[platform/upstream/bash.git] / lib / readline / readline.c

/* readline.c -- a general facility for reading lines of input
   with emacs style editing and completion. */

/* Copyright (C) 1987, 1989, 1992 Free Software Foundation, Inc.

   This file is part of the GNU Readline Library, a library for
   reading lines of text with interactive input and history editing.

   The GNU Readline Library is free software; you can redistribute it
   and/or modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; either version 1, or
   (at your option) any later version.

   The GNU Readline Library is distributed in the hope that it will be
   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   The GNU General Public License is often shipped with GNU software, and
   is generally kept in a file called COPYING or LICENSE.  If you do not
   have a copy of the license, write to the Free Software Foundation,
   675 Mass Ave, Cambridge, MA 02139, USA. */
#define READLINE_LIBRARY

#if defined (HAVE_CONFIG_H)
#  include <config.h>
#endif

#include <sys/types.h>
#include "posixstat.h"
#include <fcntl.h>
#if defined (HAVE_SYS_FILE_H)
#  include <sys/file.h>
#endif /* HAVE_SYS_FILE_H */

#if defined (HAVE_UNISTD_H)
#  include <unistd.h>
#endif /* HAVE_UNISTD_H */

#if defined (HAVE_STDLIB_H)
#  include <stdlib.h>
#else
#  include "ansi_stdlib.h"
#endif /* HAVE_STDLIB_H */

#if defined (HAVE_LOCALE_H)
#  include <locale.h>
#endif

#include <signal.h>
#include <stdio.h>
#include <setjmp.h>

/* System-specific feature definitions and include files. */
#include "rldefs.h"

#include "tcap.h"

/* Some standard library routines. */
#include "readline.h"
#include "history.h"

#define SWAP(s, e)  do { int t; t = s; s = e; e = t; } while (0)

/* NOTE: Functions and variables prefixed with `_rl_' are
   pseudo-global: they are global so they can be shared
   between files in the readline library, but are not intended
   to be visible to readline callers. */

/* Variables and functions imported from terminal.c */
extern int _rl_init_terminal_io ();
extern void _rl_enable_meta_key ();
extern int _rl_output_character_function ();
extern void _rl_get_screen_size ();

extern int _rl_enable_meta;
extern int _rl_term_autowrap;
extern char *term_backspace, *term_clreol, *term_clrpag;
extern int screenwidth, screenheight, screenchars;

/* Variables and functions imported from rltty.c. */
extern void rl_prep_terminal (), rl_deprep_terminal ();
extern void rltty_set_default_bindings ();

/* Functions imported from util.c. */
extern void _rl_abort_internal ();
extern void rl_extend_line_buffer ();
extern int alphabetic ();

/* Functions imported from bind.c. */
extern void _rl_bind_if_unbound ();
extern int rl_set_keymap_from_edit_mode ();

/* Functions imported from input.c. */
extern int _rl_any_typein ();
extern void _rl_insert_typein ();
extern int rl_read_key ();

/* Functions imported from nls.c */
extern int _rl_init_eightbit ();

/* External redisplay functions and variables from display.c */
extern void _rl_move_vert ();
extern void _rl_update_final ();

extern void _rl_erase_at_end_of_line ();
extern void _rl_move_cursor_relative ();

extern int _rl_vis_botlin;
extern int _rl_last_c_pos;
extern int _rl_horizontal_scroll_mode;
extern int rl_display_fixed;
extern int _rl_suppress_redisplay;
extern char *rl_display_prompt;

/* Variables imported from complete.c. */
extern char *rl_completer_word_break_characters;
extern char *rl_basic_word_break_characters;
extern int rl_completion_query_items;
extern int rl_complete_with_tilde_expansion;

/* Variables and functions from macro.c. */
extern void _rl_add_macro_char ();
extern void _rl_with_macro_input ();
extern int _rl_next_macro_key ();
extern int _rl_defining_kbd_macro;

