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

/* Copyright (C) 1987-2002 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 2, 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,
   59 Temple Place, Suite 330, Boston, MA 02111 USA. */
#define READLINE_LIBRARY

#include "config_readline.h"

#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 <stdio.h>
#include "posixjmp.h"

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

#if defined (__EMX__)
#  define INCL_DOSPROCESS
#  include <os2.h>
#endif /* __EMX__ */

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

#include "rlprivate.h"
#include "rlshell.h"
#include "xmalloc.h"

#ifndef RL_LIBRARY_VERSION
#  define RL_LIBRARY_VERSION "5.0"
#endif

#ifndef RL_READLINE_VERSION
#  define RL_READLINE_VERSION	0x0500
#endif

extern void _rl_free_history_entry PARAMS((HIST_ENTRY *));

/* Forward declarations used in this file. */
static char *readline_internal PARAMS((void));
static void readline_initialize_everything PARAMS((void));

static void bind_arrow_keys_internal PARAMS((Keymap));
static void bind_arrow_keys PARAMS((void));

static void readline_default_bindings PARAMS((void));
static void reset_default_bindings PARAMS((void));

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

const char *rl_library_version = RL_LIBRARY_VERSION;

int rl_readline_version = RL_READLINE_VERSION;

/* True if this is `real' readline as opposed to some stub substitute. */
int rl_gnu_readline_p = 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;

/* The current insert mode:  input (the default) or overwrite */
int rl_insert_mode = RL_IM_DEFAULT;

/* Non-zero if we called this function from _rl_dispatch().  It's present
   so functions can find out whether they were called from a key binding
   or directly from an application. */
int rl_dispatching;

/* 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 0
/* If non-zero, this program is running in an EMACS buffer. */
static int running_in_emacs;
#endif

/* Flags word encapsulating the current readline state. */
int rl_readline_state = RL_STATE_NONE;

/* 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. */
rl_command_func_t *rl_last_func = (rl_command_func_t *)NULL;

/* Top level environment for readline_internal (). */
procenv_t 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.  Defaults to no echo;
   set to 1 if there is a controlling terminal, we can get its attributes,
   and the attributes include `echo'.  Look at rltty.c:prepare_terminal_settings
   for the code that sets it. */
int readline_echoing_p = 0;

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

/* Set to non-zero by calling application if it has already printed rl_prompt
   and does not want readline to do it the first time. */
int rl_already_prompted = 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_setup () prints the first prompt. */
rl_hook_func_t *rl_startup_hook = (rl_hook_func_t *)NULL;

/* If non-zero, this is the address of a function to call just before
   readline_internal_setup () returns and readline_internal starts
   reading input characters. */
rl_hook_func_t *rl_pre_input_hook = (rl_hook_func_t *)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. */
const char *rl_terminal_name = (const 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;

/* Non-zero means to erase entire line, including prompt, on empty input lines. */
int rl_erase_empty_line = 0;

/* Non-zero means to read only this many characters rather than up to a
   character bound to accept-line. */
int rl_num_chars_to_read;

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

/* Forward declarations used by the display, termcap, and history 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 */

/* Set up the prompt and expand it.  Called from readline() and
   rl_callback_handler_install (). */
int
rl_set_prompt (prompt)
     const char *prompt;
{
  FREE (rl_prompt);
  rl_prompt = prompt ? savestring (prompt) : (char *)NULL;

  rl_visible_prompt_length = rl_expand_prompt (rl_prompt);
  return 0;
}
  
/* 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)
     const char *prompt;
{
  char *value;

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

  rl_set_prompt (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 ()
{
  char *nprompt;

  _rl_in_stream = rl_instream;
  _rl_out_stream = rl_outstream;

  if (rl_startup_hook)
    (*rl_startup_hook) ();

  /* If we're not echoing, we still want to at least print a prompt, because
     rl_redisplay will not do it for us.  If the calling application has a
     custom redisplay function, though, let that function handle it. */
  if (readline_echoing_p == 0 && rl_redisplay_function == rl_redisplay)
    {
      if (rl_prompt && rl_already_prompted == 0)
	{
	  nprompt = _rl_strip_prompt (rl_prompt);
	  fprintf (_rl_out_stream, "%s", nprompt);
	  fflush (_rl_out_stream);
	  free (nprompt);
	}
    }
  else
    {
      if (rl_prompt && rl_already_prompted)
	rl_on_new_line_with_prompt ();
      else
	rl_on_new_line ();
      (*rl_redisplay_function) ();
    }

