--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,3 +1,7 @@
+2005-05-17  Jim Meyering  <jim@meyering.net>
+
+	* fts.c, fts_.h: New files, from coreutils.
+
 2005-05-14  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Sync from coreutils.
@@ -113,7 +117,7 @@
 	ai_socktype / ai_protocol in the returned addrinfo structure.
 
 2005-05-09  Yoann Vandoorselaere <yoann.v@prelude-ids.com>
-            Bruno Haible  <bruno@clisp.org>
+	    Bruno Haible  <bruno@clisp.org>
 
 	* inet_ntop.h: New file.
 	* inet_ntop.c: New file, from glibc with modifications.

new file mode 100644
--- /dev/null
+++ b/lib/fts.c
@@ -0,0 +1,1441 @@
+/* Traverse a file hierarchy.
+
+   Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program 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 this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)fts.c	8.6 (Berkeley) 8/14/94";
+#endif /* LIBC_SCCS and not lint */
+
+#if HAVE_SYS_PARAM_H || defined _LIBC
+# include <sys/param.h>
+#endif
+#ifdef _LIBC
+# include <include/sys/stat.h>
+#else
+# include <sys/stat.h>
+#endif
+#include <fcntl.h>
+#include <errno.h>
+#include "dirfd.h"
+#include "fts_.h"
+#include "intprops.h"
+#include "unistd-safer.h"
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#if HAVE_INTTYPES_H
+# include <inttypes.h>
+#endif
+#if HAVE_STDINT_H
+# include <stdint.h>
+#endif
+#if ULONG_MAX < ULLONG_MAX
+# define LONGEST_MODIFIER "ll"
+#else
+# define LONGEST_MODIFIER "l"
+#endif
+#if PRI_MACROS_BROKEN
+# undef PRIuMAX
+#endif
+#ifndef PRIuMAX
+# define PRIuMAX LONGEST_MODIFIER "u"
+#endif
+
+#if defined _LIBC
+# include <dirent.h>
+# define NAMLEN(dirent) _D_EXACT_NAMLEN (dirent)
+#else
+# if HAVE_DIRENT_H
+#  include <dirent.h>
+#  define NAMLEN(dirent) strlen ((dirent)->d_name)
+# else
+#  define dirent direct
+#  define NAMLEN(dirent) (dirent)->d_namlen
+#  if HAVE_SYS_NDIR_H
+#   include <sys/ndir.h>
+#  endif
+#  if HAVE_SYS_DIR_H
+#   include <sys/dir.h>
+#  endif
+#  if HAVE_NDIR_H
+#   include <ndir.h>
+#  endif
+# endif
+#endif
+
+#ifdef _LIBC
+# undef close
+# define close __close
+# undef closedir
+# define closedir __closedir
+# undef fchdir
+# define fchdir __fchdir
+# undef open
+# define open __open
+# undef opendir
+# define opendir __opendir
+# undef readdir
+# define readdir __readdir
+#else
+# undef internal_function
+# define internal_function /* empty */
+#endif
+
+/* Arrange to make lstat calls go through the wrapper function
+   on systems with an lstat function that does not dereference symlinks
+   that are specified with a trailing slash.  */
+#if ! _LIBC && ! LSTAT_FOLLOWS_SLASHED_SYMLINK
+int rpl_lstat (const char *, struct stat *);
+# undef lstat
+# define lstat(Name, Stat_buf) rpl_lstat(Name, Stat_buf)
+#endif
+
+#ifndef __set_errno
+# define __set_errno(Val) errno = (Val)
+#endif
+
+#ifndef __attribute__
+# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
+#  define __attribute__(x) /* empty */
+# endif
+#endif
+
+#ifndef ATTRIBUTE_UNUSED
+# define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
+#endif
+
+
+static FTSENT	*fts_alloc (FTS *, const char *, size_t) internal_function;
+static FTSENT	*fts_build (FTS *, int) internal_function;
+static void	 fts_lfree (FTSENT *) internal_function;
+static void	 fts_load (FTS *, FTSENT *) internal_function;
+static size_t	 fts_maxarglen (char * const *) internal_function;
+static void	 fts_padjust (FTS *, FTSENT *) internal_function;
+static bool	 fts_palloc (FTS *, size_t) internal_function;
+static FTSENT	*fts_sort (FTS *, FTSENT *, size_t) internal_function;
+static unsigned short int fts_stat (FTS *, FTSENT *, bool) internal_function;
+static int      fts_safe_changedir (FTS *, FTSENT *, int, const char *)
+     internal_function;
+
+#ifndef MAX
+# define MAX(a,b) ((a) > (b) ? (a) : (b))
+#endif
+
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+
+#ifndef O_DIRECTORY
+# define O_DIRECTORY 0
+#endif
+
+#define ISDOT(a)	(a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
+
+#define CLR(opt)	(sp->fts_options &= ~(opt))
+#define ISSET(opt)	(sp->fts_options & (opt))
+#define SET(opt)	(sp->fts_options |= (opt))
+
+#define FCHDIR(sp, fd)	(!ISSET(FTS_NOCHDIR) && fchdir(fd))
+
+/* fts_build flags */
+#define BCHILD		1		/* fts_children */
+#define BNAMES		2		/* fts_children, names only */
+#define BREAD		3		/* fts_read */
+
+#define HT_INITIAL_SIZE 31
+
+#if FTS_DEBUG
+bool fts_debug = false;
+# include <stdio.h>
+# define Dprintf(x) do { if (fts_debug) printf x; } while (0)
+#else
+# define Dprintf(x)
+#endif
+
+#define ENTER_DIR(Fts, Ent, Tag)				\
+  do {								\
+      Dprintf (("  %s-entering: %s\n", Tag, (Ent)->fts_path));	\
+      enter_dir (sp, p);					\
+    } while (0)
+
+#define LEAVE_DIR(Fts, Ent, Tag)				\
+  do {								\
+      Dprintf (("  %s-leaving: %s\n", Tag, (Ent)->fts_path));	\
+      leave_dir (sp, p);					\
+    } while (0)
+
+/* Use these each of these to map a device/inode pair to an FTSENT.  */
+struct Active_dir
+{
+  dev_t dev;
+  ino_t ino;
+  FTSENT *fts_ent;
+};
+
+static bool
+AD_compare (void const *x, void const *y)
+{
+  struct Active_dir const *ax = x;
+  struct Active_dir const *ay = y;
+  return ax->ino == ay->ino
+      && ax->dev == ay->dev;
+}
+
+static size_t
+AD_hash (void const *x, size_t table_size)
+{
+  struct Active_dir const *ax = x;
+  return (uintmax_t) ax->ino % table_size;
+}
+
+static void
+enter_dir (FTS *fts, FTSENT *ent)
+{
+  if (fts->active_dir_ht)
+    {
+      struct stat const *st = ent->fts_statp;
+      struct Active_dir *ad = malloc (sizeof (struct Active_dir));
+      struct Active_dir *ad_from_table;
+
+      if (ad == NULL)
+	goto give_up;
+
+      ad->dev = st->st_dev;
+      ad->ino = st->st_ino;
+      ad->fts_ent = ent;
+
+      /* See if we've already encountered this directory.
