1 /* Traverse a file hierarchy.
3 Copyright (C) 2004-2009 Free Software Foundation, Inc.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19 * Copyright (c) 1990, 1993, 1994
20 * The Regents of the University of California. All rights reserved.
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
25 * 1. Redistributions of source code must retain the above copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 4. Neither the name of the University nor the names of its contributors
31 * may be used to endorse or promote products derived from this software
32 * without specific prior written permission.
34 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
35 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
36 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
37 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
38 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
39 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
40 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
41 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
42 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
43 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
49 #if defined(LIBC_SCCS) && !defined(lint)
50 static char sccsid[] = "@(#)fts.c 8.6 (Berkeley) 8/14/94";
51 #endif /* LIBC_SCCS and not lint */
55 #if HAVE_SYS_PARAM_H || defined _LIBC
56 # include <sys/param.h>
59 # include <include/sys/stat.h>
61 # include <sys/stat.h>
72 # include "dirent--.h"
73 # include "unistd--.h"
74 /* FIXME - use fcntl(F_DUPFD_CLOEXEC)/openat(O_CLOEXEC) once they are
78 # include "same-inode.h"
82 #ifndef _D_EXACT_NAMLEN
83 # define _D_EXACT_NAMLEN(dirent) strlen ((dirent)->d_name)
86 #if HAVE_STRUCT_DIRENT_D_TYPE
87 /* True if the type of the directory entry D is known. */
88 # define DT_IS_KNOWN(d) ((d)->d_type != DT_UNKNOWN)
89 /* True if the type of the directory entry D must be T. */
90 # define DT_MUST_BE(d, t) ((d)->d_type == (t))
91 # define D_TYPE(d) ((d)->d_type)
93 # define DT_IS_KNOWN(d) false
94 # define DT_MUST_BE(d, t) false
95 # define D_TYPE(d) DT_UNKNOWN
100 /* Any nonzero values will do here, so long as they're distinct.
101 Undef any existing macros out of the way. */
127 NOT_AN_INODE_NUMBER = 0
130 #ifdef D_INO_IN_DIRENT
131 # define D_INO(dp) (dp)->d_ino
133 /* Some systems don't have inodes, so fake them to avoid lots of ifdefs. */
134 # define D_INO(dp) NOT_AN_INODE_NUMBER
137 /* If there are more than this many entries in a directory,
138 and the conditions mentioned below are satisfied, then sort
139 the entries on inode number before any further processing. */
140 #ifndef FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
141 # define FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD 10000
145 _FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD = FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
150 FTS_NO_STAT_REQUIRED = 1,
151 FTS_STAT_REQUIRED = 2
156 # define close __close
158 # define closedir __closedir
160 # define fchdir __fchdir
164 # define opendir __opendir
166 # define readdir __readdir
168 # undef internal_function
169 # define internal_function /* empty */
173 # define __set_errno(Val) errno = (Val)
176 /* If this host provides the openat function, then we can avoid
177 attempting to open "." in some initialization code below. */
179 # define HAVE_OPENAT_SUPPORT 1
181 # define HAVE_OPENAT_SUPPORT 0
185 # define fts_assert(expr) ((void) 0)
187 # define fts_assert(expr) \
196 static FTSENT *fts_alloc (FTS *, const char *, size_t) internal_function;
197 static FTSENT *fts_build (FTS *, int) internal_function;
198 static void fts_lfree (FTSENT *) internal_function;
199 static void fts_load (FTS *, FTSENT *) internal_function;
200 static size_t fts_maxarglen (char * const *) internal_function;
201 static void fts_padjust (FTS *, FTSENT *) internal_function;
202 static bool fts_palloc (FTS *, size_t) internal_function;
203 static FTSENT *fts_sort (FTS *, FTSENT *, size_t) internal_function;
204 static unsigned short int fts_stat (FTS *, FTSENT *, bool) internal_function;
205 static int fts_safe_changedir (FTS *, FTSENT *, int, const char *)
209 # include "fts-cycle.c"
211 static bool enter_dir (FTS *fts, FTSENT *ent) { return true; }
212 static void leave_dir (FTS *fts, FTSENT *ent) {}
213 static bool setup_dir (FTS *fts) { return true; }
214 static void free_dir (FTS *fts) {}
218 # define MAX(a,b) ((a) > (b) ? (a) : (b))
222 # define SIZE_MAX ((size_t) -1)
225 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
226 #define STREQ(a, b) (strcmp ((a), (b)) == 0)
228 #define CLR(opt) (sp->fts_options &= ~(opt))
229 #define ISSET(opt) (sp->fts_options & (opt))
230 #define SET(opt) (sp->fts_options |= (opt))
232 /* FIXME: make this a function */
233 #define RESTORE_INITIAL_CWD(sp) \
234 (fd_ring_clear (&((sp)->fts_fd_ring)), \
235 FCHDIR ((sp), (ISSET (FTS_CWDFD) ? AT_FDCWD : (sp)->fts_rfd)))
237 /* FIXME: FTS_NOCHDIR is now misnamed.
238 Call it FTS_USE_FULL_RELATIVE_FILE_NAMES instead. */
239 #define FCHDIR(sp, fd) \
240 (!ISSET(FTS_NOCHDIR) && (ISSET(FTS_CWDFD) \
241 ? (cwd_advance_fd ((sp), (fd), true), 0) \
245 /* fts_build flags */
246 /* FIXME: make this an enum */
247 #define BCHILD 1 /* fts_children */
248 #define BNAMES 2 /* fts_children, names only */
249 #define BREAD 3 /* fts_read */
252 # include <inttypes.h>
255 # include "getcwdat.h"
256 bool fts_debug = false;
257 # define Dprintf(x) do { if (fts_debug) printf x; } while (false)
260 # define fd_ring_check(x)
261 # define fd_ring_print(a, b, c)
264 #define LEAVE_DIR(Fts, Ent, Tag) \
267 Dprintf ((" %s-leaving: %s\n", Tag, (Ent)->fts_path)); \
268 leave_dir (Fts, Ent); \
269 fd_ring_check (Fts); \
274 fd_ring_clear (I_ring *fd_ring)
276 while ( ! i_ring_empty (fd_ring))
278 int fd = i_ring_pop (fd_ring);
284 /* Overload the fts_statp->st_size member (otherwise unused, when
285 fts_info is FTS_NSOK) to indicate whether fts_read should stat
286 this entry or not. */
288 fts_set_stat_required (FTSENT *p, bool required)
290 fts_assert (p->fts_info == FTS_NSOK);
291 p->fts_statp->st_size = (required
293 : FTS_NO_STAT_REQUIRED);
296 /* file-descriptor-relative opendir. */
297 /* FIXME: if others need this function, move it into lib/openat.c */
300 opendirat (int fd, char const *dir)
302 int new_fd = openat (fd, dir,
303 O_RDONLY | O_DIRECTORY | O_NOCTTY | O_NONBLOCK);
308 set_cloexec_flag (new_fd, true);
309 dirp = fdopendir (new_fd);
312 int saved_errno = errno;
319 /* Virtual fchdir. Advance SP's working directory file descriptor,
320 SP->fts_cwd_fd, to FD, and push the previous value onto the fd_ring.
321 CHDIR_DOWN_ONE is true if FD corresponds to an entry in the directory
322 open on sp->fts_cwd_fd; i.e., to move the working directory one level
326 cwd_advance_fd (FTS *sp, int fd, bool chdir_down_one)
328 int old = sp->fts_cwd_fd;
329 fts_assert (old != fd || old == AT_FDCWD);
333 /* Push "old" onto the ring.
