/* complete.c -- filename completion for readline. */

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

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

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

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

   The GNU General Public License is often shipped with GNU software, and
   is generally kept in a file called COPYING or LICENSE.  If you do not
   have a copy of the license, write to the Free Software Foundation,
   59 Temple Place, Suite 330, Boston, MA 02111 USA. */
#define READLINE_LIBRARY

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

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

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

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

#include <stdio.h>

#include <errno.h>
#if !defined (errno)
extern int errno;
#endif /* !errno */

#include <pwd.h>
#if !defined (HAVE_GETPW_DECLS)
extern struct passwd *getpwent ();
#endif /* USG && !HAVE_GETPW_DECLS */

/* ISC systems don't define getpwent() if _POSIX_SOURCE is defined. */
#if defined (isc386) && defined (_POSIX_SOURCE)
#  if defined (__STDC__)
extern struct passwd *getpwent (void);
#  else
extern struct passwd *getpwent ();
#  endif /* !__STDC__ */
#endif /* isc386 && _POSIX_SOURCE */

#include "posixdir.h"
#include "posixstat.h"

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

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

extern char *tilde_expand ();
extern char *rl_copy_text ();
extern void _rl_abort_internal ();
extern int _rl_qsort_string_compare ();

extern Function *rl_last_func;
extern int rl_editing_mode;
extern int screenwidth;

extern void _rl_move_vert ();
extern int _rl_vis_botlin;
extern int rl_display_fixed;

/* Forward declarations for functions defined and used in this file. */
char *filename_completion_function ();
char **completion_matches ();

static char *rl_quote_filename ();
static char *rl_strpbrk ();

static char **remove_duplicate_matches ();
static void insert_text ();
static void insert_match ();
static void append_to_match ();
static void insert_all_matches ();
static void display_matches ();
static int compute_lcd_of_matches ();

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

/* If non-zero, then this is the address of a function to call when
   completing on a directory name.  The function is called with
   the address of a string (the current directory name) as an arg. */
Function *rl_directory_completion_hook = (Function *)NULL;

/* Non-zero means readline completion functions perform tilde expansion. */
int rl_complete_with_tilde_expansion = 0;

/* If non-zero, non-unique completions always show the list of matches. */
int _rl_complete_show_all = 0;

/* If non-zero, completed directory names have a slash appended. */
int _rl_complete_mark_directories = 1;

#if defined (VISIBLE_STATS)
#  if !defined (X_OK)
#    define X_OK 1
#  endif

static int stat_char ();

/* Non-zero means add an additional character to each filename displayed
   during listing completion iff rl_filename_completion_desired which helps
   to indicate the type of file being listed. */
int rl_visible_stats = 0;
#endif /* VISIBLE_STATS */

/* **************************************************************** */
/*								    */
/*	Completion matching, from readline's point of view.	    */
/*								    */
/* **************************************************************** */

/* Local variable states what happened during the last completion attempt. */
static int completion_changed_buffer;

/* Pointer to the generator function for completion_matches ().
   NULL means to use filename_completion_function (), the default filename
   completer. */
Function *rl_completion_entry_function = (Function *)NULL;

/* Pointer to alternative function to create matches.
   Function is called with TEXT, START, and END.
   START and END are indices in RL_LINE_BUFFER saying what the boundaries
   of TEXT are.
   If this function exists and returns NULL then call the value of
   rl_completion_entry_function to try to match, otherwise use the
   array of strings returned. */
CPPFunction *rl_attempted_completion_function = (CPPFunction *)NULL;

/* Non-zero means to suppress normal filename completion after the
   user-specified completion function has been called. */
int rl_attempted_completion_over = 0;

/* Set to a character indicating the type of completion being performed
   by rl_complete_internal, available for use by application completion
   functions. */
int rl_completion_type = 0;

/* Up to this many items will be displayed in response to a
   possible-completions call.  After that, we ask the user if
   she is sure she wants to see them all. */
int rl_completion_query_items = 100;

/* The basic list of characters that signal a break between words for the
   completer routine.  The contents of this variable is what breaks words
   in the shell, i.e. " \t\n\"\\'`@$><=" */
char *rl_basic_word_break_characters = " \t\n\"\\'`@$><=;|&{(";

/* List of basic quoting characters. */
char *rl_basic_quote_characters = "\"'";

/* The list of characters that signal a break between words for
   rl_complete_internal.  The default list is the contents of
   rl_basic_word_break_characters.  */
char *rl_completer_word_break_characters = (char *)NULL;

/* List of characters which can be used to quote a substring of the line.
   Completion occurs on the entire substring, and within the substring
   rl_completer_word_break_characters are treated as any other character,
   unless they also appear within this list. */
char *rl_completer_quote_characters = (char *)NULL;

/* List of characters that should be quoted in filenames by the completer. */
char *rl_filename_quote_characters = (char *)NULL;

/* List of characters that are word break characters, but should be left
   in TEXT when it is passed to the completion function.  The shell uses
   this to help determine what kind of completing to do. */
char *rl_special_prefixes = (char *)NULL;

/* If non-zero, then disallow duplicates in the matches. */
int rl_ignore_completion_duplicates = 1;

/* Non-zero means that the results of the matches are to be treated
   as filenames.  This is ALWAYS zero on entry, and can only be changed
   within a completion entry finder function. */
int rl_filename_completion_desired = 0;

