register struct dirent *dp; register FTSENT *p, *head; register int nitems;
struct dirent *dp; FTSENT *p, *head;
static FTSENT	*fts_alloc __P((FTS *, char *, int));static FTSENT	*fts_build __P((FTS *, int));static void	 fts_lfree __P((FTSENT *));static void	 fts_load __P((FTS *, FTSENT *));static size_t	 fts_maxarglen __P((char * const *));static void	 fts_padjust __P((FTS *, FTSENT *));static int	 fts_palloc __P((FTS *, size_t));static FTSENT	*fts_sort __P((FTS *, FTSENT *, int));static u_short	 fts_stat __P((FTS *, FTSENT *, int));static int	 fts_safe_changedir __P((FTS *, FTSENT *, int));#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	CHDIR(sp, path)	(!ISSET(FTS_NOCHDIR) && chdir(path))#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 */FTS *fts_open(argv, options, compar)	char * const *argv;	register int options;	int (*compar) __P((const FTSENT **, const FTSENT **));{	register FTS *sp;	register FTSENT *p, *root;	register int nitems;	FTSENT *parent, *tmp;	int len;	/* Options check. */	if (options & ~FTS_OPTIONMASK) {		errno = EINVAL;		return (NULL);	}	/* Allocate/initialize the stream */	if ((sp = malloc((u_int)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.	 */	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; ++argv, ++nitems) {		/* Don't allow zero-length paths. */		if ((len = strlen(*argv)) == 0) {			errno = ENOENT;			goto mem3;		}		p = fts_alloc(sp, *argv, len);		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));		/* 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 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 = open(".", O_RDONLY, 0)) < 0)		SET(FTS_NOCHDIR);	return (sp);mem3:	fts_lfree(root);	free(parent);mem2:	free(sp->fts_path);mem1:	free(sp);	return (NULL);}static voidfts_load(sp, p)	FTS *sp;	register FTSENT *p;{	register int 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_dev;}intfts_close(sp)	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 ? 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)) {		saved_errno = fchdir(sp->fts_rfd) ? errno : 0;		(void)close(sp->fts_rfd);	}	/* Set errno and return. */	if (!ISSET(FTS_NOCHDIR) && saved_errno) {		/* Free up the stream pointer. */		free(sp);		errno = saved_errno;		return (-1);	}	/* Free up the stream pointer. */	free(sp);	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(sp)	register FTS *sp;{	register FTSENT *p, *tmp;	register 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, 0);		return (p);	}	/*	 * 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, 1);		if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {			if ((p->fts_symfd = open(".", O_RDONLY, 0)) < 0) {				p->fts_errno = errno;				p->fts_info = FTS_ERR;			} else				p->fts_flags |= FTS_SYMFOLLOW;		}		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_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;			return (p);		}		/* Rebuild if only read the names and now traversing. */		if (sp->fts_child && 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) {			if (fts_safe_changedir(sp, p, -1)) {				p->fts_errno = errno;				p->fts_flags |= FTS_DONTCHDIR;				for (p = sp->fts_child; p; 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);			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)) {		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 ((sp->fts_options & FTS_CHDIRROOT)) {				if (chdir(p->fts_accpath)) {					SET(FTS_STOP);					return (NULL);				}			} else {				if (FCHDIR(sp, sp->fts_rfd)) {					SET(FTS_STOP);					return (NULL);				}			}			fts_load(sp, p);			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, 1);			if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {				if ((p->fts_symfd =				    open(".", O_RDONLY, 0)) < 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);		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);		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 ((sp->fts_options & FTS_CHDIRROOT)) {			if (chdir(p->fts_accpath)) {				SET(FTS_STOP);				return (NULL);			}		} else {			if (FCHDIR(sp, sp->fts_rfd)) {				SET(FTS_STOP);				return (NULL);			}		}	} else if (p->fts_flags & FTS_SYMFOLLOW) {		if (FCHDIR(sp, p->fts_symfd)) {			saved_errno = errno;			(void)close(p->fts_symfd);			errno = saved_errno;			SET(FTS_STOP);			return (NULL);		}		(void)close(p->fts_symfd);	} else if (!(p->fts_flags & FTS_DONTCHDIR)) {		if (CHDIR(sp, "..")) {			SET(FTS_STOP);			return (NULL);		}	}	p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;	return (sp->fts_cur = 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 */intfts_set(sp, p, instr)	FTS *sp;	FTSENT *p;	int instr;{	if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW &&	    instr != FTS_NOINSTR && instr != FTS_SKIP) {		errno = EINVAL;		return (1);	}	p->fts_instr = instr;	return (0);}FTSENT *fts_children(sp, instr)	register FTS *sp;	int instr;{	register FTSENT *p;	int fd;	if (instr && instr != FTS_NAMEONLY) {		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.	 */	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)		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 = open(".", O_RDONLY, 0)) < 0)		return (NULL);	sp->fts_child = fts_build(sp, instr);	if (fchdir(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 *fts_build(sp, type)	register FTS *sp;	int type;{	register struct dirent *dp;	register FTSENT *p, *head;	register int nitems;	FTSENT *cur, *tail;	DIR *dirp;	void *oldaddr;	int cderrno, descend, len, level, maxlen, nlinks, oflag, saved_errno,	    nostat, doadjust;	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.	 */#ifdef FTS_WHITEOUT	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, -1 if we're doing stats on everything.	 */	if (type == BNAMES)		nlinks = 0;	else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {		nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2);		nostat = 1;	} else {		nlinks = -1;		nostat = 0;	}#ifdef notdef	(void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink);	(void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n",	    ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT));#endif	/*	 * 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))) {			if (nlinks && type == BREAD)				cur->fts_errno = errno;			cur->fts_flags |= FTS_DONTCHDIR;			descend = 0;			cderrno = errno;			(void)closedir(dirp);			dirp = NULL;		} else			descend = 1;	} else		descend = 0;	/*	 * 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++ = '/';	}	len++;	maxlen = sp->fts_pathlen - len;	level = cur->fts_level + 1;	/* Read the directory, attaching each entry to the `link' pointer. */	doadjust = 0;	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, (int)dp->d_namlen)) == NULL)			goto mem1;		if (dp->d_namlen >= maxlen) {	/* include space for NUL */			oldaddr = sp->fts_path;			if (fts_palloc(sp, dp->d_namlen +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);				errno = saved_errno;				return (NULL);			}			/* Did realloc() change the pointer? */			if (oldaddr != sp->fts_path) {				doadjust = 1;				if (ISSET(FTS_NOCHDIR))					cp = sp->fts_path + len;			}			maxlen = sp->fts_pathlen - len;		}		if (len + dp->d_namlen >= USHRT_MAX) {			/*			 * In an FTSENT, fts_pathlen is a u_short so it is			 * possible to wraparound here.  If we do, 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);			errno = ENAMETOOLONG;			return (NULL);		}		p->fts_level = level;		p->fts_parent = sp->fts_cur;		p->fts_pathlen = len + dp->d_namlen;#ifdef FTS_WHITEOUT		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#ifdef DT_DIR		    || (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, 0);			/* Decrement link count if applicable. */			if (nlinks > 0 && (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) : CHDIR(sp, ".."))) {		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);}static u_shortfts_stat(sp, p, follow)	FTS *sp;	register FTSENT *p;	int follow;{	register FTSENT *t;	register dev_t dev;	register ino_t ino;	struct stat *sbp, sb;	int saved_errno;	/* If user needs stat info, stat buffer already allocated. */	sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp;#ifdef FTS_WHITEOUT	/* check for whiteout */	if (p->fts_flags & FTS_ISW) {		if (sbp != &sb) {			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)) {				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)) {		/*		 * Set the device/inode.  Used to find cycles and check for		 * crossing mount points.  Also remember the link count, used		 * in fts_build to limit the number of stat calls.  It is		 * understood that these fields are only referenced if fts_info		 * is set to FTS_D.		 */		dev = p->fts_dev = sbp->st_dev;		ino = p->fts_ino = sbp->st_ino;		p->fts_nlink = sbp->st_nlink;		if (ISDOT(p->fts_name))			return (FTS_DOT);		/*		 * Cycle detection is done by brute force when the directory		 * is first encountered.  If the tree gets deep enough or the		 * number of symbolic links to directories is high enough,		 * something faster might be worthwhile.		 */		for (t = p->fts_parent;		    t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)			if (ino == t->fts_ino && dev == t->fts_dev) {				p->fts_cycle = t;				return (FTS_DC);			}		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 FTSENT *fts_sort(sp, head, nitems)	FTS *sp;	FTSENT *head;	register int nitems;{	register FTSENT **ap, *p;	/*	 * 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 ((a = realloc(sp->fts_array,		    sp->fts_nitems * sizeof(FTSENT *))) == NULL) {			if (sp->fts_array)				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 *), sp->fts_compar);	for (head = *(ap = sp->fts_array); --nitems; ++ap)		ap[0]->fts_link = ap[1];	ap[0]->fts_link = NULL;	return (head);}static FTSENT *fts_alloc(sp, name, namelen)	FTS *sp;	char *name;	register int namelen;{	register FTSENT *p;	size_t len;	/*	 * The file name is a variable length array and no stat structure is	 * necessary if the user has set the nostat bit.  Allocate the FTSENT	 * structure, the file name and the stat structure in one chunk, but	 * be careful that the stat structure is reasonably aligned.  Since the	 * fts_name field is declared to be of size 1, the fts_name pointer is	 * namelen + 2 before the first possible address of the stat structure.	 */	len = sizeof(FTSENT) + namelen;	if (!ISSET(FTS_NOSTAT))		len += sizeof(struct stat) + ALIGNBYTES;	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';	if (!ISSET(FTS_NOSTAT))		p->fts_statp = (struct stat *)ALIGN(p->fts_name + namelen + 2);	p->fts_namelen = namelen;	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);}