334 If the displaced file descriptor is non-negative, close it. */
335 int prev_fd_in_slot = i_ring_push (&sp->fts_fd_ring, old);
336 fd_ring_print (sp, stderr, "post-push");
337 if (0 <= prev_fd_in_slot)
338 close (prev_fd_in_slot); /* ignore any close failure */
340 else if ( ! ISSET (FTS_NOCHDIR))
343 close (old); /* ignore any close failure */
349 /* Open the directory DIR if possible, and return a file
350 descriptor. Return -1 and set errno on failure. It doesn't matter
351 whether the file descriptor has read or write access. */
355 diropen (FTS const *sp, char const *dir)
357 int open_flags = (O_RDONLY | O_DIRECTORY | O_NOCTTY | O_NONBLOCK
358 | (ISSET (FTS_PHYSICAL) ? O_NOFOLLOW : 0));
360 int fd = (ISSET (FTS_CWDFD)
361 ? openat (sp->fts_cwd_fd, dir, open_flags)
362 : open (dir, open_flags));
364 set_cloexec_flag (fd, true);
369 fts_open (char * const *argv,
370 register int options,
371 int (*compar) (FTSENT const **, FTSENT const **))
374 register FTSENT *p, *root;
375 register size_t nitems;
376 FTSENT *parent = NULL;
377 FTSENT *tmp = NULL; /* pacify gcc */
381 if (options & ~FTS_OPTIONMASK) {
382 __set_errno (EINVAL);
385 if ((options & FTS_NOCHDIR) && (options & FTS_CWDFD)) {
386 __set_errno (EINVAL);
389 if ( ! (options & (FTS_LOGICAL | FTS_PHYSICAL))) {
390 __set_errno (EINVAL);
394 /* Allocate/initialize the stream */
395 if ((sp = malloc(sizeof(FTS))) == NULL)
397 memset(sp, 0, sizeof(FTS));
398 sp->fts_compar = compar;
399 sp->fts_options = options;
401 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */
402 if (ISSET(FTS_LOGICAL)) {
407 /* Initialize fts_cwd_fd. */
408 sp->fts_cwd_fd = AT_FDCWD;
409 if ( ISSET(FTS_CWDFD) && ! HAVE_OPENAT_SUPPORT)
411 /* While it isn't technically necessary to open "." this
412 early, doing it here saves us the trouble of ensuring
413 later (where it'd be messier) that "." can in fact
414 be opened. If not, revert to FTS_NOCHDIR mode. */
415 int fd = open (".", O_RDONLY);
418 /* Even if `.' is unreadable, don't revert to FTS_NOCHDIR mode
419 on systems like Linux+PROC_FS, where our openat emulation
420 is good enough. Note: on a system that emulates
421 openat via /proc, this technique can still fail, but
422 only in extreme conditions, e.g., when the working
423 directory cannot be saved (i.e. save_cwd fails) --
424 and that happens on Linux only when "." is unreadable
425 and the CWD would be longer than PATH_MAX.
426 FIXME: once Linux kernel openat support is well established,
427 replace the above open call and this entire if/else block
428 with the body of the if-block below. */
429 if ( openat_needs_fchdir ())
442 * Start out with 1K of file name space, and enough, in any case,
443 * to hold the user's file names.
446 # define MAXPATHLEN 1024
449 size_t maxarglen = fts_maxarglen(argv);
450 if (! fts_palloc(sp, MAX(maxarglen, MAXPATHLEN)))
454 /* Allocate/initialize root's parent. */
456 if ((parent = fts_alloc(sp, "", 0)) == NULL)
458 parent->fts_level = FTS_ROOTPARENTLEVEL;
461 /* The classic fts implementation would call fts_stat with
462 a new entry for each iteration of the loop below.
463 If the comparison function is not specified or if the
464 FTS_DEFER_STAT option is in effect, don't stat any entry
465 in this loop. This is an attempt to minimize the interval
466 between the initial stat/lstat/fstatat and the point at which
467 a directory argument is first opened. This matters for any
468 directory command line argument that resides on a file system
469 without genuine i-nodes. If you specify FTS_DEFER_STAT along
470 with a comparison function, that function must not access any
471 data via the fts_statp pointer. */
472 defer_stat = (compar == NULL || ISSET(FTS_DEFER_STAT));
474 /* Allocate/initialize root(s). */
475 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) {
476 /* *Do* allow zero-length file names. */
477 size_t len = strlen(*argv);
478 if ((p = fts_alloc(sp, *argv, len)) == NULL)
480 p->fts_level = FTS_ROOTLEVEL;
481 p->fts_parent = parent;
482 p->fts_accpath = p->fts_name;
483 /* Even when defer_stat is true, be sure to stat the first
484 command line argument, since fts_read (at least with
485 FTS_XDEV) requires that. */
486 if (defer_stat && root != NULL) {
487 p->fts_info = FTS_NSOK;
488 fts_set_stat_required(p, true);
490 p->fts_info = fts_stat(sp, p, false);
494 * If comparison routine supplied, traverse in sorted
495 * order; otherwise traverse in the order specified.
510 if (compar && nitems > 1)
511 root = fts_sort(sp, root, nitems);
514 * Allocate a dummy pointer and make fts_read think that we've just
515 * finished the node before the root(s); set p->fts_info to FTS_INIT
516 * so that everything about the "current" node is ignored.
518 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
520 sp->fts_cur->fts_link = root;
521 sp->fts_cur->fts_info = FTS_INIT;
522 if (! setup_dir (sp))
526 * If using chdir(2), grab a file descriptor pointing to dot to ensure
527 * that we can get back here; this could be avoided for some file names,
528 * but almost certainly not worth the effort. Slashes, symbolic links,
529 * and ".." are all fairly nasty problems. Note, if we can't get the
530 * descriptor we run anyway, just more slowly.