/* Non-zero means that the results of the matches are to be quoted using
   double quotes (or an application-specific quoting mechanism) if the
   filename contains any characters in rl_filename_quote_chars.  This is
   ALWAYS non-zero on entry, and can only be changed within a completion
   entry finder function. */
int rl_filename_quoting_desired = 1;

/* This function, if defined, is called by the completer when real
   filename completion is done, after all the matching names have been
   generated. It is passed a (char**) known as matches in the code below.
   It consists of a NULL-terminated array of pointers to potential
   matching strings.  The 1st element (matches[0]) is the maximal
   substring that is common to all matches. This function can re-arrange
   the list of matches as required, but all elements of the array must be
   free()'d if they are deleted. The main intent of this function is
   to implement FIGNORE a la SunOS csh. */
Function *rl_ignore_some_completions_function = (Function *)NULL;

/* Set to a function to quote a filename in an application-specific fashion.
   Called with the text to quote, the type of match found (single or multiple)
   and a pointer to the quoting character to be used, which the function can
   reset if desired. */
CPFunction *rl_filename_quoting_function = rl_quote_filename;
         
/* Function to call to remove quoting characters from a filename.  Called
   before completion is attempted, so the embedded quotes do not interfere
   with matching names in the file system.  Readline doesn't do anything
   with this; it's set only by applications. */
CPFunction *rl_filename_dequoting_function = (CPFunction *)NULL;

/* Function to call to decide whether or not a word break character is
   quoted.  If a character is quoted, it does not break words for the
   completer. */
Function *rl_char_is_quoted_p = (Function *)NULL;

/* Character appended to completed words when at the end of the line.  The
   default is a space. */
int rl_completion_append_character = ' ';

/* If non-zero, inhibit completion (temporarily). */
int rl_inhibit_completion;

/* Complete the word at or before point.  You have supplied the function
   that does the initial simple matching selection algorithm (see
   completion_matches ()).  The default is to do filename completion. */
int
rl_complete (ignore, invoking_key)
     int ignore, invoking_key;
{
  if (rl_inhibit_completion)
    return (rl_insert (ignore, invoking_key));
  else if (rl_last_func == rl_complete && !completion_changed_buffer)
    return (rl_complete_internal ('?'));
  else if (_rl_complete_show_all)
    return (rl_complete_internal ('!'));
  else
    return (rl_complete_internal (TAB));
}

/* List the possible completions.  See description of rl_complete (). */
int
rl_possible_completions (ignore, invoking_key)
     int ignore, invoking_key;
{
  return (rl_complete_internal ('?'));
}

int
rl_insert_completions (ignore, invoking_key)
     int ignore, invoking_key;
{
  return (rl_complete_internal ('*'));
}

/* The user must press "y" or "n". Non-zero return means "y" pressed. */
static int
get_y_or_n ()
{
  int c;

  for (;;)
    {
      c = rl_read_key ();
      if (c == 'y' || c == 'Y' || c == ' ')
	return (1);
      if (c == 'n' || c == 'N' || c == RUBOUT)
	return (0);
      if (c == ABORT_CHAR)
	_rl_abort_internal ();
      ding ();
    }
}

/* Return the portion of PATHNAME that should be output when listing
   possible completions.  If we are hacking filename completion, we
   are only interested in the basename, the portion following the
   final slash.  Otherwise, we return what we were passed. */
static char *
printable_part (pathname)
      char *pathname;
{
  char *temp;

  temp = rl_filename_completion_desired ? strrchr (pathname, '/') : (char *)NULL;
  return (temp ? ++temp : pathname);
}

/* Output TO_PRINT to rl_outstream.  If VISIBLE_STATS is defined and we
   are using it, check for and output a single character for `special'
   filenames.  Return 1 if we printed an extension character, 0 if not. */

#define PUTX(c) \
      if (CTRL_CHAR (c)) \
        { \
          putc ('^', rl_outstream); \
          putc (UNCTRL (c), rl_outstream); \
        } \
      else if (c == RUBOUT) \
	{ \
	  putc ('^', rl_outstream); \
	  putc ('?', rl_outstream); \
	} \
      else \
	putc (c, rl_outstream)

static int
print_filename (to_print, full_pathname)
     char *to_print, *full_pathname;
{
#if !defined (VISIBLE_STATS)
  char *s;

  for (s = to_print; *s; s++)
    {
      PUTX (*s);
    }
  return 0;
#else  
  char *s, c, *new_full_pathname;
  int extension_char, slen, tlen;

  for (s = to_print; *s; s++)
    {
      PUTX (*s);
    }

 if (rl_filename_completion_desired && rl_visible_stats)
    {
      /* If to_print != full_pathname, to_print is the basename of the
	 path passed.  In this case, we try to expand the directory
	 name before checking for the stat character. */
      if (to_print != full_pathname)
	{
	  /* Terminate the directory name. */
	  c = to_print[-1];
	  to_print[-1] = '\0';

	  s = tilde_expand (full_pathname);
	  if (rl_directory_completion_hook)
	    (*rl_directory_completion_hook) (&s);

	  slen = strlen (s);
	  tlen = strlen (to_print);
	  new_full_pathname = xmalloc (slen + tlen + 2);
	  strcpy (new_full_pathname, s);
	  new_full_pathname[slen] = '/';
	  strcpy (new_full_pathname + slen + 1, to_print);

	  extension_char = stat_char (new_full_pathname);

	  free (new_full_pathname);
	  to_print[-1] = c;
	}
      else
	{
	  s = tilde_expand (full_pathname);
	  extension_char = stat_char (s);
	}

      free (s);
      if (extension_char)
	putc (extension_char, rl_outstream);
      return (extension_char != 0);
    }
  else
    return 0;
#endif /* VISIBLE_STATS */
}

static char *
rl_quote_filename (s, rtype, qcp)
     char *s;
     int rtype;
     char *qcp;
{
  char *r;

  r = xmalloc (strlen (s) + 2);
  *r = *rl_completer_quote_characters;
  strcpy (r + 1, s);
  if (qcp)
    *qcp = *rl_completer_quote_characters;
  return r;
}