#if defined (VI_MODE)
/* Functions imported from vi_mode.c. */
extern void _rl_vi_set_last ();
extern void _rl_vi_reset_last ();
extern void _rl_vi_done_inserting ();
extern int _rl_vi_textmod_command ();
extern void _rl_vi_initialize_line ();
#endif /* VI_MODE */

extern UNDO_LIST *rl_undo_list;
extern int _rl_doing_an_undo;

/* Forward declarations used in this file. */
void _rl_free_history_entry ();

int _rl_dispatch ();
int _rl_init_argument ();

static char *readline_internal ();
static void readline_initialize_everything ();
static void start_using_history ();
static void bind_arrow_keys ();

#if !defined (__GO32__)
static void readline_default_bindings ();
#endif /* !__GO32__ */

#if defined (__GO32__)
#  include <pc.h>
#  undef HANDLE_SIGNALS
#endif /* __GO32__ */

extern char *xmalloc (), *xrealloc ();

/* **************************************************************** */
/*                                                                  */
/*                      Line editing input utility                  */
/*                                                                  */
/* **************************************************************** */

char *rl_library_version = "2.1";

/* A pointer to the keymap that is currently in use.
   By default, it is the standard emacs keymap. */
Keymap _rl_keymap = emacs_standard_keymap;

/* The current style of editing. */
int rl_editing_mode = emacs_mode;

/* Non-zero if the previous command was a kill command. */
int _rl_last_command_was_kill = 0;

/* The current value of the numeric argument specified by the user. */
int rl_numeric_arg = 1;

/* Non-zero if an argument was typed. */
int rl_explicit_arg = 0;

/* Temporary value used while generating the argument. */
int rl_arg_sign = 1;

/* Non-zero means we have been called at least once before. */
static int rl_initialized;

/* If non-zero, this program is running in an EMACS buffer. */
static int running_in_emacs;

/* The current offset in the current input line. */
int rl_point;

/* Mark in the current input line. */
int rl_mark;

/* Length of the current input line. */
int rl_end;

/* Make this non-zero to return the current input_line. */
int rl_done;

/* The last function executed by readline. */
Function *rl_last_func = (Function *)NULL;

/* Top level environment for readline_internal (). */
jmp_buf readline_top_level;

/* The streams we interact with. */
FILE *_rl_in_stream, *_rl_out_stream;

/* The names of the streams that we do input and output to. */
FILE *rl_instream = (FILE *)NULL;
FILE *rl_outstream = (FILE *)NULL;

/* Non-zero means echo characters as they are read. */
int readline_echoing_p = 1;

/* Current prompt. */
char *rl_prompt;
int rl_visible_prompt_length = 0;

/* The number of characters read in order to type this complete command. */
int rl_key_sequence_length = 0;

/* If non-zero, then this is the address of a function to call just
   before readline_internal () prints the first prompt. */
Function *rl_startup_hook = (Function *)NULL;

/* What we use internally.  You should always refer to RL_LINE_BUFFER. */
static char *the_line;

/* The character that can generate an EOF.  Really read from
   the terminal driver... just defaulted here. */
int _rl_eof_char = CTRL ('D');

/* Non-zero makes this the next keystroke to read. */
int rl_pending_input = 0;

/* Pointer to a useful terminal name. */
char *rl_terminal_name = (char *)NULL;

/* Non-zero means to always use horizontal scrolling in line display. */
int _rl_horizontal_scroll_mode = 0;

/* Non-zero means to display an asterisk at the starts of history lines
   which have been modified. */
int _rl_mark_modified_lines = 0;  

/* The style of `bell' notification preferred.  This can be set to NO_BELL,
   AUDIBLE_BELL, or VISIBLE_BELL. */
int _rl_bell_preference = AUDIBLE_BELL;
     
/* String inserted into the line by rl_insert_comment (). */
char *_rl_comment_begin;

/* Keymap holding the function currently being executed. */
Keymap rl_executing_keymap;

/* Line buffer and maintenence. */
char *rl_line_buffer = (char *)NULL;
int rl_line_buffer_len = 0;