532 if (!ISSET(FTS_NOCHDIR) && !ISSET(FTS_CWDFD)
533 && (sp->fts_rfd = diropen (sp, ".")) < 0)
536 i_ring_init (&sp->fts_fd_ring, -1);
539 mem3: fts_lfree(root);
541 mem2: free(sp->fts_path);
548 fts_load (FTS *sp, register FTSENT *p)
554 * Load the stream structure for the next traversal. Since we don't
555 * actually enter the directory until after the preorder visit, set
556 * the fts_accpath field specially so the chdir gets done to the right
557 * place and the user can access the first node. From fts_open it's
558 * known that the file name will fit.
560 len = p->fts_pathlen = p->fts_namelen;
561 memmove(sp->fts_path, p->fts_name, len + 1);
562 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
564 memmove(p->fts_name, cp, len + 1);
565 p->fts_namelen = len;
567 p->fts_accpath = p->fts_path = sp->fts_path;
573 register FTSENT *freep, *p;
577 * This still works if we haven't read anything -- the dummy structure
578 * points to the root list, so we step through to the end of the root
579 * list which has a valid parent pointer.
582 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
584 p = p->fts_link != NULL ? p->fts_link : p->fts_parent;
590 /* Free up child linked list, sort array, file name buffer. */
592 fts_lfree(sp->fts_child);
596 if (ISSET(FTS_CWDFD))
598 if (0 <= sp->fts_cwd_fd)
599 if (close (sp->fts_cwd_fd))
602 else if (!ISSET(FTS_NOCHDIR))
604 /* Return to original directory, save errno if necessary. */
605 if (fchdir(sp->fts_rfd))
608 /* If close fails, record errno only if saved_errno is zero,
609 so that we report the probably-more-meaningful fchdir errno. */
610 if (close (sp->fts_rfd))
611 if (saved_errno == 0)
615 fd_ring_clear (&sp->fts_fd_ring);
618 if (sp->fts_leaf_optimization_works_ht)
619 hash_free (sp->fts_leaf_optimization_works_ht);
624 /* Free up the stream pointer. */
627 /* Set errno and return. */
629 __set_errno (saved_errno);
636 #if defined __linux__ \
637 && HAVE_SYS_VFS_H && HAVE_FSTATFS && HAVE_STRUCT_STATFS_F_TYPE
641 /* Linux-specific constants from coreutils' src/fs.h */
642 # define S_MAGIC_TMPFS 0x1021994
643 # define S_MAGIC_NFS 0x6969
644 # define S_MAGIC_REISERFS 0x52654973
645 # define S_MAGIC_PROC 0x9FA0
647 /* Return false if it is easy to determine the file system type of
648 the directory on which DIR_FD is open, and sorting dirents on
649 inode numbers is known not to improve traversal performance with
650 that type of file system. Otherwise, return true. */
652 dirent_inode_sort_may_be_useful (int dir_fd)
654 /* Skip the sort only if we can determine efficiently
655 that skipping it is the right thing to do.
656 The cost of performing an unnecessary sort is negligible,
657 while the cost of *not* performing it can be O(N^2) with
658 a very large constant. */
659 struct statfs fs_buf;
661 /* If fstatfs fails, assume sorting would be useful. */
662 if (fstatfs (dir_fd, &fs_buf) != 0)
665 /* FIXME: what about when f_type is not an integral type?
666 deal with that if/when it's encountered. */
667 switch (fs_buf.f_type)
671 /* On a file system of any of these types, sorting
672 is unnecessary, and hence wasteful. */
680 /* Given a file descriptor DIR_FD open on a directory D,
681 return true if it is valid to apply the leaf-optimization
682 technique of counting directories in D via stat.st_nlink. */
684 leaf_optimization_applies (int dir_fd)
686 struct statfs fs_buf;
688 /* If fstatfs fails, assume we can't use the optimization. */
689 if (fstatfs (dir_fd, &fs_buf) != 0)
692 /* FIXME: do we need to detect AFS mount points? I doubt it,
693 unless fstatfs can report S_MAGIC_REISERFS for such a directory. */
695 switch (fs_buf.f_type)
697 /* List here the file system types that lack useable dirent.d_type
698 info, yet for which the optimization does apply. */
699 case S_MAGIC_REISERFS:
703 /* Explicitly listing this or any other file system type for which
704 the optimization is not applicable is not necessary, but we leave
705 it here to document the risk. Per http://bugs.debian.org/143111,
706 /proc may have bogus stat.st_nlink values. */
715 dirent_inode_sort_may_be_useful (int dir_fd _UNUSED_PARAMETER_) { return true; }
717 leaf_optimization_applies (int dir_fd _UNUSED_PARAMETER_) { return false; }
721 /* link-count-optimization entry:
722 map an stat.st_dev number to a boolean: leaf_optimization_works */
729 /* Use a tiny initial size. If a traversal encounters more than
730 a few devices, the cost of growing/rehashing this table will be
731 rendered negligible by the number of inodes processed. */
732 enum { LCO_HT_INITIAL_SIZE = 13 };
735 LCO_hash (void const *x, size_t table_size)
737 struct LCO_ent const *ax = x;
738 return (uintmax_t) ax->st_dev % table_size;
742 LCO_compare (void const *x, void const *y)
744 struct LCO_ent const *ax = x;
745 struct LCO_ent const *ay = y;
746 return ax->st_dev == ay->st_dev;
749 /* Ask the same question as leaf_optimization_applies, but query
750 the cache first (FTS.fts_leaf_optimization_works_ht), and if necessary,
751 update that cache. */
753 link_count_optimize_ok (FTSENT const *p)
755 FTS *sp = p->fts_fts;
756 Hash_table *h = sp->fts_leaf_optimization_works_ht;
762 /* If we're not in CWDFD mode, don't bother with this optimization,
763 since the caller is not serious about performance. */
764 if (!ISSET(FTS_CWDFD))
767 /* map st_dev to the boolean, leaf_optimization_works */
770 h = sp->fts_leaf_optimization_works_ht
771 = hash_initialize (LCO_HT_INITIAL_SIZE, NULL, LCO_hash,
776 tmp.st_dev = p->fts_statp->st_dev;
777 ent = hash_lookup (h, &tmp);
781 /* Look-up failed. Query directly and cache the result. */
782 t2 = malloc (sizeof *t2);
786 /* Is it ok to perform the optimization in the dir, FTS_CWD_FD? */
787 opt_ok = leaf_optimization_applies (sp->fts_cwd_fd);
789 t2->st_dev = p->fts_statp->st_dev;
791 ent = hash_insert (h, t2);
794 /* insertion failed */
798 fts_assert (ent == t2);
805 * Special case of "/" at the end of the file name so that slashes aren't
806 * appended which would cause file names to be written as "....//foo".
