fix nofork comsub overwriting currently executing command; free readline undo list...

[thirdparty/bash.git] / bashline.c

/* bashline.c -- Bash's interface to the readline library. */

/* Copyright (C) 1987-2024 Free Software Foundation, Inc.

   This file is part of GNU Bash, the Bourne Again SHell.

   Bash 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 3 of the License, or
   (at your option) any later version.

   Bash 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.

   You should have received a copy of the GNU General Public License
   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "config.h"

#if defined (READLINE)

#include "bashtypes.h"
#include "posixstat.h"

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

#if defined (HAVE_GRP_H)
#  include <grp.h>
#endif

#if defined (HAVE_NETDB_H)
#  include <netdb.h>
#endif

#include <signal.h>

#include <stdio.h>
#include "chartypes.h"
#include "bashansi.h"
#include "bashintl.h"

#include "shell.h"
#include "input.h"
#include "parser.h"
#include "builtins.h"
#include "bashhist.h"
#include "bashline.h"
#include "execute_cmd.h"
#include "findcmd.h"
#include "pathexp.h"
#include "shmbutil.h"
#include "trap.h"
#include "flags.h"
#include "timer.h"

#if defined (HAVE_MBSTR_H) && defined (HAVE_MBSCHR)
#  include <mbstr.h>            /* mbschr */
#endif

#include "builtins/common.h"
#include "builtins/builtext.h"          /* for read_builtin */

#include <readline/rlconf.h>
#include <readline/readline.h>
#include <readline/history.h>
#include <readline/rlmbutil.h>

#include <glob/glob.h>

#if defined (ALIAS)
#  include "alias.h"
#endif

#if defined (PROGRAMMABLE_COMPLETION)
#  include "pcomplete.h"
#endif

/* These should agree with the defines for emacs_mode and vi_mode in
   rldefs.h, even though that's not a public readline header file. */
#ifndef EMACS_EDITING_MODE
#  define NO_EDITING_MODE       -1
#  define EMACS_EDITING_MODE     1
#  define VI_EDITING_MODE        0
#endif

/* Copied from rldefs.h, since that's not a public readline header file. */
#ifndef FUNCTION_TO_KEYMAP

#if defined (CRAY)
#  define FUNCTION_TO_KEYMAP(map, key)  (Keymap)((int)map[key].function)
#  define KEYMAP_TO_FUNCTION(data)      (rl_command_func_t *)((int)(data))
#else
#  define FUNCTION_TO_KEYMAP(map, key)  (Keymap)(map[key].function)
#  define KEYMAP_TO_FUNCTION(data)      (rl_command_func_t *)(data)
#endif

#endif

#define RL_BOOLEAN_VARIABLE_VALUE(s)    ((s)[0] == 'o' && (s)[1] == 'n' && (s)[2] == '\0')

#if defined (BRACE_COMPLETION)
extern int bash_brace_completion (int, int);
#endif /* BRACE_COMPLETION */

/* To avoid including curses.h/term.h/termcap.h and that whole mess. */
#ifdef _MINIX
extern int tputs (const char *string, int nlines, void (*outx)(int));
#else
extern int tputs (const char *string, int nlines, int (*outx)(int));
#endif

/* Forward declarations */

/* Functions bound to keys in Readline for Bash users. */
static int shell_expand_line (int, int);
static int display_shell_version (int, int);

static int bash_ignore_filenames (char **);
static int bash_ignore_everything (char **);
static int bash_progcomp_ignore_filenames (char **);

#if defined (BANG_HISTORY)
static char *history_expand_line_internal (char *);
static int history_expand_line (int, int);
static int tcsh_magic_space (int, int);
#endif /* BANG_HISTORY */
#ifdef ALIAS
static int alias_expand_line (int, int);
#endif
#if defined (BANG_HISTORY) && defined (ALIAS)
static int history_and_alias_expand_line (int, int);
#endif

static int bash_forward_shellword (int, int);
static int bash_backward_shellword (int, int);
static int bash_kill_shellword (int, int);
static int bash_backward_kill_shellword (int, int);
static int bash_transpose_shellwords (int, int);

static int bash_spell_correct_shellword (int, int);

/* Helper functions for Readline. */
static char *restore_tilde (const char *, char *);
static char *maybe_restore_tilde (char *, char *);

static char *bash_filename_rewrite_hook (char *, int);

static void bash_directory_expansion (char **);
static char *bash_expand_filename (char *);
static int bash_filename_stat_hook (char **);
static int bash_command_name_stat_hook (char **);
static int bash_directory_completion_hook (char **);
static int filename_completion_ignore (char **);
static int bash_push_line (void);

static int executable_completion (const char *, int);

static rl_icppfunc_t *save_directory_hook (void);
static void restore_directory_hook (rl_icppfunc_t);

static int directory_exists (const char *, int);

static void cleanup_expansion_error (void);
static void maybe_make_readline_line (const char *);
static void set_up_new_line (char *);

static int check_redir (int);
static char **attempt_shell_completion (const char *, int, int);
static char *variable_completion_function (const char *, int);
static char *hostname_completion_function (const char *, int);
static char *command_subst_completion_function (const char *, int);

static void build_history_completion_array (void);
static char *history_completion_generator (const char *, int);
static int dynamic_complete_history (int, int);
static int bash_dabbrev_expand (int, int);

static void initialize_hostname_list (void);
static void add_host_name (const char *);
static void snarf_hosts_from_file (const char *);
static char **hostnames_matching (const char *);

static void _ignore_completion_names (char **, sh_ignore_func_t *);
static int name_is_acceptable (const char *);
static int test_for_directory (const char *);
static int test_for_canon_directory (const char *);
static int return_zero (const char *);

static char *bash_dequote_filename (char *, int);
static char *quote_word_break_chars (char *);
static int bash_check_expchar (char *, int, int *, int *);
static void set_filename_quote_chars (int, int, int);
static void set_filename_bstab (const char *);
static char *bash_quote_filename (char *, int, char *);

#ifdef _MINIX
static void putx (int);
#else
static int putx (int);
#endif
static int readline_get_char_offset (int);
static void readline_set_char_offset (int, int *);

static Keymap get_cmd_xmap_from_edit_mode (void);
static Keymap get_cmd_xmap_from_keymap (Keymap);

static void init_unix_command_map (void);
static int isolate_sequence (char *, int, int, int *);

static int set_saved_history (void);

#if defined (ALIAS)
static int posix_edit_macros (int, int);
#endif

static int bash_event_hook (void);

#if defined (PROGRAMMABLE_COMPLETION)
static int find_cmd_start (int);
static int find_cmd_end (int);
static char *find_cmd_name (int, int *, int *);
static char *prog_complete_return (const char *, int);

static char **prog_complete_matches;
#endif

extern int no_symbolic_links;
extern STRING_INT_ALIST word_token_alist[];
extern sh_timer *read_timeout;

/* SPECIFIC_COMPLETION_FUNCTIONS specifies that we have individual
   completion functions which indicate what type of completion should be
   done (at or before point) that can be bound to key sequences with
   the readline library. */
#define SPECIFIC_COMPLETION_FUNCTIONS

#if defined (SPECIFIC_COMPLETION_FUNCTIONS)
static int bash_specific_completion (int, rl_compentry_func_t *);

static int bash_complete_filename_internal (int);
static int bash_complete_username_internal (int);
static int bash_complete_hostname_internal (int);
static int bash_complete_variable_internal (int);
static int bash_complete_command_internal (int);

static int bash_complete_filename (int, int);
static int bash_possible_filename_completions (int, int);
static int bash_complete_username (int, int);
static int bash_possible_username_completions (int, int);
static int bash_complete_hostname (int, int);
static int bash_possible_hostname_completions (int, int);
static int bash_complete_variable (int, int);
static int bash_possible_variable_completions (int, int);
static int bash_complete_command (int, int);
static int bash_possible_command_completions (int, int);

static int completion_glob_pattern (const char *);
static char *glob_complete_word (const char *, int);
static int bash_glob_completion_internal (int);
static int bash_glob_complete_word (int, int);
static int bash_glob_expand_word (int, int);
static int bash_glob_list_expansions (int, int);

#endif /* SPECIFIC_COMPLETION_FUNCTIONS */

static int edit_and_execute_command (int, int, int, const char *);
#if defined (VI_MODE)
static int vi_edit_and_execute_command (int, int);
static int bash_vi_complete (int, int);
#endif
static int emacs_edit_and_execute_command (int, int);

/* Non-zero once initialize_readline () has been called. */
int bash_readline_initialized = 0;

/* If non-zero, we do hostname completion, breaking words at `@' and
   trying to complete the stuff after the `@' from our own internal
   host list. */
int perform_hostname_completion = 1;

/* If non-zero, we don't do command completion on an empty line. */
int no_empty_command_completion;

/* Set FORCE_FIGNORE if you want to honor FIGNORE even if it ignores the
   only possible matches.  Set to 0 if you want to match filenames if they
   are the only possible matches, even if FIGNORE says to. */
int force_fignore = 1;

/* Perform spelling correction on directory names during word completion */
int dircomplete_spelling = 0;

/* Expand directory names during word/filename completion. */
#if DIRCOMPLETE_EXPAND_DEFAULT
int dircomplete_expand = 1;
int dircomplete_expand_relpath = 1;
#else
int dircomplete_expand = 0;
int dircomplete_expand_relpath = 0;
#endif

/* When non-zero, perform `normal' shell quoting on completed filenames
   even when the completed name contains a directory name with a shell
   variable reference, so dollar signs in a filename get quoted appropriately.
   Set to zero to remove dollar sign (and braces or parens as needed) from
   the set of characters that will be quoted. */
int complete_fullquote = 1;

static char *bash_completer_word_break_characters = " \t\n\"'@><=;|&(:";
static char *bash_nohostname_word_break_characters = " \t\n\"'><=;|&(:";
/* )) */

static const char *default_filename_quote_characters = " \t\n\\\"'@<>=;|&()#$`?*[!:{~"; /*}*/
static char *custom_filename_quote_characters = 0;
static char filename_bstab[256];

static rl_hook_func_t *old_rl_startup_hook = (rl_hook_func_t *)NULL;

static int dot_in_path = 0;

/* Set to non-zero when dabbrev-expand is running */
static int dabbrev_expand_active = 0;

/* What kind of quoting is performed by bash_quote_filename:
        COMPLETE_DQUOTE = double-quoting the filename
        COMPLETE_SQUOTE = single_quoting the filename
        COMPLETE_BSQUOTE = backslash-quoting special chars in the filename
        COMPLETE_DQUOTE2 = double-quote filename, but leave $ and ` unquoted
*/
#define COMPLETE_DQUOTE  1
#define COMPLETE_SQUOTE  2
#define COMPLETE_BSQUOTE 3
#define COMPLETE_DQUOTE2 4

static int completion_quoting_style = COMPLETE_BSQUOTE;

/* Flag values for the final argument to bash_default_completion */
#define DEFCOMP_CMDPOS          1

static rl_command_func_t *vi_tab_binding = rl_complete;

/* Change the readline VI-mode keymaps into or out of Posix.2 compliance.
   Called when the shell is put into or out of `posix' mode. */
void
posix_readline_initialize (int on_or_off)
{
  static char kseq[2] = { CTRL ('I'), 0 };              /* TAB */

  if (on_or_off)
    rl_variable_bind ("comment-begin", "#");
#if defined (VI_MODE)
  if (on_or_off)
    {
      vi_tab_binding = rl_function_of_keyseq (kseq, vi_insertion_keymap, (int *)NULL);
      rl_bind_key_in_map (CTRL ('I'), rl_insert, vi_insertion_keymap);
    }
  else
    {
      if (rl_function_of_keyseq (kseq, vi_insertion_keymap, (int *)NULL) == rl_insert)
        rl_bind_key_in_map (CTRL ('I'), vi_tab_binding, vi_insertion_keymap);
    }
#endif
}

void
reset_completer_word_break_chars (void)
{
  rl_completer_word_break_characters = perform_hostname_completion ? savestring (bash_completer_word_break_characters) : savestring (bash_nohostname_word_break_characters);
}

/* When this function returns, rl_completer_word_break_characters points to
   dynamically allocated memory. */
int
enable_hostname_completion (int on_or_off)
{
  int old_value;
  char *nv, *nval;
  const char *at;

  old_value = perform_hostname_completion;

  if (on_or_off)
    {
      perform_hostname_completion = 1;
      rl_special_prefixes = "$@";
    }
  else
    {
      perform_hostname_completion = 0;
      rl_special_prefixes = "$";
    }

  /* Now we need to figure out how to appropriately modify and assign
     rl_completer_word_break_characters depending on whether we want
     hostname completion on or off. */

  /* If this is the first time this has been called
     (bash_readline_initialized == 0), use the sames values as before, but
     allocate new memory for rl_completer_word_break_characters. */

  if (bash_readline_initialized == 0 &&
      (rl_completer_word_break_characters == 0 || 
       rl_completer_word_break_characters == rl_basic_word_break_characters))
    {
      if (on_or_off)
        rl_completer_word_break_characters = savestring (bash_completer_word_break_characters);
      else
        rl_completer_word_break_characters = savestring (bash_nohostname_word_break_characters);
    }
  else
    {
      /* See if we have anything to do. */
      at = strchr (rl_completer_word_break_characters, '@');
      if ((at == 0 && on_or_off == 0) || (at != 0 && on_or_off != 0))
        return old_value;

      /* We have something to do.  Do it. */
      nval = (char *)xmalloc (strlen (rl_completer_word_break_characters) + 1 + on_or_off);

      if (on_or_off == 0)
        {
          /* Turn it off -- just remove `@' from word break chars.  We want
             to remove all occurrences of `@' from the char list, so we loop
             rather than just copy the rest of the list over AT. */
          for (nv = nval, at = rl_completer_word_break_characters; *at; )
            if (*at != '@')
              *nv++ = *at++;
            else
              at++;
          *nv = '\0';
        }
      else
        {
          nval[0] = '@';
          strcpy (nval + 1, rl_completer_word_break_characters);
        }

      free ((void *)rl_completer_word_break_characters);
      rl_completer_word_break_characters = nval;
    }

  return (old_value);
}

/* Called once from parse.y if we are going to use readline. */
void
initialize_readline (void)
{
  rl_command_func_t *func;
  char kseq[2];

  if (bash_readline_initialized)
    return;

  rl_terminal_name = get_string_value ("TERM");
  rl_instream = stdin;
  rl_outstream = stderr;

  /* Allow conditional parsing of the ~/.inputrc file. */
  rl_readline_name = "Bash";

  /* Add bindable names before calling rl_initialize so they may be
     referenced in the various inputrc files. */
  rl_add_defun ("shell-expand-line", shell_expand_line, -1);
#ifdef BANG_HISTORY
  rl_add_defun ("history-expand-line", history_expand_line, -1);
  rl_add_defun ("magic-space", tcsh_magic_space, -1);
#endif

  rl_add_defun ("shell-forward-word", bash_forward_shellword, -1);
  rl_add_defun ("shell-backward-word", bash_backward_shellword, -1);
  rl_add_defun ("shell-kill-word", bash_kill_shellword, -1);
  rl_add_defun ("shell-backward-kill-word", bash_backward_kill_shellword, -1);
  rl_add_defun ("shell-transpose-words", bash_transpose_shellwords, -1);

  rl_add_defun ("spell-correct-word", bash_spell_correct_shellword, -1);
  rl_bind_key_if_unbound_in_map ('s', bash_spell_correct_shellword, emacs_ctlx_keymap);

#ifdef ALIAS
  rl_add_defun ("alias-expand-line", alias_expand_line, -1);
#  ifdef BANG_HISTORY
  rl_add_defun ("history-and-alias-expand-line", history_and_alias_expand_line, -1);
#  endif
#endif

  /* Backwards compatibility. */
  rl_add_defun ("insert-last-argument", rl_yank_last_arg, -1);

  rl_add_defun ("display-shell-version", display_shell_version, -1);
  rl_add_defun ("edit-and-execute-command", emacs_edit_and_execute_command, -1);
#if defined (VI_MODE)
  rl_add_defun ("vi-edit-and-execute-command", vi_edit_and_execute_command, -1);
#endif

#if defined (BRACE_COMPLETION)
  rl_add_defun ("complete-into-braces", bash_brace_completion, -1);
#endif

#if defined (SPECIFIC_COMPLETION_FUNCTIONS)
  rl_add_defun ("complete-filename", bash_complete_filename, -1);
  rl_add_defun ("possible-filename-completions", bash_possible_filename_completions, -1);
  rl_add_defun ("complete-username", bash_complete_username, -1);
  rl_add_defun ("possible-username-completions", bash_possible_username_completions, -1);
  rl_add_defun ("complete-hostname", bash_complete_hostname, -1);
  rl_add_defun ("possible-hostname-completions", bash_possible_hostname_completions, -1);
  rl_add_defun ("complete-variable", bash_complete_variable, -1);
  rl_add_defun ("possible-variable-completions", bash_possible_variable_completions, -1);
  rl_add_defun ("complete-command", bash_complete_command, -1);
  rl_add_defun ("possible-command-completions", bash_possible_command_completions, -1);
  rl_add_defun ("glob-complete-word", bash_glob_complete_word, -1);
  rl_add_defun ("glob-expand-word", bash_glob_expand_word, -1);
  rl_add_defun ("glob-list-expansions", bash_glob_list_expansions, -1);
#endif

  rl_add_defun ("dynamic-complete-history", dynamic_complete_history, -1);
  rl_add_defun ("dabbrev-expand", bash_dabbrev_expand, -1);

  /* Bind defaults before binding our custom shell keybindings. */
  if (RL_ISSTATE(RL_STATE_INITIALIZED) == 0)
    rl_initialize ();

  /* Bind up our special shell functions. */
  rl_bind_key_if_unbound_in_map (CTRL('E'), shell_expand_line, emacs_meta_keymap);

#ifdef BANG_HISTORY
  rl_bind_key_if_unbound_in_map ('^', history_expand_line, emacs_meta_keymap);
#endif

  rl_bind_key_if_unbound_in_map (CTRL ('V'), display_shell_version, emacs_ctlx_keymap);