/* Find the bounds of the current word for completion purposes, and leave
   rl_point set to the end of the word.  This function skips quoted
   substrings (characters between matched pairs of characters in
   rl_completer_quote_characters.  First we try to find an unclosed
   quoted substring on which to do matching.  If one is not found, we use
   the word break characters to find the boundaries of the current word.
   We call an application-specific function to decide whether or not a
   particular word break character is quoted; if that function returns a
   non-zero result, the character does not break a word.  This function
   returns the opening quote character if we found an unclosed quoted
   substring, '\0' otherwise.  FP, if non-null, is set to a value saying
   which (shell-like) quote characters we found (single quote, double
   quote, or backslash) anywhere in the string.  DP, if non-null, is set to
   the value of the delimiter character that caused a word break. */

static char
find_completion_word (fp, dp)
     int *fp, *dp;
{
  int scan, end, found_quote, delimiter, pass_next, isbrk;
  char quote_char;

  end = rl_point;
  found_quote = delimiter = 0;
  quote_char = '\0';

  if (rl_completer_quote_characters)
    {
      /* We have a list of characters which can be used in pairs to
	 quote substrings for the completer.  Try to find the start
	 of an unclosed quoted substring. */
      /* FOUND_QUOTE is set so we know what kind of quotes we found. */
      for (scan = pass_next = 0; scan < end; scan++)
	{
	  if (pass_next)
	    {
	      pass_next = 0;
	      continue;
	    }

	  if (rl_line_buffer[scan] == '\\')
	    {
	      pass_next = 1;
	      found_quote |= RL_QF_BACKSLASH;
	      continue;
	    }

	  if (quote_char != '\0')
	    {
	      /* Ignore everything until the matching close quote char. */
	      if (rl_line_buffer[scan] == quote_char)
		{
		  /* Found matching close.  Abandon this substring. */
		  quote_char = '\0';
		  rl_point = end;
		}
	    }
	  else if (strchr (rl_completer_quote_characters, rl_line_buffer[scan]))
	    {
	      /* Found start of a quoted substring. */
	      quote_char = rl_line_buffer[scan];
	      rl_point = scan + 1;
	      /* Shell-like quoting conventions. */
	      if (quote_char == '\'')
		found_quote |= RL_QF_SINGLE_QUOTE;
	      else if (quote_char == '"')
		found_quote |= RL_QF_DOUBLE_QUOTE;
	    }
	}
    }

  if (rl_point == end && quote_char == '\0')
    {
      /* We didn't find an unclosed quoted substring upon which to do
         completion, so use the word break characters to find the
         substring on which to complete. */
      while (--rl_point)
	{
	  scan = rl_line_buffer[rl_point];

	  if (strchr (rl_completer_word_break_characters, scan) == 0)
	    continue;

	  /* Call the application-specific function to tell us whether
	     this word break character is quoted and should be skipped. */
	  if (rl_char_is_quoted_p && found_quote &&
	      (*rl_char_is_quoted_p) (rl_line_buffer, rl_point))
	    continue;

	  /* Convoluted code, but it avoids an n^2 algorithm with calls
	     to char_is_quoted. */
	  break;
	}
    }

  /* If we are at an unquoted word break, then advance past it. */
  scan = rl_line_buffer[rl_point];

  /* If there is an application-specific function to say whether or not
     a character is quoted and we found a quote character, let that
     function decide whether or not a character is a word break, even
     if it is found in rl_completer_word_break_characters. */
  if (rl_char_is_quoted_p)
    isbrk = (found_quote == 0 ||
 		(*rl_char_is_quoted_p) (rl_line_buffer, rl_point) == 0) &&
	      strchr (rl_completer_word_break_characters, scan) != 0;
  else
    isbrk = strchr (rl_completer_word_break_characters, scan) != 0;

  if (isbrk)
    {
      /* If the character that caused the word break was a quoting
	 character, then remember it as the delimiter. */
      if (rl_basic_quote_characters && strchr (rl_basic_quote_characters, scan) && (end - rl_point) > 1)
	delimiter = scan;

      /* If the character isn't needed to determine something special
	 about what kind of completion to perform, then advance past it. */
      if (rl_special_prefixes == 0 || strchr (rl_special_prefixes, scan) == 0)
	rl_point++;
    }

  if (fp)
    *fp = found_quote;
  if (dp)
    *dp = delimiter;

  return (quote_char);
}

static char **
gen_completion_matches (text, start, end, our_func, found_quote, quote_char)
     char *text;
     int start, end;
     Function *our_func;
     int found_quote, quote_char;
{
  char **matches, *temp;