809 (p->fts_path[p->fts_pathlen - 1] == '/' \
810 ? p->fts_pathlen - 1 : p->fts_pathlen)
813 fts_read (register FTS *sp)
815 register FTSENT *p, *tmp;
816 register unsigned short int instr;
819 /* If finished or unrecoverable error, return NULL. */
820 if (sp->fts_cur == NULL || ISSET(FTS_STOP))
823 /* Set current node pointer. */
826 /* Save and zero out user instructions. */
827 instr = p->fts_instr;
828 p->fts_instr = FTS_NOINSTR;
830 /* Any type of file may be re-visited; re-stat and re-turn. */
831 if (instr == FTS_AGAIN) {
832 p->fts_info = fts_stat(sp, p, false);
835 Dprintf (("fts_read: p=%s\n",
836 p->fts_info == FTS_INIT ? "" : p->fts_path));
839 * Following a symlink -- SLNONE test allows application to see
840 * SLNONE and recover. If indirecting through a symlink, have
841 * keep a pointer to current location. If unable to get that
842 * pointer, follow fails.
844 if (instr == FTS_FOLLOW &&
845 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
846 p->fts_info = fts_stat(sp, p, true);
847 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
848 if ((p->fts_symfd = diropen (sp, ".")) < 0) {
849 p->fts_errno = errno;
850 p->fts_info = FTS_ERR;
852 p->fts_flags |= FTS_SYMFOLLOW;
857 /* Directory in pre-order. */
858 if (p->fts_info == FTS_D) {
859 /* If skipped or crossed mount point, do post-order visit. */
860 if (instr == FTS_SKIP ||
861 (ISSET(FTS_XDEV) && p->fts_statp->st_dev != sp->fts_dev)) {
862 if (p->fts_flags & FTS_SYMFOLLOW)
863 (void)close(p->fts_symfd);
865 fts_lfree(sp->fts_child);
866 sp->fts_child = NULL;
868 p->fts_info = FTS_DP;
869 LEAVE_DIR (sp, p, "1");
873 /* Rebuild if only read the names and now traversing. */
874 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) {
876 fts_lfree(sp->fts_child);
877 sp->fts_child = NULL;
881 * Cd to the subdirectory.
883 * If have already read and now fail to chdir, whack the list
884 * to make the names come out right, and set the parent errno
885 * so the application will eventually get an error condition.
886 * Set the FTS_DONTCHDIR flag so that when we logically change
887 * directories back to the parent we don't do a chdir.
889 * If haven't read do so. If the read fails, fts_build sets
890 * FTS_STOP or the fts_info field of the node.
892 if (sp->fts_child != NULL) {
893 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
894 p->fts_errno = errno;
895 p->fts_flags |= FTS_DONTCHDIR;
896 for (p = sp->fts_child; p != NULL;
899 p->fts_parent->fts_accpath;
901 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
904 /* If fts_build's call to fts_safe_changedir failed
905 because it was not able to fchdir into a
906 subdirectory, tell the caller. */
907 if (p->fts_errno && p->fts_info != FTS_DNR)
908 p->fts_info = FTS_ERR;
909 LEAVE_DIR (sp, p, "2");
913 sp->fts_child = NULL;
917 /* Move to the next node on this level. */
919 if ((p = p->fts_link) != NULL) {
924 * If reached the top, return to the original directory (or
925 * the root of the tree), and load the file names for the next
928 if (p->fts_level == FTS_ROOTLEVEL) {
929 if (RESTORE_INITIAL_CWD(sp)) {
940 * User may have called fts_set on the node. If skipped,
941 * ignore. If followed, get a file descriptor so we can
942 * get back if necessary.
944 if (p->fts_instr == FTS_SKIP)
946 if (p->fts_instr == FTS_FOLLOW) {
947 p->fts_info = fts_stat(sp, p, true);
948 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
949 if ((p->fts_symfd = diropen (sp, ".")) < 0) {
950 p->fts_errno = errno;
951 p->fts_info = FTS_ERR;
953 p->fts_flags |= FTS_SYMFOLLOW;
955 p->fts_instr = FTS_NOINSTR;
958 name: t = sp->fts_path + NAPPEND(p->fts_parent);
960 memmove(t, p->fts_name, p->fts_namelen + 1);
963 if (p->fts_info == FTS_NSOK)
965 if (p->fts_statp->st_size == FTS_STAT_REQUIRED)
967 FTSENT *parent = p->fts_parent;
968 if (FTS_ROOTLEVEL < p->fts_level
969 /* ->fts_n_dirs_remaining is not valid
970 for command-line-specified names. */
971 && parent->fts_n_dirs_remaining == 0
973 && ISSET(FTS_PHYSICAL)
974 && link_count_optimize_ok (parent))
976 /* nothing more needed */
980 p->fts_info = fts_stat(sp, p, false);
981 if (S_ISDIR(p->fts_statp->st_mode)
982 && p->fts_level != FTS_ROOTLEVEL
983 && parent->fts_n_dirs_remaining)
984 parent->fts_n_dirs_remaining--;
988 fts_assert (p->fts_statp->st_size == FTS_NO_STAT_REQUIRED);
991 if (p->fts_info == FTS_D)
993 /* Now that P->fts_statp is guaranteed to be valid,
994 if this is a command-line directory, record its
995 device number, to be used for FTS_XDEV. */
996 if (p->fts_level == FTS_ROOTLEVEL)
997 sp->fts_dev = p->fts_statp->st_dev;
998 Dprintf ((" entering: %s\n", p->fts_path));
999 if (! enter_dir (sp, p))
1001 __set_errno (ENOMEM);
1008 /* Move up to the parent node. */
1009 p = tmp->fts_parent;
1013 if (p->fts_level == FTS_ROOTPARENTLEVEL) {
1015 * Done; free everything up and set errno to 0 so the user
1016 * can distinguish between error and EOF.
1020 return (sp->fts_cur = NULL);
1023 fts_assert (p->fts_info != FTS_NSOK);
1025 /* NUL terminate the file name. */
1026 sp->fts_path[p->fts_pathlen] = '\0';
1029 * Return to the parent directory. If at a root node, restore
1030 * the initial working directory. If we came through a symlink,
1031 * go back through the file descriptor. Otherwise, move up
1032 * one level, via "..".