  /* In Bash, the user can switch editing modes with "set -o [vi emacs]",
     so it is not necessary to allow C-M-j for context switching.  Turn
     off this occasionally confusing behaviour. */
  kseq[0] = CTRL('J');
  kseq[1] = '\0';
  func = rl_function_of_keyseq (kseq, emacs_meta_keymap, (int *)NULL);
  if (func == rl_vi_editing_mode)
    rl_unbind_key_in_map (CTRL('J'), emacs_meta_keymap);
  kseq[0] = CTRL('M');
  func = rl_function_of_keyseq (kseq, emacs_meta_keymap, (int *)NULL);
  if (func == rl_vi_editing_mode)
    rl_unbind_key_in_map (CTRL('M'), emacs_meta_keymap);
#if defined (VI_MODE)
  kseq[0] = CTRL('E');
  func = rl_function_of_keyseq (kseq, vi_movement_keymap, (int *)NULL);
  if (func == rl_emacs_editing_mode)
    rl_unbind_key_in_map (CTRL('E'), vi_movement_keymap);
#endif

#if defined (BRACE_COMPLETION)
  rl_bind_key_if_unbound_in_map ('{', bash_brace_completion, emacs_meta_keymap); /*}*/
#endif /* BRACE_COMPLETION */

#if defined (SPECIFIC_COMPLETION_FUNCTIONS)
  rl_bind_key_if_unbound_in_map ('/', bash_complete_filename, emacs_meta_keymap);
  rl_bind_key_if_unbound_in_map ('/', bash_possible_filename_completions, emacs_ctlx_keymap);

  /* Have to jump through hoops here because there is a default binding for
     M-~ (rl_tilde_expand) */
  kseq[0] = '~';
  kseq[1] = '\0';
  func = rl_function_of_keyseq (kseq, emacs_meta_keymap, (int *)NULL);
  if (func == 0 || func == rl_tilde_expand)
    rl_bind_keyseq_in_map (kseq, bash_complete_username, emacs_meta_keymap);

  rl_bind_key_if_unbound_in_map ('~', bash_possible_username_completions, emacs_ctlx_keymap);

  rl_bind_key_if_unbound_in_map ('@', bash_complete_hostname, emacs_meta_keymap);
  rl_bind_key_if_unbound_in_map ('@', bash_possible_hostname_completions, emacs_ctlx_keymap);

  rl_bind_key_if_unbound_in_map ('$', bash_complete_variable, emacs_meta_keymap);
  rl_bind_key_if_unbound_in_map ('$', bash_possible_variable_completions, emacs_ctlx_keymap);

  rl_bind_key_if_unbound_in_map ('!', bash_complete_command, emacs_meta_keymap);
  rl_bind_key_if_unbound_in_map ('!', bash_possible_command_completions, emacs_ctlx_keymap);

  rl_bind_key_if_unbound_in_map ('g', bash_glob_complete_word, emacs_meta_keymap);
  rl_bind_key_if_unbound_in_map ('*', bash_glob_expand_word, emacs_ctlx_keymap);
  rl_bind_key_if_unbound_in_map ('g', bash_glob_list_expansions, emacs_ctlx_keymap);

#endif /* SPECIFIC_COMPLETION_FUNCTIONS */

  kseq[0] = TAB;
  kseq[1] = '\0';
  func = rl_function_of_keyseq (kseq, emacs_meta_keymap, (int *)NULL);
  if (func == 0 || func == rl_tab_insert)
    rl_bind_key_in_map (TAB, dynamic_complete_history, emacs_meta_keymap);

  /* Tell the completer that we want a crack first. */
  rl_attempted_completion_function = attempt_shell_completion;

  bashline_set_filename_hooks ();

  /* Tell the filename completer we want a chance to ignore some names. */
  rl_ignore_some_completions_function = filename_completion_ignore;

  /* Bind C-xC-e to invoke emacs and run result as commands. */
  rl_bind_key_if_unbound_in_map (CTRL ('E'), emacs_edit_and_execute_command, emacs_ctlx_keymap);
#if defined (VI_MODE)
  rl_bind_key_if_unbound_in_map ('v', vi_edit_and_execute_command, vi_movement_keymap);
#  if defined (ALIAS)
  rl_bind_key_if_unbound_in_map ('@', posix_edit_macros, vi_movement_keymap);
#  endif

  rl_add_defun ("bash-vi-complete", bash_vi_complete, -1);
  rl_bind_key_in_map ('\\', bash_vi_complete, vi_movement_keymap);
  rl_bind_key_in_map ('*', bash_vi_complete, vi_movement_keymap);
  rl_bind_key_in_map ('=', bash_vi_complete, vi_movement_keymap);
#endif

  rl_completer_quote_characters = "'\"";

  /* This sets rl_completer_word_break_characters and rl_special_prefixes
     to the appropriate values, depending on whether or not hostname
     completion is enabled. */
  enable_hostname_completion (perform_hostname_completion);

  /* characters that need to be quoted when appearing in filenames. */
  rl_filename_quote_characters = default_filename_quote_characters;
  set_filename_bstab (rl_filename_quote_characters);

  rl_filename_quoting_function = bash_quote_filename;
  rl_filename_dequoting_function = bash_dequote_filename;
  rl_char_is_quoted_p = char_is_quoted;

  /* Add some default bindings for the "shellwords" functions, roughly
     parallelling the default word bindings in emacs mode. */
  rl_bind_key_if_unbound_in_map (CTRL('B'), bash_backward_shellword, emacs_meta_keymap);
  rl_bind_key_if_unbound_in_map (CTRL('D'), bash_kill_shellword, emacs_meta_keymap);
  rl_bind_key_if_unbound_in_map (CTRL('F'), bash_forward_shellword, emacs_meta_keymap);
  rl_bind_key_if_unbound_in_map (CTRL('T'), bash_transpose_shellwords, emacs_meta_keymap);

#if 0
  /* This is superfluous and makes it impossible to use tab completion in
     vi mode even when explicitly binding it in ~/.inputrc.  sv_strict_posix()
     should already have called posix_readline_initialize() when
     posixly_correct was set. */
  if (posixly_correct)
    posix_readline_initialize (1);
#endif

  bash_readline_initialized = 1;
}

void
bashline_reinitialize (void)
{
  bash_readline_initialized = 0;
}

void
bashline_set_event_hook (void)
{
  rl_signal_event_hook = bash_event_hook;
}

void
bashline_reset_event_hook (void)
{
  rl_signal_event_hook = 0;
}

/* On Sun systems at least, rl_attempted_completion_function can end up
   getting set to NULL, and rl_completion_entry_function set to do command
   word completion if Bash is interrupted while trying to complete a command
   word.  This just resets all the completion functions to the right thing.
   It's called from throw_to_top_level(). */
void
bashline_reset (void)
{
  tilde_initialize ();
  rl_attempted_completion_function = attempt_shell_completion;
  rl_completion_entry_function = NULL;
  rl_ignore_some_completions_function = filename_completion_ignore;

  complete_fullquote = 1;
  rl_filename_quote_characters = default_filename_quote_characters;
  set_filename_bstab (rl_filename_quote_characters);

  rl_filename_quoting_function = bash_quote_filename;

  bashline_set_filename_hooks ();

  bashline_reset_event_hook ();

  rl_sort_completion_matches = 1;
}

/* Contains the line to push into readline. */
static char *push_to_readline = (char *)NULL;

/* Push the contents of push_to_readline into the
   readline buffer. */
static int
bash_push_line (void)
{
  if (push_to_readline)
    {
      rl_insert_text (push_to_readline);
      free (push_to_readline);
      push_to_readline = (char *)NULL;
      rl_startup_hook = old_rl_startup_hook;
    }
  return 0;
}

/* Call this to set the initial text for the next line to read
   from readline. */
int
bash_re_edit (const char *line)
{
  FREE (push_to_readline);

  push_to_readline = savestring (line);
  old_rl_startup_hook = rl_startup_hook;
  rl_startup_hook = bash_push_line;

  return (0);
}

static int
display_shell_version (int count, int c)
{
  rl_crlf ();
  show_shell_version (0);
  putc ('\r', rl_outstream);
  fflush (rl_outstream);
  rl_on_new_line ();
  rl_redisplay ();
  return 0;
}

/* **************************************************************** */
/*                                                                  */
/*                           Readline Stuff                         */
/*                                                                  */
/* **************************************************************** */

/* If the user requests hostname completion, then simply build a list
   of hosts, and complete from that forever more, or at least until
   HOSTFILE is unset. */

/* THIS SHOULD BE A STRINGLIST. */
/* The kept list of hostnames. */
static char **hostname_list = (char **)NULL;

/* The physical size of the above list. */
static size_t hostname_list_size;

/* The number of hostnames in the above list. */
static size_t hostname_list_length;

/* Whether or not HOSTNAME_LIST has been initialized. */
int hostname_list_initialized = 0;

/* Initialize the hostname completion table. */
static void
initialize_hostname_list (void)
{
  char *temp;

  temp = get_string_value ("HOSTFILE");
  if (temp == 0)
    temp = get_string_value ("hostname_completion_file");
  if (temp == 0)
    temp = DEFAULT_HOSTS_FILE;

  snarf_hosts_from_file (temp);

  if (hostname_list)
    hostname_list_initialized++;
}

/* Add NAME to the list of hosts. */
static void
add_host_name (const char *name)
{
  if (hostname_list_length + 2 > hostname_list_size)
    {
      hostname_list_size = (hostname_list_size + 32) - (hostname_list_size % 32);
      hostname_list = strvec_resize (hostname_list, hostname_list_size);
    }

  hostname_list[hostname_list_length++] = savestring (name);
  hostname_list[hostname_list_length] = (char *)NULL;
}

#define cr_whitespace(c) ((c) == '\r' || (c) == '\n' || whitespace(c))

static void
snarf_hosts_from_file (const char *filename)
{
  FILE *file;
  char *temp, buffer[256], name[256];
  register int i, start;

  file = fopen (filename, "r");
  if (file == 0)
    return;

  while (temp = fgets (buffer, 255, file))
    {
      /* Skip to first character. */
      for (i = 0; buffer[i] && cr_whitespace (buffer[i]); i++)
        ;

      /* If comment or blank line, ignore. */
      if (buffer[i] == '\0' || buffer[i] == '#')
        continue;

      /* If `preprocessor' directive, do the include. */
      if (strncmp (buffer + i, "$include ", 9) == 0)
        {
          char *incfile, *t;

          /* Find start of filename. */
          for (incfile = buffer + i + 9; *incfile && whitespace (*incfile); incfile++)
            ;

          /* Find end of filename. */
          for (t = incfile; *t && cr_whitespace (*t) == 0; t++)
            ;

          *t = '\0';

          snarf_hosts_from_file (incfile);
          continue;
        }

      /* Skip internet address if present. */
      if (DIGIT (buffer[i]))
        for (; buffer[i] && cr_whitespace (buffer[i]) == 0; i++);

      /* Gobble up names.  Each name is separated with whitespace. */
      while (buffer[i])
        {
          for (; cr_whitespace (buffer[i]); i++)
            ;
          if (buffer[i] == '\0' || buffer[i] ==  '#')
            break;

          /* Isolate the current word. */
          for (start = i; buffer[i] && cr_whitespace (buffer[i]) == 0; i++)
            ;
          if (i == start)
            continue;
          strncpy (name, buffer + start, i - start);
          name[i - start] = '\0';
          add_host_name (name);
        }
    }
  fclose (file);
}

/* Return the hostname list. */
char **
get_hostname_list (void)
{
  if (hostname_list_initialized == 0)
    initialize_hostname_list ();
  return (hostname_list);
}

void
clear_hostname_list (void)
{
  register int i;

  if (hostname_list_initialized == 0)
    return;
  for (i = 0; i < hostname_list_length; i++)
    free (hostname_list[i]);
  hostname_list_length = hostname_list_initialized = 0;
}

/* Return a NULL terminated list of hostnames which begin with TEXT.
   Initialize the hostname list the first time if necessary.
   The array is malloc ()'ed, but not the individual strings. */
static char **
hostnames_matching (const char *text)
{
  int i, nmatch;
  char **result;
  size_t rsize, len;

  if (hostname_list_initialized == 0)
    initialize_hostname_list ();

  if (hostname_list_initialized == 0)
    return ((char **)NULL);

  /* Special case.  If TEXT consists of nothing, then the whole list is
     what is desired. */
  if (*text == '\0')
    {
      result = strvec_create (1 + hostname_list_length);
      for (i = 0; i < hostname_list_length; i++)
        result[i] = hostname_list[i];
      result[i] = (char *)NULL;
      return (result);
    }

  /* Scan until found, or failure. */
  len = strlen (text);
  result = (char **)NULL;
  for (i = nmatch = rsize = 0; i < hostname_list_length; i++)
    {
      if (STREQN (text, hostname_list[i], len) == 0)
        continue;

      /* OK, it matches.  Add it to the list. */
      if (nmatch + 1 >= rsize)
        {
          rsize = (rsize + 16) - (rsize % 16);
          result = strvec_resize (result, rsize);
        }

      result[nmatch++] = hostname_list[i];
    }
  if (nmatch)
    result[nmatch] = (char *)NULL;
  return (result);
}

/* This vi mode command causes VI_EDIT_COMMAND to be run on the current
   command being entered (if no explicit argument is given), otherwise on
   a command from the history file. */

#define VI_EDIT_COMMAND         "fc -e \"${VISUAL:-${EDITOR:-vi}}\""
#define EMACS_EDIT_COMMAND      "fc -e \"${VISUAL:-${EDITOR:-emacs}}\""
#define POSIX_VI_EDIT_COMMAND   "fc -e vi"

static int
edit_and_execute_command (int count, int c, int editing_mode, const char *edit_command)
{
  char *command, *metaval;
  int r, rrs, metaflag;
  sh_parser_state_t ps;

  rrs = rl_readline_state;
  saved_command_line_count = current_command_line_count;

  /* Accept the current line. */
  rl_newline (1, c);

  if (rl_explicit_arg)
    {
      command = (char *)xmalloc (strlen (edit_command) + 8);
      sprintf (command, "%s %d", edit_command, count);
    }
  else
    {
      /* Take the command we were just editing, add it to the history file,
         then call fc to operate on it.  We have to add a dummy command to
         the end of the history because fc ignores the last command (assumes
         it's supposed to deal with the command before the `fc'). */
      /* This breaks down when using command-oriented history and are not
         finished with the command, so we should not ignore the last command */
      using_history ();
      current_command_line_count++;     /* for rl_newline above */
      bash_add_history (rl_line_buffer);
      current_command_line_count = 0;   /* for dummy history entry */
      bash_add_history ("");
      history_lines_this_session++;
      using_history ();
      command = savestring (edit_command);
    }

  metaval = rl_variable_value ("input-meta");
  metaflag = RL_BOOLEAN_VARIABLE_VALUE (metaval);
  
  if (rl_deprep_term_function)
    (*rl_deprep_term_function) ();
  rl_clear_signals ();
  save_parser_state (&ps);
  r = parse_and_execute (command, (editing_mode == VI_EDITING_MODE) ? "v" : "C-xC-e", SEVAL_NOHIST);
  restore_parser_state (&ps);

  /* if some kind of reset_parser was called, undo it. */
  reset_readahead_token ();

  if (rl_prep_term_function)
    (*rl_prep_term_function) (metaflag);
  rl_set_signals ();

  current_command_line_count = saved_command_line_count;

  /* Now erase the contents of the current line and undo the effects of the
     rl_accept_line() above.  We don't even want to make the text we just
     executed available for undoing. */
  rl_line_buffer[0] = '\0';     /* XXX */
  rl_point = rl_end = 0;
  rl_done = 0;
  rl_readline_state = rrs;

#if defined (VI_MODE)
  if (editing_mode == VI_EDITING_MODE)
    rl_vi_insertion_mode (1, c);
#endif

  rl_forced_update_display ();

  return r;
}

#if defined (VI_MODE)
static int
vi_edit_and_execute_command (int count, int key)
{
  if (posixly_correct)
    return (edit_and_execute_command (count, key, VI_EDITING_MODE, POSIX_VI_EDIT_COMMAND));
  else
    return (edit_and_execute_command (count, key, VI_EDITING_MODE, VI_EDIT_COMMAND));
}
#endif /* VI_MODE */

static int
emacs_edit_and_execute_command (int count, int key)
{
  return (edit_and_execute_command (count, key, EMACS_EDITING_MODE, EMACS_EDIT_COMMAND));
}

#if defined (ALIAS)
static int
posix_edit_macros (int count, int key)
{
  int c;
  char alias_name[3], *alias_value, *macro;

  c = rl_read_key ();
  if (c <= 0)
    return 0;
  alias_name[0] = '_';
  alias_name[1] = c;
  alias_name[2] = '\0';

  alias_value = get_alias_value (alias_name);
  if (alias_value && *alias_value)
    {
      macro = savestring (alias_value);
      rl_push_macro_input (macro);
    }
  return 0;
}
#endif

/* Bindable commands that move `shell-words': that is, sequences of
   non-unquoted-metacharacters. */

#define WORDDELIM(c)    (shellmeta(c) || shellblank(c))

static int
bash_forward_shellword (int count, int key)
{
  size_t slen;
  int c, p;
  DECLARE_MBSTATE;

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

  /* The tricky part of this is deciding whether or not the first character
     we're on is an unquoted metacharacter.  Not completely handled yet. */
  /* XXX - need to test this stuff with backslash-escaped shell
     metacharacters and unclosed single- and double-quoted strings. */

  p = rl_point;
  slen = rl_end;

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

      /* Are we in a quoted string?  If we are, move to the end of the quoted
         string and continue the outer loop. We only want quoted strings, not
         backslash-escaped characters, but char_is_quoted doesn't
         differentiate. */
      if (char_is_quoted (rl_line_buffer, p) && p > 0 && rl_line_buffer[p-1] != '\\')
        {
          do
            ADVANCE_CHAR (rl_line_buffer, slen, p);
          while (p < rl_end && char_is_quoted (rl_line_buffer, p));
          count--;
          continue;
        }

