind keys to it and the code in _rl_dispatch ()
   is special cased. */
rl_do_lowercase_version (ignore1, ignore2)
     int ignore1, ignore2;
{
  return 0;
}

/* Rubout the character behind point. */
rl_rubout (count, key)
     int count, key;
{
  if (count < 0)
    {
      rl_delete (-count);
      return 0;
    }

  if (!rl_point)
    {
      ding ();
      return -1;
    }

  if (count > 1 || rl_explicit_arg)
    {
      int orig_point = rl_point;
      rl_backward (count);
      rl_kill_text (orig_point, rl_point);
    }
  else
    {
      int c = the_line[--rl_point];
      rl_delete_text (rl_point, rl_point + 1);

      if (rl_point == rl_end && isprint (c) && _rl_last_c_pos)
	{
	  int l;
	  l = rl_character_len (c, rl_point);
	  _rl_erase_at_end_of_line (l);
	}
    }
  return 0;
}

/* Delete the character under the cursor.  Given a numeric argument,
   kill that many characters instead. */
rl_delete (count, invoking_key)
     int count, invoking_key;
{
  if (count < 0)
    {
      return (rl_rubout (-count));
    }

  if (rl_point == rl_end)
    {
      ding ();
      return -1;
    }

  if (count > 1 || rl_explicit_arg)
    {
      int orig_point = rl_point;
      rl_forward (count);
      rl_kill_text (orig_point, rl_point);
      rl_point = orig_point;
      return 0;
    }
  else
    return (rl_delete_text (rl_point, rl_point + 1));
  
}

/* Delete all spaces and tabs around point. */
rl_delete_horizontal_space (count, ignore)
     int count, ignore;
{
  int start = rl_point;

  while (rl_point && whitespace (the_line[rl_point - 1]))
    rl_point--;

  start = rl_point;

  while (rl_point < rl_end && whitespace (the_line[rl_point]))
    rl_point++;

  if (start != rl_point)
    {
      rl_delete_text (start, rl_point);
      rl_point = start;
    }
  return 0;
}


/* **************************************************************** */
/*								    */
/*			Kill commands				    */
/*								    */
/* **************************************************************** */

/* The next two functions mimic unix line editing behaviour, except they
   save the deleted text on the kill ring.  This is safer than not saving
   it, and since we have a ring, nobody should get screwed. */

/* This does what C-w does in Unix.  We can't prevent people from
   using behaviour that they expect. */
rl_unix_word_rubout (count, key)
     int count, key;
{
  if (!rl_point)
    ding ();
  else
    {