+	 This can happen when following symlinks as well as
+	 with a corrupted directory hierarchy. */
+      ad_from_table = hash_insert (fts->active_dir_ht, ad);
+
+      if (ad_from_table == NULL)
+	{
+	give_up:
+	  /* Insertion failed due to lack of memory.  Free the hash
+	     table and turn off this sort of cycle detection.  */
+	  hash_free (fts->active_dir_ht);
+	  fts->active_dir_ht = NULL;
+	  return;
+	}
+
+      if (ad_from_table != ad)
+	{
+	  /* There was an entry with matching dev/inode already in the table.
+	     Record the fact that we've found a cycle.  */
+	  ent->fts_cycle = ad_from_table->fts_ent;
+	  ent->fts_info = FTS_DC;
+
+	  /* ad was not inserted, so free it.  */
+	  free (ad);
+	}
+    }
+  else if (fts->cycle_state)
+    {
+      if (cycle_check (fts->cycle_state, ent->fts_statp))
+	{
+	  /* FIXME: setting fts_cycle like this isn't proper.
+	     To do what the documentation requires, we'd have to
+	     go around the cycle again and find the right entry.
+	     But no callers in coreutils use the fts_cycle member. */
+	  ent->fts_cycle = ent;
+	  ent->fts_info = FTS_DC;
+	}
+    }
+}
+
+static void
+leave_dir (FTS *fts, FTSENT *ent)
+{
+  if (fts->active_dir_ht)
+    {
+      struct stat const *st = ent->fts_statp;
+      struct Active_dir obj;
+      void *found;
+      obj.dev = st->st_dev;
+      obj.ino = st->st_ino;
+      found = hash_delete (fts->active_dir_ht, &obj);
+      if (!found)
+	abort ();
+      free (found);
+    }
+}
+
+/* Open the directory DIR if possible, and return a file
+   descriptor.  Return -1 and set errno on failure.  It doesn't matter
+   whether the file descriptor has read or write access.  */
+
+static int
+internal_function
+diropen (char const *dir)
+{
+  int fd = open (dir, O_RDONLY | O_DIRECTORY);
+  if (fd < 0)
+    fd = open (dir, O_WRONLY | O_DIRECTORY);
+  return fd;
+}
+
+FTS *
+fts_open (char * const *argv,
+	  register int options,
+	  int (*compar) (FTSENT const **, FTSENT const **))
+{
+	register FTS *sp;
+	register FTSENT *p, *root;
+	register size_t nitems;
+	FTSENT *parent, *tmp = NULL;	/* pacify gcc */
+	size_t len;
+
+	/* Options check. */
+	if (options & ~FTS_OPTIONMASK) {
+		__set_errno (EINVAL);
+		return (NULL);
+	}
+
+	/* Allocate/initialize the stream */
+	if ((sp = malloc(sizeof(FTS))) == NULL)
+		return (NULL);
+	memset(sp, 0, sizeof(FTS));
+	sp->fts_compar = compar;
+	sp->fts_options = options;
+
+	/* Logical walks turn on NOCHDIR; symbolic links are too hard. */
+	if (ISSET(FTS_LOGICAL))
+		SET(FTS_NOCHDIR);
+
+	/*
+	 * Start out with 1K of path space, and enough, in any case,
+	 * to hold the user's paths.
+	 */
+#ifndef MAXPATHLEN
+# define MAXPATHLEN 1024
+#endif
+	if (! fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN)))
+		goto mem1;
+
+	/* Allocate/initialize root's parent. */
+	if ((parent = fts_alloc(sp, "", 0)) == NULL)
+		goto mem2;
+	parent->fts_level = FTS_ROOTPARENTLEVEL;
+
+	/* Allocate/initialize root(s). */
+	for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) {
+		/* Don't allow zero-length paths. */
+		if ((len = strlen(*argv)) == 0) {
+			__set_errno (ENOENT);
+			goto mem3;
+		}
+
+		if ((p = fts_alloc(sp, *argv, len)) == NULL)
+			goto mem3;
+		p->fts_level = FTS_ROOTLEVEL;
+		p->fts_parent = parent;
+		p->fts_accpath = p->fts_name;
+		p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW) != 0);
+
+		/* Command-line "." and ".." are real directories. */
+		if (p->fts_info == FTS_DOT)
+			p->fts_info = FTS_D;
+
+		/*
+		 * If comparison routine supplied, traverse in sorted
+		 * order; otherwise traverse in the order specified.
+		 */
+		if (compar) {
+			p->fts_link = root;
+			root = p;
+		} else {
+			p->fts_link = NULL;
+			if (root == NULL)
+				tmp = root = p;
+			else {
+				tmp->fts_link = p;
+				tmp = p;
+			}
+		}
+	}
+	if (compar && nitems > 1)
+		root = fts_sort(sp, root, nitems);
+
+	/*
+	 * Allocate a dummy pointer and make fts_read think that we've just
+	 * finished the node before the root(s); set p->fts_info to FTS_INIT
+	 * so that everything about the "current" node is ignored.
+	 */
+	if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
+		goto mem3;
+	sp->fts_cur->fts_link = root;
+	sp->fts_cur->fts_info = FTS_INIT;
+
+	if (ISSET (FTS_TIGHT_CYCLE_CHECK))
+	  {
+	    sp->active_dir_ht = hash_initialize (HT_INITIAL_SIZE,
+						 NULL, AD_hash,
+						 AD_compare, free);
+	    if (sp->active_dir_ht == NULL)
+	      goto mem3;
+	    sp->cycle_state = malloc (sizeof *sp->cycle_state);
+	  }
+	else
+	  {
+	    sp->cycle_state = malloc (sizeof *sp->cycle_state);
+	    if (sp->cycle_state == NULL)
+	      goto mem3;
+	    cycle_check_init (sp->cycle_state);
+	    sp->active_dir_ht = NULL;
+	  }
+
+	/*
+	 * If using chdir(2), grab a file descriptor pointing to dot to ensure
+	 * that we can get back here; this could be avoided for some paths,
+	 * but almost certainly not worth the effort.  Slashes, symbolic links,
+	 * and ".." are all fairly nasty problems.  Note, if we can't get the
+	 * descriptor we run anyway, just more slowly.