#if defined (VI_MODE)
  if (rl_editing_mode == vi_mode)
    rl_vi_insertion_mode (1, 'i');
#endif /* VI_MODE */

  if (rl_pre_input_hook)
    (*rl_pre_input_hook) ();
}

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, (histdata_t)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)
    rl_free_undo_list ();

  /* Restore normal cursor, if available. */
  _rl_set_insert_mode (RL_IM_INSERT, 0);

  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;
	}

      RL_SETSTATE(RL_STATE_READCMD);
      c = rl_read_key ();
      RL_UNSETSTATE(RL_STATE_READCMD);

      /* 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)
	  RL_SETSTATE(RL_STATE_DONE);
	  return (rl_done = 1);
#else
	  eof_found = 1;
	  break;
#endif
	}

      lastc = c;
      _rl_dispatch ((unsigned char)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_num_chars_to_read && rl_end >= rl_num_chars_to_read)
        {
          (*rl_redisplay_function) ();
          rl_newline (1, '\n');
        }

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

      /* If the application writer has told us to erase the entire line if
	  the only character typed was something bound to rl_newline, do so. */
      if (rl_erase_empty_line && rl_done && rl_last_func == rl_newline &&
	  rl_point == 0 && rl_end == 0)
	_rl_erase_entire_line ();

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

  return (eof_found);
#endif
}

#if defined (READLINE_CALLBACKS)
static int
readline_internal_charloop ()
{
  int eof = 1;

  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_init_line_state ()
{
  rl_point = rl_end = rl_mark = 0;
  the_line = rl_line_buffer;
  the_line[0] = 0;
}

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;
{
  return _rl_dispatch_subseq (key, map, 0);
}

int
_rl_dispatch_subseq (key, map, got_subseq)
     register int key;
     Keymap map;
     int got_subseq;
{
  int r, newkey;
  char *macro;
  rl_command_func_t *func;

  if (META_CHAR (key) && _rl_convert_meta_chars_to_ascii)
    {
      if (map[ESC].type == ISKMAP)
	{
	  if (RL_ISSTATE (RL_STATE_MACRODEF))
	    _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
	rl_ding ();
      return 0;
    }

  if (RL_ISSTATE (RL_STATE_MACRODEF))
    _rl_add_macro_char (key);

  r = 0;
  switch (map[key].type)
    {
    case ISFUNC:
      func = map[key].function;
      if (func)
	{
	  /* 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

	  rl_dispatching = 1;
	  RL_SETSTATE(RL_STATE_DISPATCHING);
	  r = (*map[key].function)(rl_numeric_arg * rl_arg_sign, key);
	  RL_UNSETSTATE(RL_STATE_DISPATCHING);
	  rl_dispatching = 0;

	  /* 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 == 0 && map[key].function != rl_digit_argument)
	    rl_last_func = map[key].function;
	}
      else if (map[ANYOTHERKEY].function)
	{
	  /* OK, there's no function bound in this map, but there is a
	     shadow function that was overridden when the current keymap
	     was created.  Return -2 to note  that. */
	  _rl_unget_char  (key);
	  return -2;
	}
      else if (got_subseq)
	{
	  /* Return -1 to note that we're in a subsequence, but  we don't
	     have a matching key, nor was one overridden.  This means
	     we need to back up the recursion chain and find the last
	     subsequence that is bound to a function. */
	  _rl_unget_char (key);
	  return -1;
	}
      else
	{
	  _rl_abort_internal ();
	  return -1;
	}
      break;

    case ISKMAP:
      if (map[key].function != 0)
	{
#if defined (VI_MODE)
	  /* The only way this test will be true is if a subsequence has been
	     bound starting with ESC, generally the arrow keys.  What we do is
	     check whether there's input in the queue, which there generally
	     will be if an arrow key has been pressed, and, if there's not,
	     just dispatch to (what we assume is) rl_vi_movement_mode right
	     away.  This is essentially an input test with a zero timeout. */
	  if (rl_editing_mode == vi_mode && key == ESC && map == vi_insertion_keymap
	      && _rl_input_queued (0) == 0)
	    return (_rl_dispatch (ANYOTHERKEY, FUNCTION_TO_KEYMAP (map, key)));
#endif

	  rl_key_sequence_length++;