/* Forward declarations used by the display and termcap code. */

/* **************************************************************** */
/*                                                                  */
/*                      `Forward' declarations                      */
/*                                                                  */
/* **************************************************************** */

/* Non-zero means do not parse any lines other than comments and
   parser directives. */
unsigned char _rl_parsing_conditionalized_out = 0;

/* Non-zero means to convert characters with the meta bit set to
   escape-prefixed characters so we can indirect through
   emacs_meta_keymap or vi_escape_keymap. */
int _rl_convert_meta_chars_to_ascii = 1;

/* Non-zero means to output characters with the meta bit set directly
   rather than as a meta-prefixed escape sequence. */
int _rl_output_meta_chars = 0;

/* **************************************************************** */
/*                                                                  */
/*                      Top Level Functions                         */
/*                                                                  */
/* **************************************************************** */

/* Non-zero means treat 0200 bit in terminal input as Meta bit. */
int _rl_meta_flag = 0;  /* Forward declaration */

/* Read a line of input.  Prompt with PROMPT.  An empty PROMPT means
   none.  A return value of NULL means that EOF was encountered. */
char *
readline (prompt)
     char *prompt;
{
  char *value;

  rl_prompt = prompt;

  /* If we are at EOF return a NULL string. */
  if (rl_pending_input == EOF)
    {
      rl_pending_input = 0;
      return ((char *)NULL);
    }

  rl_visible_prompt_length = rl_expand_prompt (rl_prompt);

  rl_initialize ();
  (*rl_prep_term_function) (_rl_meta_flag);

#if defined (HANDLE_SIGNALS)
  rl_set_signals ();
#endif

  value = readline_internal ();
  (*rl_deprep_term_function) ();

#if defined (HANDLE_SIGNALS)
  rl_clear_signals ();
#endif

  return (value);
}

#if defined (READLINE_CALLBACKS)
#  define STATIC_CALLBACK
#else
#  define STATIC_CALLBACK static
#endif

STATIC_CALLBACK void
readline_internal_setup ()
{
  _rl_in_stream = rl_instream;
  _rl_out_stream = rl_outstream;

  if (rl_startup_hook)
    (*rl_startup_hook) ();

  if (readline_echoing_p == 0)
    {
      if (rl_prompt)
        {
          fprintf (_rl_out_stream, "%s", rl_prompt);
          fflush (_rl_out_stream);
        }
    }
  else
    {
      rl_on_new_line ();
      (*rl_redisplay_function) ();
#if defined (VI_MODE)
      if (rl_editing_mode == vi_mode)
        rl_vi_insertion_mode ();
#endif /* VI_MODE */
    }
}

STATIC_CALLBACK char *
readline_internal_teardown (eof)
     int eof;
{
  char *temp;
  HIST_ENTRY *entry;

  /* Restore the original of this history line, iff the line that we
     are editing was originally in the history, AND the line has changed. */
  entry = current_history ();

  if (entry && rl_undo_list)
    {
      temp = savestring (the_line);
      rl_revert_line (1, 0);
      entry = replace_history_entry (where_history (), the_line, (HIST_ENTRY *)NULL);
      _rl_free_history_entry (entry);

      strcpy (the_line, temp);
      free (temp);
    }

  /* At any rate, it is highly likely that this line has an undo list.  Get
     rid of it now. */
  if (rl_undo_list)
    free_undo_list ();

  return (eof ? (char *)NULL : savestring (the_line));
}

STATIC_CALLBACK int
#if defined (READLINE_CALLBACKS)
readline_internal_char ()
#else
readline_internal_charloop ()
#endif
{
  static int lastc, eof_found;
  int c, code, lk;

  lastc = -1;
  eof_found = 0;

#if !defined (READLINE_CALLBACKS)
  while (rl_done == 0)
    {
#endif
      lk = _rl_last_command_was_kill;

      code = setjmp (readline_top_level);

      if (code)
        (*rl_redisplay_function) ();

      if (rl_pending_input == 0)
        {
          /* Then initialize the argument and number of keys read. */
          _rl_init_argument ();
          rl_key_sequence_length = 0;
        }

      c = rl_read_key ();