+	 */
+	if (!ISSET(FTS_NOCHDIR)
+	    && (sp->fts_rfd = diropen (".")) < 0)
+		SET(FTS_NOCHDIR);
+
+	return (sp);
+
+mem3:	fts_lfree(root);
+	free(parent);
+mem2:	free(sp->fts_path);
+mem1:	free(sp);
+	return (NULL);
+}
+
+static void
+internal_function
+fts_load (FTS *sp, register FTSENT *p)
+{
+	register size_t len;
+	register char *cp;
+
+	/*
+	 * Load the stream structure for the next traversal.  Since we don't
+	 * actually enter the directory until after the preorder visit, set
+	 * the fts_accpath field specially so the chdir gets done to the right
+	 * place and the user can access the first node.  From fts_open it's
+	 * known that the path will fit.
+	 */
+	len = p->fts_pathlen = p->fts_namelen;
+	memmove(sp->fts_path, p->fts_name, len + 1);
+	if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
+		len = strlen(++cp);
+		memmove(p->fts_name, cp, len + 1);
+		p->fts_namelen = len;
+	}
+	p->fts_accpath = p->fts_path = sp->fts_path;
+	sp->fts_dev = p->fts_statp->st_dev;
+}
+
+int
+fts_close (FTS *sp)
+{
+	register FTSENT *freep, *p;
+	int saved_errno = 0;
+
+	/*
+	 * This still works if we haven't read anything -- the dummy structure
+	 * points to the root list, so we step through to the end of the root
+	 * list which has a valid parent pointer.
+	 */
+	if (sp->fts_cur) {
+		for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
+			freep = p;
+			p = p->fts_link != NULL ? p->fts_link : p->fts_parent;
+			free(freep);
+		}
+		free(p);
+	}
+
+	/* Free up child linked list, sort array, path buffer. */
+	if (sp->fts_child)
+		fts_lfree(sp->fts_child);
+	if (sp->fts_array)
+		free(sp->fts_array);
+	free(sp->fts_path);
+
+	/* Return to original directory, save errno if necessary. */
+	if (!ISSET(FTS_NOCHDIR)) {
+		if (fchdir(sp->fts_rfd))
+			saved_errno = errno;
+		(void)close(sp->fts_rfd);
+	}
+
+	/* Free any memory used for cycle detection.  */
+	if (sp->active_dir_ht)
+	  hash_free (sp->active_dir_ht);
+	if (sp->cycle_state)
+	  free (sp->cycle_state);
+
+	/* Free up the stream pointer. */
+	free(sp);
+
+	/* Set errno and return. */
+	if (saved_errno) {
+		__set_errno (saved_errno);
+		return (-1);
+	}
+
+	return (0);
+}
+
+/*
+ * Special case of "/" at the end of the path so that slashes aren't
+ * appended which would cause paths to be written as "....//foo".
+ */
+#define NAPPEND(p)							\
+	(p->fts_path[p->fts_pathlen - 1] == '/'				\
+	    ? p->fts_pathlen - 1 : p->fts_pathlen)
+
+FTSENT *
+fts_read (register FTS *sp)
+{
+	register FTSENT *p, *tmp;
+	register unsigned short int instr;
+	register char *t;
+	int saved_errno;
+
+	/* If finished or unrecoverable error, return NULL. */
+	if (sp->fts_cur == NULL || ISSET(FTS_STOP))
+		return (NULL);
+
+	/* Set current node pointer. */
+	p = sp->fts_cur;
+
+	/* Save and zero out user instructions. */
+	instr = p->fts_instr;
+	p->fts_instr = FTS_NOINSTR;
+
+	/* Any type of file may be re-visited; re-stat and re-turn. */
+	if (instr == FTS_AGAIN) {
+		p->fts_info = fts_stat(sp, p, false);
+		return (p);
+	}
+	Dprintf (("fts_read: p=%s\n",
+		  p->fts_info == FTS_INIT ? "" : p->fts_path));
+
+	/*
+	 * Following a symlink -- SLNONE test allows application to see
+	 * SLNONE and recover.  If indirecting through a symlink, have
+	 * keep a pointer to current location.  If unable to get that
+	 * pointer, follow fails.
+	 */
+	if (instr == FTS_FOLLOW &&
+	    (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
+		p->fts_info = fts_stat(sp, p, true);
+		if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
+			if ((p->fts_symfd = diropen (".")) < 0) {
+				p->fts_errno = errno;
+				p->fts_info = FTS_ERR;
+			} else
+				p->fts_flags |= FTS_SYMFOLLOW;
+		}
+		if (p->fts_info == FTS_D)
+			ENTER_DIR (sp, p, "7");
+		return (p);
+	}
+
+	/* Directory in pre-order. */
+	if (p->fts_info == FTS_D) {
+		/* If skipped or crossed mount point, do post-order visit. */
+		if (instr == FTS_SKIP ||
+		    (ISSET(FTS_XDEV) && p->fts_statp->st_dev != sp->fts_dev)) {
+			if (p->fts_flags & FTS_SYMFOLLOW)
+				(void)close(p->fts_symfd);
+			if (sp->fts_child) {
+				fts_lfree(sp->fts_child);
+				sp->fts_child = NULL;
+			}
+			p->fts_info = FTS_DP;
+			LEAVE_DIR (sp, p, "1");
+			return (p);
+		}
+
+		/* Rebuild if only read the names and now traversing. */
+		if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) {
+			CLR(FTS_NAMEONLY);
+			fts_lfree(sp->fts_child);
+			sp->fts_child = NULL;
+		}
+
+		/*
+		 * Cd to the subdirectory.
+		 *
+		 * If have already read and now fail to chdir, whack the list
+		 * to make the names come out right, and set the parent errno
+		 * so the application will eventually get an error condition.
+		 * Set the FTS_DONTCHDIR flag so that when we logically change
+		 * directories back to the parent we don't do a chdir.
+		 *
+		 * If haven't read do so.  If the read fails, fts_build sets
+		 * FTS_STOP or the fts_info field of the node.
+		 */
+		if (sp->fts_child != NULL) {
+			if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
+				p->fts_errno = errno;
+				p->fts_flags |= FTS_DONTCHDIR;
+				for (p = sp->fts_child; p != NULL;
+				     p = p->fts_link)
+					p->fts_accpath =
+					    p->fts_parent->fts_accpath;
+			}
+		} else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
+			if (ISSET(FTS_STOP))
+				return (NULL);
+			/* If fts_build's call to fts_safe_changedir failed
+			   because it was not able to fchdir into a
+			   subdirectory, tell the caller.  */
+			if (p->fts_errno)
+				p->fts_info = FTS_ERR;
+			/* FIXME: see if this should be in an else block */
+			LEAVE_DIR (sp, p, "2");
+			return (p);
+		}
+		p = sp->fts_child;
+		sp->fts_child = NULL;
+		goto name;
+	}
+
+	/* Move to the next node on this level. */
+next:	tmp = p;
+	if ((p = p->fts_link) != NULL) {
+		free(tmp);
+
+		/*
+		 * If reached the top, return to the original directory (or
+		 * the root of the tree), and load the paths for the next root.