1034 if (p->fts_level == FTS_ROOTLEVEL) {
1035 if (RESTORE_INITIAL_CWD(sp)) {
1036 p->fts_errno = errno;
1039 } else if (p->fts_flags & FTS_SYMFOLLOW) {
1040 if (FCHDIR(sp, p->fts_symfd)) {
1041 int saved_errno = errno;
1042 (void)close(p->fts_symfd);
1043 __set_errno (saved_errno);
1044 p->fts_errno = errno;
1047 (void)close(p->fts_symfd);
1048 } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
1049 fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
1050 p->fts_errno = errno;
1053 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
1054 if (p->fts_errno == 0)
1055 LEAVE_DIR (sp, p, "3");
1056 return ISSET(FTS_STOP) ? NULL : p;
1060 * Fts_set takes the stream as an argument although it's not used in this
1061 * implementation; it would be necessary if anyone wanted to add global
1062 * semantics to fts using fts_set. An error return is allowed for similar
1067 fts_set(FTS *sp _UNUSED_PARAMETER_, FTSENT *p, int instr)
1069 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
1070 instr != FTS_NOINSTR && instr != FTS_SKIP) {
1071 __set_errno (EINVAL);
1074 p->fts_instr = instr;
1079 fts_children (register FTS *sp, int instr)
1084 if (instr != 0 && instr != FTS_NAMEONLY) {
1085 __set_errno (EINVAL);
1089 /* Set current node pointer. */
1093 * Errno set to 0 so user can distinguish empty directory from
1098 /* Fatal errors stop here. */
1099 if (ISSET(FTS_STOP))
1102 /* Return logical hierarchy of user's arguments. */
1103 if (p->fts_info == FTS_INIT)
1104 return (p->fts_link);
1107 * If not a directory being visited in pre-order, stop here. Could
1108 * allow FTS_DNR, assuming the user has fixed the problem, but the
1109 * same effect is available with FTS_AGAIN.
1111 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
1114 /* Free up any previous child list. */
1115 if (sp->fts_child != NULL)
1116 fts_lfree(sp->fts_child);
1118 if (instr == FTS_NAMEONLY) {
1125 * If using chdir on a relative file name and called BEFORE fts_read
1126 * does its chdir to the root of a traversal, we can lose -- we need to
1127 * chdir into the subdirectory, and we don't know where the current
1128 * directory is, so we can't get back so that the upcoming chdir by
1129 * fts_read will work.
1131 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
1133 return (sp->fts_child = fts_build(sp, instr));
1135 if ((fd = diropen (sp, ".")) < 0)
1136 return (sp->fts_child = NULL);
1137 sp->fts_child = fts_build(sp, instr);
1138 if (ISSET(FTS_CWDFD))
1140 cwd_advance_fd (sp, fd, true);
1146 int saved_errno = errno;
1148 __set_errno (saved_errno);
1153 return (sp->fts_child);
1156 /* A comparison function to sort on increasing inode number.
1157 For some file system types, sorting either way makes a huge
1158 performance difference for a directory with very many entries,
1159 but sorting on increasing values is slightly better than sorting
1160 on decreasing values. The difference is in the 5% range. */
1162 fts_compare_ino (struct _ftsent const **a, struct _ftsent const **b)
1164 return (a[0]->fts_statp->st_ino < b[0]->fts_statp->st_ino ? -1
1165 : b[0]->fts_statp->st_ino < a[0]->fts_statp->st_ino ? 1 : 0);
1168 /* Map the dirent.d_type value, DTYPE, to the corresponding stat.st_mode
1169 S_IF* bit and set ST.st_mode, thus clearing all other bits in that field. */
1171 set_stat_type (struct stat *st, unsigned int dtype)
1204 * This is the tricky part -- do not casually change *anything* in here. The
1205 * idea is to build the linked list of entries that are used by fts_children
1206 * and fts_read. There are lots of special cases.
1208 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is
1209 * set and it's a physical walk (so that symbolic links can't be directories),
1210 * we can do things quickly. First, if it's a 4.4BSD file system, the type
1211 * of the file is in the directory entry. Otherwise, we assume that the number
1212 * of subdirectories in a node is equal to the number of links to the parent.
1213 * The former skips all stat calls. The latter skips stat calls in any leaf
1214 * directories and for any files after the subdirectories in the directory have
1215 * been found, cutting the stat calls by about 2/3.
1219 fts_build (register FTS *sp, int type)
1221 register struct dirent *dp;
1222 register FTSENT *p, *head;
1223 register size_t nitems;
1233 size_t len, maxlen, new_len;
1236 /* Set current node pointer. */
1240 * Open the directory for reading. If this fails, we're done.
1241 * If being called from fts_read, set the fts_info field.
1243 #if defined FTS_WHITEOUT && 0
1244 if (ISSET(FTS_WHITEOUT))
1245 oflag = DTF_NODUP|DTF_REWIND;
1247 oflag = DTF_HIDEW|DTF_NODUP|DTF_REWIND;
1249 # define __opendir2(file, flag) \
1250 ( ! ISSET(FTS_NOCHDIR) && ISSET(FTS_CWDFD) \
1251 ? opendirat(sp->fts_cwd_fd, file) \
1254 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) {
1255 if (type == BREAD) {
1256 cur->fts_info = FTS_DNR;
1257 cur->fts_errno = errno;
1261 /* Rather than calling fts_stat for each and every entry encountered
1262 in the readdir loop (below), stat each directory only right after
1264 if (cur->fts_info == FTS_NSOK)
1265 cur->fts_info = fts_stat(sp, cur, false);
1266 else if (sp->fts_options & FTS_TIGHT_CYCLE_CHECK) {
1267 /* Now read the stat info again after opening a directory to
1268 * reveal eventual changes caused by a submount triggered by
1269 * the traversal. But do it only for utilities which use
1270 * FTS_TIGHT_CYCLE_CHECK. Therefore, only find and du
1271 * benefit/suffer from this feature for now.
1273 LEAVE_DIR (sp, cur, "4");
1274 fts_stat (sp, cur, false);
1275 if (! enter_dir (sp, cur)) {
1276 __set_errno (ENOMEM);
1282 * Nlinks is the number of possible entries of type directory in the
1283 * directory if we're cheating on stat calls, 0 if we're not doing
1284 * any stat calls at all, (nlink_t) -1 if we're statting everything.
1286 if (type == BNAMES) {
1288 /* Be quiet about nostat, GCC. */
1290 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
1291 nlinks = (cur->fts_statp->st_nlink
1292 - (ISSET(FTS_SEEDOT) ? 0 : 2));
1300 * If we're going to need to stat anything or we want to descend
1301 * and stay in the directory, chdir. If this fails we keep going,
1302 * but set a flag so we don't chdir after the post-order visit.
1303 * We won't be able to stat anything, but we can still return the
1304 * names themselves. Note, that since fts_read won't be able to
1305 * chdir into the directory, it will have to return different file
1306 * names than before, i.e. "a/b" instead of "b". Since the node
1307 * has already been visited in pre-order, have to wait until the
1308 * post-order visit to return the error. There is a special case
1309 * here, if there was nothing to stat then it's not an error to
1310 * not be able to stat. This is all fairly nasty. If a program
1311 * needed sorted entries or stat information, they had better be
1312 * checking FTS_NS on the returned nodes.
