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>
73 # include "unistd--.h"
74 # include "same-inode.h"
78 #ifndef _D_EXACT_NAMLEN
79 # define _D_EXACT_NAMLEN(dirent) strlen ((dirent)->d_name)
82 #if HAVE_STRUCT_DIRENT_D_TYPE
83 /* True if the type of the directory entry D is known. */
84 # define DT_IS_KNOWN(d) ((d)->d_type != DT_UNKNOWN)
85 /* True if the type of the directory entry D must be T. */
86 # define DT_MUST_BE(d, t) ((d)->d_type == (t))
87 # define D_TYPE(d) ((d)->d_type)
89 # define DT_IS_KNOWN(d) false
90 # define DT_MUST_BE(d, t) false
91 # define D_TYPE(d) DT_UNKNOWN
96 /* Any nonzero values will do here, so long as they're distinct.
97 Undef any existing macros out of the way. */
123 NOT_AN_INODE_NUMBER = 0
126 #ifdef D_INO_IN_DIRENT
127 # define D_INO(dp) (dp)->d_ino
129 /* Some systems don't have inodes, so fake them to avoid lots of ifdefs. */
130 # define D_INO(dp) NOT_AN_INODE_NUMBER
133 /* If there are more than this many entries in a directory,
134 and the conditions mentioned below are satisfied, then sort
135 the entries on inode number before any further processing. */
136 #ifndef FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
137 # define FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD 10000
141 _FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD = FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
146 FTS_NO_STAT_REQUIRED = 1,
147 FTS_STAT_REQUIRED = 2
152 # define close __close
154 # define closedir __closedir
156 # define fchdir __fchdir
160 # define opendir __opendir
162 # define readdir __readdir
164 # undef internal_function
165 # define internal_function /* empty */
169 # define __set_errno(Val) errno = (Val)
172 #ifndef __attribute__
173 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8)
174 # define __attribute__(x) /* empty */
178 #ifndef ATTRIBUTE_UNUSED
179 # define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
182 /* If this host provides the openat function, then we can avoid
183 attempting to open "." in some initialization code below. */
185 # define HAVE_OPENAT_SUPPORT 1
187 # define HAVE_OPENAT_SUPPORT 0
191 # define fts_assert(expr) ((void) 0)
193 # define fts_assert(expr) \
202 static FTSENT *fts_alloc (FTS *, const char *, size_t) internal_function;
203 static FTSENT *fts_build (FTS *, int) internal_function;
204 static void fts_lfree (FTSENT *) internal_function;
205 static void fts_load (FTS *, FTSENT *) internal_function;
206 static size_t fts_maxarglen (char * const *) internal_function;
207 static void fts_padjust (FTS *, FTSENT *) internal_function;
208 static bool fts_palloc (FTS *, size_t) internal_function;
209 static FTSENT *fts_sort (FTS *, FTSENT *, size_t) internal_function;
210 static unsigned short int fts_stat (FTS *, FTSENT *, bool) internal_function;
211 static int fts_safe_changedir (FTS *, FTSENT *, int, const char *)
215 # include "fts-cycle.c"
217 static bool enter_dir (FTS *fts, FTSENT *ent) { return true; }
218 static void leave_dir (FTS *fts, FTSENT *ent) {}
219 static bool setup_dir (FTS *fts) { return true; }
220 static void free_dir (FTS *fts) {}
224 # define MAX(a,b) ((a) > (b) ? (a) : (b))
228 # define SIZE_MAX ((size_t) -1)
232 # define O_DIRECTORY 0
235 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
236 #define STREQ(a, b) (strcmp ((a), (b)) == 0)
238 #define CLR(opt) (sp->fts_options &= ~(opt))
239 #define ISSET(opt) (sp->fts_options & (opt))
240 #define SET(opt) (sp->fts_options |= (opt))
242 /* FIXME: make this a function */
243 #define RESTORE_INITIAL_CWD(sp) \
244 (fd_ring_clear (&((sp)->fts_fd_ring)), \
245 FCHDIR ((sp), (ISSET (FTS_CWDFD) ? AT_FDCWD : (sp)->fts_rfd)))
247 /* FIXME: FTS_NOCHDIR is now misnamed.
248 Call it FTS_USE_FULL_RELATIVE_FILE_NAMES instead. */
249 #define FCHDIR(sp, fd) \
250 (!ISSET(FTS_NOCHDIR) && (ISSET(FTS_CWDFD) \
251 ? (cwd_advance_fd ((sp), (fd), true), 0) \
255 /* fts_build flags */
256 /* FIXME: make this an enum */
257 #define BCHILD 1 /* fts_children */
258 #define BNAMES 2 /* fts_children, names only */
259 #define BREAD 3 /* fts_read */
262 # include <inttypes.h>
265 # include "getcwdat.h"
266 bool fts_debug = false;
267 # define Dprintf(x) do { if (fts_debug) printf x; } while (false)
270 # define fd_ring_check(x)
271 # define fd_ring_print(a, b, c)
274 #define LEAVE_DIR(Fts, Ent, Tag) \
277 Dprintf ((" %s-leaving: %s\n", Tag, (Ent)->fts_path)); \
278 leave_dir (Fts, Ent); \
279 fd_ring_check (Fts); \
284 fd_ring_clear (I_ring *fd_ring)
286 while ( ! i_ring_empty (fd_ring))
288 int fd = i_ring_pop (fd_ring);
294 /* Overload the fts_statp->st_size member (otherwise unused, when
295 fts_info is FTS_NSOK) to indicate whether fts_read should stat
296 this entry or not. */
298 fts_set_stat_required (FTSENT *p, bool required)
300 fts_assert (p->fts_info == FTS_NSOK);
301 p->fts_statp->st_size = (required
303 : FTS_NO_STAT_REQUIRED);
306 /* file-descriptor-relative opendir. */
307 /* FIXME: if others need this function, move it into lib/openat.c */
310 opendirat (int fd, char const *dir)
312 int new_fd = openat (fd, dir, O_RDONLY);
317 dirp = fdopendir (new_fd);
320 int saved_errno = errno;
327 /* Virtual fchdir. Advance SP's working directory file descriptor,
328 SP->fts_cwd_fd, to FD, and push the previous value onto the fd_ring.
329 CHDIR_DOWN_ONE is true if FD corresponds to an entry in the directory
330 open on sp->fts_cwd_fd; i.e., to move the working directory one level
334 cwd_advance_fd (FTS *sp, int fd, bool chdir_down_one)
336 int old = sp->fts_cwd_fd;
337 fts_assert (old != fd || old == AT_FDCWD);
341 /* Push "old" onto the ring.