+		 */
+		if (p->fts_level == FTS_ROOTLEVEL) {
+			if (FCHDIR(sp, sp->fts_rfd)) {
+				SET(FTS_STOP);
+				return (NULL);
+			}
+			fts_load(sp, p);
+			if (p->fts_info == FTS_D)
+				ENTER_DIR (sp, p, "8");
+			return (sp->fts_cur = p);
+		}
+
+		/*
+		 * User may have called fts_set on the node.  If skipped,
+		 * ignore.  If followed, get a file descriptor so we can
+		 * get back if necessary.
+		 */
+		if (p->fts_instr == FTS_SKIP)
+			goto next;
+		if (p->fts_instr == FTS_FOLLOW) {
+			p->fts_info = fts_stat(sp, p, true);
+			if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
+				if ((p->fts_symfd = diropen (".")) < 0) {
+					p->fts_errno = errno;
+					p->fts_info = FTS_ERR;
+				} else
+					p->fts_flags |= FTS_SYMFOLLOW;
+			}
+			p->fts_instr = FTS_NOINSTR;
+		}
+
+name:		t = sp->fts_path + NAPPEND(p->fts_parent);
+		*t++ = '/';
+		memmove(t, p->fts_name, p->fts_namelen + 1);
+		if (p->fts_info == FTS_D)
+			ENTER_DIR (sp, p, "9");
+		return (sp->fts_cur = p);
+	}
+
+	/* Move up to the parent node. */
+	p = tmp->fts_parent;
+	free(tmp);
+
+	if (p->fts_level == FTS_ROOTPARENTLEVEL) {
+		/*
+		 * Done; free everything up and set errno to 0 so the user
+		 * can distinguish between error and EOF.
+		 */
+		free(p);
+		__set_errno (0);
+		return (sp->fts_cur = NULL);
+	}
+
+	/* NUL terminate the pathname. */
+	sp->fts_path[p->fts_pathlen] = '\0';
+
+	/*
+	 * Return to the parent directory.  If at a root node or came through
+	 * a symlink, go back through the file descriptor.  Otherwise, cd up
+	 * one directory.
+	 */
+	if (p->fts_level == FTS_ROOTLEVEL) {
+		if (FCHDIR(sp, sp->fts_rfd)) {
+			p->fts_errno = errno;
+			SET(FTS_STOP);
+		}
+	} else if (p->fts_flags & FTS_SYMFOLLOW) {
+		if (FCHDIR(sp, p->fts_symfd)) {
+			saved_errno = errno;
+			(void)close(p->fts_symfd);
+			__set_errno (saved_errno);
+			p->fts_errno = errno;
+			SET(FTS_STOP);
+		}
+		(void)close(p->fts_symfd);
+	} else if (!(p->fts_flags & FTS_DONTCHDIR) &&
+		   fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
+		p->fts_errno = errno;
+		SET(FTS_STOP);
+	}
+	p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
+	if (p->fts_errno == 0)
+		LEAVE_DIR (sp, p, "3");
+	sp->fts_cur = p;
+	return ISSET(FTS_STOP) ? NULL : p;
+}
+
+/*
+ * Fts_set takes the stream as an argument although it's not used in this
+ * implementation; it would be necessary if anyone wanted to add global
+ * semantics to fts using fts_set.  An error return is allowed for similar
+ * reasons.
+ */
+/* ARGSUSED */
+int
+fts_set(FTS *sp ATTRIBUTE_UNUSED, FTSENT *p, int instr)
+{
+	if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
+	    instr != FTS_NOINSTR && instr != FTS_SKIP) {
+		__set_errno (EINVAL);
+		return (1);
+	}
+	p->fts_instr = instr;
+	return (0);
+}
+
+FTSENT *
+fts_children (register FTS *sp, int instr)
+{
+	register FTSENT *p;
+	int fd;
+
+	if (instr != 0 && instr != FTS_NAMEONLY) {
+		__set_errno (EINVAL);
+		return (NULL);
+	}
+
+	/* Set current node pointer. */
+	p = sp->fts_cur;
+
+	/*
+	 * Errno set to 0 so user can distinguish empty directory from
+	 * an error.
+	 */
+	__set_errno (0);
+
+	/* Fatal errors stop here. */
+	if (ISSET(FTS_STOP))
+		return (NULL);
+
+	/* Return logical hierarchy of user's arguments. */
+	if (p->fts_info == FTS_INIT)
+		return (p->fts_link);
+
+	/*
+	 * If not a directory being visited in pre-order, stop here.  Could
+	 * allow FTS_DNR, assuming the user has fixed the problem, but the
+	 * same effect is available with FTS_AGAIN.
+	 */
+	if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
+		return (NULL);
+
+	/* Free up any previous child list. */
+	if (sp->fts_child != NULL)
+		fts_lfree(sp->fts_child);
+
+	if (instr == FTS_NAMEONLY) {
+		SET(FTS_NAMEONLY);
+		instr = BNAMES;
+	} else
+		instr = BCHILD;
+
+	/*
+	 * If using chdir on a relative path and called BEFORE fts_read does
+	 * its chdir to the root of a traversal, we can lose -- we need to
+	 * chdir into the subdirectory, and we don't know where the current
+	 * directory is, so we can't get back so that the upcoming chdir by
+	 * fts_read will work.
+	 */
+	if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
+	    ISSET(FTS_NOCHDIR))
+		return (sp->fts_child = fts_build(sp, instr));
+
+	if ((fd = diropen (".")) < 0)
+		return (sp->fts_child = NULL);
+	sp->fts_child = fts_build(sp, instr);
+	if (fchdir(fd)) {
+		(void)close(fd);
+		return (NULL);
+	}
+	(void)close(fd);
+	return (sp->fts_child);
+}
+
+/*
+ * This is the tricky part -- do not casually change *anything* in here.  The
+ * idea is to build the linked list of entries that are used by fts_children
+ * and fts_read.  There are lots of special cases.
+ *
+ * The real slowdown in walking the tree is the stat calls.  If FTS_NOSTAT is
+ * set and it's a physical walk (so that symbolic links can't be directories),
+ * we can do things quickly.  First, if it's a 4.4BSD file system, the type
+ * of the file is in the directory entry.  Otherwise, we assume that the number
+ * of subdirectories in a node is equal to the number of links to the parent.
+ * The former skips all stat calls.  The latter skips stat calls in any leaf
+ * directories and for any files after the subdirectories in the directory have
+ * been found, cutting the stat calls by about 2/3.