      /* Rest of code assumes we are not in a quoted string. */
      /* Move forward until we hit a non-metacharacter. */
      while (p < rl_end && (c = rl_line_buffer[p]) && WORDDELIM (c))
        {
          switch (c)
            {
            default:
              ADVANCE_CHAR (rl_line_buffer, slen, p);
              continue;         /* straight back to loop, don't increment p */
            case '\\':
              if (p < rl_end && rl_line_buffer[p])
                ADVANCE_CHAR (rl_line_buffer, slen, p);
              break;
            case '\'':
              p = skip_to_delim (rl_line_buffer, ++p, "'", SD_NOJMP);
              break;
            case '"':
              p = skip_to_delim (rl_line_buffer, ++p, "\"", SD_NOJMP);
              break;
            }

          if (p < rl_end)
            p++;
        }

      if (rl_line_buffer[p] == 0 || p == rl_end)
        {
          rl_point = rl_end;
          rl_ding ();
          return 0;
        }
        
      /* Now move forward until we hit a non-quoted metacharacter or EOL */
      while (p < rl_end && (c = rl_line_buffer[p]) && WORDDELIM (c) == 0)
        {
          switch (c)
            {
            default:
              ADVANCE_CHAR (rl_line_buffer, slen, p);
              continue;         /* straight back to loop, don't increment p */
            case '\\':
              if (p < rl_end && rl_line_buffer[p])
                ADVANCE_CHAR (rl_line_buffer, slen, p);
              break;
            case '\'':
              p = skip_to_delim (rl_line_buffer, ++p, "'", SD_NOJMP);
              break;
            case '"':
              p = skip_to_delim (rl_line_buffer, ++p, "\"", SD_NOJMP);
              break;
            }

          if (p < rl_end)
            p++;
        }

      if (p == rl_end || rl_line_buffer[p] == 0)
        {
          rl_point = rl_end;
          return (0);
        }

      count--;      
    }

  rl_point = p;
  return (0);
}

static int
bash_backward_shellword (int count, int key)
{
  size_t slen;
  int c, p, prev_p;
  DECLARE_MBSTATE;

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

  p = rl_point;
  slen = rl_end;

  while (count)
    {
      if (p == 0)
        {
          rl_point = 0;
          return 0;
        }

      /* Move backward until we hit a non-metacharacter. We want to deal
         with the characters before point, so we move off a word if we're
         at its first character. */
      BACKUP_CHAR (rl_line_buffer, slen, p);
      while (p > 0)
        {
          c = rl_line_buffer[p];
          if (WORDDELIM (c) == 0 || char_is_quoted (rl_line_buffer, p))
            break;
          BACKUP_CHAR (rl_line_buffer, slen, p);
        }

      if (p == 0)
        {
          rl_point = 0;
          return 0;
        }

      /* Now move backward until we hit a metacharacter or BOL. Leave point
         at the start of the shellword or at BOL. */
      prev_p = p;
      while (p > 0)
        {
          c = rl_line_buffer[p];
          if (WORDDELIM (c) && char_is_quoted (rl_line_buffer, p) == 0)
            {
              p = prev_p;
              break;
            }
          prev_p = p;
          BACKUP_CHAR (rl_line_buffer, slen, p);
        }

      count--;
    }

  rl_point = p;
  return 0;
}

static int
bash_kill_shellword (int count, int key)
{
  int p;

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

  p = rl_point;
  bash_forward_shellword (count, key);

  if (rl_point != p)
    rl_kill_text (p, rl_point);

  rl_point = p;
  if (rl_editing_mode == EMACS_EDITING_MODE)    /* 1 == emacs_mode */
    rl_mark = rl_point;

  return 0;
}

static int
bash_backward_kill_shellword (int count, int key)
{
  int p;

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

  p = rl_point;
  bash_backward_shellword (count, key);

  if (rl_point != p)
    rl_kill_text (p, rl_point);

  if (rl_editing_mode == EMACS_EDITING_MODE)    /* 1 == emacs_mode */
    rl_mark = rl_point;

  return 0;
}

static int
bash_transpose_shellwords (int count, int key)
{
  char *word1, *word2;
  int w1_beg, w1_end, w2_beg, w2_end;
  int orig_point = rl_point;

  if (count == 0)
    return 0;

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

  /* check that there really are two words. */
  if ((w1_beg == w2_beg) || (w2_beg < w1_end))
    {
      rl_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 ();
  xfree (word1);
  xfree (word2);

  return 0;
}

/* Directory name spelling correction on the current word (not shellword).
   COUNT > 1 is not exactly correct yet. */
static int
bash_spell_correct_shellword (int count, int key)
{
  int wbeg, wend;
  char *text, *newdir;

  while (count)
    {
      bash_backward_shellword (1, key);
      wbeg = rl_point;
      bash_forward_shellword (1, key);
      wend = rl_point;

      if (wbeg > wend)
        break;

      text = rl_copy_text (wbeg, wend);
      if (text == 0 || *text == 0)
        break;

      newdir = dirspell (text);
      if (newdir)
        {
          rl_begin_undo_group ();
          rl_delete_text (wbeg, wend);
          rl_point = wbeg;
          if (*newdir)
            rl_insert_text (newdir);
          rl_mark = wbeg;
          rl_end_undo_group ();
        }

      free (text);
      free (newdir);

      if (rl_point >= rl_end)
        break;

      count--;

      if (count)
        bash_forward_shellword (1, key);                /* XXX */
    }

  return 0;
}

/* **************************************************************** */
/*                                                                  */
/*                      How To Do Shell Completion                  */
/*                                                                  */
/* **************************************************************** */

#define COMMAND_SEPARATORS ";|&{(`"
/* )} */ 
#define COMMAND_SEPARATORS_PLUS_WS ";|&{(` \t"
/* )} */ 

/* check for redirections and other character combinations that are not
   command separators */
static inline int
check_redir (int ti)
{
  int this_char, prev_char, next_char;

  /* Handle the two character tokens `>&', `<&', and `>|'.
     We are not in a command position after one of these. */
  this_char = rl_line_buffer[ti];
  prev_char = (ti > 0) ? rl_line_buffer[ti - 1] : 0;
  next_char = (ti < rl_end) ? rl_line_buffer[ti + 1] : 0;

  if ((this_char == '&' && (prev_char == '<' || prev_char == '>')) ||
      (this_char == '|' && prev_char == '>'))
    return (1);
  else if (this_char == '{' && prev_char == '$' && FUNSUB_CHAR (next_char) == 0) /*}*/
    return (1);
#if 0   /* Not yet */
  else if (this_char == '(' && prev_char == '$') /*)*/
    return (1);
  else if (this_char == '(' && prev_char == '<') /*)*/
    return (1);
#if defined (EXTENDED_GLOB)
  else if (extended_glob && this_char == '(' && prev_char == '!') /*)*/
    return (1);
#endif
#endif
  else if (char_is_quoted (rl_line_buffer, ti))
    return (1);
  return (0);
}

#if defined (PROGRAMMABLE_COMPLETION)
/*
 * XXX - because of the <= start test, and setting os = s+1, this can
 * potentially return os > start.  This is probably not what we want to
 * happen, but fix later after 2.05a-release.
 */
static int
find_cmd_start (int start)
{
  register int s, os, ns;

  os = 0;
  /* Flags == SD_NOJMP only because we want to skip over command substitutions
     in assignment statements.  Have to test whether this affects `standalone'
     command substitutions as individual words. */
  while (((s = skip_to_delim (rl_line_buffer, os, COMMAND_SEPARATORS, SD_NOJMP|SD_COMPLETE/*|SD_NOSKIPCMD*/)) <= start) &&
         rl_line_buffer[s])
    {
      /* Handle >| token crudely; treat as > not | */
      if (s > 0 && rl_line_buffer[s] == '|' && rl_line_buffer[s-1] == '>')
        {
          ns = skip_to_delim (rl_line_buffer, s+1, COMMAND_SEPARATORS, SD_NOJMP|SD_COMPLETE/*|SD_NOSKIPCMD*/);
          if (ns > start || rl_line_buffer[ns] == 0)
            return os;
          os = ns+1;
          continue;
        }
      /* The only reserved word in COMMAND_SEPARATORS is `{', so handle that
         specially, making sure it's in a spot acceptable for reserved words */
      if (s >= os && rl_line_buffer[s] == '{')
        {
          int pc, nc;   /* index of previous non-whitespace, next char */
          for (pc = (s > os) ? s - 1 : os; pc > os && whitespace(rl_line_buffer[pc]); pc--)
            ;
          nc = rl_line_buffer[s+1];
          /* must be preceded by a command separator or be the first non-
             whitespace character since the last command separator, and
             followed by a shell break character (not another `{') to be a reserved word. */
          if ((pc > os && (rl_line_buffer[s-1] == '{' || strchr (COMMAND_SEPARATORS, rl_line_buffer[pc]) == 0)) ||
              (shellbreak(nc) == 0))    /* }} */
            {
              /* Not a reserved word, look for another delim */
              ns = skip_to_delim (rl_line_buffer, s+1, COMMAND_SEPARATORS, SD_NOJMP|SD_COMPLETE/*|SD_NOSKIPCMD*/);
              if (ns > start || rl_line_buffer[ns] == 0)
                return os;
              os = ns+1;
              continue;
            }
        }
      os = s+1;
    }
  return os;
}

static int
find_cmd_end (int end)
{
  register int e;

  e = skip_to_delim (rl_line_buffer, end, COMMAND_SEPARATORS, SD_NOJMP|SD_COMPLETE);
  return e;
}

static char *
find_cmd_name (int start, int *sp, int *ep)
{
  char *name;
  register int s, e;

  for (s = start; whitespace (rl_line_buffer[s]); s++)
    ;

  /* skip until a shell break character */
  e = skip_to_delim (rl_line_buffer, s, "()<>;&| \t\n", SD_NOJMP|SD_COMPLETE);

  name = substring (rl_line_buffer, s, e);

  if (sp)
    *sp = s;
  if (ep)
    *ep = e;

  return (name);
}

static char *
prog_complete_return (const char *text, int matchnum)
{
  static int ind;

  if (matchnum == 0)
    ind = 0;

  if (prog_complete_matches == 0 || prog_complete_matches[ind] == 0)
    return (char *)NULL;
  return (prog_complete_matches[ind++]);
}

#endif /* PROGRAMMABLE_COMPLETION */

/* Try and catch completion attempts that are syntax errors or otherwise
   invalid. */
static int
invalid_completion (const char *text, int ind)
{
  int pind;

  /* If we don't catch these here, the next clause will */
  if (ind > 0 && rl_line_buffer[ind] == '(' &&  /*)*/
                 member (rl_line_buffer[ind-1], "$<>"))
    return 0;

  pind = ind - 1;
  while (pind > 0 && whitespace (rl_line_buffer[pind]))
    pind--;
  /* If we have only whitespace preceding a paren, it's valid */
  if (ind >= 0 && pind <= 0 && rl_line_buffer[ind] == '(')      /*)*/
    return 0;
  /* Flag the invalid completions, which are mostly syntax errors */
  if (ind > 0 && rl_line_buffer[ind] == '(' &&  /*)*/
                 member (rl_line_buffer[pind], COMMAND_SEPARATORS) == 0)
    return 1;

  return 0;
}

/* Do some completion on TEXT.  The indices of TEXT in RL_LINE_BUFFER are
   at START and END.  Return an array of matches, or NULL if none. */
static char **
attempt_shell_completion (const char *text, int start, int end)
{
  int in_command_position, ti, qc, dflags;
  char **matches, *command_separator_chars;
#if defined (PROGRAMMABLE_COMPLETION)
  int have_progcomps, was_assignment;
  COMPSPEC *iw_compspec;
#endif

  command_separator_chars = COMMAND_SEPARATORS;
  matches = (char **)NULL;
  rl_ignore_some_completions_function = filename_completion_ignore;

  complete_fullquote = 1;               /* full filename quoting by default */
  rl_filename_quote_characters = default_filename_quote_characters;
  set_filename_bstab (rl_filename_quote_characters);
  bashline_set_filename_hooks ();

  rl_sort_completion_matches = 1;       /* sort by default */

  /* Determine if this could be a command word.  It is if it appears at
     the start of the line (ignoring preceding whitespace), or if it
     appears after a character that separates commands.  It cannot be a
     command word if we aren't at the top-level prompt. */
  ti = start - 1;
  qc = -1;

  while ((ti > -1) && (whitespace (rl_line_buffer[ti])))
    ti--;

#if 1
  /* If this is an open quote, maybe we're trying to complete a quoted
     command name. */
  if (ti >= 0 && (rl_line_buffer[ti] == '"' || rl_line_buffer[ti] == '\''))
    {
      qc = rl_line_buffer[ti];
      ti--;
      while (ti > -1 && (whitespace (rl_line_buffer[ti])))
        ti--;
    }
#endif
      
  in_command_position = 0;
  if (ti < 0)
    {
      /* Only do command completion at the start of a line when we
         are prompting at the top level. */
      if (current_prompt_string == ps1_prompt)
        in_command_position++;
      else if (parser_in_command_position ())
        in_command_position++;
    }
  else if (member (rl_line_buffer[ti], command_separator_chars))
    {
      in_command_position++;

      if (check_redir (ti) == 1)
        in_command_position = -1;       /* sentinel that we're not the first word on the line */
    }
  else
    {
      /* This still could be in command position.  It is possible
         that all of the previous words on the line are variable
         assignments. */
    }

  if (in_command_position > 0 && invalid_completion (text, ti))
    {
      rl_attempted_completion_over = 1;
      return ((char **)NULL);
    }

  /* Check that we haven't incorrectly flagged a closed command substitution
     as indicating we're in a command position. */
  if (in_command_position > 0 && ti >= 0 && rl_line_buffer[ti] == '`' &&
        *text != '`' && unclosed_pair (rl_line_buffer, end, "`") == 0)
    in_command_position = -1;   /* not following a command separator */

  /* Special handling for command substitution.  If *TEXT is a backquote,
     it can be the start or end of an old-style command substitution, or
     unmatched.  If it's unmatched, both calls to unclosed_pair will
     succeed.  Don't bother if readline found a single quote and we are
     completing on the substring.  */
  if (*text == '`' && rl_completion_quote_character != '\'' &&
        (in_command_position > 0 || (unclosed_pair (rl_line_buffer, start, "`") &&
                                     unclosed_pair (rl_line_buffer, end, "`"))))
    matches = rl_completion_matches (text, command_subst_completion_function);

#if defined (PROGRAMMABLE_COMPLETION)
  /* Attempt programmable completion. */
  have_progcomps = prog_completion_enabled && (progcomp_size () > 0);
  iw_compspec = progcomp_search (INITIALWORD);
  if (matches == 0 &&
      (in_command_position == 0 || text[0] == '\0' || (in_command_position > 0 && iw_compspec)) &&
      current_prompt_string == ps1_prompt)
    {
      int s, e, s1, e1, os, foundcs;
      char *n;

      /* XXX - don't free the members */
      if (prog_complete_matches)
        free (prog_complete_matches);
      prog_complete_matches = (char **)NULL;

      os = start;
      n = 0;
      was_assignment = 0;
      s = find_cmd_start (os);
      e = find_cmd_end (end);
      do
        {
          /* Don't read past the end of rl_line_buffer */
          if (s > rl_end)
            {
              s1 = s = e1;
              break;
            }
          /* Or past point if point is within an assignment statement */
          else if (was_assignment && s > rl_point)
            {
              s1 = s = e1;
              break;
            }
          else if (s > e)
            {
              s = s1 = start; e = e1 = end;     /* reset */
            }
          /* Skip over assignment statements preceding a command name.  If we
             don't find a command name at all, we can perform command name
             completion.  If we find a partial command name, we should perform
             command name completion on it. */
          FREE (n);
          n = find_cmd_name (s, &s1, &e1);
          s = e1 + 1;
        }
      while (was_assignment = assignment (n, 0));
      s = s1;           /* reset to index where name begins */

      /* s == index of where command name begins (reset above)
         e == end of current command, may be end of line
         s1 = index of where command name begins
         e1 == index of where command name ends
         start == index of where word to be completed begins
         end == index of where word to be completed ends
         if (s == start) we are doing command word completion for sure
         if (e1 == end) we are at the end of the command name and completing it */
      if (start == 0 && end == 0 && e != 0 && e1 < rl_end && text[0] == '\0')   /* beginning of non-empty line */
        foundcs = 0;
      else if (start == end && start == s1 && e != 0 && e1 > end)       /* beginning of command name, leading whitespace */
        foundcs = 0;
      else if (start == 0 && start == end && start < s1 && e != 0 && e1 > end && text[0] == '\0' && have_progcomps)     /* no command name, leading whitespace only */
        prog_complete_matches = programmable_completions (EMPTYCMD, text, s, e, &foundcs);
      else if (e == 0 && e == s && text[0] == '\0' && have_progcomps)   /* beginning of empty line */
        prog_complete_matches = programmable_completions (EMPTYCMD, text, s, e, &foundcs);
      else if (start == end && text[0] == '\0' && s1 > start && whitespace (rl_line_buffer[start]))
        foundcs = 0;            /* whitespace before command name */
      else if (e > s && was_assignment == 0 && e1 == end && rl_line_buffer[e] == 0 && whitespace (rl_line_buffer[e-1]) == 0)
        {
          /* not assignment statement, but still want to perform command
             completion if we are composing command word. */
          foundcs = 0;
          in_command_position = s == start && STREQ (n, text);  /* XXX */
        }
      else if (e > s && was_assignment == 0 && have_progcomps)
        {
          prog_complete_matches = programmable_completions (n, text, s, e, &foundcs);
          /* command completion if programmable completion fails */
          /* If we have a completion for the initial word, we can prefer that */
          in_command_position = s == start && (iw_compspec || STREQ (n, text)); /* XXX */
          if (iw_compspec && in_command_position)
            foundcs = 0;
        }
      /* empty command name following command separator */
      else if (s >= e && n[0] == '\0' && text[0] == '\0' && start > 0 &&
                was_assignment == 0 && member (rl_line_buffer[start-1], COMMAND_SEPARATORS))
        {
          foundcs = 0;
          in_command_position = 1;
        }
      else if (s >= e && n[0] == '\0' && text[0] == '\0' && start > 0)
        {
          foundcs = 0;  /* empty command name following optional assignments */
          in_command_position += was_assignment;
        }
      else if (s == start && e == end && STREQ (n, text) && start > 0)
        {
          foundcs = 0;  /* partial command name following assignments */
          in_command_position = 1;
        }
      else
        foundcs = 0;