      /* EOF typed to a non-blank line is a <NL>. */
      if (c == EOF && rl_end)
        c = NEWLINE;

      /* The character _rl_eof_char typed to blank line, and not as the
         previous character is interpreted as EOF. */
      if (((c == _rl_eof_char && lastc != c) || c == EOF) && !rl_end)
        {
#if defined (READLINE_CALLBACKS)
          return (rl_done = 1);
#else
          eof_found = 1;
          break;
#endif
        }

      lastc = c;
      _rl_dispatch (c, _rl_keymap);

      /* If there was no change in _rl_last_command_was_kill, then no kill
         has taken place.  Note that if input is pending we are reading
         a prefix command, so nothing has changed yet. */
      if (rl_pending_input == 0 && lk == _rl_last_command_was_kill)
        _rl_last_command_was_kill = 0;

#if defined (VI_MODE)
      /* In vi mode, when you exit insert mode, the cursor moves back
         over the previous character.  We explicitly check for that here. */
      if (rl_editing_mode == vi_mode && _rl_keymap == vi_movement_keymap)
        rl_vi_check ();
#endif /* VI_MODE */

      if (rl_done == 0)
        (*rl_redisplay_function) ();

#if defined (READLINE_CALLBACKS)
      return 0;
#else
    }

  return (eof_found);
#endif
}

#if defined (READLINE_CALLBACKS)
static int
readline_internal_charloop ()
{
  int eof;

  while (rl_done == 0)
    eof = readline_internal_char ();
  return (eof);
}
#endif /* READLINE_CALLBACKS */

/* Read a line of input from the global rl_instream, doing output on
   the global rl_outstream.
   If rl_prompt is non-null, then that is our prompt. */
static char *
readline_internal ()
{
  int eof;

  readline_internal_setup ();
  eof = readline_internal_charloop ();
  return (readline_internal_teardown (eof));
}

void
_rl_set_the_line ()
{
  the_line = rl_line_buffer;
}

/* Do the command associated with KEY in MAP.
   If the associated command is really a keymap, then read
   another key, and dispatch into that map. */
int
_rl_dispatch (key, map)
     register int key;
     Keymap map;
{
  int r, newkey;
  char *macro;
  Function *func;

  if (META_CHAR (key) && _rl_convert_meta_chars_to_ascii)
    {
      if (map[ESC].type == ISKMAP)
        {
          if (_rl_defining_kbd_macro)
            _rl_add_macro_char (ESC);
          map = FUNCTION_TO_KEYMAP (map, ESC);
          key = UNMETA (key);
          rl_key_sequence_length += 2;
          return (_rl_dispatch (key, map));
        }
      else
        ding ();
      return 0;
    }

  if (_rl_defining_kbd_macro)
    _rl_add_macro_char (key);

  r = 0;
  switch (map[key].type)
    {
    case ISFUNC:
      func = map[key].function;
      if (func != (Function *)NULL)
        {
          /* Special case rl_do_lowercase_version (). */
          if (func == rl_do_lowercase_version)
            return (_rl_dispatch (_rl_to_lower (key), map));

          rl_executing_keymap = map;

#if 0
          _rl_suppress_redisplay = (map[key].function == rl_insert) && _rl_input_available ();
#endif

          r = (*map[key].function)(rl_numeric_arg * rl_arg_sign, key);

          /* If we have input pending, then the last command was a prefix
             command.  Don't change the state of rl_last_func.  Otherwise,
             remember the last command executed in this variable. */
          if (!rl_pending_input)
            rl_last_func = map[key].function;
        }
      else
        {
          _rl_abort_internal ();
          return -1;
        }
      break;

    case ISKMAP:
      if (map[key].function != (Function *)NULL)
        {
          rl_key_sequence_length++;
          newkey = rl_read_key ();
          r = _rl_dispatch (newkey, FUNCTION_TO_KEYMAP (map, key));
        }
      else
        {
          _rl_abort_internal ();
          return -1;
        }
      break;

    case ISMACR:
      if (map[key].function != (Function *)NULL)
        {
          macro = savestring ((char *)map[key].function);
          _rl_with_macro_input (macro);
          return 0;
        }
      break;
    }
#if defined (VI_MODE)
  if (rl_editing_mode == vi_mode && _rl_keymap == vi_movement_keymap &&
      _rl_vi_textmod_command (key))
    _rl_vi_set_last (key, rl_numeric_arg, rl_arg_sign);
#endif
  return (r);
}