342 If the displaced file descriptor is non-negative, close it. */
343 int prev_fd_in_slot = i_ring_push (&sp->fts_fd_ring, old);
344 fd_ring_print (sp, stderr, "post-push");
345 if (0 <= prev_fd_in_slot)
346 close (prev_fd_in_slot); /* ignore any close failure */
348 else if ( ! ISSET (FTS_NOCHDIR))
351 close (old); /* ignore any close failure */
357 /* Open the directory DIR if possible, and return a file
358 descriptor. Return -1 and set errno on failure. It doesn't matter
359 whether the file descriptor has read or write access. */
363 diropen (FTS const *sp, char const *dir)
365 int open_flags = (O_RDONLY | O_DIRECTORY | O_NOCTTY | O_NONBLOCK
366 | (ISSET (FTS_PHYSICAL) ? O_NOFOLLOW : 0));
368 return (ISSET (FTS_CWDFD)
369 ? openat (sp->fts_cwd_fd, dir, open_flags)
370 : open (dir, open_flags));
374 fts_open (char * const *argv,
375 register int options,
376 int (*compar) (FTSENT const **, FTSENT const **))
379 register FTSENT *p, *root;
380 register size_t nitems;
381 FTSENT *parent = NULL;
382 FTSENT *tmp = NULL; /* pacify gcc */
387 if (options & ~FTS_OPTIONMASK) {
388 __set_errno (EINVAL);
391 if ((options & FTS_NOCHDIR) && (options & FTS_CWDFD)) {
392 __set_errno (EINVAL);
395 if ( ! (options & (FTS_LOGICAL | FTS_PHYSICAL))) {
396 __set_errno (EINVAL);
400 /* Allocate/initialize the stream */
401 if ((sp = malloc(sizeof(FTS))) == NULL)
403 memset(sp, 0, sizeof(FTS));
404 sp->fts_compar = compar;
405 sp->fts_options = options;
407 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */
408 if (ISSET(FTS_LOGICAL)) {
413 /* Initialize fts_cwd_fd. */
414 sp->fts_cwd_fd = AT_FDCWD;
415 if ( ISSET(FTS_CWDFD) && ! HAVE_OPENAT_SUPPORT)
417 /* While it isn't technically necessary to open "." this
418 early, doing it here saves us the trouble of ensuring
419 later (where it'd be messier) that "." can in fact
420 be opened. If not, revert to FTS_NOCHDIR mode. */
421 int fd = open (".", O_RDONLY);
424 /* Even if `.' is unreadable, don't revert to FTS_NOCHDIR mode
425 on systems like Linux+PROC_FS, where our openat emulation
426 is good enough. Note: on a system that emulates
427 openat via /proc, this technique can still fail, but
428 only in extreme conditions, e.g., when the working
429 directory cannot be saved (i.e. save_cwd fails) --
430 and that happens on Linux only when "." is unreadable
431 and the CWD would be longer than PATH_MAX.
432 FIXME: once Linux kernel openat support is well established,
433 replace the above open call and this entire if/else block
434 with the body of the if-block below. */
435 if ( openat_needs_fchdir ())
448 * Start out with 1K of file name space, and enough, in any case,
449 * to hold the user's file names.
452 # define MAXPATHLEN 1024
455 size_t maxarglen = fts_maxarglen(argv);
456 if (! fts_palloc(sp, MAX(maxarglen, MAXPATHLEN)))
460 /* Allocate/initialize root's parent. */
462 if ((parent = fts_alloc(sp, "", 0)) == NULL)
464 parent->fts_level = FTS_ROOTPARENTLEVEL;
467 /* The classic fts implementation would call fts_stat with
468 a new entry for each iteration of the loop below.
469 If the comparison function is not specified or if the
470 FTS_DEFER_STAT option is in effect, don't stat any entry
471 in this loop. This is an attempt to minimize the interval
472 between the initial stat/lstat/fstatat and the point at which
473 a directory argument is first opened. This matters for any
474 directory command line argument that resides on a file system
475 without genuine i-nodes. If you specify FTS_DEFER_STAT along
476 with a comparison function, that function must not access any
477 data via the fts_statp pointer. */
478 defer_stat = (compar == NULL || ISSET(FTS_DEFER_STAT));
480 /* Allocate/initialize root(s). */
481 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) {
482 /* Don't allow zero-length file names. */
483 if ((len = strlen(*argv)) == 0) {
484 __set_errno (ENOENT);
488 if ((p = fts_alloc(sp, *argv, len)) == NULL)
490 p->fts_level = FTS_ROOTLEVEL;
491 p->fts_parent = parent;
492 p->fts_accpath = p->fts_name;
493 /* Even when defer_stat is true, be sure to stat the first
494 command line argument, since fts_read (at least with
495 FTS_XDEV) requires that. */
496 if (defer_stat && root != NULL) {
497 p->fts_info = FTS_NSOK;
498 fts_set_stat_required(p, true);
500 p->fts_info = fts_stat(sp, p, false);
504 * If comparison routine supplied, traverse in sorted
505 * order; otherwise traverse in the order specified.
520 if (compar && nitems > 1)
521 root = fts_sort(sp, root, nitems);
524 * Allocate a dummy pointer and make fts_read think that we've just
525 * finished the node before the root(s); set p->fts_info to FTS_INIT
526 * so that everything about the "current" node is ignored.
528 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
530 sp->fts_cur->fts_link = root;
531 sp->fts_cur->fts_info = FTS_INIT;
532 if (! setup_dir (sp))
536 * If using chdir(2), grab a file descriptor pointing to dot to ensure
537 * that we can get back here; this could be avoided for some file names,
538 * but almost certainly not worth the effort. Slashes, symbolic links,
539 * and ".." are all fairly nasty problems. Note, if we can't get the
540 * descriptor we run anyway, just more slowly.
542 if (!ISSET(FTS_NOCHDIR) && !ISSET(FTS_CWDFD)
543 && (sp->fts_rfd = diropen (sp, ".")) < 0)
546 i_ring_init (&sp->fts_fd_ring, -1);
549 mem3: fts_lfree(root);
551 mem2: free(sp->fts_path);
558 fts_load (FTS *sp, register FTSENT *p)
564 * Load the stream structure for the next traversal. Since we don't
565 * actually enter the directory until after the preorder visit, set
566 * the fts_accpath field specially so the chdir gets done to the right
567 * place and the user can access the first node. From fts_open it's
568 * known that the file name will fit.