  /* If the user wants to TRY to complete, but then wants to give
     up and use the default completion function, they set the
     variable rl_attempted_completion_function. */
  if (rl_attempted_completion_function)
    {
      matches = (*rl_attempted_completion_function) (text, start, end);

      if (matches || rl_attempted_completion_over)
	{
	  rl_attempted_completion_over = 0;
	  return (matches);
	}
    }

  /* Beware -- we're stripping the quotes here.  Do this only if we know
     we are doing filename completion and the application has defined a
     filename dequoting function. */
  temp = (char *)NULL;
  if (found_quote && our_func == (Function *)filename_completion_function &&
      rl_filename_dequoting_function)
    {
      /* delete single and double quotes */
      temp = (*rl_filename_dequoting_function) (text, quote_char);
      text = temp;	/* not freeing text is not a memory leak */
    }

  matches = completion_matches (text, our_func);
  FREE (temp);
  return matches;  
}

/* Filter out duplicates in MATCHES.  This frees up the strings in
   MATCHES. */
static char **
remove_duplicate_matches (matches)
     char **matches;
{
  char *lowest_common;
  int i, j, newlen;
  char dead_slot;
  char **temp_array;

  /* Sort the items. */
  for (i = 0; matches[i]; i++)
    ;

  /* Sort the array without matches[0], since we need it to
     stay in place no matter what. */
  if (i)
    qsort (matches+1, i-1, sizeof (char *), _rl_qsort_string_compare);

  /* Remember the lowest common denominator for it may be unique. */
  lowest_common = savestring (matches[0]);

  for (i = newlen = 0; matches[i + 1]; i++)
    {
      if (strcmp (matches[i], matches[i + 1]) == 0)
	{
	  free (matches[i]);
	  matches[i] = (char *)&dead_slot;
	}
      else
	newlen++;
    }

  /* We have marked all the dead slots with (char *)&dead_slot.
     Copy all the non-dead entries into a new array. */
  temp_array = (char **)xmalloc ((3 + newlen) * sizeof (char *));
  for (i = j = 1; matches[i]; i++)
    {
      if (matches[i] != (char *)&dead_slot)
	temp_array[j++] = matches[i];
    }
  temp_array[j] = (char *)NULL;

  if (matches[0] != (char *)&dead_slot)
    free (matches[0]);

  /* Place the lowest common denominator back in [0]. */
  temp_array[0] = lowest_common;

  /* If there is one string left, and it is identical to the
     lowest common denominator, then the LCD is the string to
     insert. */
  if (j == 2 && strcmp (temp_array[0], temp_array[1]) == 0)
    {
      free (temp_array[1]);
      temp_array[1] = (char *)NULL;
    }
  return (temp_array);
}

static void
display_matches (matches)
     char **matches;
{
  int len, count, limit, max, printed_len;
  int i, j, k, l;
  char *temp;

  /* Move to the last visible line of a possibly-multiple-line command. */
  _rl_move_vert (_rl_vis_botlin);

  /* Handle simple case first.  What if there is only one answer? */
  if (matches[1] == 0)
    {
      temp = printable_part (matches[0]);
      crlf ();
      print_filename (temp, matches[0]);
      crlf ();
#if 0
      rl_on_new_line ();
#else
      rl_forced_update_display ();
      rl_display_fixed = 1;
#endif
      return;
    }

  /* There is more than one answer.  Find out how many there are,
     and find the maximum printed length of a single entry. */
  for (max = 0, i = 1; matches[i]; i++)
    {
      temp = printable_part (matches[i]);
      len = strlen (temp);

      if (len > max)
	max = len;
    }

  len = i - 1;

  /* If there are many items, then ask the user if she really wants to
     see them all. */
  if (len >= rl_completion_query_items)
    {
      crlf ();
      fprintf (rl_outstream, "Display all %d possibilities? (y or n)", len);
      fflush (rl_outstream);
      if (get_y_or_n () == 0)
	{
	  crlf ();
#if 0
	  rl_on_new_line ();
#else
	  rl_forced_update_display ();
	  rl_display_fixed = 1;
#endif
	  return;
	}
    }

  /* How many items of MAX length can we fit in the screen window? */
  max += 2;
  limit = screenwidth / max;
  if (limit != 1 && (limit * max == screenwidth))
    limit--;

  /* Avoid a possible floating exception.  If max > screenwidth,
     limit will be 0 and a divide-by-zero fault will result. */
  if (limit == 0)
    limit = 1;

  /* How many iterations of the printing loop? */
  count = (len + (limit - 1)) / limit;

  /* Watch out for special case.  If LEN is less than LIMIT, then
     just do the inner printing loop.
	   0 < len <= limit  implies  count = 1. */

  /* Sort the items if they are not already sorted. */
  if (rl_ignore_completion_duplicates == 0)
    qsort (matches + 1, len, sizeof (char *), _rl_qsort_string_compare);

  /* Print the sorted items, up-and-down alphabetically, like ls. */
  crlf ();

  for (i = 1; i <= count; i++)
    {
      for (j = 0, l = i; j < limit; j++)
	{
	  if (l > len || matches[l] == 0)
	    break;
	  else
	    {
	      temp = printable_part (matches[l]);
	      printed_len = strlen (temp) + print_filename (temp, matches[l]);

	      if (j + 1 < limit)
		for (k = 0; k < max - printed_len; k++)
		  putc (' ', rl_outstream);
	    }
	  l += count;
	}
      crlf ();
    }