      /* If we have defined a compspec for the initial (command) word, call
         it and process the results like any other programmable completion. */
      if (in_command_position && have_progcomps && foundcs == 0 && iw_compspec)
        {
          /* Do some sanity checking on S and E. Room for more here. */
          if (s > rl_point)
            s = rl_point;
          if (e > rl_end)
            e = rl_end;
          prog_complete_matches = programmable_completions (INITIALWORD, text, s, e, &foundcs);
        }

      FREE (n);
      /* XXX - if we found a COMPSPEC for the command, just return whatever
         the programmable completion code returns, and disable the default
         filename completion that readline will do unless the COPT_DEFAULT
         option has been set with the `-o default' option to complete or
         compopt. */
      if (foundcs)
        {
          pcomp_set_readline_variables (foundcs, 1);
          /* Turn what the programmable completion code returns into what
             readline wants.  I should have made compute_lcd_of_matches
             external... */
          matches = rl_completion_matches (text, prog_complete_return);
          if ((foundcs & COPT_DEFAULT) == 0)
            rl_attempted_completion_over = 1;   /* no default */
          if (matches || ((foundcs & COPT_BASHDEFAULT) == 0))
            return (matches);
        }
    }
#endif

  if (matches == 0)
    {
      dflags = 0;
      if (in_command_position > 0)
        dflags |= DEFCOMP_CMDPOS;
      matches = bash_default_completion (text, start, end, qc, dflags);
    }

  return matches;
}

char **
bash_default_completion (const char *text, int start, int end, int qc, int compflags)
{
  char **matches, *t;

  matches = (char **)NULL;

  /* New posix-style command substitution or variable name? */
  if (*text == '$')
    {
      if (qc != '\'' && text[1] == '(') /* ) */
        matches = rl_completion_matches (text, command_subst_completion_function);
      else if (qc != '\'' && text[1] == '{' && FUNSUB_CHAR (text[2])) /* } */
        matches = rl_completion_matches (text, command_subst_completion_function);
      else
        {
          matches = rl_completion_matches (text, variable_completion_function);
          /* If a single match, see if it expands to a directory name and append
             a slash if it does.  This requires us to expand the variable name,
             so we don't want to display errors if the variable is unset.  This
             can happen with dynamic variables whose value has never been
             requested. */
          if (matches && matches[0] && matches[1] == 0)
            {
              t = savestring (matches[0]);
              bash_filename_stat_hook (&t);
              /* doesn't use test_for_directory because that performs tilde
                 expansion */
              if (file_isdir (t))
                rl_completion_append_character = '/';
              free (t);
            }
        }
    }

  /* If the word starts in `~', and there is no slash in the word, then
     try completing this word as a username. */
  if (matches == 0 && *text == '~' && mbschr (text, '/') == 0)
    matches = rl_completion_matches (text, rl_username_completion_function);

  /* Another one.  Why not?  If the word starts in '@', then look through
     the world of known hostnames for completion first. */
  if (matches == 0 && perform_hostname_completion && *text == '@')
    matches = rl_completion_matches (text, hostname_completion_function);

  /* And last, (but not least) if this word is in a command position, then
     complete over possible command names, including aliases, functions,
     and command names. */
  if (matches == 0 && (compflags & DEFCOMP_CMDPOS))
    {
      /* If END == START and text[0] == 0, we are trying to complete an empty
         command word. */
      if (no_empty_command_completion && end == start && text[0] == '\0')
        {
          matches = (char **)NULL;
          rl_ignore_some_completions_function = bash_ignore_everything;
        }
      else
        {
#define CMD_IS_DIR(x)   (absolute_pathname(x) == 0 && absolute_program(x) == 0 && *(x) != '~' && test_for_directory (x))

          dot_in_path = 0;
          matches = rl_completion_matches (text, command_word_completion_function);

          /* If we are attempting command completion and nothing matches, we
             do not want readline to perform filename completion for us.  We
             still want to be able to complete partial pathnames, so set the
             completion ignore function to something which will remove
             filenames and leave directories in the match list. */
          if (matches == (char **)NULL)
            rl_ignore_some_completions_function = bash_ignore_filenames;
          else if (matches[1] == 0 && CMD_IS_DIR(matches[0]) && dot_in_path == 0)
            /* If we found a single match, without looking in the current
               directory (because it's not in $PATH), but the found name is
               also a command in the current directory, suppress appending any
               terminating character, since it's ambiguous. */
            {
              rl_completion_suppress_append = 1;
              rl_filename_completion_desired = 0;
            }
#if 1
          else if (matches[0] && matches[1] && STREQ (matches[0], matches[1]) &&
                   matches[2] && STREQ (matches[1], matches[2]) && CMD_IS_DIR (matches[0]))
#else
          else if (matches[0] && matches[1] && STREQ (matches[0], matches[1]) && CMD_IS_DIR (matches[0]))
#endif
            /* There are multiple instances of the same match (duplicate
               completions haven't yet been removed).  In this case, all of
               the matches will be the same, and the duplicate removal code
               will distill them all down to one.  We turn on
               rl_completion_suppress_append for the same reason as above.
               Remember: we only care if there's eventually a single unique
               completion.  If there are multiple completions this won't
               make a difference and the problem won't occur. */
            {
              rl_completion_suppress_append = 1;
              rl_filename_completion_desired = 0;
            }
        }
    }

  /* This could be a globbing pattern, so try to expand it using pathname
     expansion. */
  if (!matches && completion_glob_pattern (text))
    {
      matches = rl_completion_matches (text, glob_complete_word);
      /* A glob expression that matches more than one filename is problematic.
         If we match more than one filename, punt. */
      if (matches && matches[1] && rl_completion_type == TAB)
        {
          strvec_dispose (matches);
          matches = (char **)0;
        }
      else if (matches && matches[1] && rl_completion_type == '!')
        {
          rl_completion_suppress_append = 1;
          rl_filename_completion_desired = 0;
        }
    }

  return (matches);
}

static int
bash_command_name_stat_hook (char **name)
{
  char *cname, *result;

  /* If it's not something we're going to look up in $PATH, just call the
     normal filename stat hook. */
  if (absolute_program (*name))
    return (bash_filename_stat_hook (name));

  cname = *name;
  /* XXX - we could do something here with converting aliases, builtins,
     and functions into something that came out as executable, but we don't. */
  result = search_for_command (cname, 0);
  if (result)
    {
      FREE (*name);
      *name = result;
      return 1;
    }
  return 0;
}

static int
executable_completion (const char *filename, int searching_path)
{
  char *f, c;
  int r;

  /* This gets an unquoted filename, so we need to quote special characters
     in the filename before the completion hook gets it. */
  c = 0;
  f = bash_quote_filename ((char *)filename, SINGLE_MATCH, &c);
  bash_directory_completion_hook (&f);
  
  r = searching_path ? executable_file (f) : executable_or_directory (f);
  free (f);
  return r;
}

/* This is the function to call when the word to complete is in a position
   where a command word can be found.  It grovels $PATH, looking for commands
   that match.  It also scans aliases, function names, and the shell_builtin
   table. */
char *
command_word_completion_function (const char *hint_text, int state)
{
  static char *hint = (char *)NULL;
  static char *path = (char *)NULL;
  static char *val = (char *)NULL;
  static char *filename_hint = (char *)NULL;
  static char *fnhint = (char *)NULL;
  static char *dequoted_hint = (char *)NULL;
  static char *directory_part = (char *)NULL;
  static char **glob_matches = (char **)NULL;
  static int path_index, istate, igncase;
  static size_t hint_len;
  static int mapping_over, local_index, searching_path, hint_is_dir;
  static int old_glob_ignore_case, globpat;
  static SHELL_VAR **varlist = (SHELL_VAR **)NULL;
#if defined (ALIAS)
  static alias_t **alias_list = (alias_t **)NULL;
#endif /* ALIAS */
  char *temp, *cval;

  /* We have to map over the possibilities for command words.  If we have
     no state, then make one just for that purpose. */
  if (state == 0)
    {
      rl_filename_stat_hook = bash_command_name_stat_hook;

      if (dequoted_hint && dequoted_hint != hint)
        free (dequoted_hint);
      if (hint)
        free (hint);
      dequoted_hint = hint = (char *)NULL;

      mapping_over = searching_path = 0;
      hint_is_dir = CMD_IS_DIR (hint_text);
      val = (char *)NULL;

      temp = rl_variable_value ("completion-ignore-case");
      igncase = RL_BOOLEAN_VARIABLE_VALUE (temp);

      old_glob_ignore_case = glob_ignore_case;

      if (glob_matches)
        {
          free (glob_matches);
          glob_matches = (char **)NULL;
        }

      globpat = completion_glob_pattern (hint_text);

      /* If this is an absolute program name, do not check it against
         aliases, reserved words, functions or builtins.  We must check
         whether or not it is unique, and, if so, whether that filename
         is executable. */
      if (globpat || absolute_program (hint_text))
        {
          /* Perform tilde expansion on what's passed, so we don't end up
             passing filenames with tildes directly to stat().  The rest of
             the shell doesn't do variable expansion on the word following
             the tilde, so we don't do it here even if direxpand is set. */
          if (*hint_text == '~')
            {
              hint = bash_tilde_expand (hint_text, 0);
              directory_part = savestring (hint_text);
              temp = strchr (directory_part, '/');
              if (temp)
                *temp = 0;
              else
                {
                  free (directory_part);
                  directory_part = (char *)NULL;
                }
            }
          else if (dircomplete_expand)
            {
              hint = savestring (hint_text);
              bash_directory_completion_hook (&hint);
            }
          else
            hint = savestring (hint_text);

          dequoted_hint = hint;
          /* If readline's completer found a quote character somewhere, but
             didn't set the quote character, there must have been a quote
             character embedded in the filename.  It can't be at the start of
             the filename, so we need to dequote the filename before we look
             in the file system for it. */
          if (rl_completion_found_quote && rl_completion_quote_character == 0)
            {
              dequoted_hint = bash_dequote_filename (hint, 0);
              free (hint);
              hint = dequoted_hint;
            }
          hint_len = strlen (hint);

          if (filename_hint)
            free (filename_hint);

          fnhint = filename_hint = savestring (hint);

          istate = 0;

          if (globpat)
            {
              mapping_over = 5;
              goto globword;
            }
          else
            {
             if (dircomplete_expand && path_dot_or_dotdot (filename_hint))
                {
                  dircomplete_expand = 0;
                  set_directory_hook ();
                  dircomplete_expand = 1;
                }
              mapping_over = 4;
              goto inner;
            }
        }

      dequoted_hint = hint = savestring (hint_text);
      hint_len = strlen (hint);

      if (rl_completion_found_quote && rl_completion_quote_character == 0)
        dequoted_hint = bash_dequote_filename (hint, 0);
      
      path = path_value ("PATH", 0);
      path_index = dot_in_path = 0;

      /* Initialize the variables for each type of command word. */
      local_index = 0;

      if (varlist)
        free (varlist);

      varlist = all_visible_functions ();

#if defined (ALIAS)
      if (alias_list)
        free (alias_list);

      alias_list = all_aliases ();
#endif /* ALIAS */
    }

  /* mapping_over says what we are currently hacking.  Note that every case
     in this list must fall through when there are no more possibilities. */

  switch (mapping_over)
    {
    case 0:                     /* Aliases come first. */
#if defined (ALIAS)
      while (alias_list && alias_list[local_index])
        {
          register char *alias;

          alias = alias_list[local_index++]->name;

          if (igncase == 0 && (STREQN (alias, hint, hint_len)))
            return (savestring (alias));
          else if (igncase && strncasecmp (alias, hint, hint_len) == 0)
            return (savestring (alias));
        }
#endif /* ALIAS */
      local_index = 0;
      mapping_over++;

    case 1:                     /* Then shell reserved words. */
      {
        while (word_token_alist[local_index].word)
          {
            register char *reserved_word;

            reserved_word = word_token_alist[local_index++].word;

            if (STREQN (reserved_word, hint, hint_len))
              return (savestring (reserved_word));
          }
        local_index = 0;
        mapping_over++;
      }

    case 2:                     /* Then function names. */
      while (varlist && varlist[local_index])
        {
          register char *varname;

          varname = varlist[local_index++]->name;

          /* Honor completion-ignore-case for shell function names. */
          if (igncase == 0 && (STREQN (varname, hint, hint_len)))
            return (savestring (varname));
          else if (igncase && strncasecmp (varname, hint, hint_len) == 0)
            return (savestring (varname));
        }
      local_index = 0;
      mapping_over++;

    case 3:                     /* Then shell builtins. */
      for (; local_index < num_shell_builtins; local_index++)
        {
          /* Ignore it if it doesn't have a function pointer or if it
             is not currently enabled. */
          if (!shell_builtins[local_index].function ||
              (shell_builtins[local_index].flags & BUILTIN_ENABLED) == 0)
            continue;

          if (STREQN (shell_builtins[local_index].name, hint, hint_len))
            {
              int i = local_index++;

              return (savestring (shell_builtins[i].name));
            }
        }
      local_index = 0;
      mapping_over++;
    }

globword:
  /* Limited support for completing command words with globbing chars.  Only
     a single match (multiple matches that end up reducing the number of
     characters in the common prefix are bad) will ever be returned on
     regular completion. */
  if (globpat)
    {
      if (state == 0)
        {
          rl_filename_completion_desired = 1;

          glob_ignore_case = igncase;
          glob_matches = shell_glob_filename (hint, 0);
          glob_ignore_case = old_glob_ignore_case;

          if (GLOB_FAILED (glob_matches) || glob_matches == 0)
            {
              glob_matches = (char **)NULL;
              return ((char *)NULL);
            }

          local_index = 0;
                
          if (glob_matches[1] && rl_completion_type == TAB)     /* multiple matches are bad */
            {
              strvec_dispose (glob_matches);
              glob_matches = (char **)NULL;
              return ((char *)NULL);
            }
        }

      while (val = glob_matches[local_index++])
        {
          if (executable_or_directory (val))
            {
              if (*hint_text == '~' && directory_part)
                {
                  temp = maybe_restore_tilde (val, directory_part);
                  free (val);
                  val = temp;
                }
              return (val);
            }
          free (val);
        }

      glob_ignore_case = old_glob_ignore_case;
      return ((char *)NULL);
    }

  /* If the text passed is a directory in the current directory, return it
     as a possible match.  Executables in directories in the current
     directory can be specified using relative pathnames and successfully
     executed even when `.' is not in $PATH. */
  if (hint_is_dir)
    {
      hint_is_dir = 0;  /* only return the hint text once */
      return (savestring (hint_text));
    }
    
  /* Repeatedly call filename_completion_function while we have
     members of PATH left.  Question:  should we stat each file?
     Answer: we call executable_file () on each file. */
 outer:

  istate = (val != (char *)NULL);

  if (istate == 0)
    {
      char *current_path;

      /* Get the next directory from the path.  If there is none, then we
         are all done. */
      if (path == 0 || path[path_index] == 0 ||
          (current_path = extract_colon_unit (path, &path_index)) == 0)
        return ((char *)NULL);

      searching_path = 1;
      if (*current_path == 0)
        {
          free (current_path);
          current_path = savestring (".");
        }

      if (*current_path == '~')
        {
          char *t;

          t = bash_tilde_expand (current_path, 0);
          free (current_path);
          current_path = t;
        }

      if (current_path[0] == '.' && current_path[1] == '\0')
        dot_in_path = 1;

      if (fnhint && fnhint != filename_hint)
        free (fnhint);
      if (filename_hint)
        free (filename_hint);
      fnhint = filename_hint = (char *)NULL;

      filename_hint = sh_makepath (current_path, hint, 0);
      /* Need a quoted version (though it doesn't matter much in most
         cases) because rl_filename_completion_function dequotes the
         filename it gets, assuming that it's been quoted as part of
         the input line buffer. */
      if (strpbrk (filename_hint, "\"'\\"))
        fnhint = sh_backslash_quote (filename_hint, filename_bstab, 0);
      else
        fnhint = filename_hint;
      free (current_path);              /* XXX */
    }

 inner:
  val = rl_filename_completion_function (fnhint, istate);
  if (mapping_over == 4 && dircomplete_expand)
    set_directory_hook ();

  istate = 1;

  if (val == 0)
    {
      /* If the hint text is an absolute program, then don't bother
         searching through PATH. */
      if (absolute_program (hint))
        return ((char *)NULL);

      goto outer;
    }
  else
    {
      int match, freetemp;

      if (absolute_program (hint))
        {
#if 0
          if (igncase == 0)
            match = strncmp (val, hint, hint_len) == 0;
          else
            match = strncasecmp (val, hint, hint_len) == 0;
#else
          /* Why duplicate the comparison rl_filename_completion_function
             already performs? */
          match = 1;
#endif

          /* If we performed tilde expansion, restore the original
             filename. */
          if (*hint_text == '~')
            temp = maybe_restore_tilde (val, directory_part);
          else
            temp = savestring (val);
          freetemp = 1;
        }
      else
        {
          temp = strrchr (val, '/');

          if (temp)
            {
              temp++;
              if (igncase == 0)
                freetemp = match = strncmp (temp, hint, hint_len) == 0;
              else
                freetemp = match = strncasecmp (temp, hint, hint_len) == 0;
              if (match)
                temp = savestring (temp);
            }
          else
            freetemp = match = 0;
        }