570 len = p->fts_pathlen = p->fts_namelen;
571 memmove(sp->fts_path, p->fts_name, len + 1);
572 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
574 memmove(p->fts_name, cp, len + 1);
575 p->fts_namelen = len;
577 p->fts_accpath = p->fts_path = sp->fts_path;
583 register FTSENT *freep, *p;
587 * This still works if we haven't read anything -- the dummy structure
588 * points to the root list, so we step through to the end of the root
589 * list which has a valid parent pointer.
592 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
594 p = p->fts_link != NULL ? p->fts_link : p->fts_parent;
600 /* Free up child linked list, sort array, file name buffer. */
602 fts_lfree(sp->fts_child);
606 if (ISSET(FTS_CWDFD))
608 if (0 <= sp->fts_cwd_fd)
609 close (sp->fts_cwd_fd);
611 else if (!ISSET(FTS_NOCHDIR))
613 /* Return to original directory, save errno if necessary. */
614 if (fchdir(sp->fts_rfd))
619 fd_ring_clear (&sp->fts_fd_ring);
622 if (sp->fts_leaf_optimization_works_ht)
623 hash_free (sp->fts_leaf_optimization_works_ht);
628 /* Free up the stream pointer. */
631 /* Set errno and return. */
633 __set_errno (saved_errno);
640 #if defined __linux__ \
641 && HAVE_SYS_VFS_H && HAVE_FSTATFS && HAVE_STRUCT_STATFS_F_TYPE
645 /* Linux-specific constants from coreutils' src/fs.h */
646 # define S_MAGIC_TMPFS 0x1021994
647 # define S_MAGIC_NFS 0x6969
648 # define S_MAGIC_REISERFS 0x52654973
649 # define S_MAGIC_PROC 0x9FA0
651 /* Return false if it is easy to determine the file system type of
652 the directory on which DIR_FD is open, and sorting dirents on
653 inode numbers is known not to improve traversal performance with
654 that type of file system. Otherwise, return true. */
656 dirent_inode_sort_may_be_useful (int dir_fd)
658 /* Skip the sort only if we can determine efficiently
659 that skipping it is the right thing to do.
660 The cost of performing an unnecessary sort is negligible,
661 while the cost of *not* performing it can be O(N^2) with
662 a very large constant. */
663 struct statfs fs_buf;
665 /* If fstatfs fails, assume sorting would be useful. */
666 if (fstatfs (dir_fd, &fs_buf) != 0)
669 /* FIXME: what about when f_type is not an integral type?
670 deal with that if/when it's encountered. */
671 switch (fs_buf.f_type)
675 /* On a file system of any of these types, sorting
676 is unnecessary, and hence wasteful. */
684 /* Given a file descriptor DIR_FD open on a directory D,
685 return true if it is valid to apply the leaf-optimization
686 technique of counting directories in D via stat.st_nlink. */
688 leaf_optimization_applies (int dir_fd)
690 struct statfs fs_buf;
692 /* If fstatfs fails, assume we can't use the optimization. */
693 if (fstatfs (dir_fd, &fs_buf) != 0)
696 /* FIXME: do we need to detect AFS mount points? I doubt it,
697 unless fstatfs can report S_MAGIC_REISERFS for such a directory. */
699 switch (fs_buf.f_type)
701 /* List here the file system types that lack useable dirent.d_type
702 info, yet for which the optimization does apply. */
703 case S_MAGIC_REISERFS:
707 /* Explicitly listing this or any other file system type for which
708 the optimization is not applicable is not necessary, but we leave
709 it here to document the risk. Per http://bugs.debian.org/143111,
710 /proc may have bogus stat.st_nlink values. */
718 static bool dirent_inode_sort_may_be_useful (int dir_fd) { return true; }
719 static bool leaf_optimization_applies (int dir_fd) { return false; }
723 /* link-count-optimization entry:
724 map an stat.st_dev number to a boolean: leaf_optimization_works */
731 /* Use a tiny initial size. If a traversal encounters more than
732 a few devices, the cost of growing/rehashing this table will be
733 rendered negligible by the number of inodes processed. */
734 enum { LCO_HT_INITIAL_SIZE = 13 };
737 LCO_hash (void const *x, size_t table_size)
739 struct LCO_ent const *ax = x;
740 return (uintmax_t) ax->st_dev % table_size;
744 LCO_compare (void const *x, void const *y)
746 struct LCO_ent const *ax = x;
747 struct LCO_ent const *ay = y;
748 return ax->st_dev == ay->st_dev;
751 /* Ask the same question as leaf_optimization_applies, but query
752 the cache first (FTS.fts_leaf_optimization_works_ht), and if necessary,
753 update that cache. */
755 link_count_optimize_ok (FTSENT const *p)
757 FTS *sp = p->fts_fts;
758 Hash_table *h = sp->fts_leaf_optimization_works_ht;
764 /* If we're not in CWDFD mode, don't bother with this optimization,
765 since the caller is not serious about performance. */
766 if (!ISSET(FTS_CWDFD))
769 /* map st_dev to the boolean, leaf_optimization_works */
772 h = sp->fts_leaf_optimization_works_ht
773 = hash_initialize (LCO_HT_INITIAL_SIZE, NULL, LCO_hash,
778 tmp.st_dev = p->fts_statp->st_dev;
779 ent = hash_lookup (h, &tmp);
783 /* Look-up failed. Query directly and cache the result. */
784 t2 = malloc (sizeof *t2);
788 /* Is it ok to perform the optimization in the dir, FTS_CWD_FD? */
789 opt_ok = leaf_optimization_applies (sp->fts_cwd_fd);
791 t2->st_dev = p->fts_statp->st_dev;
793 ent = hash_insert (h, t2);
796 /* insertion failed */
800 fts_assert (ent == t2);
807 * Special case of "/" at the end of the file name so that slashes aren't
808 * appended which would cause file names to be written as "....//foo".
