readline.c

linux下bash的源码

      int orig_point = rl_point;
      if (count <= 0)
	count = 1;

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

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

      rl_kill_text (orig_point, rl_point);
    }
  return 0;
}

/* Here is C-u doing what Unix does.  You don't *have* to use these
   key-bindings.  We have a choice of killing the entire line, or
   killing from where we are to the start of the line.  We choose the
   latter, because if you are a Unix weenie, then you haven't backspaced
   into the line at all, and if you aren't, then you know what you are
   doing. */
rl_unix_line_discard (count, key)
     int count, key;
{
  if (!rl_point)
    ding ();
  else
    {
      rl_kill_text (rl_point, 0);
      rl_point = 0;
    }
  return 0;
}


/* **************************************************************** */
/*								    */
/*			Commands For Typos			    */
/*								    */
/* **************************************************************** */

/* Random and interesting things in here.  */

/* **************************************************************** */
/*								    */
/*			Changing Case				    */
/*								    */
/* **************************************************************** */

/* The three kinds of things that we know how to do. */
#define UpCase 1
#define DownCase 2
#define CapCase 3

static int rl_change_case ();

/* Uppercase the word at point. */
rl_upcase_word (count, key)
     int count, key;
{
  return (rl_change_case (count, UpCase));
}

/* Lowercase the word at point. */
rl_downcase_word (count, key)
     int count, key;
{
  return (rl_change_case (count, DownCase));
}

/* Upcase the first letter, downcase the rest. */
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 = rl_point, end;
  int state = 0;

  rl_forward_word (count);
  end = rl_point;

  if (count < 0)
    {
      int temp = start;
      start = end;
      end = temp;
    }

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

  for (; start < end; start++)
    {
      switch (op)
	{
	case UpCase:
	  the_line[start] = to_upper (the_line[start]);
	  break;

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

	case CapCase:
	  if (state == 0)
	    {
	      the_line[start] = to_upper (the_line[start]);
	      state = 1;
	    }
	  else
	    {
	      the_line[start] = to_lower (the_line[start]);
	    }
	  if (!pure_alphabetic (the_line[start]))
	    state = 0;
	  break;

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

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

/* Transpose the words at point. */
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);
  w2_end = rl_point;
  rl_backward_word (1);
  w2_beg = rl_point;
  rl_backward_word (count);
  w1_beg = rl_point;
  rl_forward_word (1);
  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. */
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;
  if (rl_point > rl_end)
    rl_point = rl_end;
  else if (rl_point < 0)
    rl_point = 0;
  rl_insert_text (dummy);

  rl_end_undo_group ();
  return 0;
}

/* **************************************************************** */
/*								    */
/*			Undo, and Undoing			    */
/*								    */
/* **************************************************************** */

/* The current undo list for THE_LINE. */
UNDO_LIST *rl_undo_list = (UNDO_LIST *)NULL;

/* Remember how to undo something.  Concatenate some undos if that
   seems right. */
void
rl_add_undo (what, start, end, text)
     enum undo_code what;
     int start, end;
     char *text;
{
  UNDO_LIST *temp = (UNDO_LIST *)xmalloc (sizeof (UNDO_LIST));
  temp->what = what;
  temp->start = start;
  temp->end = end;
  temp->text = text;
  temp->next = rl_undo_list;
  rl_undo_list = temp;
}

/* Free the existing undo list. */
void
free_undo_list ()
{
  while (rl_undo_list)
    {
      UNDO_LIST *release = rl_undo_list;
      rl_undo_list = rl_undo_list->next;

      if (release->what == UNDO_DELETE)
	free (release->text);

      free (release);
    }
  rl_undo_list = (UNDO_LIST *)NULL;
}

/* Undo the next thing in the list.  Return 0 if there
   is nothing to undo, or non-zero if there was. */
int
rl_do_undo ()
{
  UNDO_LIST *release;
  int waiting_for_begin = 0;

undo_thing:
  if (!rl_undo_list)
    return (0);

  doing_an_undo = 1;

  switch (rl_undo_list->what) {

    /* Undoing deletes means inserting some text. */
  case UNDO_DELETE:
    rl_point = rl_undo_list->start;
    rl_insert_text (rl_undo_list->text);
    free (rl_undo_list->text);
    break;

    /* Undoing inserts means deleting some text. */
  case UNDO_INSERT:
    rl_delete_text (rl_undo_list->start, rl_undo_list->end);
    rl_point = rl_undo_list->start;
    break;

    /* Undoing an END means undoing everything 'til we get to
       a BEGIN. */
  case UNDO_END:
    waiting_for_begin++;
    break;

    /* Undoing a BEGIN means that we are done with this group. */
  case UNDO_BEGIN:
    if (waiting_for_begin)
      waiting_for_begin--;
    else
      ding ();
    break;
  }

  doing_an_undo = 0;

  release = rl_undo_list;
  rl_undo_list = rl_undo_list->next;
  free (release);

  if (waiting_for_begin)
    goto undo_thing;

  return (1);
}

/* Begin a group.  Subsequent undos are undone as an atomic operation. */
int
rl_begin_undo_group ()
{
  rl_add_undo (UNDO_BEGIN, 0, 0, 0);
  return 0;
}

/* End an undo group started with rl_begin_undo_group (). */
int
rl_end_undo_group ()
{
  rl_add_undo (UNDO_END, 0, 0, 0);
  return 0;
}

/* Save an undo entry for the text from START to END. */
rl_modifying (start, end)
     int start, end;
{
  if (start > end)
    {
      int t = start;
      start = end;
      end = t;
    }

  if (start != end)
    {
      char *temp = rl_copy_text (start, end);
      rl_begin_undo_group ();
      rl_add_undo (UNDO_DELETE, start, end, temp);
      rl_add_undo (UNDO_INSERT, start, end, (char *)NULL);
      rl_end_undo_group ();
    }
  return 0;
}

/* Revert the current line to its previous state. */
int
rl_revert_line (count, key)
     int count, key;
{
  if (!rl_undo_list)
    ding ();
  else
    {
      while (rl_undo_list)
	rl_do_undo ();
    }
  return 0;
}

/* Do some undoing of things that were done. */
int
rl_undo_command (count, key)
     int count, key;
{
  if (count < 0)
    return 0;	/* Nothing to do. */

  while (count)
    {
      if (rl_do_undo ())
	count--;
      else
	{
	  ding ();
	  break;
	}
    }
  return 0;
}

/* **************************************************************** */
/*								    */
/*			History Utilities			    */
/*								    */
/* **************************************************************** */

/* We already have a history library, and that is what we use to control
   the history features of readline.  However, 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)
    return;
  if (entry->line)
    free (entry->line);
  free (entry);
}

/* Perhaps put back the current line if it has changed. */
maybe_replace_line ()
{
  HIST_ENTRY *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, rl_undo_list);
      free (temp->line);
      free (temp);
    }
  return 0;
}

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

      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. */
maybe_save_line ()
{
  if (!saved_line_for_history)
    {
      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. */
rl_beginning_of_history (count, key)
     int count, key;
{
  return (rl_get_previous_history (1 + where_history ()));
}

/* Meta-> goes to the end of the history.  (The current line). */
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. */
rl_get_next_history (count, key)
     int count, key;
{
  HIST_ENTRY *temp = (HIST_ENTRY *)NULL;

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

  if (!count)
    return 0;

  maybe_replace_line ();

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

  if (!temp)
    maybe_unsave_line ();
  else
    {
      int line_len;

      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);
#