+ */
+static FTSENT *
+internal_function
+fts_build (register FTS *sp, int type)
+{
+	register struct dirent *dp;
+	register FTSENT *p, *head;
+	register size_t nitems;
+	FTSENT *cur, *tail;
+	DIR *dirp;
+	void *oldaddr;
+	int cderrno;
+	int saved_errno;
+	bool descend;
+	bool doadjust;
+	ptrdiff_t level;
+	nlink_t nlinks;
+	bool nostat;
+	size_t len, maxlen, new_len;
+	char *cp;
+
+	/* Set current node pointer. */
+	cur = sp->fts_cur;
+
+	/*
+	 * Open the directory for reading.  If this fails, we're done.
+	 * If being called from fts_read, set the fts_info field.
+	 */
+#if defined FTS_WHITEOUT && 0
+	if (ISSET(FTS_WHITEOUT))
+		oflag = DTF_NODUP|DTF_REWIND;
+	else
+		oflag = DTF_HIDEW|DTF_NODUP|DTF_REWIND;
+#else
+# define __opendir2(path, flag) opendir(path)
+#endif
+       if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) {
+		if (type == BREAD) {
+			cur->fts_info = FTS_DNR;
+			cur->fts_errno = errno;
+		}
+		return (NULL);
+	}
+
+	/*
+	 * Nlinks is the number of possible entries of type directory in the
+	 * directory if we're cheating on stat calls, 0 if we're not doing
+	 * any stat calls at all, (nlink_t) -1 if we're statting everything.
+	 */
+	if (type == BNAMES) {
+		nlinks = 0;
+		/* Be quiet about nostat, GCC. */
+		nostat = false;
+	} else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
+		nlinks = (cur->fts_statp->st_nlink
+			  - (ISSET(FTS_SEEDOT) ? 0 : 2));
+		nostat = true;
+	} else {
+		nlinks = -1;
+		nostat = false;
+	}
+
+	/*
+	 * If we're going to need to stat anything or we want to descend
+	 * and stay in the directory, chdir.  If this fails we keep going,
+	 * but set a flag so we don't chdir after the post-order visit.
+	 * We won't be able to stat anything, but we can still return the
+	 * names themselves.  Note, that since fts_read won't be able to
+	 * chdir into the directory, it will have to return different path
+	 * names than before, i.e. "a/b" instead of "b".  Since the node
+	 * has already been visited in pre-order, have to wait until the
+	 * post-order visit to return the error.  There is a special case
+	 * here, if there was nothing to stat then it's not an error to
+	 * not be able to stat.  This is all fairly nasty.  If a program
+	 * needed sorted entries or stat information, they had better be
+	 * checking FTS_NS on the returned nodes.
+	 */
+	cderrno = 0;
+	if (nlinks || type == BREAD) {
+		if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) {
+			if (nlinks && type == BREAD)
+				cur->fts_errno = errno;
+			cur->fts_flags |= FTS_DONTCHDIR;
+			descend = false;
+			cderrno = errno;
+			(void)closedir(dirp);
+			dirp = NULL;
+		} else
+			descend = true;
+	} else
+		descend = false;
+
+	/*
+	 * Figure out the max file name length that can be stored in the
+	 * current path -- the inner loop allocates more path as necessary.
+	 * We really wouldn't have to do the maxlen calculations here, we
+	 * could do them in fts_read before returning the path, but it's a
+	 * lot easier here since the length is part of the dirent structure.
+	 *
+	 * If not changing directories set a pointer so that can just append
+	 * each new name into the path.
+	 */
+	len = NAPPEND(cur);
+	if (ISSET(FTS_NOCHDIR)) {
+		cp = sp->fts_path + len;
+		*cp++ = '/';
+	} else {
+		/* GCC, you're too verbose. */
+		cp = NULL;
+	}
+	len++;
+	maxlen = sp->fts_pathlen - len;
+
+	level = cur->fts_level + 1;
+
+	/* Read the directory, attaching each entry to the `link' pointer. */
+	doadjust = false;
+	for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
+		if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
+			continue;
+
+		if ((p = fts_alloc(sp, dp->d_name, NAMLEN (dp))) == NULL)
+			goto mem1;
+		if (NAMLEN (dp) >= maxlen) {/* include space for NUL */
+			oldaddr = sp->fts_path;
+			if (! fts_palloc(sp, NAMLEN (dp) + len + 1)) {
+				/*
+				 * No more memory for path or structures.  Save
+				 * errno, free up the current structure and the
+				 * structures already allocated.
+				 */
+mem1:				saved_errno = errno;
+				if (p)
+					free(p);
+				fts_lfree(head);
+				(void)closedir(dirp);
+				cur->fts_info = FTS_ERR;
+				SET(FTS_STOP);
+				__set_errno (saved_errno);
+				return (NULL);
+			}
+			/* Did realloc() change the pointer? */
+			if (oldaddr != sp->fts_path) {
+				doadjust = true;
+				if (ISSET(FTS_NOCHDIR))
+					cp = sp->fts_path + len;
+			}
+			maxlen = sp->fts_pathlen - len;
+		}
+
+		new_len = len + NAMLEN (dp);
+		if (new_len < len) {
+			/*
+			 * In the unlikely even that we would end up
+			 * with a path longer than SIZE_MAX, free up
+			 * the current structure and the structures already
+			 * allocated, then error out with ENAMETOOLONG.
+			 */
+			free(p);
+			fts_lfree(head);
+			(void)closedir(dirp);
+			cur->fts_info = FTS_ERR;
+			SET(FTS_STOP);
+			__set_errno (ENAMETOOLONG);
+			return (NULL);
+		}
+		p->fts_level = level;
+		p->fts_parent = sp->fts_cur;
+		p->fts_pathlen = new_len;
+
+#if defined FTS_WHITEOUT && 0
+		if (dp->d_type == DT_WHT)
+			p->fts_flags |= FTS_ISW;
+#endif
+
+		if (cderrno) {
+			if (nlinks) {
+				p->fts_info = FTS_NS;
+				p->fts_errno = cderrno;
+			} else
+				p->fts_info = FTS_NSOK;
+			p->fts_accpath = cur->fts_accpath;
+		} else if (nlinks == 0
+#if HAVE_STRUCT_DIRENT_D_TYPE
+			   || (nostat &&
+			       dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN)
+#endif
+		    ) {
+			p->fts_accpath =
+			    ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name;
+			p->fts_info = FTS_NSOK;
+		} else {
+			/* Build a file name for fts_stat to stat. */
+			if (ISSET(FTS_NOCHDIR)) {
+				p->fts_accpath = p->fts_path;
+				memmove(cp, p->fts_name, p->fts_namelen + 1);
+			} else
+				p->fts_accpath = p->fts_name;
+			/* Stat it. */
+			p->fts_info = fts_stat(sp, p, false);
+
+			/* Decrement link count if applicable. */
+			if (nlinks > 0
+			    && (TYPE_SIGNED (nlink_t) || nostat)
+			    && (p->fts_info == FTS_D ||
+			    p->fts_info == FTS_DC || p->fts_info == FTS_DOT))
+				--nlinks;
+		}
+
+		/* We walk in directory order so "ls -f" doesn't get upset. */
+		p->fts_link = NULL;
+		if (head == NULL)
+			head = tail = p;
+		else {
+			tail->fts_link = p;
+			tail = p;
+		}
+		++nitems;
+	}
+	if (dirp)
+		(void)closedir(dirp);
+
+	/*
+	 * If realloc() changed the address of the path, adjust the
+	 * addresses for the rest of the tree and the dir list.