811 (p->fts_path[p->fts_pathlen - 1] == '/' \
812 ? p->fts_pathlen - 1 : p->fts_pathlen)
815 fts_read (register FTS *sp)
817 register FTSENT *p, *tmp;
818 register unsigned short int instr;
821 /* If finished or unrecoverable error, return NULL. */
822 if (sp->fts_cur == NULL || ISSET(FTS_STOP))
825 /* Set current node pointer. */
828 /* Save and zero out user instructions. */
829 instr = p->fts_instr;
830 p->fts_instr = FTS_NOINSTR;
832 /* Any type of file may be re-visited; re-stat and re-turn. */
833 if (instr == FTS_AGAIN) {
834 p->fts_info = fts_stat(sp, p, false);
837 Dprintf (("fts_read: p=%s\n",
838 p->fts_info == FTS_INIT ? "" : p->fts_path));
841 * Following a symlink -- SLNONE test allows application to see
842 * SLNONE and recover. If indirecting through a symlink, have
843 * keep a pointer to current location. If unable to get that
844 * pointer, follow fails.
846 if (instr == FTS_FOLLOW &&
847 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
848 p->fts_info = fts_stat(sp, p, true);
849 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
850 if ((p->fts_symfd = diropen (sp, ".")) < 0) {
851 p->fts_errno = errno;
852 p->fts_info = FTS_ERR;
854 p->fts_flags |= FTS_SYMFOLLOW;
859 /* Directory in pre-order. */
860 if (p->fts_info == FTS_D) {
861 /* If skipped or crossed mount point, do post-order visit. */
862 if (instr == FTS_SKIP ||
863 (ISSET(FTS_XDEV) && p->fts_statp->st_dev != sp->fts_dev)) {
864 if (p->fts_flags & FTS_SYMFOLLOW)
865 (void)close(p->fts_symfd);
867 fts_lfree(sp->fts_child);
868 sp->fts_child = NULL;
870 p->fts_info = FTS_DP;
871 LEAVE_DIR (sp, p, "1");
875 /* Rebuild if only read the names and now traversing. */
876 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) {
878 fts_lfree(sp->fts_child);
879 sp->fts_child = NULL;
883 * Cd to the subdirectory.
885 * If have already read and now fail to chdir, whack the list
886 * to make the names come out right, and set the parent errno
887 * so the application will eventually get an error condition.
888 * Set the FTS_DONTCHDIR flag so that when we logically change
889 * directories back to the parent we don't do a chdir.
891 * If haven't read do so. If the read fails, fts_build sets
892 * FTS_STOP or the fts_info field of the node.
894 if (sp->fts_child != NULL) {
895 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
896 p->fts_errno = errno;
897 p->fts_flags |= FTS_DONTCHDIR;
898 for (p = sp->fts_child; p != NULL;
901 p->fts_parent->fts_accpath;
903 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
906 /* If fts_build's call to fts_safe_changedir failed
907 because it was not able to fchdir into a
908 subdirectory, tell the caller. */
909 if (p->fts_errno && p->fts_info != FTS_DNR)
910 p->fts_info = FTS_ERR;
911 LEAVE_DIR (sp, p, "2");
915 sp->fts_child = NULL;
919 /* Move to the next node on this level. */
921 if ((p = p->fts_link) != NULL) {
926 * If reached the top, return to the original directory (or
927 * the root of the tree), and load the file names for the next
930 if (p->fts_level == FTS_ROOTLEVEL) {
931 if (RESTORE_INITIAL_CWD(sp)) {
942 * User may have called fts_set on the node. If skipped,
943 * ignore. If followed, get a file descriptor so we can
944 * get back if necessary.
946 if (p->fts_instr == FTS_SKIP)
948 if (p->fts_instr == FTS_FOLLOW) {
949 p->fts_info = fts_stat(sp, p, true);
950 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
951 if ((p->fts_symfd = diropen (sp, ".")) < 0) {
952 p->fts_errno = errno;
953 p->fts_info = FTS_ERR;
955 p->fts_flags |= FTS_SYMFOLLOW;
957 p->fts_instr = FTS_NOINSTR;
960 name: t = sp->fts_path + NAPPEND(p->fts_parent);
962 memmove(t, p->fts_name, p->fts_namelen + 1);
965 if (p->fts_info == FTS_NSOK)
967 if (p->fts_statp->st_size == FTS_STAT_REQUIRED)
969 FTSENT *parent = p->fts_parent;
970 if (FTS_ROOTLEVEL < p->fts_level
971 /* ->fts_n_dirs_remaining is not valid
972 for command-line-specified names. */
973 && parent->fts_n_dirs_remaining == 0
975 && ISSET(FTS_PHYSICAL)
976 && link_count_optimize_ok (parent))
978 /* nothing more needed */
982 p->fts_info = fts_stat(sp, p, false);
983 if (S_ISDIR(p->fts_statp->st_mode)
984 && p->fts_level != FTS_ROOTLEVEL
985 && parent->fts_n_dirs_remaining)
986 parent->fts_n_dirs_remaining--;
990 fts_assert (p->fts_statp->st_size == FTS_NO_STAT_REQUIRED);
993 if (p->fts_info == FTS_D)
995 /* Now that P->fts_statp is guaranteed to be valid,
996 if this is a command-line directory, record its
997 device number, to be used for FTS_XDEV. */
998 if (p->fts_level == FTS_ROOTLEVEL)
999 sp->fts_dev = p->fts_statp->st_dev;
1000 Dprintf ((" entering: %s\n", p->fts_path));
1001 if (! enter_dir (sp, p))
1003 __set_errno (ENOMEM);
1010 /* Move up to the parent node. */
1011 p = tmp->fts_parent;
1015 if (p->fts_level == FTS_ROOTPARENTLEVEL) {
1017 * Done; free everything up and set errno to 0 so the user
1018 * can distinguish between error and EOF.
1022 return (sp->fts_cur = NULL);
1025 fts_assert (p->fts_info != FTS_NSOK);
1027 /* NUL terminate the file name. */
1028 sp->fts_path[p->fts_pathlen] = '\0';
1031 * Return to the parent directory. If at a root node, restore
1032 * the initial working directory. If we came through a symlink,
1033 * go back through the file descriptor. Otherwise, move up
1034 * one level, via "..".