	  if (key == ESC)
	    RL_SETSTATE(RL_STATE_METANEXT);
	  RL_SETSTATE(RL_STATE_MOREINPUT);
	  newkey = rl_read_key ();
	  RL_UNSETSTATE(RL_STATE_MOREINPUT);
	  if (key == ESC)
	    RL_UNSETSTATE(RL_STATE_METANEXT);

	  if (newkey < 0)
	    {
	      _rl_abort_internal ();
	      return -1;
	    }

	  r = _rl_dispatch_subseq (newkey, FUNCTION_TO_KEYMAP (map, key), got_subseq || map[ANYOTHERKEY].function);

	  if (r == -2)
	    /* We didn't match anything, and the keymap we're indexed into
	       shadowed a function previously bound to that prefix.  Call
	       the function.  The recursive call to _rl_dispatch_subseq has
	       already taken care of pushing any necessary input back onto
	       the input queue with _rl_unget_char. */
	    {
#if 0
	      r = _rl_dispatch (ANYOTHERKEY, FUNCTION_TO_KEYMAP (map, key));
#else
	      /* XXX - experimental code -- might never be executed.  Save
		 for later. */
	      Keymap m = FUNCTION_TO_KEYMAP (map, key);
	      int type = m[ANYOTHERKEY].type;
	      func = m[ANYOTHERKEY].function;
	      if (type == ISFUNC && func == rl_do_lowercase_version)
		r = _rl_dispatch (_rl_to_lower (key), map);
	      else
		r = _rl_dispatch (ANYOTHERKEY, m);
#endif
	    }
	  else if (r && map[ANYOTHERKEY].function)
	    {
	      /* We didn't match (r is probably -1), so return something to
		 tell the caller that it should try ANYOTHERKEY for an
		 overridden function. */
	      _rl_unget_char (key);
	      return -2;
	    }
	  else if (r && got_subseq)
	    {
	      /* OK, back up the chain. */
	      _rl_unget_char (key);
	      return -1;
	    }
	}
      else
	{
	  _rl_abort_internal ();
	  return -1;
	}
      break;

    case ISMACR:
      if (map[key].function != 0)
	{
	  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 &&
      key != ANYOTHERKEY &&
      _rl_vi_textmod_command (key))
    _rl_vi_set_last (key, rl_numeric_arg, rl_arg_sign);
#endif
  return (r);
}

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

/* Initialize 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)
    {
      RL_SETSTATE(RL_STATE_INITIALIZING);
      readline_initialize_everything ();
      RL_UNSETSTATE(RL_STATE_INITIALIZING);
      rl_initialized++;
      RL_SETSTATE(RL_STATE_INITIALIZED);
    }

  /* Initalize the current line information. */
  _rl_init_line_state ();

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

  /* Tell the history routines what is going on. */
  _rl_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 = (rl_command_func_t *)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

  /* Each line starts in insert mode (the default). */
  _rl_set_insert_mode (RL_IM_DEFAULT, 1);

  return 0;
}

#if 0
#if defined (__EMX__)
static void
_emx_build_environ ()
{
  TIB *tibp;
  PIB *pibp;
  char *t, **tp;
  int c;

  DosGetInfoBlocks (&tibp, &pibp);
  t = pibp->pib_pchenv;
  for (c = 1; *t; c++)
    t += strlen (t) + 1;
  tp = environ = (char **)xmalloc ((c + 1) * sizeof (char *));
  t = pibp->pib_pchenv;
  while (*t)
    {
      *tp++ = t;
      t += strlen (t) + 1;
    }
  *tp = 0;
}
#endif /* __EMX__ */
#endif

/* Initialize the entire state of the world. */
static void
readline_initialize_everything ()
{
#if 0
#if defined (__EMX__)
  if (environ == 0)
    _emx_build_environ ();
#endif
#endif

#if 0
  /* Find out if we are running in Emacs -- UNUSED. */
  running_in_emacs = sh_get_env_value ("EMACS") != (char *)0;
#endif

  /* 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 == 0)
    rl_line_buffer = (char *)xmalloc (rl_line_buffer_len = DEFAULT_BUFFER_SIZE);

  /* Initialize the terminal interface. */
  if (rl_terminal_name == 0)
    rl_terminal_name = sh_get_env_value ("TERM");
  _rl_init_terminal_io (rl_terminal_name);

  /* Bind tty characters to readline functions. */
  readline_default_bindings ();

  /* 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)
    {
      _rl_screenwidth--;
      _rl_screenchars -= _rl_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 = (char *)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 ()
{
  rl_tty_set_default_bindings (_rl_keymap);
}

