readline.c

UNIX下SH的实现源码

/* Upcase the first letter, downcase the rest. */
int
rl_capitalize_word (count, key)
     int count, key;
{
 return (rl_change_case (count, CapCase));
}

/* The meaty function.
   Change the case of COUNT words, performing OP on them.
   OP is one of UpCase, DownCase, or CapCase.
   If a negative argument is given, leave point where it started,
   otherwise, leave it where it moves to. */
static int
rl_change_case (count, op)
     int count, op;
{
  register int start, end;
  int inword, c;

  start = rl_point;
  rl_forward_word (count, 0);
  end = rl_point;

  if (count < 0)
    SWAP (start, end);

  /* We are going to modify some text, so let's prepare to undo it. */
  rl_modifying (start, end);

  for (inword = 0; start < end; start++)
    {
      c = the_line[start];
      switch (op)
	{
	case UpCase:
	  the_line[start] = _rl_to_upper (c);
	  break;

	case DownCase:
	  the_line[start] = _rl_to_lower (c);
	  break;

	case CapCase:
	  the_line[start] = (inword == 0) ? _rl_to_upper (c) : _rl_to_lower (c);
	  inword = alphabetic (the_line[start]);
	  break;

	default:
	  ding ();
	  return -1;
	}
    }
  rl_point = end;
  return 0;
}

/* **************************************************************** */
/*								    */
/*			Transposition				    */
/*								    */
/* **************************************************************** */

/* Transpose the words at point. */
int
rl_transpose_words (count, key)
     int count, key;
{
  char *word1, *word2;
  int w1_beg, w1_end, w2_beg, w2_end;
  int orig_point = rl_point;

  if (!count)
    return 0;

  /* Find the two words. */
  rl_forward_word (count, key);
  w2_end = rl_point;
  rl_backward_word (1, key);
  w2_beg = rl_point;
  rl_backward_word (count, key);
  w1_beg = rl_point;
  rl_forward_word (1, key);
  w1_end = rl_point;

  /* Do some check to make sure that there really are two words. */
  if ((w1_beg == w2_beg) || (w2_beg < w1_end))
    {
      ding ();
      rl_point = orig_point;
      return -1;
    }

  /* Get the text of the words. */
  word1 = rl_copy_text (w1_beg, w1_end);
  word2 = rl_copy_text (w2_beg, w2_end);

  /* We are about to do many insertions and deletions.  Remember them
     as one operation. */
  rl_begin_undo_group ();

  /* Do the stuff at word2 first, so that we don't have to worry
     about word1 moving. */
  rl_point = w2_beg;
  rl_delete_text (w2_beg, w2_end);
  rl_insert_text (word1);

  rl_point = w1_beg;
  rl_delete_text (w1_beg, w1_end);
  rl_insert_text (word2);

  /* This is exactly correct since the text before this point has not
     changed in length. */
  rl_point = w2_end;

  /* I think that does it. */
  rl_end_undo_group ();
  free (word1);
  free (word2);

  return 0;
}

/* Transpose the characters at point.  If point is at the end of the line,
   then transpose the characters before point. */
int
rl_transpose_chars (count, key)
     int count, key;
{
  char dummy[2];

  if (!count)
    return 0;

  if (!rl_point || rl_end < 2)
    {
      ding ();
      return -1;
    }

  rl_begin_undo_group ();

  if (rl_point == rl_end)
    {
      --rl_point;
      count = 1;
    }
  rl_point--;

  dummy[0] = the_line[rl_point];
  dummy[1] = '\0';

  rl_delete_text (rl_point, rl_point + 1);

  rl_point += count;
  _rl_fix_point (0);
  rl_insert_text (dummy);

  rl_end_undo_group ();
  return 0;
}

/* **************************************************************** */
/*								    */
/*			Character Searching			    */
/*								    */
/* **************************************************************** */

int
_rl_char_search_internal (count, dir, schar)
     int count, dir, schar;
{
  int pos, inc;