/* **************************************************************** */
/*                                                                  */
/*                      Initializations                             */
/*                                                                  */
/* **************************************************************** */

/* Initliaze readline (and terminal if not already). */
int
rl_initialize ()
{
  /* If we have never been called before, initialize the
     terminal and data structures. */
  if (!rl_initialized)
    {
      readline_initialize_everything ();
      rl_initialized++;
    }

  /* Initalize the current line information. */
  rl_point = rl_end = 0;
  the_line = rl_line_buffer;
  the_line[0] = 0;

  /* We aren't done yet.  We haven't even gotten started yet! */
  rl_done = 0;

  /* Tell the history routines what is going on. */
  start_using_history ();

  /* Make the display buffer match the state of the line. */
  rl_reset_line_state ();

  /* No such function typed yet. */
  rl_last_func = (Function *)NULL;

  /* Parsing of key-bindings begins in an enabled state. */
  _rl_parsing_conditionalized_out = 0;

#if defined (VI_MODE)
  if (rl_editing_mode == vi_mode)
    _rl_vi_initialize_line ();
#endif

  return 0;
}

/* Initialize the entire state of the world. */
static void
readline_initialize_everything ()
{
  /* Find out if we are running in Emacs. */
  running_in_emacs = getenv ("EMACS") != (char *)0;

  /* Set up input and output if they are not already set up. */
  if (!rl_instream)
    rl_instream = stdin;

  if (!rl_outstream)
    rl_outstream = stdout;

  /* Bind _rl_in_stream and _rl_out_stream immediately.  These values
     may change, but they may also be used before readline_internal ()
     is called. */
  _rl_in_stream = rl_instream;
  _rl_out_stream = rl_outstream;

  /* Allocate data structures. */
  if (!rl_line_buffer)
    rl_line_buffer = xmalloc (rl_line_buffer_len = DEFAULT_BUFFER_SIZE);

  /* Initialize the terminal interface. */
  _rl_init_terminal_io ((char *)NULL);

#if !defined (__GO32__)
  /* Bind tty characters to readline functions. */
  readline_default_bindings ();
#endif /* !__GO32__ */

  /* Initialize the function names. */
  rl_initialize_funmap ();

  /* Decide whether we should automatically go into eight-bit mode. */
  _rl_init_eightbit ();
      
  /* Read in the init file. */
  rl_read_init_file ((char *)NULL);

  /* XXX */
  if (_rl_horizontal_scroll_mode && _rl_term_autowrap)
    {
      screenwidth--;
      screenchars -= screenheight;
    }

  /* Override the effect of any `set keymap' assignments in the
     inputrc file. */
  rl_set_keymap_from_edit_mode ();

  /* Try to bind a common arrow key prefix, if not already bound. */
  bind_arrow_keys ();

  /* Enable the meta key, if this terminal has one. */
  if (_rl_enable_meta)
    _rl_enable_meta_key ();

  /* If the completion parser's default word break characters haven't
     been set yet, then do so now. */
  if (rl_completer_word_break_characters == (char *)NULL)
    rl_completer_word_break_characters = rl_basic_word_break_characters;
}