/* Reset the default bindings for the terminal special characters we're
   interested in back to rl_insert and read the new ones. */
static void
reset_default_bindings ()
{
  rl_tty_unset_default_bindings (_rl_keymap);
  rl_tty_set_default_bindings (_rl_keymap);
}

/* Bind some common arrow key sequences in MAP. */
static void
bind_arrow_keys_internal (map)
     Keymap map;
{
  Keymap xkeymap;

  xkeymap = _rl_keymap;
  _rl_keymap = map;

#if defined (__MSDOS__)
  rl_bind_keyseq_if_unbound ("\033[0A", rl_get_previous_history);
  rl_bind_keyseq_if_unbound ("\033[0B", rl_backward_char);
  rl_bind_keyseq_if_unbound ("\033[0C", rl_forward_char);
  rl_bind_keyseq_if_unbound ("\033[0D", rl_get_next_history);
#endif

  rl_bind_keyseq_if_unbound ("\033[A", rl_get_previous_history);
  rl_bind_keyseq_if_unbound ("\033[B", rl_get_next_history);
  rl_bind_keyseq_if_unbound ("\033[C", rl_forward_char);
  rl_bind_keyseq_if_unbound ("\033[D", rl_backward_char);
  rl_bind_keyseq_if_unbound ("\033[H", rl_beg_of_line);
  rl_bind_keyseq_if_unbound ("\033[F", rl_end_of_line);

  rl_bind_keyseq_if_unbound ("\033OA", rl_get_previous_history);
  rl_bind_keyseq_if_unbound ("\033OB", rl_get_next_history);
  rl_bind_keyseq_if_unbound ("\033OC", rl_forward_char);
  rl_bind_keyseq_if_unbound ("\033OD", rl_backward_char);
  rl_bind_keyseq_if_unbound ("\033OH", rl_beg_of_line);
  rl_bind_keyseq_if_unbound ("\033OF", rl_end_of_line);

  _rl_keymap = xkeymap;
}

/* Try and bind the common arrow key prefixes 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 ()
{
  bind_arrow_keys_internal (emacs_standard_keymap);

#if defined (VI_MODE)
  bind_arrow_keys_internal (vi_movement_keymap);
  bind_arrow_keys_internal (vi_insertion_keymap);
#endif
}

/* **************************************************************** */
/*								    */
/*		Saving and Restoring Readline's state		    */
/*								    */
/* **************************************************************** */

int
rl_save_state (sp)
     struct readline_state *sp;
{
  if (sp == 0)
    return -1;

  sp->point = rl_point;
  sp->end = rl_end;
  sp->mark = rl_mark;
  sp->buffer = rl_line_buffer;
  sp->buflen = rl_line_buffer_len;
  sp->ul = rl_undo_list;
  sp->prompt = rl_prompt;

  sp->rlstate = rl_readline_state;
  sp->done = rl_done;
  sp->kmap = _rl_keymap;

  sp->lastfunc = rl_last_func;
  sp->insmode = rl_insert_mode;
  sp->edmode = rl_editing_mode;
  sp->kseqlen = rl_key_sequence_length;
  sp->inf = rl_instream;
  sp->outf = rl_outstream;
  sp->pendingin = rl_pending_input;
  sp->macro = rl_executing_macro;

  sp->catchsigs = rl_catch_signals;
  sp->catchsigwinch = rl_catch_sigwinch;

  return (0);
}

int
rl_restore_state (sp)
     struct readline_state *sp;
{
  if (sp == 0)
    return -1;

  rl_point = sp->point;
  rl_end = sp->end;
  rl_mark = sp->mark;
  the_line = rl_line_buffer = sp->buffer;
  rl_line_buffer_len = sp->buflen;
  rl_undo_list = sp->ul;
  rl_prompt = sp->prompt;

  rl_readline_state = sp->rlstate;
  rl_done = sp->done;
  _rl_keymap = sp->kmap;

  rl_last_func = sp->lastfunc;
  rl_insert_mode = sp->insmode;
  rl_editing_mode = sp->edmode;
  rl_key_sequence_length = sp->kseqlen;
  rl_instream = sp->inf;
  rl_outstream = sp->outf;
  rl_pending_input = sp->pendingin;
  rl_executing_macro = sp->macro;

  rl_catch_signals = sp->catchsigs;
  rl_catch_sigwinch = sp->catchsigwinch;

  return (0);
}