1314 if (nlinks || type == BREAD) {
1315 int dir_fd = dirfd(dirp);
1316 if (ISSET(FTS_CWDFD) && 0 <= dir_fd)
1318 dir_fd = dup (dir_fd);
1319 set_cloexec_flag (dir_fd, true);
1321 if (dir_fd < 0 || fts_safe_changedir(sp, cur, dir_fd, NULL)) {
1322 if (nlinks && type == BREAD)
1323 cur->fts_errno = errno;
1324 cur->fts_flags |= FTS_DONTCHDIR;
1327 if (ISSET(FTS_CWDFD) && 0 <= dir_fd)
1336 * Figure out the max file name length that can be stored in the
1337 * current buffer -- the inner loop allocates more space as necessary.
1338 * We really wouldn't have to do the maxlen calculations here, we
1339 * could do them in fts_read before returning the name, but it's a
1340 * lot easier here since the length is part of the dirent structure.
1342 * If not changing directories set a pointer so that can just append
1343 * each new component into the file name.
1346 if (ISSET(FTS_NOCHDIR)) {
1347 cp = sp->fts_path + len;
1350 /* GCC, you're too verbose. */
1354 maxlen = sp->fts_pathlen - len;
1356 level = cur->fts_level + 1;
1358 /* Read the directory, attaching each entry to the `link' pointer. */
1360 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
1363 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
1366 if ((p = fts_alloc (sp, dp->d_name,
1367 _D_EXACT_NAMLEN (dp))) == NULL)
1369 if (_D_EXACT_NAMLEN (dp) >= maxlen) {
1370 /* include space for NUL */
1371 oldaddr = sp->fts_path;
1372 if (! fts_palloc(sp, _D_EXACT_NAMLEN (dp) + len + 1)) {
1374 * No more memory. Save
1375 * errno, free up the current structure and the
1376 * structures already allocated.
1378 mem1: saved_errno = errno;
1382 cur->fts_info = FTS_ERR;
1384 __set_errno (saved_errno);
1387 /* Did realloc() change the pointer? */
1388 if (oldaddr != sp->fts_path) {
1390 if (ISSET(FTS_NOCHDIR))
1391 cp = sp->fts_path + len;
1393 maxlen = sp->fts_pathlen - len;
1396 new_len = len + _D_EXACT_NAMLEN (dp);
1397 if (new_len < len) {
1399 * In the unlikely event that we would end up
1400 * with a file name longer than SIZE_MAX, free up
1401 * the current structure and the structures already
1402 * allocated, then error out with ENAMETOOLONG.
1407 cur->fts_info = FTS_ERR;
1409 __set_errno (ENAMETOOLONG);
1412 p->fts_level = level;
1413 p->fts_parent = sp->fts_cur;
1414 p->fts_pathlen = new_len;
1416 #if defined FTS_WHITEOUT && 0
1417 if (dp->d_type == DT_WHT)
1418 p->fts_flags |= FTS_ISW;
1420 /* Store dirent.d_ino, in case we need to sort
1421 entries before processing them. */
1422 p->fts_statp->st_ino = D_INO (dp);
1424 /* Build a file name for fts_stat to stat. */
1425 if (ISSET(FTS_NOCHDIR)) {
1426 p->fts_accpath = p->fts_path;
1427 memmove(cp, p->fts_name, p->fts_namelen + 1);
1429 p->fts_accpath = p->fts_name;
1431 if (sp->fts_compar == NULL || ISSET(FTS_DEFER_STAT)) {
1432 /* Record what fts_read will have to do with this
1433 entry. In many cases, it will simply fts_stat it,
1434 but we can take advantage of any d_type information
1435 to optimize away the unnecessary stat calls. I.e.,
1436 if FTS_NOSTAT is in effect and we're not following
1437 symlinks (FTS_PHYSICAL) and d_type indicates this
1438 is *not* a directory, then we won't have to stat it
1439 at all. If it *is* a directory, then (currently)
1440 we stat it regardless, in order to get device and
1441 inode numbers. Some day we might optimize that
1442 away, too, for directories where d_ino is known to
1444 bool skip_stat = (ISSET(FTS_PHYSICAL)
1445 && ISSET(FTS_NOSTAT)
1447 && ! DT_MUST_BE(dp, DT_DIR));
1448 p->fts_info = FTS_NSOK;
1449 /* Propagate dirent.d_type information back
1450 to caller, when possible. */
1451 set_stat_type (p->fts_statp, D_TYPE (dp));
1452 fts_set_stat_required(p, !skip_stat);
1453 is_dir = (ISSET(FTS_PHYSICAL)
1454 && DT_MUST_BE(dp, DT_DIR));
1456 p->fts_info = fts_stat(sp, p, false);
1457 is_dir = (p->fts_info == FTS_D
1458 || p->fts_info == FTS_DC
1459 || p->fts_info == FTS_DOT);
1462 /* Decrement link count if applicable. */
1463 if (nlinks > 0 && is_dir)
1466 /* We walk in directory order so "ls -f" doesn't get upset. */
1480 * If realloc() changed the address of the file name, adjust the
1481 * addresses for the rest of the tree and the dir list.
1484 fts_padjust(sp, head);
1487 * If not changing directories, reset the file name back to original
1490 if (ISSET(FTS_NOCHDIR)) {
1491 if (len == sp->fts_pathlen || nitems == 0)
1497 * If descended after called from fts_children or after called from
1498 * fts_read and nothing found, get back. At the root level we use
1499 * the saved fd; if one of fts_open()'s arguments is a relative name
1500 * to an empty directory, we wind up here with no other way back. If
1501 * can't get back, we're done.
1503 if (descend && (type == BCHILD || !nitems) &&
1504 (cur->fts_level == FTS_ROOTLEVEL
1505 ? RESTORE_INITIAL_CWD(sp)
1506 : fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
1507 cur->fts_info = FTS_ERR;
1513 /* If didn't find anything, return NULL. */
1516 cur->fts_info = FTS_DP;
1521 /* If there are many entries, no sorting function has been specified,
1522 and this file system is of a type that may be slow with a large
1523 number of entries, then sort the directory entries on increasing
1525 if (nitems > _FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
1527 && ISSET (FTS_CWDFD)
1528 && dirent_inode_sort_may_be_useful (sp->fts_cwd_fd)) {
1529 sp->fts_compar = fts_compare_ino;
1530 head = fts_sort (sp, head, nitems);
1531 sp->fts_compar = NULL;
1534 /* Sort the entries. */
1535 if (sp->fts_compar && nitems > 1)
1536 head = fts_sort(sp, head, nitems);
1542 /* Walk ->fts_parent links starting at E_CURR, until the root of the
1543 current hierarchy. There should be a directory with dev/inode
1544 matching those of AD. If not, print a lot of diagnostics. */
1546 find_matching_ancestor (FTSENT const *e_curr, struct Active_dir const *ad)
1549 for (ent = e_curr; ent->fts_level >= FTS_ROOTLEVEL; ent = ent->fts_parent)
1551 if (ad->ino == ent->fts_statp->st_ino
1552 && ad->dev == ent->fts_statp->st_dev)
1555 printf ("ERROR: tree dir, %s, not active\n", ad->fts_ent->fts_accpath);
1556 printf ("active dirs:\n");
1558 ent->fts_level >= FTS_ROOTLEVEL; ent = ent->fts_parent)
1559 printf (" %s(%"PRIuMAX"/%"PRIuMAX") to %s(%"PRIuMAX"/%"PRIuMAX")...\n",
1560 ad->fts_ent->fts_accpath,
1561 (uintmax_t) ad->dev,
1562 (uintmax_t) ad->ino,
1564 (uintmax_t) ent->fts_statp->st_dev,
1565 (uintmax_t) ent->fts_statp->st_ino);
1569 fts_cross_check (FTS const *sp)
1571 FTSENT const *ent = sp->fts_cur;
1573 if ( ! ISSET (FTS_TIGHT_CYCLE_CHECK))
1576 Dprintf (("fts-cross-check cur=%s\n", ent->fts_path));
1577 /* Make sure every parent dir is in the tree. */
1578 for (t = ent->fts_parent; t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
1580 struct Active_dir ad;
1581 ad.ino = t->fts_statp->st_ino;
1582 ad.dev = t->fts_statp->st_dev;
1583 if ( ! hash_lookup (sp->fts_cycle.ht, &ad))
1584 printf ("ERROR: active dir, %s, not in tree\n", t->fts_path);
1587 /* Make sure every dir in the tree is an active dir.