  pos = rl_point;
  inc = (dir < 0) ? -1 : 1;
  while (count)
    {
      if ((dir < 0 && pos <= 0) || (dir > 0 && pos >= rl_end))
	{
	  ding ();
	  return -1;
	}

      pos += inc;
      do
	{
	  if (rl_line_buffer[pos] == schar)
	    {
	      count--;
	      if (dir < 0)
	        rl_point = (dir == BTO) ? pos + 1 : pos;
	      else
		rl_point = (dir == FTO) ? pos - 1 : pos;
	      break;
	    }
	}
      while ((dir < 0) ? pos-- : ++pos < rl_end);
    }
  return (0);
}

/* Search COUNT times for a character read from the current input stream.
   FDIR is the direction to search if COUNT is non-negative; otherwise
   the search goes in BDIR. */
static int
_rl_char_search (count, fdir, bdir)
     int count, fdir, bdir;
{
  int c;

  c = rl_read_key ();
  if (count < 0)
    return (_rl_char_search_internal (-count, bdir, c));
  else
    return (_rl_char_search_internal (count, fdir, c));
}

int
rl_char_search (count, key)
     int count, key;
{
  return (_rl_char_search (count, FFIND, BFIND));
}

int
rl_backward_char_search (count, key)
     int count, key;
{
  return (_rl_char_search (count, BFIND, FFIND));
}

/* **************************************************************** */
/*								    */
/*			History Utilities			    */
/*								    */
/* **************************************************************** */

/* We already have a history library, and that is what we use to control
   the history features of readline.  This is our local interface to
   the history mechanism. */

/* While we are editing the history, this is the saved
   version of the original line. */
HIST_ENTRY *saved_line_for_history = (HIST_ENTRY *)NULL;

/* Set the history pointer back to the last entry in the history. */
static void
start_using_history ()
{
  using_history ();
  if (saved_line_for_history)
    _rl_free_history_entry (saved_line_for_history);

  saved_line_for_history = (HIST_ENTRY *)NULL;
}

/* Free the contents (and containing structure) of a HIST_ENTRY. */
void
_rl_free_history_entry (entry)
     HIST_ENTRY *entry;
{
  if (entry == 0)
    return;
  if (entry->line)
    free (entry->line);
  free (entry);
}

/* Perhaps put back the current line if it has changed. */
int
maybe_replace_line ()
{
  HIST_ENTRY *temp;

  temp = current_history ();
  /* If the current line has changed, save the changes. */
  if (temp && ((UNDO_LIST *)(temp->data) != rl_undo_list))
    {
      temp = replace_history_entry (where_history (), the_line, (histdata_t)rl_undo_list);
      free (temp->line);
      free (temp);
    }
  return 0;
}

/* Put back the saved_line_for_history if there is one. */
int
maybe_unsave_line ()
{
  int line_len;

  if (saved_line_for_history)
    {
      line_len = strlen (saved_line_for_history->line);

      if (line_len >= rl_line_buffer_len)
	rl_extend_line_buffer (line_len);

      strcpy (the_line, saved_line_for_history->line);
      rl_undo_list = (UNDO_LIST *)saved_line_for_history->data;
      _rl_free_history_entry (saved_line_for_history);
      saved_line_for_history = (HIST_ENTRY *)NULL;
      rl_end = rl_point = strlen (the_line);
    }
  else
    ding ();
  return 0;
}

/* Save the current line in saved_line_for_history. */
int
maybe_save_line ()
{
  if (saved_line_for_history == 0)
    {
      saved_line_for_history = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY));
      saved_line_for_history->line = savestring (the_line);
      saved_line_for_history->data = (char *)rl_undo_list;
    }
  return 0;
}

/* **************************************************************** */
/*								    */
/*			History Commands			    */
/*								    */
/* **************************************************************** */

/* Meta-< goes to the start of the history. */
int
rl_beginning_of_history (count, key)
     int count, key;
{
  return (rl_get_previous_history (1 + where_history (), key));
}