#if 0
  rl_on_new_line ();
#else
  rl_forced_update_display ();
  rl_display_fixed = 1;
#endif
}

static void
insert_text (text, start, end)
     char *text;
     int start, end;
{
  rl_begin_undo_group ();
  rl_delete_text (start, end + 1);
  rl_point = start;
  rl_insert_text (text);
  rl_end_undo_group ();
}

static char *
make_quoted_replacement (match, mtype, qc)
     char *match;
     int mtype;
     char *qc;	/* Pointer to quoting character, if any */
{
  int should_quote, do_replace;
  char *replacement;

  /* If we are doing completion on quoted substrings, and any matches
     contain any of the completer_word_break_characters, then auto-
     matically prepend the substring with a quote character (just pick
     the first one from the list of such) if it does not already begin
     with a quote string.  FIXME: Need to remove any such automatically
     inserted quote character when it no longer is necessary, such as
     if we change the string we are completing on and the new set of
     matches don't require a quoted substring. */
  replacement = match;

  should_quote = match && rl_completer_quote_characters &&
			rl_filename_completion_desired &&
			rl_filename_quoting_desired;

  if (should_quote)
#if defined (SHELL)
    should_quote = should_quote && (!qc || !*qc || *qc == '"' || *qc == '\'');
#else /* !SHELL */
    should_quote = should_quote && (!qc || !*qc);
#endif /* !SHELL */

  if (should_quote)
    {
      /* If there is a single match, see if we need to quote it.
         This also checks whether the common prefix of several
	 matches needs to be quoted. */
      should_quote = rl_strpbrk (match, rl_filename_quote_characters) != 0;

      do_replace = should_quote ? mtype : NO_MATCH;
      /* Quote the replacement, since we found an embedded
	 word break character in a potential match. */
      if (do_replace != NO_MATCH && rl_filename_quoting_function)
	replacement = (*rl_filename_quoting_function) (match, do_replace, qc);
    }
  return (replacement);
}

static void
insert_match (match, start, mtype, qc)
     char *match;
     int start, mtype;
     char *qc;
{
  char *replacement;
  char oqc;

  oqc = qc ? *qc : '\0';
  replacement = make_quoted_replacement (match, mtype, qc);

  /* Now insert the match. */
  if (replacement)
    {
      /* Don't double an opening quote character. */
      if (qc && *qc && start && rl_line_buffer[start - 1] == *qc &&
	    replacement[0] == *qc)
	start--;
      /* If make_quoted_replacement changed the quoting character, remove
	 the opening quote and insert the (fully-quoted) replacement. */
      else if (qc && (*qc != oqc) && start && rl_line_buffer[start - 1] == oqc &&
	    replacement[0] != oqc)
	start--;
      insert_text (replacement, start, rl_point - 1);
      if (replacement != match)
        free (replacement);
    }
}

/* Append any necessary closing quote and a separator character to the
   just-inserted match.  If the user has specified that directories
   should be marked by a trailing `/', append one of those instead.  The
   default trailing character  */
static void
append_to_match (text, delimiter, quote_char)
     char *text;
     int delimiter, quote_char;
{
  char temp_string[4], *filename;
  int temp_string_index;
  struct stat finfo;

  temp_string_index = 0;
  if (quote_char && rl_point && rl_line_buffer[rl_point - 1] != quote_char)
    temp_string[temp_string_index++] = quote_char;

  if (delimiter)
    temp_string[temp_string_index++] = delimiter;
  else if (rl_completion_append_character)
    temp_string[temp_string_index++] = rl_completion_append_character;

  temp_string[temp_string_index++] = '\0';

  if (rl_filename_completion_desired)
    {
      filename = tilde_expand (text);
      if (stat (filename, &finfo) == 0 && S_ISDIR (finfo.st_mode))
	{
	  if (_rl_complete_mark_directories && rl_line_buffer[rl_point] != '/')
	    rl_insert_text ("/");
	}
      else
	{
	  if (rl_point == rl_end)
	    rl_insert_text (temp_string);
	}
      free (filename);
    }
  else
    {
      if (rl_point == rl_end)
	rl_insert_text (temp_string);
    }
}

static void
insert_all_matches (matches, point, qc)
     char **matches;
     int point;
     char *qc;
{
  int i;
  char *rp;

  rl_begin_undo_group ();
  /* remove any opening quote character; make_quoted_replacement will add
     it back. */
  if (qc && *qc && point && rl_line_buffer[point - 1] == *qc)
    point--;
  rl_delete_text (point, rl_point);
  rl_point = point;

  if (matches[1])
    {
      for (i = 1; matches[i]; i++)
	{
	  rp = make_quoted_replacement (matches[i], SINGLE_MATCH, qc);
	  rl_insert_text (rp);
	  rl_insert_text (" ");
	  if (rp != matches[i])
	    free (rp);
	}
    }
  else
    {
      rp = make_quoted_replacement (matches[0], SINGLE_MATCH, qc);
      rl_insert_text (rp);
      rl_insert_text (" ");
      if (rp != matches[0])
	free (rp);
    }
  rl_end_undo_group ();
}