+	 */
+	if (doadjust)
+		fts_padjust(sp, head);
+
+	/*
+	 * If not changing directories, reset the path back to original
+	 * state.
+	 */
+	if (ISSET(FTS_NOCHDIR)) {
+		if (len == sp->fts_pathlen || nitems == 0)
+			--cp;
+		*cp = '\0';
+	}
+
+	/*
+	 * If descended after called from fts_children or after called from
+	 * fts_read and nothing found, get back.  At the root level we use
+	 * the saved fd; if one of fts_open()'s arguments is a relative path
+	 * to an empty directory, we wind up here with no other way back.  If
+	 * can't get back, we're done.
+	 */
+	if (descend && (type == BCHILD || !nitems) &&
+	    (cur->fts_level == FTS_ROOTLEVEL ?
+	     FCHDIR(sp, sp->fts_rfd) :
+	     fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
+		cur->fts_info = FTS_ERR;
+		SET(FTS_STOP);
+		return (NULL);
+	}
+
+	/* If didn't find anything, return NULL. */
+	if (!nitems) {
+		if (type == BREAD)
+			cur->fts_info = FTS_DP;
+		return (NULL);
+	}
+
+	/* Sort the entries. */
+	if (sp->fts_compar && nitems > 1)
+		head = fts_sort(sp, head, nitems);
+	return (head);
+}
+
+#if FTS_DEBUG
+
+/* Walk ->fts_parent links starting at E_CURR, until the root of the
+   current hierarchy.  There should be a directory with dev/inode
+   matching those of AD.  If not, print a lot of diagnostics.  */
+static void
+find_matching_ancestor (FTSENT const *e_curr, struct Active_dir const *ad)
+{
+  FTSENT const *ent;
+  for (ent = e_curr; ent->fts_level >= FTS_ROOTLEVEL; ent = ent->fts_parent)
+    {
+      if (ad->ino == ent->fts_statp->st_ino
+	  && ad->dev == ent->fts_statp->st_dev)
+	return;
+    }
+  printf ("ERROR: tree dir, %s, not active\n", ad->fts_ent->fts_accpath);
+  printf ("active dirs:\n");
+  for (ent = e_curr;
+       ent->fts_level >= FTS_ROOTLEVEL; ent = ent->fts_parent)
+    printf ("  %s(%"PRIuMAX"/%"PRIuMAX") to %s(%"PRIuMAX"/%"PRIuMAX")...\n",
+	    ad->fts_ent->fts_accpath,
+	    (uintmax_t) ad->dev,
+	    (uintmax_t) ad->ino,
+	    ent->fts_accpath,
+	    (uintmax_t) ent->fts_statp->st_dev,
+	    (uintmax_t) ent->fts_statp->st_ino);
+}
+
+void
+fts_cross_check (FTS const *sp)
+{
+  FTSENT const *ent = sp->fts_cur;
+  FTSENT const *t;
+  if ( ! ISSET (FTS_TIGHT_CYCLE_CHECK))
+    return;
+
+  Dprintf (("fts-cross-check cur=%s\n", ent->fts_path));
+  /* Make sure every parent dir is in the tree.  */
+  for (t = ent->fts_parent; t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
+    {
+      struct Active_dir ad;
+      ad.ino = t->fts_statp->st_ino;
+      ad.dev = t->fts_statp->st_dev;
+      if ( ! hash_lookup (sp->active_dir_ht, &ad))
+	printf ("ERROR: active dir, %s, not in tree\n", t->fts_path);
+    }
+
+  /* Make sure every dir in the tree is an active dir.
+     But ENT is not necessarily a directory.  If so, just skip this part. */
+  if (ent->fts_parent->fts_level >= FTS_ROOTLEVEL
+      && (ent->fts_info == FTS_DP
+	  || ent->fts_info == FTS_D))
+    {
+      struct Active_dir *ad;
+      for (ad = hash_get_first (sp->active_dir_ht); ad != NULL;
+	   ad = hash_get_next (sp->active_dir_ht, ad))
+	{
+	  find_matching_ancestor (ent, ad);
+	}
+    }
+}
+#endif
+
+static unsigned short int
+internal_function
+fts_stat(FTS *sp, register FTSENT *p, bool follow)
+{
+	struct stat *sbp = p->fts_statp;
+	int saved_errno;
+
+#if defined FTS_WHITEOUT && 0
+	/* check for whiteout */
+	if (p->fts_flags & FTS_ISW) {
+		memset(sbp, '\0', sizeof (*sbp));
+		sbp->st_mode = S_IFWHT;
+		return (FTS_W);
+       }
+#endif
+
+	/*
+	 * If doing a logical walk, or application requested FTS_FOLLOW, do
+	 * a stat(2).  If that fails, check for a non-existent symlink.  If
+	 * fail, set the errno from the stat call.