/* Meta-> goes to the end of the history.  (The current line). */
int
rl_end_of_history (count, key)
     int count, key;
{
  maybe_replace_line ();
  using_history ();
  maybe_unsave_line ();
  return 0;
}

/* Move down to the next history line. */
int
rl_get_next_history (count, key)
     int count, key;
{
  HIST_ENTRY *temp;
  int line_len;

  if (count < 0)
    return (rl_get_previous_history (-count, key));

  if (count == 0)
    return 0;

  maybe_replace_line ();

  temp = (HIST_ENTRY *)NULL;
  while (count)
    {
      temp = next_history ();
      if (!temp)
	break;
      --count;
    }

  if (temp == 0)
    maybe_unsave_line ();
  else
    {
      line_len = strlen (temp->line);

      if (line_len >= rl_line_buffer_len)
	rl_extend_line_buffer (line_len);

      strcpy (the_line, temp->line);
      rl_undo_list = (UNDO_LIST *)temp->data;
      rl_end = rl_point = strlen (the_line);
#if defined (VI_MODE)
      if (rl_editing_mode == vi_mode)
	rl_point = 0;
#endif /* VI_MODE */
    }
  return 0;
}

/* Get the previous item out of our interactive history, making it the current
   line.  If there is no previous history, just ding. */
int
rl_get_previous_history (count, key)
     int count, key;
{
  HIST_ENTRY *old_temp, *temp;
  int line_len;

  if (count < 0)
    return (rl_get_next_history (-count, key));

  if (count == 0)
    return 0;

  /* If we don't have a line saved, then save this one. */
  maybe_save_line ();

  /* If the current line has changed, save the changes. */
  maybe_replace_line ();

  temp = old_temp = (HIST_ENTRY *)NULL;
  while (count)
    {
      temp = previous_history ();
      if (temp == 0)
	break;

      old_temp = temp;
      --count;
    }

  /* If there was a large argument, and we moved back to the start of the
     history, that is not an error.  So use the last value found. */
  if (!temp && old_temp)
    temp = old_temp;

  if (temp == 0)
    ding ();
  else
    {
      line_len = strlen (temp->line);

      if (line_len >= rl_line_buffer_len)
	rl_extend_line_buffer (line_len);

      strcpy (the_line, temp->line);
      rl_undo_list = (UNDO_LIST *)temp->data;
      rl_end = rl_point = line_len;

#if defined (VI_MODE)
      if (rl_editing_mode == vi_mode)
	rl_point = 0;
#endif /* VI_MODE */
    }
  return 0;
}

/* **************************************************************** */
/*								    */
/*		   The Mark and the Region.			    */
/*								    */
/* **************************************************************** */

/* Set the mark at POSITION. */
int
_rl_set_mark_at_pos (position)
     int position;
{
  if (position > rl_end)
    return -1;

  rl_mark = position;
  return 0;
}

/* A bindable command to set the mark. */
int
rl_set_mark (count, key)
     int count, key;
{
  return (_rl_set_mark_at_pos (rl_explicit_arg ? count : rl_point));
}

/* Exchange the position of mark and point. */
int
rl_exchange_point_and_mark (count, key)
     int count, key;
{
  if (rl_mark > rl_end)
    rl_mark = -1;

  if (rl_mark == -1)
    {
      ding ();
      return -1;
    }
  else
    SWAP (rl_point, rl_mark);

  return 0;
}

/* **************************************************************** */
/*								    */
/*			    Editing Modes			    */
/*								    */
/* **************************************************************** */
/* How to toggle back and forth between editing modes. */
int
rl_vi_editing_mode (count, key)
     int count, key;
{
#if defined (VI_MODE)
  rl_editing_mode = vi_mode;
  rl_vi_insertion_mode (1, key);
#endif /* VI_MODE */
  return 0;
}

int
rl_emacs_editing_mode (count, key)
     int count, key;
{
  rl_editing_mode = emacs_mode;
  _rl_keymap = emacs_standard_keymap;
  return 0;
}