1036 if (p->fts_level == FTS_ROOTLEVEL) {
1037 if (RESTORE_INITIAL_CWD(sp)) {
1038 p->fts_errno = errno;
1041 } else if (p->fts_flags & FTS_SYMFOLLOW) {
1042 if (FCHDIR(sp, p->fts_symfd)) {
1043 int saved_errno = errno;
1044 (void)close(p->fts_symfd);
1045 __set_errno (saved_errno);
1046 p->fts_errno = errno;
1049 (void)close(p->fts_symfd);
1050 } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
1051 fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
1052 p->fts_errno = errno;
1055 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
1056 if (p->fts_errno == 0)
1057 LEAVE_DIR (sp, p, "3");
1058 return ISSET(FTS_STOP) ? NULL : p;
1062 * Fts_set takes the stream as an argument although it's not used in this
1063 * implementation; it would be necessary if anyone wanted to add global
1064 * semantics to fts using fts_set. An error return is allowed for similar
1069 fts_set(FTS *sp ATTRIBUTE_UNUSED, FTSENT *p, int instr)
1071 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
1072 instr != FTS_NOINSTR && instr != FTS_SKIP) {
1073 __set_errno (EINVAL);
1076 p->fts_instr = instr;
1081 fts_children (register FTS *sp, int instr)
1086 if (instr != 0 && instr != FTS_NAMEONLY) {
1087 __set_errno (EINVAL);
1091 /* Set current node pointer. */
1095 * Errno set to 0 so user can distinguish empty directory from
1100 /* Fatal errors stop here. */
1101 if (ISSET(FTS_STOP))
1104 /* Return logical hierarchy of user's arguments. */
1105 if (p->fts_info == FTS_INIT)
1106 return (p->fts_link);
1109 * If not a directory being visited in pre-order, stop here. Could
1110 * allow FTS_DNR, assuming the user has fixed the problem, but the
1111 * same effect is available with FTS_AGAIN.
1113 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
1116 /* Free up any previous child list. */
1117 if (sp->fts_child != NULL)
1118 fts_lfree(sp->fts_child);
1120 if (instr == FTS_NAMEONLY) {
1127 * If using chdir on a relative file name and called BEFORE fts_read
1128 * does its chdir to the root of a traversal, we can lose -- we need to
1129 * chdir into the subdirectory, and we don't know where the current
1130 * directory is, so we can't get back so that the upcoming chdir by
1131 * fts_read will work.
1133 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
1135 return (sp->fts_child = fts_build(sp, instr));
1137 if ((fd = diropen (sp, ".")) < 0)
1138 return (sp->fts_child = NULL);
1139 sp->fts_child = fts_build(sp, instr);
1140 if (ISSET(FTS_CWDFD))
1142 cwd_advance_fd (sp, fd, true);
1148 int saved_errno = errno;
1150 __set_errno (saved_errno);
1155 return (sp->fts_child);
1158 /* A comparison function to sort on increasing inode number.
1159 For some file system types, sorting either way makes a huge
1160 performance difference for a directory with very many entries,
1161 but sorting on increasing values is slightly better than sorting
1162 on decreasing values. The difference is in the 5% range. */
1164 fts_compare_ino (struct _ftsent const **a, struct _ftsent const **b)
1166 return (a[0]->fts_statp->st_ino < b[0]->fts_statp->st_ino ? -1
1167 : b[0]->fts_statp->st_ino < a[0]->fts_statp->st_ino ? 1 : 0);
1170 /* Map the dirent.d_type value, DTYPE, to the corresponding stat.st_mode
1171 S_IF* bit and set ST.st_mode, thus clearing all other bits in that field. */
1173 set_stat_type (struct stat *st, unsigned int dtype)
1206 * This is the tricky part -- do not casually change *anything* in here. The
1207 * idea is to build the linked list of entries that are used by fts_children
1208 * and fts_read. There are lots of special cases.
1210 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is
1211 * set and it's a physical walk (so that symbolic links can't be directories),
1212 * we can do things quickly. First, if it's a 4.4BSD file system, the type
1213 * of the file is in the directory entry. Otherwise, we assume that the number
1214 * of subdirectories in a node is equal to the number of links to the parent.
1215 * The former skips all stat calls. The latter skips stat calls in any leaf
1216 * directories and for any files after the subdirectories in the directory have
1217 * been found, cutting the stat calls by about 2/3.
1221 fts_build (register FTS *sp, int type)
1223 register struct dirent *dp;
1224 register FTSENT *p, *head;
1225 register size_t nitems;
1235 size_t len, maxlen, new_len;
1238 /* Set current node pointer. */
1242 * Open the directory for reading. If this fails, we're done.
1243 * If being called from fts_read, set the fts_info field.
1245 #if defined FTS_WHITEOUT && 0
1246 if (ISSET(FTS_WHITEOUT))
1247 oflag = DTF_NODUP|DTF_REWIND;
1249 oflag = DTF_HIDEW|DTF_NODUP|DTF_REWIND;
1251 # define __opendir2(file, flag) \
1252 ( ! ISSET(FTS_NOCHDIR) && ISSET(FTS_CWDFD) \
1253 ? opendirat(sp->fts_cwd_fd, file) \
1256 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) {
1257 if (type == BREAD) {
1258 cur->fts_info = FTS_DNR;
1259 cur->fts_errno = errno;
1263 /* Rather than calling fts_stat for each and every entry encountered
1264 in the readdir loop (below), stat each directory only right after
1266 if (cur->fts_info == FTS_NSOK)
1267 cur->fts_info = fts_stat(sp, cur, false);
1270 * Nlinks is the number of possible entries of type directory in the
1271 * directory if we're cheating on stat calls, 0 if we're not doing
1272 * any stat calls at all, (nlink_t) -1 if we're statting everything.
1274 if (type == BNAMES) {
1276 /* Be quiet about nostat, GCC. */
1278 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
1279 nlinks = (cur->fts_statp->st_nlink
1280 - (ISSET(FTS_SEEDOT) ? 0 : 2));
1288 * If we're going to need to stat anything or we want to descend
1289 * and stay in the directory, chdir. If this fails we keep going,
1290 * but set a flag so we don't chdir after the post-order visit.
1291 * We won't be able to stat anything, but we can still return the
1292 * names themselves. Note, that since fts_read won't be able to
1293 * chdir into the directory, it will have to return different file
1294 * names than before, i.e. "a/b" instead of "b". Since the node
1295 * has already been visited in pre-order, have to wait until the
1296 * post-order visit to return the error. There is a special case
1297 * here, if there was nothing to stat then it's not an error to
1298 * not be able to stat. This is all fairly nasty. If a program
1299 * needed sorted entries or stat information, they had better be
1300 * checking FTS_NS on the returned nodes.