      /* If we have found a match, and it is an executable file, return it.
         We don't return directory names when searching $PATH, since the
         bash execution code won't find executables in directories which
         appear in directories in $PATH when they're specified using
         relative pathnames.  */
#if 0
      /* If we're not searching $PATH and we have a relative pathname, we
         need to re-canonicalize it before testing whether or not it's an
         executable or a directory so the shell treats .. relative to $PWD
         according to the physical/logical option.  The shell already
         canonicalizes the directory name in order to tell readline where
         to look, so not doing it here will be inconsistent. */
      /* XXX -- currently not used -- will introduce more inconsistency,
         since shell does not canonicalize ../foo before passing it to
         shell_execve().  */
      if (match && searching_path == 0 && *val == '.')
        {
          char *t, *t1;

          t = get_working_directory ("command-word-completion");
          t1 = make_absolute (val, t);
          free (t);
          cval = sh_canonpath (t1, PATH_CHECKDOTDOT|PATH_CHECKEXISTS);
          free (t1);
        }
      else
#endif
        cval = val;

      if (match && executable_completion ((searching_path ? val : cval), searching_path))
        {
          if (cval != val)
            free (cval);
          free (val);
          val = "";             /* So it won't be NULL. */
          return (temp);
        }
      else
        {
          if (freetemp)
            free (temp);
          if (cval != val)
            free (cval);
          free (val);
          goto inner;
        }
    }
}

/* Completion inside an unterminated command substitution. */
static char *
command_subst_completion_function (const char *text, int state)
{
  static char **matches = (char **)NULL;
  static const char *orig_start;
  static char *filename_text = (char *)NULL;
  static int cmd_index, start_len;
  char *value;

  if (state == 0)
    {
      if (filename_text)
        free (filename_text);
      orig_start = text;
      if (*text == '`')
        text++;
      else if (*text == '$' && text[1] == '(')  /* ) */
        text += 2;
      else if (*text == '$' && text[1] == '{' && FUNSUB_CHAR (text[2])) /*}*/
        text += 3;      /* nofork command substitution */
      /* If the text was quoted, suppress any quote character that the
         readline completion code would insert. */
      rl_completion_suppress_quote = 1;
      start_len = text - orig_start;
      filename_text = savestring (text);
      if (matches)
        {
          free (matches);
          matches = (char **)NULL;
        }

      /*
       * At this point we can entertain the idea of re-parsing
       * `filename_text' into a (possibly incomplete) command name and
       * arguments, and doing completion based on that.  This is
       * currently very rudimentary, but it is a small improvement.
       */
      for (value = filename_text + strlen (filename_text) - 1; value > filename_text; value--)
        if (whitespace (*value) || member (*value, COMMAND_SEPARATORS))
          break;
      if (value <= filename_text)
        matches = rl_completion_matches (filename_text, command_word_completion_function);
      else
        {
          value++;
          start_len += value - filename_text;
          if (whitespace (value[-1]))
            matches = rl_completion_matches (value, rl_filename_completion_function);
          else
            matches = rl_completion_matches (value, command_word_completion_function);
        }

      /* If there is more than one match, rl_completion_matches has already
         put the lcd in matches[0].  Skip over it. */
      cmd_index = matches && matches[0] && matches[1];

      /* If there's a single match and it's a directory, set the append char
         to the expected `/'.  Otherwise, don't append anything. */
      if (matches && matches[0] && matches[1] == 0 && test_for_directory (matches[0]))
        rl_completion_append_character = '/';
      else
        rl_completion_suppress_append = 1;
    }

  if (matches == 0 || matches[cmd_index] == 0)
    {
      rl_filename_quoting_desired = 0;  /* disable quoting */
      return ((char *)NULL);
    }
  else
    {
      value = (char *)xmalloc (1 + start_len + strlen (matches[cmd_index]));

      if (start_len == 1)
        value[0] = *orig_start;
      else
        strncpy (value, orig_start, start_len);

      strcpy (value + start_len, matches[cmd_index]);

      cmd_index++;
      return (value);
    }
}

/* Okay, now we write the entry_function for variable completion. */
static char *
variable_completion_function (const char *text, int state)
{
  static char **varlist = (char **)NULL;
  static int varlist_index;
  static char *varname = (char *)NULL;
  static int first_char, first_char_loc;

  if (!state)
    {
      if (varname)
        free (varname);

      first_char_loc = 0;
      first_char = text[0];

      if (first_char == '$')
        first_char_loc++;

      if (text[first_char_loc] == '{')
        first_char_loc++;

      varname = savestring (text + first_char_loc);

      if (varlist)
        strvec_dispose (varlist);

      varlist = all_variables_matching_prefix (varname);
      varlist_index = 0;
    }

  if (!varlist || !varlist[varlist_index])
    {
      return ((char *)NULL);
    }
  else
    {
      char *value;

      value = (char *)xmalloc (4 + strlen (varlist[varlist_index]));

      if (first_char_loc)
        {
          value[0] = first_char;
          if (first_char_loc == 2)
            value[1] = '{';
        }

      strcpy (value + first_char_loc, varlist[varlist_index]);
      if (first_char_loc == 2)
        strcat (value, "}");

      varlist_index++;
      return (value);
    }
}

/* How about a completion function for hostnames? */
static char *
hostname_completion_function (const char *text, int state)
{
  static char **list = (char **)NULL;
  static int list_index = 0;
  static int first_char, first_char_loc;

  /* If we don't have any state, make some. */
  if (state == 0)
    {
      FREE (list);

      list = (char **)NULL;

      first_char_loc = 0;
      first_char = *text;

      if (first_char == '@')
        first_char_loc++;

      list = hostnames_matching ((char *)text+first_char_loc);
      list_index = 0;
    }

  if (list && list[list_index])
    {
      char *t;

      t = (char *)xmalloc (2 + strlen (list[list_index]));
      *t = first_char;
      strcpy (t + first_char_loc, list[list_index]);
      list_index++;
      return (t);
    }

  return ((char *)NULL);
}

/*
 * A completion function for service names from /etc/services (or wherever).
 */
char *
bash_servicename_completion_function (const char *text, int state)
{
#if defined (__WIN32__) || defined (__OPENNT) || !defined (HAVE_GETSERVENT)
  return ((char *)NULL);
#else
  static char *sname = (char *)NULL;
  static struct servent *srvent;
  static size_t snamelen;
  char *value;
  char **alist, *aentry;
  int afound;

  if (state == 0)
    {
      FREE (sname);

      sname = savestring (text);
      snamelen = strlen (sname);
      setservent (0);
    }

  while (srvent = getservent ())
    {
      afound = 0;
      if (snamelen == 0 || (STREQN (sname, srvent->s_name, snamelen)))
        break;
      /* Not primary, check aliases */
      for (alist = srvent->s_aliases; *alist; alist++)
        {
          aentry = *alist;
          if (STREQN (sname, aentry, snamelen))
            {
              afound = 1;
              break;
            }
        }

      if (afound)
        break;
    }

  if (srvent == 0)
    {
      endservent ();
      return ((char *)NULL);
    }

  value = afound ? savestring (aentry) : savestring (srvent->s_name);
  return value;
#endif
}

/*
 * A completion function for group names from /etc/group (or wherever).
 */
char *
bash_groupname_completion_function (const char *text, int state)
{
#if defined (__WIN32__) || defined (__OPENNT) || !defined (HAVE_GRP_H)
  return ((char *)NULL);
#else
  static char *gname = (char *)NULL;
  static struct group *grent;
  static size_t gnamelen;
  char *value;

  if (state == 0)
    {
      FREE (gname);
      gname = savestring (text);
      gnamelen = strlen (gname);

      setgrent ();
    }

  while (grent = getgrent ())
    {
      if (gnamelen == 0 || (STREQN (gname, grent->gr_name, gnamelen)))
        break;
    }

  if (grent == 0)
    {
      endgrent ();
      return ((char *)NULL);
    }

  value = savestring (grent->gr_name);
  return (value);
#endif
}

/* Functions to perform history and alias expansions on the current line. */

#if defined (BANG_HISTORY)
/* Perform history expansion on the current line.  If no history expansion
   is done, pre_process_line() returns what it was passed, so we need to
   allocate a new line here. */
static char *
history_expand_line_internal (char *line)
{
  char *new_line;
  int old_verify;

  old_verify = hist_verify;
  hist_verify = 0;
  new_line = pre_process_line (line, 0, 0);
  hist_verify = old_verify;

  return (new_line == line) ? savestring (line) : new_line;
}
#endif

/* There was an error in expansion.  Let the preprocessor print
   the error here. */
static void
cleanup_expansion_error (void)
{
  char *to_free;
#if defined (BANG_HISTORY)
  int old_verify;

  old_verify = hist_verify;
  hist_verify = 0;
#endif

  fprintf (rl_outstream, "\r\n");
  to_free = pre_process_line (rl_line_buffer, 1, 0);
#if defined (BANG_HISTORY)
  hist_verify = old_verify;
#endif
  if (to_free != rl_line_buffer)
    FREE (to_free);
  putc ('\r', rl_outstream);
  rl_forced_update_display ();
}

/* If NEW_LINE differs from what is in the readline line buffer, add an
   undo record to get from the readline line buffer contents to the new
   line and make NEW_LINE the current readline line. */
static void
maybe_make_readline_line (const char *new_line)
{
  if (new_line && strcmp (new_line, rl_line_buffer) != 0)
    {
      rl_point = rl_end;

      rl_add_undo (UNDO_BEGIN, 0, 0, 0);
      rl_delete_text (0, rl_point);
      rl_point = rl_end = rl_mark = 0;
      rl_insert_text (new_line);
      rl_add_undo (UNDO_END, 0, 0, 0);
    }
}

/* Make NEW_LINE be the current readline line.  This frees NEW_LINE. We use
   several heuristics to decide where to put rl_point. */

static void
set_up_new_line (char *new_line)
{

  int old_point, old_end, dist, nb;
  char *s, *t;

  /* If we didn't expand anything, don't change anything. */
  if (STREQ (new_line, rl_line_buffer))
    {
      free (new_line);
      return;
    }

  old_point = rl_point;
  old_end = rl_end;
  dist = rl_end - rl_point;
  nb = rl_end - old_end;

  /* If the line was history and alias expanded, then make that
     be one thing to undo. */
  maybe_make_readline_line (new_line);
  free (new_line);

  /* Place rl_point where we think it should go. */
  if (dist == 0)
    rl_point = rl_end;
  else if (old_point == 0)
    {
      /* this is what the old code did, but separate it out so we can treat
         it differently */
      rl_point = 0;
      if (!whitespace (rl_line_buffer[rl_point]))
        rl_forward_word (1, 0);
    }
  else if (rl_point < old_point+nb)
    {
      /* let's assume that this means the new point is within the changed region */
      rl_point = old_point;
      if (!whitespace (rl_line_buffer[rl_point]))
        rl_forward_word (1, 0);
    }
  else
    rl_point = rl_end - dist;   /* try to put point the same distance from end */

  if (rl_point < 0)
    rl_point = 0;
  else if (rl_point > rl_end)
    rl_point = rl_end;
  rl_mark = 0;          /* XXX */
}

#if defined (ALIAS)
/* Expand aliases in the current readline line. */
static int
alias_expand_line (int count, int ignore)
{
  char *new_line;

  new_line = alias_expand (rl_line_buffer);

  if (new_line)
    {
      set_up_new_line (new_line);
      return (0);
    }
  else
    {
      cleanup_expansion_error ();
      return (1);
    }
}
#endif

#if defined (BANG_HISTORY)
/* History expand the line. */
static int
history_expand_line (int count, int ignore)
{
  char *new_line;

  new_line = history_expand_line_internal (rl_line_buffer);

  if (new_line)
    {
      set_up_new_line (new_line);
      return (0);
    }
  else
    {
      cleanup_expansion_error ();
      return (1);
    }
}

/* Expand history substitutions in the current line and then insert a
   space (hopefully close to where we were before). */
static int
tcsh_magic_space (int count, int ignore)
{
  int dist_from_end, old_point;

  old_point = rl_point;
  dist_from_end = rl_end - rl_point;
  if (history_expand_line (count, ignore) == 0)
    {
      /* Try a simple heuristic from Stephen Gildea <gildea@intouchsys.com>.
         This works if all expansions were before rl_point or if no expansions
         were performed. */
      rl_point = (old_point == 0) ? old_point : rl_end - dist_from_end;
      rl_insert (1, ' ');
      return (0);
    }
  else
    return (1);
}
#endif /* BANG_HISTORY */

/* History and alias expand the line. */
static int
history_and_alias_expand_line (int count, int ignore)
{
  char *new_line;

  new_line = 0;
#if defined (BANG_HISTORY)
  new_line = history_expand_line_internal (rl_line_buffer);
#endif

#if defined (ALIAS)
  if (new_line)
    {
      char *alias_line;

      alias_line = alias_expand (new_line);
      free (new_line);
      new_line = alias_line;
    }
#endif /* ALIAS */

  if (new_line)
    {
      set_up_new_line (new_line);
      return (0);
    }
  else
    {
      cleanup_expansion_error ();
      return (1);
    }
}

/* History and alias expand the line, then perform the shell word
   expansions by calling expand_string.  This can't use set_up_new_line()
   because we want the variable expansions as a separate undo'able
   set of operations. */
static int
shell_expand_line (int count, int ignore)
{
  char *new_line, *t;
  WORD_LIST *expanded_string;
  WORD_DESC *w;

  new_line = 0;
#if defined (BANG_HISTORY)
  new_line = history_expand_line_internal (rl_line_buffer);
#endif

  t = expand_string_dollar_quote (new_line ? new_line : rl_line_buffer, 0);
  FREE (new_line);
  new_line = t;

#if defined (ALIAS)
  if (new_line)
    {
      char *alias_line;

      alias_line = alias_expand (new_line);
      free (new_line);
      new_line = alias_line;
    }
#endif /* ALIAS */

  if (new_line)
    {
      int old_point = rl_point;
      int at_end = rl_point == rl_end;

      /* If the line was history and alias expanded, then make that
         be one thing to undo. */
      maybe_make_readline_line (new_line);
      free (new_line);

      /* If there is variable expansion to perform, do that as a separate
         operation to be undone. */

#if 1
      w = alloc_word_desc ();
      w->word = savestring (rl_line_buffer);
      w->flags = rl_explicit_arg ? (W_NOPROCSUB|W_NOCOMSUB) : 0;
      expanded_string = expand_word (w, rl_explicit_arg ? Q_HERE_DOCUMENT : 0);
      dispose_word (w);
#else
      new_line = savestring (rl_line_buffer);
      expanded_string = expand_string (new_line, 0);
      FREE (new_line);
#endif

      if (expanded_string == 0)
        {
          new_line = (char *)xmalloc (1);
          new_line[0] = '\0';
        }
      else
        {
          new_line = string_list (expanded_string);
          dispose_words (expanded_string);
        }

      maybe_make_readline_line (new_line);
      free (new_line);

      /* Place rl_point where we think it should go. */
      if (at_end)
        rl_point = rl_end;
      else if (old_point < rl_end)
        {
          rl_point = old_point;
          if (!whitespace (rl_line_buffer[rl_point]))
            rl_forward_word (1, 0);
        }
      return 0;
    }
  else
    {
      cleanup_expansion_error ();
      return 1;
    }
}

/* If FIGNORE is set, then don't match files with the given suffixes when
   completing filenames.  If only one of the possibilities has an acceptable
   suffix, delete the others, else just return and let the completer
   signal an error.  It is called by the completer when real
   completions are done on filenames by the completer's internal
   function, not for completion lists (M-?) and not on "other"
   completion types, such as hostnames or commands. */

static struct ignorevar fignore =
{
  "FIGNORE",
  (struct ign *)0,
  0,
  (char *)0,
  (sh_iv_item_func_t *) 0,
};

static void
_ignore_completion_names (char **names, sh_ignore_func_t *name_func)
{
  char **newnames;
  size_t idx, nidx;
  char **oldnames;
  int oidx;

  /* If there is only one completion, see if it is acceptable.  If it is
     not, free it up.  In any case, short-circuit and return.  This is a
     special case because names[0] is not the prefix of the list of names
     if there is only one completion; it is the completion itself. */
  if (names[1] == (char *)0)
    {
      if (force_fignore)
        if ((*name_func) (names[0]) == 0)
          {
            free (names[0]);
            names[0] = (char *)NULL;
          }

      return;
    }

  /* Allocate space for array to hold list of pointers to matching
     filenames.  The pointers are copied back to NAMES when done. */
  for (nidx = 1; names[nidx]; nidx++)
    ;
  newnames = strvec_create (nidx + 1);

  if (force_fignore == 0)
    {
      oldnames = strvec_create (nidx - 1);
      oidx = 0;
    }

  newnames[0] = names[0];
  for (idx = nidx = 1; names[idx]; idx++)
    {
      if ((*name_func) (names[idx]))
        newnames[nidx++] = names[idx];
      else if (force_fignore == 0)
        oldnames[oidx++] = names[idx];
      else
        free (names[idx]);
    }

  newnames[nidx] = (char *)NULL;

  /* If none are acceptable then let the completer handle it. */
  if (nidx == 1)
    {
      if (force_fignore)
        {
          free (names[0]);
          names[0] = (char *)NULL;
        }
      else
        free (oldnames);

      free (newnames);
      return;
    }

  if (force_fignore == 0)
    {
      while (oidx)
        free (oldnames[--oidx]);
      free (oldnames);
    }

  /* If only one is acceptable, copy it to names[0] and return. */
  if (nidx == 2)
    {
      free (names[0]);
      names[0] = newnames[1];
      names[1] = (char *)NULL;
      free (newnames);
      return;
    }

  /* Copy the acceptable names back to NAMES, set the new array end,
     and return. */
  for (nidx = 1; newnames[nidx]; nidx++)
    names[nidx] = newnames[nidx];
  names[nidx] = (char *)NULL;
  free (newnames);
}

static int
name_is_acceptable (const char *name)
{
  struct ign *p;
  size_t nlen;

  for (nlen = strlen (name), p = fignore.ignores; p->val; p++)
    {
      if (nlen >= p->len && p->len > 0 && STREQ (p->val, &name[nlen - p->len]))
        return (0);
    }

  return (1);
}

#if 0
static int
ignore_dot_names (const char *name)
{
  return (name[0] != '.');
}
#endif

static int
filename_completion_ignore (char **names)
{
#if 0
  if (glob_dot_filenames == 0)
    _ignore_completion_names (names, ignore_dot_names);
#endif

  setup_ignore_patterns (&fignore);

  if (fignore.num_ignores == 0)
    return 0;