/* Complete the word at or before point.
   WHAT_TO_DO says what to do with the completion.
   `?' means list the possible completions.
   TAB means do standard completion.
   `*' means insert all of the possible completions.
   `!' means to do standard completion, and list all possible completions if
   there is more than one. */
int
rl_complete_internal (what_to_do)
     int what_to_do;
{
  char **matches, **temp_matches;
  Function *our_func;
  int start, end, delimiter, found_quote, nmatch, i;
  char *text, *saved_line_buffer, *t;
  char quote_char;

  saved_line_buffer = rl_line_buffer ? savestring (rl_line_buffer) : (char *)NULL;

  our_func = rl_completion_entry_function
		? rl_completion_entry_function
		: (Function *)filename_completion_function;

  /* Only the completion entry function can change these. */
  rl_filename_completion_desired = 0;
  rl_filename_quoting_desired = 1;

  rl_completion_type = what_to_do;

  /* We now look backwards for the start of a filename/variable word. */
  end = rl_point;

  found_quote = delimiter = 0;
  quote_char = '\0';

  if (rl_point)
    /* This (possibly) changes rl_point.  If it returns a non-zero char,
       we know we have an open quote. */
    quote_char = find_completion_word (&found_quote, &delimiter);

  start = rl_point;
  rl_point = end;

  text = rl_copy_text (start, end);
  matches = gen_completion_matches (text, start, end, our_func, found_quote, quote_char);

  if (matches == 0)
    {
      ding ();
      FREE (saved_line_buffer);
      free (text);
      return 0;
    }
    
  /* It seems to me that in all the cases we handle we would like
     to ignore duplicate possiblilities.  Scan for the text to
     insert being identical to the other completions. */
  if (rl_ignore_completion_duplicates)
    {
      temp_matches = remove_duplicate_matches (matches);
      free (matches);
      matches = temp_matches;
    }

  /* If we are matching filenames, then here is our chance to
     do clever processing by re-examining the list.  Call the
     ignore function with the array as a parameter.  It can
     munge the array, deleting matches as it desires. */
  if (rl_ignore_some_completions_function &&
      our_func == (Function *)filename_completion_function)
    {
      for (nmatch = 1; matches[nmatch]; nmatch++)
	;
      (void)(*rl_ignore_some_completions_function) (matches);
      if (matches == 0 || matches[0] == 0)
	{
	  FREE (matches);
	  ding ();
	  FREE (saved_line_buffer);
	  FREE (text);
	  return 0;
        }
      else
	{
	  /* If we removed some matches, recompute the common prefix. */
	  for (i = 1; matches[i]; i++)
	    ;
	  if (i > 1 && i < nmatch)
	    {
	      t = matches[0];
	      compute_lcd_of_matches (matches, i - 1, text);
	      FREE (t);
	    }
	}
    }
  free (text);

  switch (what_to_do)
    {
    case TAB:
    case '!':
      /* Insert the first match with proper quoting. */
      if (*matches[0])
	insert_match (matches[0], start, matches[1] ? MULT_MATCH : SINGLE_MATCH, &quote_char);

      /* If there are more matches, ring the bell to indicate.
	 If we are in vi mode, Posix.2 says to not ring the bell.
	 If the `show-all-if-ambiguous' variable is set, display
	 all the matches immediately.  Otherwise, if this was the
	 only match, and we are hacking files, check the file to
	 see if it was a directory.  If so, and the `mark-directories'
	 variable is set, add a '/' to the name.  If not, and we
	 are at the end of the line, then add a space.  */
      if (matches[1])
	{
	  if (what_to_do == '!')
	    {
	      display_matches (matches);
	      break;
	    }
	  else if (rl_editing_mode != vi_mode)
	    ding ();	/* There are other matches remaining. */
	}
      else
	append_to_match (matches[0], delimiter, quote_char);

      break;

    case '*':
      insert_all_matches (matches, start, &quote_char);
      break;

    case '?':
      display_matches (matches);
      break;

    default:
      fprintf (stderr, "\r\nreadline: bad value %d for what_to_do in rl_complete\n", what_to_do);
      ding ();
      FREE (saved_line_buffer);
      return 1;
    }

  for (i = 0; matches[i]; i++)
    free (matches[i]);
  free (matches);

  /* Check to see if the line has changed through all of this manipulation. */
  if (saved_line_buffer)
    {
      completion_changed_buffer = strcmp (rl_line_buffer, saved_line_buffer) != 0;
      free (saved_line_buffer);
    }

  return 0;
}

#if defined (VISIBLE_STATS)
/* Return the character which best describes FILENAME.
     `@' for symbolic links
     `/' for directories
     `*' for executables
     `=' for sockets
     `|' for FIFOs
     `%' for character special devices
     `#' for block special devices */
static int
stat_char (filename)
     char *filename;
{
  struct stat finfo;
  int character, r;

#if defined (HAVE_LSTAT) && defined (S_ISLNK)
  r = lstat (filename, &finfo);
#else
  r = stat (filename, &finfo);
#endif

  if (r == -1)
    return (0);

  character = 0;
  if (S_ISDIR (finfo.st_mode))
    character = '/';
#if defined (S_ISCHR)
  else if (S_ISCHR (finfo.st_mode))
    character = '%';
#endif /* S_ISCHR */
#if defined (S_ISBLK)
  else if (S_ISBLK (finfo.st_mode))
    character = '#';
#endif /* S_ISBLK */
#if defined (S_ISLNK)
  else if (S_ISLNK (finfo.st_mode))
    character = '@';
#endif /* S_ISLNK */
#if defined (S_ISSOCK)
  else if (S_ISSOCK (finfo.st_mode))
    character = '=';
#endif /* S_ISSOCK */
#if defined (S_ISFIFO)
  else if (S_ISFIFO (finfo.st_mode))
    character = '|';
#endif
  else if (S_ISREG (finfo.st_mode))
    {
      if (access (filename, X_OK) == 0)
	character = '*';
    }
  return (character);
}
#endif /* VISIBLE_STATS */