1302 if (nlinks || type == BREAD) {
1303 int dir_fd = dirfd(dirp);
1304 if (ISSET(FTS_CWDFD) && 0 <= dir_fd)
1305 dir_fd = dup (dir_fd);
1306 if (dir_fd < 0 || fts_safe_changedir(sp, cur, dir_fd, NULL)) {
1307 if (nlinks && type == BREAD)
1308 cur->fts_errno = errno;
1309 cur->fts_flags |= FTS_DONTCHDIR;
1312 if (ISSET(FTS_CWDFD) && 0 <= dir_fd)
1321 * Figure out the max file name length that can be stored in the
1322 * current buffer -- the inner loop allocates more space as necessary.
1323 * We really wouldn't have to do the maxlen calculations here, we
1324 * could do them in fts_read before returning the name, but it's a
1325 * lot easier here since the length is part of the dirent structure.
1327 * If not changing directories set a pointer so that can just append
1328 * each new component into the file name.
1331 if (ISSET(FTS_NOCHDIR)) {
1332 cp = sp->fts_path + len;
1335 /* GCC, you're too verbose. */
1339 maxlen = sp->fts_pathlen - len;
1341 level = cur->fts_level + 1;
1343 /* Read the directory, attaching each entry to the `link' pointer. */
1345 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
1348 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
1351 if ((p = fts_alloc (sp, dp->d_name,
1352 _D_EXACT_NAMLEN (dp))) == NULL)
1354 if (_D_EXACT_NAMLEN (dp) >= maxlen) {
1355 /* include space for NUL */
1356 oldaddr = sp->fts_path;
1357 if (! fts_palloc(sp, _D_EXACT_NAMLEN (dp) + len + 1)) {
1359 * No more memory. Save
1360 * errno, free up the current structure and the
1361 * structures already allocated.
1363 mem1: saved_errno = errno;
1367 cur->fts_info = FTS_ERR;
1369 __set_errno (saved_errno);
1372 /* Did realloc() change the pointer? */
1373 if (oldaddr != sp->fts_path) {
1375 if (ISSET(FTS_NOCHDIR))
1376 cp = sp->fts_path + len;
1378 maxlen = sp->fts_pathlen - len;
1381 new_len = len + _D_EXACT_NAMLEN (dp);
1382 if (new_len < len) {
1384 * In the unlikely event that we would end up
1385 * with a file name longer than SIZE_MAX, free up
1386 * the current structure and the structures already
1387 * allocated, then error out with ENAMETOOLONG.
1392 cur->fts_info = FTS_ERR;
1394 __set_errno (ENAMETOOLONG);
1397 p->fts_level = level;
1398 p->fts_parent = sp->fts_cur;
1399 p->fts_pathlen = new_len;
1401 #if defined FTS_WHITEOUT && 0
1402 if (dp->d_type == DT_WHT)
1403 p->fts_flags |= FTS_ISW;
1405 /* Store dirent.d_ino, in case we need to sort
1406 entries before processing them. */
1407 p->fts_statp->st_ino = D_INO (dp);
1409 /* Build a file name for fts_stat to stat. */
1410 if (ISSET(FTS_NOCHDIR)) {
1411 p->fts_accpath = p->fts_path;
1412 memmove(cp, p->fts_name, p->fts_namelen + 1);
1414 p->fts_accpath = p->fts_name;
1416 if (sp->fts_compar == NULL || ISSET(FTS_DEFER_STAT)) {
1417 /* Record what fts_read will have to do with this
1418 entry. In many cases, it will simply fts_stat it,
1419 but we can take advantage of any d_type information
1420 to optimize away the unnecessary stat calls. I.e.,
1421 if FTS_NOSTAT is in effect and we're not following
1422 symlinks (FTS_PHYSICAL) and d_type indicates this
1423 is *not* a directory, then we won't have to stat it
1424 at all. If it *is* a directory, then (currently)
1425 we stat it regardless, in order to get device and
1426 inode numbers. Some day we might optimize that
1427 away, too, for directories where d_ino is known to
1429 bool skip_stat = (ISSET(FTS_PHYSICAL)
1430 && ISSET(FTS_NOSTAT)
1432 && ! DT_MUST_BE(dp, DT_DIR));
1433 p->fts_info = FTS_NSOK;
1434 /* Propagate dirent.d_type information back
1435 to caller, when possible. */
1436 set_stat_type (p->fts_statp, D_TYPE (dp));
1437 fts_set_stat_required(p, !skip_stat);
1438 is_dir = (ISSET(FTS_PHYSICAL)
1439 && DT_MUST_BE(dp, DT_DIR));
1441 p->fts_info = fts_stat(sp, p, false);
1442 is_dir = (p->fts_info == FTS_D
1443 || p->fts_info == FTS_DC
1444 || p->fts_info == FTS_DOT);
1447 /* Decrement link count if applicable. */
1448 if (nlinks > 0 && is_dir)
1451 /* We walk in directory order so "ls -f" doesn't get upset. */
1465 * If realloc() changed the address of the file name, adjust the
1466 * addresses for the rest of the tree and the dir list.
1469 fts_padjust(sp, head);
1472 * If not changing directories, reset the file name back to original
1475 if (ISSET(FTS_NOCHDIR)) {
1476 if (len == sp->fts_pathlen || nitems == 0)
1482 * If descended after called from fts_children or after called from
1483 * fts_read and nothing found, get back. At the root level we use
1484 * the saved fd; if one of fts_open()'s arguments is a relative name
1485 * to an empty directory, we wind up here with no other way back. If
1486 * can't get back, we're done.