  _ignore_completion_names (names, name_is_acceptable);

  return 0;
}

/* Return 1 if NAME is a directory.  NAME undergoes tilde expansion. */
static int
test_for_directory (const char *name)
{
  char *fn;
  int r;

  fn = bash_tilde_expand (name, 0);
  r = file_isdir (fn);
  free (fn);

  return (r);
}

static int
test_for_canon_directory (const char *name)
{
  char *fn;
  int r;

  fn = (*name == '~') ? bash_tilde_expand (name, 0) : savestring (name);
  bash_filename_stat_hook (&fn);
  r = file_isdir (fn);
  free (fn);

  return (r);
}

/* Remove files from NAMES, leaving directories. */
static int
bash_ignore_filenames (char **names)
{
  _ignore_completion_names (names, test_for_directory);
  return 0;
}

static int
bash_progcomp_ignore_filenames (char **names)
{
  _ignore_completion_names (names, test_for_canon_directory);
  return 0;
}

static int
return_zero (const char *name)
{
  return 0;
}

static int
bash_ignore_everything (char **names)
{
  _ignore_completion_names (names, return_zero);
  return 0;
}

/* Replace a tilde-prefix in VAL with a `~', assuming the user typed it.  VAL
   is an expanded filename.  DIRECTORY_PART is the tilde-prefix portion
   of the un-tilde-expanded version of VAL (what the user typed). */
static char *
restore_tilde (const char *val, char *directory_part)
{
  size_t l, vl, dl2, xl;
  char *dh2, *expdir, *ret, *v;

  vl = strlen (val);

  /* We need to duplicate the expansions readline performs on the directory
     portion before passing it to our completion function. */
  dh2 = directory_part ? bash_dequote_filename (directory_part, 0) : 0;
  bash_directory_expansion (&dh2);
  dl2 = strlen (dh2);

  expdir = bash_tilde_expand (directory_part, 0);
  xl = strlen (expdir);
  if (*directory_part == '~' && STREQ (directory_part, expdir))
    {
      /* tilde expansion failed, so what should we return? we use what the
         user typed. */
      v = mbschr (val, '/');
      vl = STRLEN (v);
      ret = (char *)xmalloc (xl + vl + 2);
      strcpy (ret, directory_part);
      if (v && *v)
        strcpy (ret + xl, v);

      free (dh2);
      free (expdir);

      return ret;
    }
  free (expdir);

  /*
     dh2 = unexpanded but dequoted tilde-prefix
     dl2 = length of tilde-prefix
     expdir = tilde-expanded tilde-prefix
     xl = length of expanded tilde-prefix
     l = length of remainder after tilde-prefix
  */
  l = (vl - xl) + 1;
  if (l <= 0)
    {
      free (dh2);
      return (savestring (val));                /* XXX - just punt */
    }

  ret = (char *)xmalloc (dl2 + 2 + l);
  strcpy (ret, dh2);
  strcpy (ret + dl2, val + xl);

  free (dh2);
  return (ret);
}

static char *
maybe_restore_tilde (char *val, char *directory_part)
{
  rl_icppfunc_t *save;
  char *ret;

  save = (dircomplete_expand == 0) ? save_directory_hook () : (rl_icppfunc_t *)0;
  ret = restore_tilde (val, directory_part);
  if (save)
    restore_directory_hook (save);
  return ret;
}

/* Simulate the expansions that will be performed by
   rl_filename_completion_function.  This must be called with the address of
   a pointer to malloc'd memory. */
static void
bash_directory_expansion (char **dirname)
{
  char *d, *nd;

  d = savestring (*dirname);

  if ((rl_directory_rewrite_hook) && (*rl_directory_rewrite_hook) (&d))
    {
      free (*dirname);
      *dirname = d;
    }
  else if (rl_directory_completion_hook && (*rl_directory_completion_hook) (&d))
    {
      free (*dirname);
      *dirname = d;
    }
  else if (rl_completion_found_quote)
    {
      nd = bash_dequote_filename (d, rl_completion_quote_character);
      free (*dirname);
      free (d);
      *dirname = nd;
    }
  else
    free (d);
}

/* If necessary, rewrite directory entry */
static char *
bash_filename_rewrite_hook (char *fname, int fnlen)
{
  char *conv;

  conv = fnx_fromfs (fname, fnlen);
  if (conv != fname)
    conv = savestring (conv);
  return conv;
}

/* Functions to save and restore the appropriate directory hook */
/* This is not static so the shopt code can call it */
void
set_directory_hook (void)
{
  if (dircomplete_expand)
    {
      rl_directory_completion_hook = bash_directory_completion_hook;
      rl_directory_rewrite_hook = (rl_icppfunc_t *)0;
    }
  else
    {
      rl_directory_rewrite_hook = bash_directory_completion_hook;
      rl_directory_completion_hook = (rl_icppfunc_t *)0;
    }
}

static rl_icppfunc_t *
save_directory_hook (void)
{
  rl_icppfunc_t *ret;

  if (dircomplete_expand)
    {
      ret = rl_directory_completion_hook;
      rl_directory_completion_hook = (rl_icppfunc_t *)NULL;
    }
  else
    {
      ret = rl_directory_rewrite_hook;
      rl_directory_rewrite_hook = (rl_icppfunc_t *)NULL;
    }

  return ret;
}

static void
restore_directory_hook (rl_icppfunc_t *hookf)
{
  if (dircomplete_expand)
    rl_directory_completion_hook = hookf;
  else
    rl_directory_rewrite_hook = hookf;
}

/* Set the readline hooks that affect how directories and filenames are
   converted. Extern so other parts of the shell can use. */
void
bashline_set_filename_hooks (void)
{
  /* Tell the completer that we might want to follow symbolic links or
     do other expansion on directory names. */
  set_directory_hook ();

  rl_filename_rewrite_hook = bash_filename_rewrite_hook;
  rl_completion_rewrite_hook = bash_filename_rewrite_hook;
  rl_filename_stat_hook = bash_filename_stat_hook;
}

/* Check whether not DIRNAME, with any trailing slash removed, exists.  If
   SHOULD_DEQUOTE is non-zero, we dequote the directory name first. */
static int
directory_exists (const char *dirname, int should_dequote)
{
  char *new_dirname;
  int dirlen, r;
  struct stat sb;

  /* We save the string and chop the trailing slash because stat/lstat behave
     inconsistently if one is present. */
  new_dirname = should_dequote ? bash_dequote_filename ((char *)dirname, rl_completion_quote_character) : savestring (dirname);
  dirlen = STRLEN (new_dirname);
  if (new_dirname[dirlen - 1] == '/')
    new_dirname[dirlen - 1] = '\0';
#if defined (HAVE_LSTAT)
  r = lstat (new_dirname, &sb) == 0;
#else
  r = stat (new_dirname, &sb) == 0;
#endif
  free (new_dirname);
  return (r);
}

static char *
bash_expand_filename (char *filename)
{
  char *newname;
  int global_nounset;
  WORD_LIST *wl;

  newname = savestring (filename);
  /* no error messages, and expand_prompt_string doesn't longjmp so we don't
     have to worry about restoring this setting. */
  global_nounset = unbound_vars_is_error;
  unbound_vars_is_error = 0;
  wl = expand_prompt_string (newname, 0, W_NOCOMSUB|W_NOPROCSUB|W_COMPLETE);    /* does the right thing */
  unbound_vars_is_error = global_nounset;
  free (newname);

  if (wl == 0)
    return filename;
  else
    {
      newname = string_list (wl);
      dispose_words (wl);
      if (newname && *newname && STREQ (newname, filename))
        {
          free (newname);
          return filename;
        }
      return newname;
    }
}
  
/* Expand a filename before the readline completion code passes it to stat(2).
   The filename will already have had tilde expansion performed. */
static int
bash_filename_stat_hook (char **dirname)
{
  char *local_dirname, *new_dirname, *t;
  int should_expand_dirname, return_value;
  int global_nounset;
  WORD_LIST *wl;

  local_dirname = *dirname;
  should_expand_dirname = return_value = 0;
  if (t = mbschr (local_dirname, '$'))
    should_expand_dirname = '$';
  else if (t = mbschr (local_dirname, '`'))     /* XXX */
    should_expand_dirname = '`';

  if (should_expand_dirname && directory_exists (local_dirname, 0))
    should_expand_dirname = 0;
  
  if (should_expand_dirname)  
    {
      new_dirname = savestring (local_dirname);
      /* no error messages, and expand_prompt_string doesn't longjmp so we don't
         have to worry about restoring this setting. */
      global_nounset = unbound_vars_is_error;
      unbound_vars_is_error = 0;
      wl = expand_prompt_string (new_dirname, 0, W_NOCOMSUB|W_NOPROCSUB|W_COMPLETE);    /* does the right thing */
      unbound_vars_is_error = global_nounset;
      if (wl)
        {
          free (new_dirname);
          new_dirname = string_list (wl);
          /* Tell the completer we actually expanded something and change
             *dirname only if we expanded to something non-null -- stat
             behaves unpredictably when passed null or empty strings */
          if (new_dirname && *new_dirname)
            {
              free (local_dirname);     /* XXX */
              local_dirname = *dirname = new_dirname;
              return_value = STREQ (local_dirname, *dirname) == 0;
            }
          else
            free (new_dirname);
          dispose_words (wl);
        }
      else
        free (new_dirname);
    }   

  /* This is very similar to the code in bash_directory_completion_hook below,
     but without spelling correction and not worrying about whether or not
     we change relative pathnames. */
  if (no_symbolic_links == 0 && (local_dirname[0] != '.' || local_dirname[1]))
    {
      char *temp1, *temp2;

      t = get_working_directory ("symlink-hook");
      temp1 = make_absolute (local_dirname, t);
      free (t);
      temp2 = sh_canonpath (temp1, PATH_CHECKDOTDOT|PATH_CHECKEXISTS);

      /* If we can't canonicalize, bail. */
      if (temp2 == 0)
        {
          free (temp1);
          return return_value;
        }

      free (local_dirname);
      *dirname = temp2;
      free (temp1);
    }

  return (return_value);
}

/* Handle symbolic link references and other directory name
   expansions while hacking completion.  This should return 1 if it modifies
   the DIRNAME argument, 0 otherwise.  It should make sure not to modify
   DIRNAME if it returns 0. */
static int
bash_directory_completion_hook (char **dirname)
{
  char *local_dirname, *new_dirname, *t;
  int return_value, should_expand_dirname, nextch, closer;
  WORD_LIST *wl;

  return_value = should_expand_dirname = nextch = closer = 0;
  local_dirname = *dirname;

  should_expand_dirname = bash_check_expchar (local_dirname, 1, &nextch, &closer);

  if (should_expand_dirname && directory_exists (local_dirname, 1))
    should_expand_dirname = 0;

  if (should_expand_dirname)  
    {
      new_dirname = savestring (local_dirname);
      wl = expand_prompt_string (new_dirname, 0, W_NOCOMSUB|W_NOPROCSUB|W_COMPLETE);    /* does the right thing */
      if (wl)
        {
          *dirname = string_list (wl);
          /* Tell the completer to replace the directory name only if we
             actually expanded something. */
          return_value = STREQ (local_dirname, *dirname) == 0;
          free (local_dirname);
          free (new_dirname);
          dispose_words (wl);
          local_dirname = *dirname;

          set_filename_quote_chars (should_expand_dirname, nextch, closer);
        }
      else
        {
          free (new_dirname);
          free (local_dirname);
          *dirname = (char *)xmalloc (1);
          **dirname = '\0';
          return 1;
        }
    }
  else 
    {
      /* Dequote the filename even if we don't expand it. */
      new_dirname = bash_dequote_filename (local_dirname, rl_completion_quote_character);
      return_value = STREQ (local_dirname, new_dirname) == 0;
      free (local_dirname);
      local_dirname = *dirname = new_dirname;
    }

  /* no_symbolic_links == 0 -> use (default) logical view of the file system.
     local_dirname[0] == '.' && local_dirname[1] == '/' means files in the
     current directory (./).
     local_dirname[0] == '.' && local_dirname[1] == 0 means relative pathnames
     in the current directory (e.g., lib/sh).
     XXX - should we do spelling correction on these? */

  /* This is test as it was in bash-4.2: skip relative pathnames in current
     directory.  Change test to
      (local_dirname[0] != '.' || (local_dirname[1] && local_dirname[1] != '/'))
     if we want to skip paths beginning with ./ also. */
  if (no_symbolic_links == 0 && (local_dirname[0] != '.' || local_dirname[1]))
    {
      char *temp1, *temp2;
      size_t len1, len2;

      /* If we have a relative path
                (local_dirname[0] != '/' && local_dirname[0] != '.')
         that is canonical after appending it to the current directory, then
                temp1 = temp2+'/'
         That is,
                strcmp (temp1, temp2) == 0
         after adding a slash to temp2 below.  It should be safe to not
         change those.
      */
      t = get_working_directory ("symlink-hook");
      temp1 = make_absolute (local_dirname, t);
      free (t);
      temp2 = sh_canonpath (temp1, PATH_CHECKDOTDOT|PATH_CHECKEXISTS);

      /* Try spelling correction if initial canonicalization fails.  Make
         sure we are set to replace the directory name with the results so
         subsequent directory checks don't fail. */
      if (temp2 == 0 && dircomplete_spelling && dircomplete_expand)
        {
          size_t l1, l2;

          temp2 = dirspell (temp1);
          l2 = STRLEN (temp2);
          /* Don't take matches if they are shorter than the original path */
          if (temp2 && l2 < strlen (temp1) && STREQN (temp1, temp2, l2))
            {
              free (temp2);
              temp2 = 0;
            }
          if (temp2)
            {
              free (temp1);
              temp1 = temp2;
              temp2 = sh_canonpath (temp1, PATH_CHECKDOTDOT|PATH_CHECKEXISTS);
              return_value |= temp2 != 0;
            }
        }
      /* If we can't canonicalize, bail. */
      if (temp2 == 0)
        {
          free (temp1);
          return return_value;
        }
      len1 = strlen (temp1);
      if (temp1[len1 - 1] == '/')
        {
          len2 = strlen (temp2);
          if (len2 > 2)         /* don't append `/' to `/' or `//' */
            {
              temp2 = (char *)xrealloc (temp2, len2 + 2);
              temp2[len2] = '/';
              temp2[len2 + 1] = '\0';
            }
        }

      /* dircomplete_expand_relpath == 0 means we want to leave relative
         pathnames that are unchanged by canonicalization alone.
         *local_dirname != '/' && *local_dirname != '.' == relative pathname
         (consistent with general.c:absolute_pathname())
         temp1 == temp2 (after appending a slash to temp2) means the pathname
         is not changed by canonicalization as described above. */
      if (dircomplete_expand_relpath || ((local_dirname[0] != '/' && local_dirname[0] != '.') && STREQ (temp1, temp2) == 0))
        return_value |= STREQ (local_dirname, temp2) == 0;
      free (local_dirname);
      *dirname = temp2;
      free (temp1);
    }

  return (return_value);
}

static char **history_completion_array = (char **)NULL;
static size_t harry_size;
static size_t harry_len;

static void
build_history_completion_array (void)
{
  register int i, j;
  HIST_ENTRY **hlist;
  char **tokens;

  /* First, clear out the current dynamic history completion list. */
  if (harry_size)
    {
      strvec_dispose (history_completion_array);
      history_completion_array = (char **)NULL;
      harry_size = 0;
      harry_len = 0;
    }

  /* Next, grovel each line of history, making each shell-sized token
     a separate entry in the history_completion_array. */
  hlist = history_list ();

  if (hlist)
    {
      for (i = 0; hlist[i]; i++)
        ;
      for ( --i; i >= 0; i--)
        {
          /* Separate each token, and place into an array. */
          tokens = history_tokenize (hlist[i]->line);

          for (j = 0; tokens && tokens[j]; j++)
            {
              if (harry_len + 2 > harry_size)
                history_completion_array = strvec_resize (history_completion_array, harry_size += 10);

              history_completion_array[harry_len++] = tokens[j];
              history_completion_array[harry_len] = (char *)NULL;
            }
          free (tokens);
        }

      /* Sort the complete list of tokens. */
      if (dabbrev_expand_active == 0)
        qsort (history_completion_array, harry_len, sizeof (char *), (QSFUNC *)strvec_strcmp);
    }
}

static char *
history_completion_generator (const char *hint_text, int state)
{
  static int local_index;
  static size_t len;
  static const char *text;

  /* If this is the first call to the generator, then initialize the
     list of strings to complete over. */
  if (state == 0)
    {
      if (dabbrev_expand_active)        /* This is kind of messy */
        rl_completion_suppress_append = 1;
      local_index = 0;
      build_history_completion_array ();
      text = hint_text;
      len = strlen (text);
    }

  while (history_completion_array && history_completion_array[local_index])
    {
      /* XXX - should this use completion-ignore-case? */
      if (strncmp (text, history_completion_array[local_index++], len) == 0)
        return (savestring (history_completion_array[local_index - 1]));
    }
  return ((char *)NULL);
}

static int
dynamic_complete_history (int count, int key)
{
  int r;
  rl_compentry_func_t *orig_func;
  rl_completion_func_t *orig_attempt_func;
  rl_compignore_func_t *orig_ignore_func;

  orig_func = rl_completion_entry_function;
  orig_attempt_func = rl_attempted_completion_function;
  orig_ignore_func = rl_ignore_some_completions_function;

  rl_completion_entry_function = history_completion_generator;
  rl_attempted_completion_function = (rl_completion_func_t *)NULL;
  rl_ignore_some_completions_function = filename_completion_ignore;