/* If this system allows us to look at the values of the regular
   input editing characters, then bind them to their readline
   equivalents, iff the characters are not bound to keymaps. */
static void
readline_default_bindings ()
{
  rltty_set_default_bindings (_rl_keymap);
}

static void
bind_arrow_keys_internal ()
{
  Function *f;

  f = rl_function_of_keyseq ("\033[A", _rl_keymap, (int *)NULL);
  if (!f || f == rl_do_lowercase_version)
    {
      _rl_bind_if_unbound ("\033[A", rl_get_previous_history);
      _rl_bind_if_unbound ("\033[B", rl_get_next_history);
      _rl_bind_if_unbound ("\033[C", rl_forward);
      _rl_bind_if_unbound ("\033[D", rl_backward);
    }

  f = rl_function_of_keyseq ("\033OA", _rl_keymap, (int *)NULL);
  if (!f || f == rl_do_lowercase_version)
    {
      _rl_bind_if_unbound ("\033OA", rl_get_previous_history);
      _rl_bind_if_unbound ("\033OB", rl_get_next_history);
      _rl_bind_if_unbound ("\033OC", rl_forward);
      _rl_bind_if_unbound ("\033OD", rl_backward);
    }
}

/* Try and bind the common arrow key prefix after giving termcap and
   the inputrc file a chance to bind them and create `real' keymaps
   for the arrow key prefix. */
static void
bind_arrow_keys ()
{
  Keymap xkeymap;

  xkeymap = _rl_keymap;

  _rl_keymap = emacs_standard_keymap;
  bind_arrow_keys_internal ();

#if defined (VI_MODE)
  _rl_keymap = vi_movement_keymap;
  bind_arrow_keys_internal ();
#endif

  _rl_keymap = xkeymap;
}

\f
/* **************************************************************** */
/*                                                                  */
/*                      Numeric Arguments                           */
/*                                                                  */
/* **************************************************************** */

/* Handle C-u style numeric args, as well as M--, and M-digits. */
static int
rl_digit_loop ()
{
  int key, c, sawminus;

  _rl_save_prompt ();

  sawminus = 0;
  while (1)
    {
      rl_message ("(arg: %d) ", rl_arg_sign * rl_numeric_arg);
      key = c = rl_read_key ();

      if (_rl_keymap[c].type == ISFUNC &&
          _rl_keymap[c].function == rl_universal_argument)
        {
          rl_numeric_arg *= 4;
          continue;
        }
      c = UNMETA (c);
      if (_rl_digit_p (c))
        {
          rl_numeric_arg = rl_explicit_arg ? (rl_numeric_arg * 10) + c - '0' : c - '0';
          rl_explicit_arg = 1;
        }
      else
        {
          if (c == '-' && rl_explicit_arg == 0)
            {
              rl_numeric_arg = sawminus = 1;
              rl_arg_sign = -1;
            }
          else
            {
              /* Make M-- command equivalent to M--1 command. */
              if (sawminus && rl_numeric_arg == 1 && rl_explicit_arg == 0)
                rl_explicit_arg = 1;
              _rl_restore_prompt ();
              rl_clear_message ();
              return (_rl_dispatch (key, _rl_keymap));
            }
        }
    }

  return 0;
}

/* Add the current digit to the argument in progress. */
int
rl_digit_argument (ignore, key)
     int ignore, key;
{
  rl_pending_input = key;
  return (rl_digit_loop ());
}

/* What to do when you abort reading an argument. */
int
rl_discard_argument ()
{
  ding ();
  rl_clear_message ();
  _rl_init_argument ();
  return 0;
}

/* Create a default argument. */
int
_rl_init_argument ()
{
  rl_numeric_arg = rl_arg_sign = 1;
  rl_explicit_arg = 0;
  return 0;
}

/* C-u, universal argument.  Multiply the current argument by 4.
   Read a key.  If the key has nothing to do with arguments, then
   dispatch on it.  If the key is the abort character then abort. */
int
rl_universal_argument (count, key)
     int count, key;
{
  rl_numeric_arg *= 4;
  return (rl_digit_loop ());
}

/* **************************************************************** */
/*                                                                  */
/*                      Insert and Delete                           */
/*                                                                  */
/* **************************************************************** */