/* A completion function for usernames.
   TEXT contains a partial username preceded by a random
   character (usually `~').  */
char *
username_completion_function (text, state)
     int state;
     char *text;
{
#if defined (__GO32__) || defined (__WIN32__)
  return (char *)NULL;
#else /* !__GO32__ */
  static char *username = (char *)NULL;
  static struct passwd *entry;
  static int namelen, first_char, first_char_loc;
  char *value;

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

      first_char = *text;
      first_char_loc = first_char == '~';

      username = savestring (&text[first_char_loc]);
      namelen = strlen (username);
      setpwent ();
    }

  while (entry = getpwent ())
    {
      /* Null usernames should result in all users as possible completions. */
      if (namelen == 0 || (STREQN (username, entry->pw_name, namelen)))
	break;
    }

  if (entry == 0)
    {
      endpwent ();
      return ((char *)NULL);
    }
  else
    {
      value = xmalloc (2 + strlen (entry->pw_name));

      *value = *text;

      strcpy (value + first_char_loc, entry->pw_name);

      if (first_char == '~')
	rl_filename_completion_desired = 1;

      return (value);
    }
#endif /* !__GO32__ */
}

/* **************************************************************** */
/*								    */
/*			     Completion				    */
/*								    */
/* **************************************************************** */

/* Non-zero means that case is not significant in completion. */
int completion_case_fold = 0;

/* Find the common prefix of the list of matches, and put it into
   matches[0]. */
static int
compute_lcd_of_matches (match_list, matches, text)
     char **match_list;
     int matches;
     char *text;
{
  register int i, c1, c2, si;
  int low;		/* Count of max-matched characters. */

  /* If only one match, just use that.  Otherwise, compare each
     member of the list with the next, finding out where they
     stop matching. */
  if (matches == 1)
    {
      match_list[0] = match_list[1];
      match_list[1] = (char *)NULL;
      return 1;
    }

  for (i = 1, low = 100000; i < matches; i++)
    {
      if (completion_case_fold)
	{
	  for (si = 0;
	       (c1 = _rl_to_lower(match_list[i][si])) &&
	       (c2 = _rl_to_lower(match_list[i + 1][si]));
	       si++)
	    if (c1 != c2)
	      break;
	}
      else
	{
	  for (si = 0;
	       (c1 = match_list[i][si]) &&
	       (c2 = match_list[i + 1][si]);
	       si++)
	    if (c1 != c2)
	      break;
	}

      if (low > si)
	low = si;
    }

  /* If there were multiple matches, but none matched up to even the
     first character, and the user typed something, use that as the
     value of matches[0]. */
  if (low == 0 && text && *text)
    {
      match_list[0] = xmalloc (strlen (text) + 1);
      strcpy (match_list[0], text);
    }
  else
    {
      match_list[0] = xmalloc (low + 1);
      strncpy (match_list[0], match_list[1], low);
      match_list[0][low] = '\0';
    }

  return matches;
}

/* Return an array of (char *) which is a list of completions for TEXT.
   If there are no completions, return a NULL pointer.
   The first entry in the returned array is the substitution for TEXT.
   The remaining entries are the possible completions.
   The array is terminated with a NULL pointer.

   ENTRY_FUNCTION is a function of two args, and returns a (char *).
     The first argument is TEXT.
     The second is a state argument; it should be zero on the first call, and
     non-zero on subsequent calls.  It returns a NULL pointer to the caller
     when there are no more matches.
 */
char **
completion_matches (text, entry_function)
     char *text;
     CPFunction *entry_function;
{
  /* Number of slots in match_list. */
  int match_list_size;

  /* The list of matches. */
  char **match_list;

  /* Number of matches actually found. */
  int matches;

  /* Temporary string binder. */
  char *string;

  matches = 0;
  match_list_size = 10;
  match_list = (char **)xmalloc ((match_list_size + 1) * sizeof (char *));
  match_list[1] = (char *)NULL;

  while (string = (*entry_function) (text, matches))
    {
      if (matches + 1 == match_list_size)
	match_list = (char **)xrealloc
	  (match_list, ((match_list_size += 10) + 1) * sizeof (char *));

      match_list[++matches] = string;
      match_list[matches + 1] = (char *)NULL;
    }

  /* If there were any matches, then look through them finding out the
     lowest common denominator.  That then becomes match_list[0]. */
  if (matches)
    compute_lcd_of_matches (match_list, matches, text);
  else				/* There were no matches. */
    {
      free (match_list);
      match_list = (char **)NULL;
    }
  return (match_list);
}

/* Okay, now we write the entry_function for filename completion.  In the
   general case.  Note that completion in the shell is a little different
   because of all the pathnames that must be followed when looking up the
   completion for a command. */
char *
filename_completion_function (text, state)
     int state;
     char *text;
{
  static DIR *directory = (DIR *)NULL;
  static char *filename = (char *)NULL;
  static char *dirname = (char *)NULL;
  static char *users_dirname = (char *)NULL;
  static int filename_len;
  char *temp;
  int dirlen;
  struct dirent *entry;