1588 But ENT is not necessarily a directory. If so, just skip this part. */
1589 if (ent->fts_parent->fts_level >= FTS_ROOTLEVEL
1590 && (ent->fts_info == FTS_DP
1591 || ent->fts_info == FTS_D))
1593 struct Active_dir *ad;
1594 for (ad = hash_get_first (sp->fts_cycle.ht); ad != NULL;
1595 ad = hash_get_next (sp->fts_cycle.ht, ad))
1597 find_matching_ancestor (ent, ad);
1603 same_fd (int fd1, int fd2)
1605 struct stat sb1, sb2;
1606 return (fstat (fd1, &sb1) == 0
1607 && fstat (fd2, &sb2) == 0
1608 && SAME_INODE (sb1, sb2));
1612 fd_ring_print (FTS const *sp, FILE *stream, char const *msg)
1614 I_ring const *fd_ring = &sp->fts_fd_ring;
1615 unsigned int i = fd_ring->fts_front;
1616 char *cwd = getcwdat (sp->fts_cwd_fd, NULL, 0);
1617 fprintf (stream, "=== %s ========== %s\n", msg, cwd);
1619 if (i_ring_empty (fd_ring))
1624 int fd = fd_ring->fts_fd_ring[i];
1626 fprintf (stream, "%d: %d:\n", i, fd);
1629 char *wd = getcwdat (fd, NULL, 0);
1630 fprintf (stream, "%d: %d: %s\n", i, fd, wd);
1633 if (i == fd_ring->fts_back)
1635 i = (i + I_RING_SIZE - 1) % I_RING_SIZE;
1639 /* Ensure that each file descriptor on the fd_ring matches a
1640 parent, grandparent, etc. of the current working directory. */
1642 fd_ring_check (FTS const *sp)
1647 /* Make a writable copy. */
1648 I_ring fd_w = sp->fts_fd_ring;
1650 int cwd_fd = sp->fts_cwd_fd;
1651 cwd_fd = dup (cwd_fd);
1652 char *dot = getcwdat (cwd_fd, NULL, 0);
1653 error (0, 0, "===== check ===== cwd: %s", dot);
1655 while ( ! i_ring_empty (&fd_w))
1657 int fd = i_ring_pop (&fd_w);
1660 int parent_fd = openat (cwd_fd, "..", O_RDONLY);
1666 if (!same_fd (fd, parent_fd))
1668 char *cwd = getcwdat (fd, NULL, 0);
1669 error (0, errno, "ring : %s", cwd);
1670 char *c2 = getcwdat (parent_fd, NULL, 0);
1671 error (0, errno, "parent: %s", c2);
1684 static unsigned short int
1686 fts_stat(FTS *sp, register FTSENT *p, bool follow)
1688 struct stat *sbp = p->fts_statp;
1691 if (p->fts_level == FTS_ROOTLEVEL && ISSET(FTS_COMFOLLOW))
1694 #if defined FTS_WHITEOUT && 0
1695 /* check for whiteout */
1696 if (p->fts_flags & FTS_ISW) {
1697 memset(sbp, '\0', sizeof (*sbp));
1698 sbp->st_mode = S_IFWHT;
1704 * If doing a logical walk, or application requested FTS_FOLLOW, do
1705 * a stat(2). If that fails, check for a non-existent symlink. If
1706 * fail, set the errno from the stat call.
1708 if (ISSET(FTS_LOGICAL) || follow) {
1709 if (stat(p->fts_accpath, sbp)) {
1710 saved_errno = errno;
1712 && lstat(p->fts_accpath, sbp) == 0) {
1714 return (FTS_SLNONE);
1716 p->fts_errno = saved_errno;
1719 } else if (fstatat(sp->fts_cwd_fd, p->fts_accpath, sbp,
1720 AT_SYMLINK_NOFOLLOW)) {
1721 p->fts_errno = errno;
1722 err: memset(sbp, 0, sizeof(struct stat));
1726 if (S_ISDIR(sbp->st_mode)) {
1727 p->fts_n_dirs_remaining = (sbp->st_nlink
1728 - (ISSET(FTS_SEEDOT) ? 0 : 2));
1729 if (ISDOT(p->fts_name)) {
1730 /* Command-line "." and ".." are real directories. */
1731 return (p->fts_level == FTS_ROOTLEVEL ? FTS_D : FTS_DOT);
1737 * Cycle detection is done by brute force when the directory
1738 * is first encountered. If the tree gets deep enough or the
1739 * number of symbolic links to directories is high enough,
1740 * something faster might be worthwhile.
1744 for (t = p->fts_parent;
1745 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
1746 if (sbp->st_ino == t->fts_statp->st_ino
1747 && sbp->st_dev == t->fts_statp->st_dev)
1757 if (S_ISLNK(sbp->st_mode))
1759 if (S_ISREG(sbp->st_mode))
1761 return (FTS_DEFAULT);
1765 fts_compar (void const *a, void const *b)
1767 /* Convert A and B to the correct types, to pacify the compiler, and
1768 for portability to bizarre hosts where "void const *" and "FTSENT
1769 const **" differ in runtime representation. The comparison
1770 function cannot modify *a and *b, but there is no compile-time
1772 FTSENT const **pa = (FTSENT const **) a;
1773 FTSENT const **pb = (FTSENT const **) b;
1774 return pa[0]->fts_fts->fts_compar (pa, pb);
1779 fts_sort (FTS *sp, FTSENT *head, register size_t nitems)
1781 register FTSENT **ap, *p;
1783 /* On most modern hosts, void * and FTSENT ** have the same
1784 run-time representation, and one can convert sp->fts_compar to
1785 the type qsort expects without problem. Use the heuristic that
1786 this is OK if the two pointer types are the same size, and if
1787 converting FTSENT ** to long int is the same as converting
1788 FTSENT ** to void * and then to long int. This heuristic isn't
1789 valid in general but we don't know of any counterexamples. */
1791 int (*compare) (void const *, void const *) =
1792 ((sizeof &dummy == sizeof (void *)
1793 && (long int) &dummy == (long int) (void *) &dummy)
1794 ? (int (*) (void const *, void const *)) sp->fts_compar
1798 * Construct an array of pointers to the structures and call qsort(3).