+	 */
+	if (ISSET(FTS_LOGICAL) || follow) {
+		if (stat(p->fts_accpath, sbp)) {
+			saved_errno = errno;
+			if (!lstat(p->fts_accpath, sbp)) {
+				__set_errno (0);
+				return (FTS_SLNONE);
+			}
+			p->fts_errno = saved_errno;
+			goto err;
+		}
+	} else if (lstat(p->fts_accpath, sbp)) {
+		p->fts_errno = errno;
+err:		memset(sbp, 0, sizeof(struct stat));
+		return (FTS_NS);
+	}
+
+	if (S_ISDIR(sbp->st_mode)) {
+		if (ISDOT(p->fts_name))
+			return (FTS_DOT);
+		return (FTS_D);
+	}
+	if (S_ISLNK(sbp->st_mode))
+		return (FTS_SL);
+	if (S_ISREG(sbp->st_mode))
+		return (FTS_F);
+	return (FTS_DEFAULT);
+}
+
+static int
+fts_compar (void const *a, void const *b)
+{
+  /* Convert A and B to the correct types, to pacify the compiler, and
+     for portability to bizarre hosts where "void const *" and "FTSENT
+     const **" differ in runtime representation.  The comparison
+     function cannot modify *a and *b, but there is no compile-time
+     check for this.  */
+  FTSENT const **pa = (FTSENT const **) a;
+  FTSENT const **pb = (FTSENT const **) b;
+  return pa[0]->fts_fts->fts_compar (pa, pb);
+}
+
+static FTSENT *
+internal_function
+fts_sort (FTS *sp, FTSENT *head, register size_t nitems)
+{
+	register FTSENT **ap, *p;
+
+	/* On most modern hosts, void * and FTSENT ** have the same
+	   run-time representation, and one can convert sp->fts_compar to
+	   the type qsort expects without problem.  Use the heuristic that
+	   this is OK if the two pointer types are the same size, and if
+	   converting FTSENT ** to long int is the same as converting
+	   FTSENT ** to void * and then to long int.  This heuristic isn't
+	   valid in general but we don't know of any counterexamples.  */
+	FTSENT *dummy;
+	int (*compare) (void const *, void const *) =
+	  ((sizeof &dummy == sizeof (void *)
+	    && (long int) &dummy == (long int) (void *) &dummy)
+	   ? (int (*) (void const *, void const *)) sp->fts_compar
+	   : fts_compar);
+
+	/*
+	 * Construct an array of pointers to the structures and call qsort(3).
+	 * Reassemble the array in the order returned by qsort.  If unable to
+	 * sort for memory reasons, return the directory entries in their
+	 * current order.  Allocate enough space for the current needs plus
+	 * 40 so don't realloc one entry at a time.
+	 */
+	if (nitems > sp->fts_nitems) {
+		struct _ftsent **a;
+
+		sp->fts_nitems = nitems + 40;
+		if (SIZE_MAX / sizeof *a < sp->fts_nitems
+		    || ! (a = realloc (sp->fts_array,
+				       sp->fts_nitems * sizeof *a))) {
+			free(sp->fts_array);
+			sp->fts_array = NULL;
+			sp->fts_nitems = 0;
+			return (head);
+		}
+		sp->fts_array = a;
+	}
+	for (ap = sp->fts_array, p = head; p; p = p->fts_link)
+		*ap++ = p;
+	qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), compare);
+	for (head = *(ap = sp->fts_array); --nitems; ++ap)
+		ap[0]->fts_link = ap[1];
+	ap[0]->fts_link = NULL;
+	return (head);
+}
+
+static FTSENT *
+internal_function
+fts_alloc (FTS *sp, const char *name, register size_t namelen)
+{
+	register FTSENT *p;
+	size_t len;
+
+	/*
+	 * The file name is a variable length array.  Allocate the FTSENT
+	 * structure and the file name in one chunk.
+	 */
+	len = sizeof(FTSENT) + namelen;
+	if ((p = malloc(len)) == NULL)
+		return (NULL);
+
+	/* Copy the name and guarantee NUL termination. */
+	memmove(p->fts_name, name, namelen);
+	p->fts_name[namelen] = '\0';
+
+	p->fts_namelen = namelen;
+	p->fts_fts = sp;
+	p->fts_path = sp->fts_path;
+	p->fts_errno = 0;
+	p->fts_flags = 0;
+	p->fts_instr = FTS_NOINSTR;
+	p->fts_number = 0;
+	p->fts_pointer = NULL;
+	return (p);
+}
+
+static void
+internal_function
+fts_lfree (register FTSENT *head)
+{
+	register FTSENT *p;
+
+	/* Free a linked list of structures. */
+	while ((p = head)) {
+		head = head->fts_link;
+		free(p);
+	}
+}
+
+/*
+ * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
+ * Most systems will allow creation of paths much longer than MAXPATHLEN, even
+ * though the kernel won't resolve them.  Add the size (not just what's needed)
+ * plus 256 bytes so don't realloc the path 2 bytes at a time.
+ */
+static bool
+internal_function
+fts_palloc (FTS *sp, size_t more)
+{
+	char *p;
+	size_t new_len = sp->fts_pathlen + more + 256;
+
+	/*
+	 * See if fts_pathlen would overflow.
+	 */
+	if (new_len < sp->fts_pathlen) {
+		if (sp->fts_path) {
+			free(sp->fts_path);
+			sp->fts_path = NULL;
+		}
+		sp->fts_path = NULL;
+		__set_errno (ENAMETOOLONG);
+		return false;
+	}
+	sp->fts_pathlen = new_len;
+	p = realloc(sp->fts_path, sp->fts_pathlen);
+	if (p == NULL) {
+		free(sp->fts_path);
+		sp->fts_path = NULL;
+		return false;
+	}
+	sp->fts_path = p;
+	return true;
+}
+
+/*
+ * When the path is realloc'd, have to fix all of the pointers in structures
+ * already returned.
+ */
+static void
+internal_function
+fts_padjust (FTS *sp, FTSENT *head)
+{
+	FTSENT *p;
+	char *addr = sp->fts_path;
+
+#define ADJUST(p) do {							\
+	if ((p)->fts_accpath != (p)->fts_name) {			\
+		(p)->fts_accpath =					\
+		    (char *)addr + ((p)->fts_accpath - (p)->fts_path);	\
+	}								\
+	(p)->fts_path = addr;						\
+} while (0)
+	/* Adjust the current set of children. */
+	for (p = sp->fts_child; p; p = p->fts_link)
+		ADJUST(p);
+
+	/* Adjust the rest of the tree, including the current level. */
+	for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
+		ADJUST(p);
+		p = p->fts_link ? p->fts_link : p->fts_parent;
+	}
+}
+
+static size_t
+internal_function
+fts_maxarglen (char * const *argv)
+{
+	size_t len, max;
+
+	for (max = 0; *argv; ++argv)
+		if ((len = strlen(*argv)) > max)
+			max = len;
+	return (max + 1);
+}
+
+/*
+ * Change to dir specified by fd or path without getting
+ * tricked by someone changing the world out from underneath us.
+ * Assumes p->fts_statp->st_dev and p->fts_statp->st_ino are filled in.
+ */
+static int
+internal_function
+fts_safe_changedir (FTS *sp, FTSENT *p, int fd, char const *path)
+{
+	int ret, oerrno, newfd;
+	struct stat sb;
+
+	newfd = fd;
+	if (ISSET(FTS_NOCHDIR))
+		return (0);
+	if (fd < 0 && (newfd = fd_safer (diropen (path))) < 0)
+		return (-1);
+	if (fstat(newfd, &sb)) {
+		ret = -1;
+		goto bail;
+	}
+	if (p->fts_statp->st_dev != sb.st_dev
+	    || p->fts_statp->st_ino != sb.st_ino) {
+		__set_errno (ENOENT);		/* disinformation */
+		ret = -1;
+		goto bail;
+	}
+	ret = fchdir(newfd);
+bail:
+	oerrno = errno;
+	if (fd < 0)
+		(void)close(newfd);
+	__set_errno (oerrno);
+	return (ret);
+}

new file mode 100644
--- /dev/null
+++ b/lib/fts_.h
@@ -0,0 +1,182 @@
+/* Traverse a file hierarchy.