  /* XXX - use rl_completion_mode here? */
  if (rl_last_func == dynamic_complete_history)
    r = rl_complete_internal ('?');
  else
    r = rl_complete_internal (TAB);

  rl_completion_entry_function = orig_func;
  rl_attempted_completion_function = orig_attempt_func;
  rl_ignore_some_completions_function = orig_ignore_func;

  return r;
}

static int
bash_dabbrev_expand (int count, int key)
{
  int r, orig_suppress, orig_sort;
  rl_compentry_func_t *orig_func;
  rl_completion_func_t *orig_attempt_func;
  rl_compignore_func_t *orig_ignore_func;

  orig_func = rl_menu_completion_entry_function;
  orig_attempt_func = rl_attempted_completion_function;
  orig_ignore_func = rl_ignore_some_completions_function;
  orig_suppress = rl_completion_suppress_append;
  orig_sort = rl_sort_completion_matches;

  rl_menu_completion_entry_function = history_completion_generator;
  rl_attempted_completion_function = (rl_completion_func_t *)NULL;
  rl_ignore_some_completions_function = filename_completion_ignore;
  rl_filename_completion_desired = 0;
  rl_completion_suppress_append = 1;
  rl_sort_completion_matches = 0;

  /* XXX - use rl_completion_mode here? */
  dabbrev_expand_active = 1;
  if (rl_last_func == bash_dabbrev_expand)
    rl_last_func = rl_menu_complete;
  r = rl_menu_complete (count, key);
  dabbrev_expand_active = 0;

  rl_last_func = bash_dabbrev_expand;
  rl_menu_completion_entry_function = orig_func;
  rl_attempted_completion_function = orig_attempt_func;
  rl_ignore_some_completions_function = orig_ignore_func;
  rl_completion_suppress_append = orig_suppress;
  rl_sort_completion_matches = orig_sort;

  return r;
}

#if defined (SPECIFIC_COMPLETION_FUNCTIONS)
static int
bash_complete_username (int ignore, int ignore2)
{
  return bash_complete_username_internal (rl_completion_mode (bash_complete_username));
}

static int
bash_possible_username_completions (int ignore, int ignore2)
{
  return bash_complete_username_internal ('?');
}

static int
bash_complete_username_internal (int what_to_do)
{
  return bash_specific_completion (what_to_do, rl_username_completion_function);
}

static int
bash_complete_filename (int ignore, int ignore2)
{
  return bash_complete_filename_internal (rl_completion_mode (bash_complete_filename));
}

static int
bash_possible_filename_completions (int ignore, int ignore2)
{
  return bash_complete_filename_internal ('?');
}

static int
bash_complete_filename_internal (int what_to_do)
{
  rl_compentry_func_t *orig_func;
  rl_completion_func_t *orig_attempt_func;
  rl_icppfunc_t *orig_dir_func;
  rl_compignore_func_t *orig_ignore_func;
  const char *orig_rl_completer_word_break_characters;
  int r;

  orig_func = rl_completion_entry_function;
  orig_attempt_func = rl_attempted_completion_function;
  orig_ignore_func = rl_ignore_some_completions_function;
  orig_rl_completer_word_break_characters = rl_completer_word_break_characters;

  orig_dir_func = save_directory_hook ();

  rl_completion_entry_function = rl_filename_completion_function;
  rl_attempted_completion_function = (rl_completion_func_t *)NULL;
  rl_ignore_some_completions_function = filename_completion_ignore;
  rl_completer_word_break_characters = " \t\n\"\'";

  r = rl_complete_internal (what_to_do);

  rl_completion_entry_function = orig_func;
  rl_attempted_completion_function = orig_attempt_func;
  rl_ignore_some_completions_function = orig_ignore_func;
  rl_completer_word_break_characters = orig_rl_completer_word_break_characters;

  restore_directory_hook (orig_dir_func);

  return r;
}

static int
bash_complete_hostname (int ignore, int ignore2)
{
  return bash_complete_hostname_internal (rl_completion_mode (bash_complete_hostname));
}

static int
bash_possible_hostname_completions (int ignore, int ignore2)
{
  return bash_complete_hostname_internal ('?');
}

static int
bash_complete_variable (int ignore, int ignore2)
{
  return bash_complete_variable_internal (rl_completion_mode (bash_complete_variable));
}

static int
bash_possible_variable_completions (int ignore, int ignore2)
{
  return bash_complete_variable_internal ('?');
}

static int
bash_complete_command (int ignore, int ignore2)
{
  return bash_complete_command_internal (rl_completion_mode (bash_complete_command));
}

static int
bash_possible_command_completions (int ignore, int ignore2)
{
  return bash_complete_command_internal ('?');
}

static int
bash_complete_hostname_internal (int what_to_do)
{
  return bash_specific_completion (what_to_do, hostname_completion_function);
}

static int
bash_complete_variable_internal (int what_to_do)
{
  return bash_specific_completion (what_to_do, variable_completion_function);
}

static int
bash_complete_command_internal (int what_to_do)
{
  return bash_specific_completion (what_to_do, command_word_completion_function);
}

static int
completion_glob_pattern (const char *string)
{
  return (glob_pattern_p (string) == 1);
}

static char *globtext;
static char *globorig;

static char *
glob_complete_word (const char *text, int state)
{
  static char **matches = (char **)NULL;
  static int ind;
  size_t glen;
  char *ret, *ttext;

  if (state == 0)
    {
      rl_filename_completion_desired = 1;
      FREE (matches);
      matches = (char **)NULL;
      if (globorig != globtext)
        FREE (globorig);
      FREE (globtext);
      globorig = globtext = (char *)NULL;

      ttext = bash_tilde_expand (text, 0);

      if (rl_explicit_arg)
        {
          globorig = savestring (ttext);
          glen = strlen (ttext);
          globtext = (char *)xmalloc (glen + 2);
          strcpy (globtext, ttext);
          globtext[glen] = '*';
          globtext[glen+1] = '\0';
        }
      else
        globtext = globorig = savestring (ttext);

      if (ttext != text)
        free (ttext);

      matches = shell_glob_filename (globtext, 0);
      if (GLOB_FAILED (matches))
        matches = (char **)NULL;
      ind = 0;
    }

  ret = matches ? matches[ind] : (char *)NULL;
  ind++;
  return ret;
}

static int
bash_glob_completion_internal (int what_to_do)
{
  return bash_specific_completion (what_to_do, glob_complete_word);
}

/* A special quoting function so we don't end up quoting globbing characters
   in the word if there are no matches or multiple matches. */
static char *
bash_glob_quote_filename (char *s, int rtype, char *qcp)
{
  if (globorig && qcp && *qcp == '\0' && STREQ (s, globorig))
    return (savestring (s));
  else
    return (bash_quote_filename (s, rtype, qcp));
}

static int
bash_glob_complete_word (int count, int key)
{
  int r;
  rl_quote_func_t *orig_quoting_function;

  if (rl_editing_mode == EMACS_EDITING_MODE)
    rl_explicit_arg = 1;        /* force `*' append */
  orig_quoting_function = rl_filename_quoting_function;
  rl_filename_quoting_function = bash_glob_quote_filename;
  
  r = bash_glob_completion_internal (rl_completion_mode (bash_glob_complete_word));

  rl_filename_quoting_function = orig_quoting_function;
  return r;
}

static int
bash_glob_expand_word (int count, int key)
{
  return bash_glob_completion_internal ('*');
}

static int
bash_glob_list_expansions (int count, int key)
{
  return bash_glob_completion_internal ('?');
}

static int
bash_specific_completion (int what_to_do, rl_compentry_func_t *generator)
{
  rl_compentry_func_t *orig_func;
  rl_completion_func_t *orig_attempt_func;
  rl_compignore_func_t *orig_ignore_func;
  int r;

  orig_func = rl_completion_entry_function;
  orig_attempt_func = rl_attempted_completion_function;
  orig_ignore_func = rl_ignore_some_completions_function;
  rl_completion_entry_function = generator;
  rl_attempted_completion_function = NULL;
  rl_ignore_some_completions_function = orig_ignore_func;

  r = rl_complete_internal (what_to_do);

  rl_completion_entry_function = orig_func;
  rl_attempted_completion_function = orig_attempt_func;
  rl_ignore_some_completions_function = orig_ignore_func;

  return r;
}

#endif  /* SPECIFIC_COMPLETION_FUNCTIONS */

#if defined (VI_MODE)
/* This does pretty much what _rl_vi_advance_point does. */
static inline int
vi_advance_point (void)
{
  int point;
  DECLARE_MBSTATE;

  point = rl_point;
  if (rl_point < rl_end)
#if defined (HANDLE_MULTIBYTE)
    {
      if (locale_mb_cur_max == 1)
        rl_point++;
      else
        {
          point = rl_point;
          ADVANCE_CHAR (rl_line_buffer, rl_end, rl_point);
          if (point == rl_point || rl_point > rl_end)
            rl_point = rl_end;
        }
    }
#else
    rl_point++:
#endif
  return point;
}

/* Completion, from vi mode's point of view.  This is a modified version of
   rl_vi_complete which uses the bash globbing code to implement what POSIX
   specifies, which is to optinally append a `*' and attempt filename
   generation (which has the side effect of expanding any globbing characters
   in the word). */
static int
bash_vi_complete (int count, int key)
{
#if defined (SPECIFIC_COMPLETION_FUNCTIONS)
  int p, r;
  char *t;

  if ((rl_point < rl_end) && (!whitespace (rl_line_buffer[rl_point])))
    {
      if (!whitespace (rl_line_buffer[rl_point + 1]))
        rl_vi_end_word (1, 'E');
      vi_advance_point ();
    }

  /* Find boundaries of current word, according to vi definition of a
     `bigword'. */
  t = 0;
  if (rl_point > 0)
    {
      p = rl_point;
      rl_vi_bWord (1, 'B');
      r = rl_point;
      rl_point = p;
      p = r;

      t = substring (rl_line_buffer, p, rl_point);
    }      

  if (t && completion_glob_pattern (t) == 0)
    rl_explicit_arg = 1;        /* XXX - force glob_complete_word to append `*' */
  FREE (t);

  if (key == '*')       /* Expansion and replacement. */
    r = bash_glob_expand_word (count, key);
  else if (key == '=')  /* List possible completions. */
    r = bash_glob_list_expansions (count, key);
  else if (key == '\\') /* Standard completion */
    r = bash_glob_complete_word (count, key);
  else
    r = rl_complete (0, key);

  if (key == '*' || key == '\\')
    rl_vi_start_inserting (key, 1, 1);

  return (r);
#else
  return rl_vi_complete (count, key);
#endif /* !SPECIFIC_COMPLETION_FUNCTIONS */
}
#endif /* VI_MODE */

/* Filename quoting for completion. */
/* A function to strip unquoted quote characters (single quotes, double
   quotes, and backslashes).  It allows single quotes to appear
   within double quotes, and vice versa.  It should be smarter. */
static char *
bash_dequote_filename (char *text, int quote_char)
{
  char *ret, *p, *r;
  int quoted;
  size_t l;

  l = strlen (text);
  ret = (char *)xmalloc (l + 1);
  for (quoted = quote_char, p = text, r = ret; p && *p; p++)
    {
      /* Allow backslash-escaped characters to pass through unscathed. Backslashes
         aren't special in single quotes. */
      if (quoted != '\'' && *p == '\\')
        {
          /* Backslashes are preserved within double quotes unless the
             character is one that is defined to be escaped */
          if (quoted == '"' && ((sh_syntaxtab[(unsigned char)p[1]] & CBSDQUOTE) == 0))
            *r++ = *p;

          *r++ = *++p;
          if (*p == '\0')
            return ret;         /* XXX - was break; */
          continue;
        }
      /* Close quote. */
      if (quoted && *p == quoted)
        {
          quoted = 0;
          continue;
        }
      /* Open quote. */
      if (quoted == 0 && (*p == '\'' || *p == '"'))
        {
          quoted = *p;
          continue;
        }
      *r++ = *p;
    }
  *r = '\0';
  return ret;
}

/* Quote characters that the readline completion code would treat as
   word break characters with backslashes.  Pass backslash-quoted
   characters through without examination. */
static char *
quote_word_break_chars (char *text)
{
  char *ret, *r, *s;
  size_t l;

  l = strlen (text);
  ret = (char *)xmalloc ((2 * l) + 1);
  for (s = text, r = ret; *s; s++)
    {
      /* Pass backslash-quoted characters through, including the backslash. */
      if (*s == '\\')
        {
          *r++ = '\\';
          *r++ = *++s;
          if (*s == '\0')
            break;
          continue;
        }
      /* OK, we have an unquoted character.  Check its presence in
         rl_completer_word_break_characters. */
      if (mbschr (rl_completer_word_break_characters, *s))
        *r++ = '\\';
      /* XXX -- check for standalone tildes here and backslash-quote them */
      if (s == text && *s == '~' && file_exists (text))
        *r++ = '\\';
      *r++ = *s;
    }
  *r = '\0';
  return ret;
}

/* Return a character in DIRNAME that will cause shell expansion to be
   performed. If NEXTP is non-null, *NEXTP gets the expansion character that
   follows RET (e.g., '{' or `(' for `$'). If CLOSERP is non-null, *CLOSERP
   gets the character that should close <RET><NEXTP>. If NEED_CLOSER is non-
   zero, any expansion pair that isn't closed causes this function to
   return 0, which indicates that we didn't find an expansion character. It's
   used in case DIRNAME is going to be expanded. If DIRNAME is just going to
   be quoted, NEED_CLOSER will be 0. */
static int
bash_check_expchar (char *dirname, int need_closer, int *nextp, int *closerp)
{
  char *t;
  int ret, n, c;

  ret = n = c = 0;
  if (t = mbschr (dirname, '$'))
    {
      ret = '$';
      n = t[1];
      /* Deliberately does not handle the deprecated $[...] arithmetic
         expansion syntax */
      if (n == '(')
        c = ')';
      else if (n == '{')
        c = '}';
      else
        n = 0;

      if (c && need_closer)             /* XXX */
        {
          int p;
          char delims[2];

          delims[0] = c; delims[1] = 0;
          p = skip_to_delim (t, 1, delims, SD_NOJMP|SD_COMPLETE);
          if (t[p] != c)
            ret = 0;
        }
    }
  else if (dirname[0] == '~')
    ret = '~';
  else
    {
      t = mbschr (dirname, '`');
      if (t)
        {
          if (need_closer == 0)
            ret = '`';
          else if (unclosed_pair (dirname, strlen (dirname), "`") == 0)
            ret = '`';
        }
    }

  if (nextp)
    *nextp = n;
  if (closerp)
    *closerp = c;

  return ret;
}

/* Make sure EXPCHAR and, if non-zero, NEXTCH and CLOSER are not in the set
   of characters to be backslash-escaped. This is the only place
   custom_filename_quote_characters is modified. */
static void
set_filename_quote_chars (int expchar, int nextch, int closer)
{
  size_t i, j;
  int c;

  if (rl_filename_quote_characters && *rl_filename_quote_characters)
    {
      i = strlen (default_filename_quote_characters);
      custom_filename_quote_characters = xrealloc (custom_filename_quote_characters, i+1);
      for (i = j = 0; c = default_filename_quote_characters[i]; i++)
        {
          if (c == expchar || c == nextch || c == closer)
            continue;
          custom_filename_quote_characters[j++] = c;
        }
      custom_filename_quote_characters[j] = '\0';
      rl_filename_quote_characters = custom_filename_quote_characters;
      set_filename_bstab (rl_filename_quote_characters);
    }
}

/* Use characters in STRING to populate the table of characters that should
   be backslash-quoted.  The table will be used for sh_backslash_quote from
   this file. */
static void
set_filename_bstab (const char *string)
{
  const char *s;

  memset (filename_bstab, 0, sizeof (filename_bstab));
  for (s = string; s && *s; s++)
    filename_bstab[(unsigned char)*s] = 1;
}

/* Quote a filename using double quotes, single quotes, or backslashes
   depending on the value of completion_quoting_style.  If we're
   completing using backslashes, we need to quote some additional
   characters (those that readline treats as word breaks), so we call
   quote_word_break_chars on the result.  This returns newly-allocated
   memory. */
static char *
bash_quote_filename (char *s, int rtype, char *qcp)
{
  char *rtext, *mtext, *ret;
  size_t rlen;
  int cs, expchar, nextch, closer;

  rtext = (char *)NULL;

  /* If RTYPE == MULT_MATCH, it means that there is
     more than one match.  In this case, we do not add
     the closing quote or attempt to perform tilde
     expansion.  If RTYPE == SINGLE_MATCH, we try
     to perform tilde expansion, because single and double
     quotes inhibit tilde expansion by the shell. */

  cs = completion_quoting_style;
  /* Might need to modify the default completion style based on *qcp,
     since it's set to any user-provided opening quote.  We also change
     to single-quoting if there is no user-provided opening quote and
     the word being completed contains newlines, since those are not
     quoted correctly using backslashes (a backslash-newline pair is
     special to the shell parser). */
  expchar = nextch = closer = 0;
  if (*qcp == '\0' && cs == COMPLETE_BSQUOTE && dircomplete_expand == 0 &&
      (expchar = bash_check_expchar (s, 0, &nextch, &closer)) &&
      file_exists (s) == 0)
    {
      /* If it looks like the name is subject to expansion, see if we want to
         double-quote it. */
      if (expchar == '$' || expchar == '`')
        {
          char *newname;
          newname = bash_expand_filename (s);
          if (newname && strpbrk (newname, rl_filename_quote_characters))
            cs = COMPLETE_DQUOTE2;
          if (newname != s)
            free (newname);
        }
      /* Usually this will have been set by bash_directory_completion_hook,
         but there are cases where it will not be. */
      if (rl_filename_quote_characters != custom_filename_quote_characters)
        set_filename_quote_chars (expchar, nextch, closer);
      complete_fullquote = 0;
    }
  else if (*qcp == '\0' && cs == COMPLETE_BSQUOTE && mbschr (s, '\n'))
    cs = COMPLETE_SQUOTE;
  else if (*qcp == '"')
    {
      if ((expchar = bash_check_expchar (s, 0, &nextch, &closer)) == '$' || expchar == '`')
        cs = COMPLETE_DQUOTE2;
      else
        cs = COMPLETE_DQUOTE;
    }
  else if (*qcp == '\'')
    cs = COMPLETE_SQUOTE;
#if defined (BANG_HISTORY)
  else if (*qcp == '\0' && history_expansion && cs == COMPLETE_DQUOTE &&
           history_expansion_inhibited == 0 && mbschr (s, '!'))
    cs = COMPLETE_BSQUOTE;

  if (*qcp == '"' && history_expansion && cs == COMPLETE_DQUOTE &&
        history_expansion_inhibited == 0 && mbschr (s, '!'))
    {
      cs = COMPLETE_BSQUOTE;
      *qcp = '\0';
    }
#endif