1799 * Reassemble the array in the order returned by qsort. If unable to
1800 * sort for memory reasons, return the directory entries in their
1801 * current order. Allocate enough space for the current needs plus
1802 * 40 so don't realloc one entry at a time.
1804 if (nitems > sp->fts_nitems) {
1807 sp->fts_nitems = nitems + 40;
1808 if (SIZE_MAX / sizeof *a < sp->fts_nitems
1809 || ! (a = realloc (sp->fts_array,
1810 sp->fts_nitems * sizeof *a))) {
1811 free(sp->fts_array);
1812 sp->fts_array = NULL;
1818 for (ap = sp->fts_array, p = head; p; p = p->fts_link)
1820 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), compare);
1821 for (head = *(ap = sp->fts_array); --nitems; ++ap)
1822 ap[0]->fts_link = ap[1];
1823 ap[0]->fts_link = NULL;
1829 fts_alloc (FTS *sp, const char *name, register size_t namelen)
1835 * The file name is a variable length array. Allocate the FTSENT
1836 * structure and the file name in one chunk.
1838 len = sizeof(FTSENT) + namelen;
1839 if ((p = malloc(len)) == NULL)
1842 /* Copy the name and guarantee NUL termination. */
1843 memmove(p->fts_name, name, namelen);
1844 p->fts_name[namelen] = '\0';
1846 p->fts_namelen = namelen;
1848 p->fts_path = sp->fts_path;
1851 p->fts_instr = FTS_NOINSTR;
1853 p->fts_pointer = NULL;
1859 fts_lfree (register FTSENT *head)
1863 /* Free a linked list of structures. */
1864 while ((p = head)) {
1865 head = head->fts_link;
1871 * Allow essentially unlimited file name lengths; find, rm, ls should
1872 * all work on any tree. Most systems will allow creation of file
1873 * names much longer than MAXPATHLEN, even though the kernel won't
1874 * resolve them. Add the size (not just what's needed) plus 256 bytes
1875 * so don't realloc the file name 2 bytes at a time.
1879 fts_palloc (FTS *sp, size_t more)
1882 size_t new_len = sp->fts_pathlen + more + 256;
1885 * See if fts_pathlen would overflow.
1887 if (new_len < sp->fts_pathlen) {
1889 sp->fts_path = NULL;
1890 __set_errno (ENAMETOOLONG);
1893 sp->fts_pathlen = new_len;
1894 p = realloc(sp->fts_path, sp->fts_pathlen);
1897 sp->fts_path = NULL;
1905 * When the file name is realloc'd, have to fix all of the pointers in
1906 * structures already returned.
1910 fts_padjust (FTS *sp, FTSENT *head)
1913 char *addr = sp->fts_path;
1915 #define ADJUST(p) do { \
1916 if ((p)->fts_accpath != (p)->fts_name) { \
1917 (p)->fts_accpath = \
1918 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \
1920 (p)->fts_path = addr; \
1922 /* Adjust the current set of children. */
1923 for (p = sp->fts_child; p; p = p->fts_link)
1926 /* Adjust the rest of the tree, including the current level. */
1927 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
1929 p = p->fts_link ? p->fts_link : p->fts_parent;
1935 fts_maxarglen (char * const *argv)
1939 for (max = 0; *argv; ++argv)
1940 if ((len = strlen(*argv)) > max)
1946 * Change to dir specified by fd or file name without getting
1947 * tricked by someone changing the world out from underneath us.
1948 * Assumes p->fts_statp->st_dev and p->fts_statp->st_ino are filled in.
1949 * If FD is non-negative, expect it to be used after this function returns,
1950 * and to be closed eventually. So don't pass e.g., `dirfd(dirp)' and then
1951 * do closedir(dirp), because that would invalidate the saved FD.
1952 * Upon failure, close FD immediately and return nonzero.
1956 fts_safe_changedir (FTS *sp, FTSENT *p, int fd, char const *dir)
1959 bool is_dotdot = dir && STREQ (dir, "..");
1962 /* This clause handles the unusual case in which FTS_NOCHDIR
1963 is specified, along with FTS_CWDFD. In that case, there is
1964 no need to change even the virtual cwd file descriptor.
1965 However, if FD is non-negative, we do close it here. */
1966 if (ISSET (FTS_NOCHDIR))
1968 if (ISSET (FTS_CWDFD) && 0 <= fd)
1973 if (fd < 0 && is_dotdot && ISSET (FTS_CWDFD))
1975 /* When possible, skip the diropen and subsequent fstat+dev/ino
1976 comparison. I.e., when changing to parent directory
1977 (chdir ("..")), use a file descriptor from the ring and
1978 save the overhead of diropen+fstat, as well as avoiding
1979 failure when we lack "x" access to the virtual cwd. */
1980 if ( ! i_ring_empty (&sp->fts_fd_ring))
1983 fd_ring_print (sp, stderr, "pre-pop");
1984 parent_fd = i_ring_pop (&sp->fts_fd_ring);
1995 if (fd < 0 && (newfd = diropen (sp, dir)) < 0)
1998 /* The following dev/inode check is necessary if we're doing a
1999 `logical' traversal (through symlinks, a la chown -L), if the
2000 system lacks O_NOFOLLOW support, or if we're changing to ".."
2001 (but not via a popped file descriptor). When changing to the
2002 name "..", O_NOFOLLOW can't help. In general, when the target is
2003 not "..", diropen's use of O_NOFOLLOW ensures we don't mistakenly
2004 follow a symlink, so we can avoid the expense of this fstat. */
2005 if (ISSET(FTS_LOGICAL) || ! HAVE_WORKING_O_NOFOLLOW
2006 || (dir && STREQ (dir, "..")))
2009 if (fstat(newfd, &sb))
2014 if (p->fts_statp->st_dev != sb.st_dev
2015 || p->fts_statp->st_ino != sb.st_ino)
2017 __set_errno (ENOENT); /* disinformation */
2023 if (ISSET(FTS_CWDFD))
2025 cwd_advance_fd (sp, newfd, ! is_dotdot);
2029 ret = fchdir(newfd);
2035 __set_errno (oerrno);