/* Insert a string of text into the line at point.  This is the only
   way that you should do insertion.  rl_insert () calls this
   function. */
int
rl_insert_text (string)
     char *string;
{
  register int i, l = strlen (string);

  if (rl_end + l >= rl_line_buffer_len)
    rl_extend_line_buffer (rl_end + l);

  for (i = rl_end; i >= rl_point; i--)
    the_line[i + l] = the_line[i];
  strncpy (the_line + rl_point, string, l);

  /* Remember how to undo this if we aren't undoing something. */
  if (!_rl_doing_an_undo)
    {
      /* If possible and desirable, concatenate the undos. */
      if ((l == 1) &&
          rl_undo_list &&
          (rl_undo_list->what == UNDO_INSERT) &&
          (rl_undo_list->end == rl_point) &&
          (rl_undo_list->end - rl_undo_list->start < 20))
        rl_undo_list->end++;
      else
        rl_add_undo (UNDO_INSERT, rl_point, rl_point + l, (char *)NULL);
    }
  rl_point += l;
  rl_end += l;
  the_line[rl_end] = '\0';
  return l;
}

/* Delete the string between FROM and TO.  FROM is
   inclusive, TO is not. */
int
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)
    SWAP (from, to);

  /* fix boundaries */
  if (to > rl_end)
    {
      to = rl_end;
      if (from > to)
        from = to;
    }

  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 (_rl_doing_an_undo == 0)
    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. */
int
rl_forward (count, key)
     int count, key;
{
  if (count < 0)
    rl_backward (-count, key);
  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. */
int
rl_backward (count, key)
     int count, key;
{
  if (count < 0)
    rl_forward (-count, key);
  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. */
int
rl_beg_of_line (count, key)
     int count, key;
{
  rl_point = 0;
  return 0;
}

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

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

  if (count < 0)
    {
      rl_backward_word (-count, key);
      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) == 0)
        {
          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) == 0)
            break;
        }
      --count;
    }
  return 0;
}

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

  if (count < 0)
    {
      rl_forward_word (-count, key);
      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) == 0)
        {
          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) == 0)
            break;
          else
            --rl_point;
        }
      --count;
    }
  return 0;
}

/* Clear the current line.  Numeric argument to C-l does this. */
int
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. */
int
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;
}

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

  ch = rl_read_key ();

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

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

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

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

    default:
      ding ();
    }
  return 0;
}

\f
/* **************************************************************** */
/*                                                                  */
/*                      Text commands                               */
/*                                                                  */
/* **************************************************************** */

/* Insert the character C at the current location, moving point forward. */
int
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 (_rl_any_typein ())
    _rl_insert_typein (c);
  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. */
int
rl_quoted_insert (count, key)
     int count, key;
{
  int c;

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

/* Insert a tab character. */
int
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. */
int
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;
}

/* 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. */
int
rl_do_lowercase_version (ignore1, ignore2)
     int ignore1, ignore2;
{
  return 0;
}

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

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

  if (count > 1 || rl_explicit_arg)
    {
      int orig_point = rl_point;
      rl_backward (count, key);
      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. */
int
rl_delete (count, key)
     int count, key;
{
  if (count < 0)
    return (rl_rubout (-count, key));

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

  if (count > 1 || rl_explicit_arg)
    {
      int orig_point = rl_point;
      rl_forward (count, key);
      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. */
int
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;
}

#ifndef RL_COMMENT_BEGIN_DEFAULT
#define RL_COMMENT_BEGIN_DEFAULT "#"
#endif

/* Turn the current line into a comment in shell history.
   A K*rn shell style function. */
int
rl_insert_comment (count, key)
     int count, key;
{
  rl_beg_of_line (1, key);
  rl_insert_text (_rl_comment_begin ? _rl_comment_begin
                                    : RL_COMMENT_BEGIN_DEFAULT);
  (*rl_redisplay_function) ();
  rl_newline (1, '\n');
  return (0);
}

/* **************************************************************** */
/*                                                                  */
/*                      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. */
int
rl_upcase_word (count, key)
     int count, key;
{
  return (rl_change_case (count, UpCase));
}

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

/* 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;
  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;
}

/* **************************************************************** */
/*                                                                  */
/*                      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, 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 ();
#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;
}