+
+   Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program 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 this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/*
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)fts.h	8.3 (Berkeley) 8/14/94
+ */
+
+#ifndef	_FTS_H
+# define _FTS_H 1
+
+# ifdef _LIBC
+#  include <features.h>
+# else
+#  undef __THROW
+#  define __THROW
+#  undef __BEGIN_DECLS
+#  define __BEGIN_DECLS
+#  undef __END_DECLS
+#  define __END_DECLS
+# endif
+
+# include <stddef.h>
+# include <sys/types.h>
+# include "hash.h"
+# include "cycle-check.h"
+
+typedef struct {
+	struct _ftsent *fts_cur;	/* current node */
+	struct _ftsent *fts_child;	/* linked list of children */
+	struct _ftsent **fts_array;	/* sort array */
+	dev_t fts_dev;			/* starting device # */
+	char *fts_path;			/* path for this descent */
+	int fts_rfd;			/* fd for root */
+	size_t fts_pathlen;		/* sizeof(path) */
+	size_t fts_nitems;			/* elements in the sort array */
+	int (*fts_compar) (struct _ftsent const **, struct _ftsent const **);
+					/* compare fn */
+
+# define FTS_COMFOLLOW	0x0001		/* follow command line symlinks */
+# define FTS_LOGICAL	0x0002		/* logical walk */
+# define FTS_NOCHDIR	0x0004		/* don't change directories */
+# define FTS_NOSTAT	0x0008		/* don't get stat info */
+# define FTS_PHYSICAL	0x0010		/* physical walk */
+# define FTS_SEEDOT	0x0020		/* return dot and dot-dot */
+# define FTS_XDEV	0x0040		/* don't cross devices */
+# define FTS_WHITEOUT	0x0080		/* return whiteout information */
+
+  /* There are two ways to detect cycles.
+     The lazy way, with which one may process a directory that is a
+     part of the cycle several times before detecting the cycle.
+     The `tight' way, whereby fts uses more memory (proportional
+     to number of `active' directories, aka distance from root
+     of current tree to current directory -- see active_dir_ht)
+     to detect any cycle right away.  For example, du must use
+     this option to avoid counting disk space in a cycle multiple
+     times, but chown -R need not.
+     The default is to use the constant-memory lazy way. */
+# define FTS_TIGHT_CYCLE_CHECK	0x0100
+
+# define FTS_OPTIONMASK	0x01ff		/* valid user option mask */
+
+# define FTS_NAMEONLY	0x1000		/* (private) child names only */
+# define FTS_STOP	0x2000		/* (private) unrecoverable error */
+	int fts_options;		/* fts_open options, global flags */
+
+	/* This data structure records the directories between a starting
+	   point and the current directory.  I.e., a directory is recorded
+	   here IFF we have visited it once, but we have not yet completed
+	   processing of all its entries.  Every time we visit a new directory,
+	   we add that directory to this set.  When we finish with a directory
+	   (usually by visiting it a second time), we remove it from this
+	   set.  Each entry in this data structure is a device/inode pair.
+	   This data structure is used to detect directory cycles efficiently
+	   and promptly even when the depth of a hierarchy is in the tens
+	   of thousands.  Lazy checking, as done by GNU rm via cycle-check.c,
+	   wouldn't be appropriate for du.  */
+	Hash_table *active_dir_ht;
+	struct cycle_check_state *cycle_state;
+} FTS;
+
+typedef struct _ftsent {
+	struct _ftsent *fts_cycle;	/* cycle node */
+	struct _ftsent *fts_parent;	/* parent directory */
+	struct _ftsent *fts_link;	/* next file in directory */
+	long fts_number;	        /* local numeric value */
+	void *fts_pointer;	        /* local address value */
+	char *fts_accpath;		/* access path */
+	char *fts_path;			/* root path; == fts_fts->fts_path */
+	int fts_errno;			/* errno for this node */
+	int fts_symfd;			/* fd for symlink */
+	size_t fts_pathlen;		/* strlen(fts_path) */
+
+	FTS *fts_fts;			/* the file hierarchy itself */
+
+# define FTS_ROOTPARENTLEVEL	(-1)
+# define FTS_ROOTLEVEL		 0
+	ptrdiff_t fts_level;		/* depth (-1 to N) */
+
+	size_t fts_namelen;		/* strlen(fts_name) */
+
+# define FTS_D		 1		/* preorder directory */
+# define FTS_DC		 2		/* directory that causes cycles */
+# define FTS_DEFAULT	 3		/* none of the above */
+# define FTS_DNR	 4		/* unreadable directory */
+# define FTS_DOT	 5		/* dot or dot-dot */
+# define FTS_DP		 6		/* postorder directory */
+# define FTS_ERR	 7		/* error; errno is set */
+# define FTS_F		 8		/* regular file */
+# define FTS_INIT	 9		/* initialized only */
+# define FTS_NS		10		/* stat(2) failed */
+# define FTS_NSOK	11		/* no stat(2) requested */
+# define FTS_SL		12		/* symbolic link */
+# define FTS_SLNONE	13		/* symbolic link without target */
+# define FTS_W		14		/* whiteout object */
+	unsigned short int fts_info;	/* user flags for FTSENT structure */
+
+# define FTS_DONTCHDIR	 0x01		/* don't chdir .. to the parent */
+# define FTS_SYMFOLLOW	 0x02		/* followed a symlink to get here */
+	unsigned short int fts_flags;	/* private flags for FTSENT structure */
+
+# define FTS_AGAIN	 1		/* read node again */
+# define FTS_FOLLOW	 2		/* follow symbolic link */
+# define FTS_NOINSTR	 3		/* no instructions */
+# define FTS_SKIP	 4		/* discard node */
+	unsigned short int fts_instr;	/* fts_set() instructions */
+
+	struct stat fts_statp[1];	/* stat(2) information */
+	char fts_name[1];		/* file name */
+} FTSENT;
+
+__BEGIN_DECLS
+FTSENT	*fts_children (FTS *, int) __THROW;
+int	 fts_close (FTS *) __THROW;
+FTS	*fts_open (char * const *, int,
+		   int (*)(const FTSENT **, const FTSENT **)) __THROW;
+FTSENT	*fts_read (FTS *) __THROW;
+int	 fts_set (FTS *, FTSENT *, int) __THROW;
+__END_DECLS
+
+#endif /* fts.h */