1488 if (descend && (type == BCHILD || !nitems) &&
1489 (cur->fts_level == FTS_ROOTLEVEL
1490 ? RESTORE_INITIAL_CWD(sp)
1491 : fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
1492 cur->fts_info = FTS_ERR;
1498 /* If didn't find anything, return NULL. */
1501 cur->fts_info = FTS_DP;
1506 /* If there are many entries, no sorting function has been specified,
1507 and this file system is of a type that may be slow with a large
1508 number of entries, then sort the directory entries on increasing
1510 if (nitems > _FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
1512 && ISSET (FTS_CWDFD)
1513 && dirent_inode_sort_may_be_useful (sp->fts_cwd_fd)) {
1514 sp->fts_compar = fts_compare_ino;
1515 head = fts_sort (sp, head, nitems);
1516 sp->fts_compar = NULL;
1519 /* Sort the entries. */
1520 if (sp->fts_compar && nitems > 1)
1521 head = fts_sort(sp, head, nitems);
1527 /* Walk ->fts_parent links starting at E_CURR, until the root of the
1528 current hierarchy. There should be a directory with dev/inode
1529 matching those of AD. If not, print a lot of diagnostics. */
1531 find_matching_ancestor (FTSENT const *e_curr, struct Active_dir const *ad)
1534 for (ent = e_curr; ent->fts_level >= FTS_ROOTLEVEL; ent = ent->fts_parent)
1536 if (ad->ino == ent->fts_statp->st_ino
1537 && ad->dev == ent->fts_statp->st_dev)
1540 printf ("ERROR: tree dir, %s, not active\n", ad->fts_ent->fts_accpath);
1541 printf ("active dirs:\n");
1543 ent->fts_level >= FTS_ROOTLEVEL; ent = ent->fts_parent)
1544 printf (" %s(%"PRIuMAX"/%"PRIuMAX") to %s(%"PRIuMAX"/%"PRIuMAX")...\n",
1545 ad->fts_ent->fts_accpath,
1546 (uintmax_t) ad->dev,
1547 (uintmax_t) ad->ino,
1549 (uintmax_t) ent->fts_statp->st_dev,
1550 (uintmax_t) ent->fts_statp->st_ino);
1554 fts_cross_check (FTS const *sp)
1556 FTSENT const *ent = sp->fts_cur;
1558 if ( ! ISSET (FTS_TIGHT_CYCLE_CHECK))
1561 Dprintf (("fts-cross-check cur=%s\n", ent->fts_path));
1562 /* Make sure every parent dir is in the tree. */
1563 for (t = ent->fts_parent; t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
1565 struct Active_dir ad;
1566 ad.ino = t->fts_statp->st_ino;
1567 ad.dev = t->fts_statp->st_dev;
1568 if ( ! hash_lookup (sp->fts_cycle.ht, &ad))
1569 printf ("ERROR: active dir, %s, not in tree\n", t->fts_path);
1572 /* Make sure every dir in the tree is an active dir.
1573 But ENT is not necessarily a directory. If so, just skip this part. */
1574 if (ent->fts_parent->fts_level >= FTS_ROOTLEVEL
1575 && (ent->fts_info == FTS_DP
1576 || ent->fts_info == FTS_D))
1578 struct Active_dir *ad;
1579 for (ad = hash_get_first (sp->fts_cycle.ht); ad != NULL;
1580 ad = hash_get_next (sp->fts_cycle.ht, ad))
1582 find_matching_ancestor (ent, ad);
1588 same_fd (int fd1, int fd2)
1590 struct stat sb1, sb2;
1591 return (fstat (fd1, &sb1) == 0
1592 && fstat (fd2, &sb2) == 0
1593 && SAME_INODE (sb1, sb2));
1597 fd_ring_print (FTS const *sp, FILE *stream, char const *msg)
1599 I_ring const *fd_ring = &sp->fts_fd_ring;
1600 unsigned int i = fd_ring->fts_front;
1601 char *cwd = getcwdat (sp->fts_cwd_fd, NULL, 0);
1602 fprintf (stream, "=== %s ========== %s\n", msg, cwd);
1604 if (i_ring_empty (fd_ring))
1609 int fd = fd_ring->fts_fd_ring[i];
1611 fprintf (stream, "%d: %d:\n", i, fd);
1614 char *wd = getcwdat (fd, NULL, 0);
1615 fprintf (stream, "%d: %d: %s\n", i, fd, wd);
1618 if (i == fd_ring->fts_back)
1620 i = (i + I_RING_SIZE - 1) % I_RING_SIZE;
1624 /* Ensure that each file descriptor on the fd_ring matches a
1625 parent, grandparent, etc. of the current working directory. */
1627 fd_ring_check (FTS const *sp)
1632 /* Make a writable copy. */
1633 I_ring fd_w = sp->fts_fd_ring;
1635 int cwd_fd = sp->fts_cwd_fd;
1636 cwd_fd = dup (cwd_fd);
1637 char *dot = getcwdat (cwd_fd, NULL, 0);
1638 error (0, 0, "===== check ===== cwd: %s", dot);
1640 while ( ! i_ring_empty (&fd_w))
1642 int fd = i_ring_pop (&fd_w);
1645 int parent_fd = openat (cwd_fd, "..", O_RDONLY);
1651 if (!same_fd (fd, parent_fd))
1653 char *cwd = getcwdat (fd, NULL, 0);
1654 error (0, errno, "ring : %s", cwd);
1655 char *c2 = getcwdat (parent_fd, NULL, 0);
1656 error (0, errno, "parent: %s", c2);
1669 static unsigned short int
1671 fts_stat(FTS *sp, register FTSENT *p, bool follow)
1673 struct stat *sbp = p->fts_statp;
1676 if (p->fts_level == FTS_ROOTLEVEL && ISSET(FTS_COMFOLLOW))
1679 #if defined FTS_WHITEOUT && 0
1680 /* check for whiteout */
1681 if (p->fts_flags & FTS_ISW) {
1682 memset(sbp, '\0', sizeof (*sbp));
1683 sbp->st_mode = S_IFWHT;
1689 * If doing a logical walk, or application requested FTS_FOLLOW, do
1690 * a stat(2). If that fails, check for a non-existent symlink. If
1691 * fail, set the errno from the stat call.
1693 if (ISSET(FTS_LOGICAL) || follow) {
1694 if (stat(p->fts_accpath, sbp)) {
1695 saved_errno = errno;
1697 && lstat(p->fts_accpath, sbp) == 0) {
1699 return (FTS_SLNONE);
1701 p->fts_errno = saved_errno;
1704 } else if (fstatat(sp->fts_cwd_fd, p->fts_accpath, sbp,
1705 AT_SYMLINK_NOFOLLOW)) {
1706 p->fts_errno = errno;
1707 err: memset(sbp, 0, sizeof(struct stat));
1711 if (S_ISDIR(sbp->st_mode)) {
1712 p->fts_n_dirs_remaining = (sbp->st_nlink
1713 - (ISSET(FTS_SEEDOT) ? 0 : 2));
1714 if (ISDOT(p->fts_name)) {
1715 /* Command-line "." and ".." are real directories. */
1716 return (p->fts_level == FTS_ROOTLEVEL ? FTS_D : FTS_DOT);
1722 * Cycle detection is done by brute force when the directory
1723 * is first encountered. If the tree gets deep enough or the
1724 * number of symbolic links to directories is high enough,
1725 * something faster might be worthwhile.