  /* If we don't have any state, then do some initialization. */
  if (state == 0)
    {
      /* If we were interrupted before closing the directory or reading
	 all of its contents, close it. */
      if (directory)
	{
	  closedir (directory);
	  directory = (DIR *)NULL;
	}
      FREE (dirname);
      FREE (filename);
      FREE (users_dirname);

      filename = savestring (text);
      if (*text == 0)
	text = ".";
      dirname = savestring (text);

      temp = strrchr (dirname, '/');

      if (temp)
	{
	  strcpy (filename, ++temp);
	  *temp = '\0';
	}
      else
	{
	  dirname[0] = '.';
	  dirname[1] = '\0';
	}

      /* We aren't done yet.  We also support the "~user" syntax. */

      /* Save the version of the directory that the user typed. */
      users_dirname = savestring (dirname);

      if (*dirname == '~')
	{
	  temp = tilde_expand (dirname);
	  free (dirname);
	  dirname = temp;
	}

      if (rl_directory_completion_hook && (*rl_directory_completion_hook) (&dirname))
	{
	  free (users_dirname);
	  users_dirname = savestring (dirname);
	}

      directory = opendir (dirname);
      filename_len = strlen (filename);

      rl_filename_completion_desired = 1;
    }

  /* At this point we should entertain the possibility of hacking wildcarded
     filenames, like /usr/man/man<WILD>/te<TAB>.  If the directory name
     contains globbing characters, then build an array of directories, and
     then map over that list while completing. */
  /* *** UNIMPLEMENTED *** */

  /* Now that we have some state, we can read the directory. */

  entry = (struct dirent *)NULL;
  while (directory && (entry = readdir (directory)))
    {
      /* Special case for no filename.
	 All entries except "." and ".." match. */
      if (filename_len == 0)
	{
	  if (entry->d_name[0] != '.' ||
	       (entry->d_name[1] &&
		 (entry->d_name[1] != '.' || entry->d_name[2])))
	    break;
	}
      else
	{
	  /* Otherwise, if these match up to the length of filename, then
	     it is a match. */
	    if ((entry->d_name[0] == filename[0]) &&
		(((int)D_NAMLEN (entry)) >= filename_len) &&
		(strncmp (filename, entry->d_name, filename_len) == 0))
	      break;
	}
    }

  if (entry == 0)
    {
      if (directory)
	{
	  closedir (directory);
	  directory = (DIR *)NULL;
	}
      if (dirname)
	{
	  free (dirname);
	  dirname = (char *)NULL;
	}
      if (filename)
	{
	  free (filename);
	  filename = (char *)NULL;
	}
      if (users_dirname)
	{
	  free (users_dirname);
	  users_dirname = (char *)NULL;
	}

      return (char *)NULL;
    }
  else
    {
      /* dirname && (strcmp (dirname, ".") != 0) */
      if (dirname && (dirname[0] != '.' || dirname[1]))
	{
	  if (rl_complete_with_tilde_expansion && *users_dirname == '~')
	    {
	      dirlen = strlen (dirname);
	      temp = xmalloc (2 + dirlen + D_NAMLEN (entry));
	      strcpy (temp, dirname);
	      /* Canonicalization cuts off any final slash present.  We
		 may need to add it back. */
	      if (dirname[dirlen - 1] != '/')
	        {
	          temp[dirlen++] = '/';
	          temp[dirlen] = '\0';
	        }
	    }
	  else
	    {
	      dirlen = strlen (users_dirname);
	      temp = xmalloc (1 + dirlen + D_NAMLEN (entry));
	      strcpy (temp, users_dirname);
	    }

	  strcpy (temp + dirlen, entry->d_name); /* strcat (temp, entry->d_name); */
	}
      else
	temp = savestring (entry->d_name);

      return (temp);
    }
}

/* A function for simple tilde expansion. */
int
rl_tilde_expand (ignore, key)
     int ignore, key;
{
  register int start, end;
  char *homedir, *temp;
  int len;

  end = rl_point;
  start = end - 1;

  if (rl_point == rl_end && rl_line_buffer[rl_point] == '~')
    {
      homedir = tilde_expand ("~");
      insert_text (homedir, start, end);
      return (0);
    }
  else if (rl_line_buffer[start] != '~')
    {
      for (; !whitespace (rl_line_buffer[start]) && start >= 0; start--)
        ;
      start++;
    }

  end = start;
  do
    end++;
  while (whitespace (rl_line_buffer[end]) == 0 && end < rl_end);

  if (whitespace (rl_line_buffer[end]) || end >= rl_end)
    end--;

  /* If the first character of the current word is a tilde, perform
     tilde expansion and insert the result.  If not a tilde, do
     nothing. */
  if (rl_line_buffer[start] == '~')
    {
      len = end - start + 1;
      temp = xmalloc (len + 1);
      strncpy (temp, rl_line_buffer + start, len);
      temp[len] = '\0';
      homedir = tilde_expand (temp);
      free (temp);

      insert_text (homedir, start, end);
    }

  return (0);
}

/* Find the first occurrence in STRING1 of any character from STRING2.
   Return a pointer to the character in STRING1. */
static char *
rl_strpbrk (string1, string2)
     char *string1, *string2;
{
  register char *scan;

  for (; *string1; string1++)
    {
      for (scan = string2; *scan; scan++)
	{
	  if (*string1 == *scan)
	    {
	      return (string1);
	    }
	}
    }
  return ((char *)NULL);
}