  /* Don't tilde-expand backslash-quoted filenames, since only single and
     double quotes inhibit tilde expansion. */
  mtext = s;
  if (mtext[0] == '~' && rtype == SINGLE_MATCH && cs != COMPLETE_BSQUOTE)
    mtext = bash_tilde_expand (s, 0);

  switch (cs)
    {
    case COMPLETE_DQUOTE2:
      rtext = sh_mkdoublequoted (mtext, strlen (mtext), 1);     /* For now */
      break;
    case COMPLETE_DQUOTE:
      rtext = sh_double_quote (mtext);
      break;
    case COMPLETE_SQUOTE:
      rtext = sh_single_quote (mtext);
      break;
    case COMPLETE_BSQUOTE:
      rtext = sh_backslash_quote (mtext, complete_fullquote ? 0 : filename_bstab, 0);
      break;
    }

  if (mtext != s)
    free (mtext);

  /* We may need to quote additional characters: those that readline treats
     as word breaks that are not quoted by backslash_quote. */
  /* XXX - test complete_fullquote here? */
  if (rtext && cs == COMPLETE_BSQUOTE && rl_completer_word_break_characters)
    {
      mtext = quote_word_break_chars (rtext);
      free (rtext);
      rtext = mtext;
    }

  /* Leave the opening quote intact.  The readline completion code takes
     care of avoiding doubled opening quotes. */
  if (rtext)
    {
      rlen = strlen (rtext);
      ret = (char *)xmalloc (rlen + 1);
      strcpy (ret, rtext);
    }
  else
    {
      ret = (char *)xmalloc (rlen = 1);
      ret[0] = '\0';
    }

  /* If there are multiple matches, cut off the closing quote. */
  if (rtype == MULT_MATCH && cs != COMPLETE_BSQUOTE)
    ret[rlen - 1] = '\0';
  free (rtext);
  return ret;
}

/* Support for binding readline key sequences to Unix commands. Each editing
   mode has a separate Unix command keymap. */

static Keymap emacs_std_cmd_xmap;
#if defined (VI_MODE)
static Keymap vi_insert_cmd_xmap;
static Keymap vi_movement_cmd_xmap;
#endif

#ifdef _MINIX
static void
#else
static int
#endif
putx(int c)
{
  int x;
  x = putc (c, rl_outstream);
#ifndef _MINIX
  return x;
#endif
}

static int
readline_get_char_offset (int ind)
{
  int r, old_ch;

  r = ind;
#if defined (HANDLE_MULTIBYTE)
  if (locale_mb_cur_max > 1)
    {
      old_ch = rl_line_buffer[ind];
      rl_line_buffer[ind] = '\0';
      r = MB_STRLEN (rl_line_buffer);
      rl_line_buffer[ind] = old_ch;
    }
#endif
  return r;
}

static void
readline_set_char_offset (int ind, int *varp)
{
  int i;

  i = ind;

#if defined (HANDLE_MULTIBYTE)
  if (i > 0 && locale_mb_cur_max > 1)
    i = _rl_find_next_mbchar (rl_line_buffer, 0, i, 0);         /* XXX */
#endif
  if (i != *varp)
    {
      if (i > rl_end)
        i = rl_end;
      else if (i < 0)
        i = 0;
      *varp = i;
    }
}

void
uw_restore_parser_state (void *ps)
{
  restore_parser_state (ps);
}

void
uw_rl_set_signals (void *ignore)
{
  rl_set_signals ();
}

static void
unbind_readline_variables (void)
{
  check_unbind_variable ("READLINE_LINE");
  check_unbind_variable ("READLINE_POINT");
  check_unbind_variable ("READLINE_MARK");
  check_unbind_variable ("READLINE_ARGUMENT");
  array_needs_making = 1;
}

static void
uw_unbind_readline_variables (void *ignore)
{
  unbind_readline_variables ();
}
   
int
bash_execute_unix_command (int count, int key)
{
  int type;
  register int i, r;
  intmax_t mi;
  sh_parser_state_t ps;
  char *cmd, *value, *ce;
  SHELL_VAR *v;
  char ibuf[INT_STRLEN_BOUND(int) + 1];
  Keymap cmd_xmap;
  const char *kseq;
  size_t kslen;

  kseq = rl_executing_keyseq;
  kslen = rl_key_sequence_length;

  /* If we have a numeric argument, chop it off the front of the key sequence */
  if (count != 1 || rl_explicit_arg)
    {
      i = rl_trim_arg_from_keyseq (rl_executing_keyseq, rl_key_sequence_length, rl_get_keymap ());
      if (i > 0)
        {
         kseq = rl_executing_keyseq + i;
         kslen = rl_key_sequence_length - i;
        }
    }

  /* First, we need to find the right command to execute.  This is tricky,
     because we might have already indirected into another keymap, so we
     have to walk cmd_xmap using the entire key sequence. */
  cmd_xmap = get_cmd_xmap_from_keymap (rl_get_keymap ());
  cmd = (char *)rl_function_of_keyseq_len (kseq, kslen, cmd_xmap, &type);

  if (type == ISKMAP && (type = ((Keymap) cmd)[ANYOTHERKEY].type) == ISMACR)
    cmd = (char*)((Keymap) cmd)[ANYOTHERKEY].function;

  if (cmd == 0 || type != ISMACR)
    {
      rl_crlf ();
      internal_error (_("bash_execute_unix_command: cannot find keymap for command"));
      rl_forced_update_display ();
      return 1;
    }

  ce = rl_get_termcap ("ce");
  if (ce)       /* clear current line */
    {
      rl_clear_visible_line ();
      fflush (rl_outstream);
    }
  else
    rl_crlf (); /* move to a new line */

  v = bind_variable ("READLINE_LINE", rl_line_buffer, 0);
  if (v)
    VSETATTR (v, att_exported);

  i = readline_get_char_offset (rl_point);
  value = inttostr (i, ibuf, sizeof (ibuf));
  v = bind_int_variable ("READLINE_POINT", value, 0);
  if (v)
    VSETATTR (v, att_exported);

  i = readline_get_char_offset (rl_mark);
  value = inttostr (i, ibuf, sizeof (ibuf));
  v = bind_int_variable ("READLINE_MARK", value, 0);
  if (v)
    VSETATTR (v, att_exported);

  if (count != 1 || rl_explicit_arg)
    {
      value = inttostr (count, ibuf, sizeof (ibuf));
      v = bind_int_variable ("READLINE_ARGUMENT", value, 0);
      if (v)
        VSETATTR (v, att_exported);
    }
  array_needs_making = 1;

  begin_unwind_frame ("execute-unix-command");
  save_parser_state (&ps);
  rl_clear_signals ();
  add_unwind_protect (uw_unbind_readline_variables, 0);
  add_unwind_protect (uw_restore_parser_state, &ps);
  add_unwind_protect (uw_rl_set_signals, 0);
  r = parse_and_execute (savestring (cmd), "bash_execute_unix_command", SEVAL_NOHIST);
  rl_set_signals ();
  restore_parser_state (&ps);

  v = find_variable ("READLINE_LINE");
  maybe_make_readline_line (v ? value_cell (v) : 0);

  v = find_variable ("READLINE_POINT");
  if (v && valid_number (value_cell (v), &mi))
    readline_set_char_offset (mi, &rl_point);

  v = find_variable ("READLINE_MARK");
  if (v && valid_number (value_cell (v), &mi))
    readline_set_char_offset (mi, &rl_mark);

  unbind_readline_variables ();
  discard_unwind_frame ("execute-unix-command");

  /* and restore the readline buffer and display after command execution. */
  /* If we clear the last line of the prompt above, redraw only that last
     line.  If the command returns 124, we redraw unconditionally as in
     previous versions. */
  if (ce && r != 124)
    rl_redraw_prompt_last_line ();
  else
    rl_forced_update_display ();

  return 0;
}

/* This only has to handle macros/shell commandsfrom print_unix_command_map */
static void
print_unix_command (const char *kseq, const char *value, int readable, const char *prefix)
{
  if (readable)
    fprintf (rl_outstream, "\"%s%s\" \"%s\"\n", prefix ? prefix : "", kseq, value ? value : "");
  else
    fprintf (rl_outstream, "%s%s outputs %s\n", prefix ? prefix : "", kseq, value ? value : "");
}

int
print_unix_command_map (void)
{
  Keymap save, cmd_xmap;
  rl_macro_print_func_t *old_printer;

  save = rl_get_keymap ();
  cmd_xmap = get_cmd_xmap_from_keymap (save);
  rl_set_keymap (cmd_xmap);
  old_printer = rl_macro_display_hook;
  rl_macro_display_hook = print_unix_command;
  rl_macro_dumper (1);
  rl_macro_display_hook = old_printer;
  rl_set_keymap (save);
  return 0;
}

static void
init_unix_command_map (void)
{
  emacs_std_cmd_xmap = rl_make_bare_keymap ();

  emacs_std_cmd_xmap[CTRL('X')].type = ISKMAP;
  emacs_std_cmd_xmap[CTRL('X')].function = KEYMAP_TO_FUNCTION (rl_make_bare_keymap ());
  emacs_std_cmd_xmap[ESC].type = ISKMAP;
  emacs_std_cmd_xmap[ESC].function = KEYMAP_TO_FUNCTION (rl_make_bare_keymap ());

#if defined (VI_MODE)  
  vi_insert_cmd_xmap = rl_make_bare_keymap ();
  vi_movement_cmd_xmap = rl_make_bare_keymap ();
#endif
}

static Keymap
get_cmd_xmap_from_edit_mode (void)
{
  if (emacs_std_cmd_xmap == 0)
    init_unix_command_map ();

  switch (rl_editing_mode)
    {
    case EMACS_EDITING_MODE:
      return emacs_std_cmd_xmap;
#if defined (VI_MODE)
    case VI_EDITING_MODE:
      return (get_cmd_xmap_from_keymap (rl_get_keymap ()));
#endif
    default:
      return (Keymap)NULL;
    }
}

static Keymap
get_cmd_xmap_from_keymap (Keymap kmap)
{
  if (emacs_std_cmd_xmap == 0)
    init_unix_command_map ();

  if (kmap == emacs_standard_keymap)
    return emacs_std_cmd_xmap;
  else if (kmap == emacs_meta_keymap)
    return (FUNCTION_TO_KEYMAP (emacs_std_cmd_xmap, ESC));
  else if (kmap == emacs_ctlx_keymap)
    return (FUNCTION_TO_KEYMAP (emacs_std_cmd_xmap, CTRL('X')));
#if defined (VI_MODE)
  else if (kmap == vi_insertion_keymap)
    return vi_insert_cmd_xmap;
  else if (kmap == vi_movement_keymap)
    return vi_movement_cmd_xmap;
#endif
  else
    return (Keymap)NULL;
}

static int
isolate_sequence (char *string, int ind, int need_dquote, int *startp)
{
  register int i;
  int c, passc, delim;

  for (i = ind; string[i] && whitespace (string[i]); i++)
    ;
  /* NEED_DQUOTE means that the first non-white character *must* be `"'. */
  if (need_dquote && string[i] != '"')
    {
      builtin_error (_("%s: first non-whitespace character is not `\"'"), string);
      return -1;
    }

  /* We can have delimited strings even if NEED_DQUOTE == 0, like the command
     string to bind the key sequence to. */
  delim = (string[i] == '"' || string[i] == '\'') ? string[i] : 0;
    
  if (startp)
    *startp = delim ? ++i : i;

  for (passc = 0; c = string[i]; i++)
    {
      if (passc)
        {
          passc = 0;
          continue;
        }
      if (c == '\\')
        {
          passc++;
          continue;
        }
      if (c == delim)
        break;
    }

  if (delim && string[i] != delim)
    {
      builtin_error (_("no closing `%c' in %s"), delim, string);
      return -1;
    }

  return i;
}

int
bind_keyseq_to_unix_command (char *line)
{
  Keymap kmap, cmd_xmap;
  char *kseq, *value;
  int i, kstart, translate;

  kmap = rl_get_keymap ();

  /* We duplicate some of the work done by rl_parse_and_bind here, but
     this code only has to handle `"keyseq"[:][ \t]+["]command["]' and can
     generate an error for anything else. */
  i = isolate_sequence (line, 0, 1, &kstart);
  if (i < 0)
    return -1;

  /* Create the key sequence string to pass to rl_generic_bind */
  kseq = substring (line, kstart, i);

  /* Allow colon or whitespace to separate the key sequence and command string. */
  for ( ; line[i] && line[i] != ':' && whitespace (line[i]) == 0; i++)
    ;
  if (line[i] != ':' && whitespace (line[i]) == 0)
    {
      builtin_error (_("%s: missing separator"), line);
      FREE (kseq);
      return -1;
    }

  /* If we have a whitespace separator we're going to call rl_macro_bind so
     we get the readline-translated version of the value (backslash-escapes
     handled, etc.) */
  translate = line[i] != ':';

  /* Kind of tricky. If we use whitespace as a delimiter, we can backslash-
     quote double quotes and have them preserved in the value. However, we
     still want to be able to auto-detect quoted strings and only require
     them with whitespace delimiters. */
  i = isolate_sequence (line, i + 1, translate, &kstart);
  if (i < 0)
    {
      FREE (kseq);
      return -1;
    }

  /* Create the value string containing the command to execute. */
  value = substring (line, kstart, i);

  /* Save the command to execute and the key sequence in the CMD_XMAP */
  cmd_xmap = get_cmd_xmap_from_keymap (kmap);
  if (translate)
    rl_macro_bind (kseq, value, cmd_xmap);
  else
    rl_generic_bind (ISMACR, kseq, value, cmd_xmap);

  /* and bind the key sequence in the current keymap to a function that
     understands how to execute from CMD_XMAP */
  rl_bind_keyseq_in_map (kseq, bash_execute_unix_command, kmap);

  free (kseq);  
  return 0;
}

int
unbind_unix_command (char *kseq)
{
  Keymap cmd_xmap;

  cmd_xmap = get_cmd_xmap_from_keymap (rl_get_keymap ());
  if (rl_bind_keyseq_in_map (kseq, (rl_command_func_t *)NULL, cmd_xmap) != 0)
    {
      builtin_error (_("`%s': cannot unbind in command keymap"), kseq);
      return 0;
    }
  return 1;
}

/* Used by the programmable completion code.  Complete TEXT as a filename,
   but return only directories as matches.  Dequotes the filename before
   attempting to find matches. */
char **
bash_directory_completion_matches (const char *text)
{
  char **m1;
  char *dfn;
  int qc;

  qc = rl_dispatching ? rl_completion_quote_character : 0;  
  /* If rl_completion_found_quote != 0, rl_completion_matches will call the
     filename dequoting function, causing the directory name to be dequoted
     twice. */
  if (rl_dispatching && rl_completion_found_quote == 0)
    dfn = bash_dequote_filename ((char *)text, qc);
  else
    dfn = (char *)text;
  m1 = rl_completion_matches (dfn, rl_filename_completion_function);
  if (dfn != text)
    free (dfn);

  if (m1 == 0 || m1[0] == 0)
    return m1;
  /* We don't bother recomputing the lcd of the matches, because it will just
     get thrown away by the programmable completion code and recomputed
     later. */
  (void)bash_progcomp_ignore_filenames (m1);
  return m1;
}

char *
bash_dequote_text (const char *text)
{
  char *dtxt;
  int qc;

  qc = (text[0] == '"' || text[0] == '\'') ? text[0] : 0;
  dtxt = bash_dequote_filename ((char *)text, qc);
  return (dtxt);
}

/* This event hook is designed to be called after readline receives a signal
   that interrupts read(2).  It gives reasonable responsiveness to interrupts
   and fatal signals without executing too much code in a signal handler
   context. */
static int
bash_event_hook (void)
{
  int sig;

  /* XXX - see if we need to do anything here if sigterm_received == 1,
     we probably don't want to reset the event hook since we will not be
     jumping to the top level */
  if (sigterm_received)
    {
      /* RESET_SIGTERM; */
      return 0;
    }

  sig = 0;
  if (terminating_signal)
    sig = terminating_signal;
  else if (interrupt_state)
    sig = SIGINT;
  else if (read_timeout && read_timeout->alrmflag)
    sig = SIGALRM;
  else if (RL_ISSTATE (RL_STATE_TIMEOUT))               /* just in case */
    {
      sig = SIGALRM;
      if (read_timeout)
        read_timeout->alrmflag = 1;
    }
  else
    sig = first_pending_trap ();

  /* If we're going to longjmp to top_level, make sure we clean up readline.
     check_signals will call QUIT, which will eventually longjmp to top_level,
     calling run_interrupt_trap along the way.  The check against read_timeout
     is so we can clean up the read builtin's state. */
  if (terminating_signal || interrupt_state || (read_timeout && read_timeout->alrmflag))
    rl_cleanup_after_signal ();
  bashline_reset_event_hook ();

  RL_UNSETSTATE (RL_STATE_TIMEOUT);                     /* XXX */

  /* posix mode SIGINT during read -e. We only get here if SIGINT is trapped. */
  if (posixly_correct && this_shell_builtin == read_builtin && sig == SIGINT)
    {
      last_command_exit_value = 128|SIGINT;
      throw_to_top_level ();
    }

  check_signals_and_traps ();   /* XXX */
  return 0;
}

#endif /* READLINE */