1729 for (t = p->fts_parent;
1730 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
1731 if (sbp->st_ino == t->fts_statp->st_ino
1732 && sbp->st_dev == t->fts_statp->st_dev)
1742 if (S_ISLNK(sbp->st_mode))
1744 if (S_ISREG(sbp->st_mode))
1746 return (FTS_DEFAULT);
1750 fts_compar (void const *a, void const *b)
1752 /* Convert A and B to the correct types, to pacify the compiler, and
1753 for portability to bizarre hosts where "void const *" and "FTSENT
1754 const **" differ in runtime representation. The comparison
1755 function cannot modify *a and *b, but there is no compile-time
1757 FTSENT const **pa = (FTSENT const **) a;
1758 FTSENT const **pb = (FTSENT const **) b;
1759 return pa[0]->fts_fts->fts_compar (pa, pb);
1764 fts_sort (FTS *sp, FTSENT *head, register size_t nitems)
1766 register FTSENT **ap, *p;
1768 /* On most modern hosts, void * and FTSENT ** have the same
1769 run-time representation, and one can convert sp->fts_compar to
1770 the type qsort expects without problem. Use the heuristic that
1771 this is OK if the two pointer types are the same size, and if
1772 converting FTSENT ** to long int is the same as converting
1773 FTSENT ** to void * and then to long int. This heuristic isn't
1774 valid in general but we don't know of any counterexamples. */
1776 int (*compare) (void const *, void const *) =
1777 ((sizeof &dummy == sizeof (void *)
1778 && (long int) &dummy == (long int) (void *) &dummy)
1779 ? (int (*) (void const *, void const *)) sp->fts_compar
1783 * Construct an array of pointers to the structures and call qsort(3).
1784 * Reassemble the array in the order returned by qsort. If unable to
1785 * sort for memory reasons, return the directory entries in their
1786 * current order. Allocate enough space for the current needs plus
1787 * 40 so don't realloc one entry at a time.
1789 if (nitems > sp->fts_nitems) {
1792 sp->fts_nitems = nitems + 40;
1793 if (SIZE_MAX / sizeof *a < sp->fts_nitems
1794 || ! (a = realloc (sp->fts_array,
1795 sp->fts_nitems * sizeof *a))) {
1796 free(sp->fts_array);
1797 sp->fts_array = NULL;
1803 for (ap = sp->fts_array, p = head; p; p = p->fts_link)
1805 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), compare);
1806 for (head = *(ap = sp->fts_array); --nitems; ++ap)
1807 ap[0]->fts_link = ap[1];
1808 ap[0]->fts_link = NULL;
1814 fts_alloc (FTS *sp, const char *name, register size_t namelen)
1820 * The file name is a variable length array. Allocate the FTSENT
1821 * structure and the file name in one chunk.
1823 len = sizeof(FTSENT) + namelen;
1824 if ((p = malloc(len)) == NULL)
1827 /* Copy the name and guarantee NUL termination. */
1828 memmove(p->fts_name, name, namelen);
1829 p->fts_name[namelen] = '\0';
1831 p->fts_namelen = namelen;
1833 p->fts_path = sp->fts_path;
1836 p->fts_instr = FTS_NOINSTR;
1838 p->fts_pointer = NULL;
1844 fts_lfree (register FTSENT *head)
1848 /* Free a linked list of structures. */
1849 while ((p = head)) {
1850 head = head->fts_link;
1856 * Allow essentially unlimited file name lengths; find, rm, ls should
1857 * all work on any tree. Most systems will allow creation of file
1858 * names much longer than MAXPATHLEN, even though the kernel won't
1859 * resolve them. Add the size (not just what's needed) plus 256 bytes
1860 * so don't realloc the file name 2 bytes at a time.
1864 fts_palloc (FTS *sp, size_t more)
1867 size_t new_len = sp->fts_pathlen + more + 256;
1870 * See if fts_pathlen would overflow.
1872 if (new_len < sp->fts_pathlen) {
1874 sp->fts_path = NULL;
1875 __set_errno (ENAMETOOLONG);
1878 sp->fts_pathlen = new_len;
1879 p = realloc(sp->fts_path, sp->fts_pathlen);
1882 sp->fts_path = NULL;
1890 * When the file name is realloc'd, have to fix all of the pointers in
1891 * structures already returned.
1895 fts_padjust (FTS *sp, FTSENT *head)
1898 char *addr = sp->fts_path;
1900 #define ADJUST(p) do { \
1901 if ((p)->fts_accpath != (p)->fts_name) { \
1902 (p)->fts_accpath = \
1903 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \
1905 (p)->fts_path = addr; \
1907 /* Adjust the current set of children. */
1908 for (p = sp->fts_child; p; p = p->fts_link)
1911 /* Adjust the rest of the tree, including the current level. */
1912 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
1914 p = p->fts_link ? p->fts_link : p->fts_parent;
1920 fts_maxarglen (char * const *argv)
1924 for (max = 0; *argv; ++argv)
1925 if ((len = strlen(*argv)) > max)
1931 * Change to dir specified by fd or file name without getting
1932 * tricked by someone changing the world out from underneath us.
1933 * Assumes p->fts_statp->st_dev and p->fts_statp->st_ino are filled in.
1934 * If FD is non-negative, expect it to be used after this function returns,
1935 * and to be closed eventually. So don't pass e.g., `dirfd(dirp)' and then
1936 * do closedir(dirp), because that would invalidate the saved FD.
1937 * Upon failure, close FD immediately and return nonzero.
1941 fts_safe_changedir (FTS *sp, FTSENT *p, int fd, char const *dir)
1944 bool is_dotdot = dir && STREQ (dir, "..");
1947 /* This clause handles the unusual case in which FTS_NOCHDIR
1948 is specified, along with FTS_CWDFD. In that case, there is
1949 no need to change even the virtual cwd file descriptor.
1950 However, if FD is non-negative, we do close it here. */
1951 if (ISSET (FTS_NOCHDIR))
1953 if (ISSET (FTS_CWDFD) && 0 <= fd)
1958 if (fd < 0 && is_dotdot && ISSET (FTS_CWDFD))
1960 /* When possible, skip the diropen and subsequent fstat+dev/ino
1961 comparison. I.e., when changing to parent directory
1962 (chdir ("..")), use a file descriptor from the ring and
1963 save the overhead of diropen+fstat, as well as avoiding
1964 failure when we lack "x" access to the virtual cwd. */
1965 if ( ! i_ring_empty (&sp->fts_fd_ring))
1968 fd_ring_print (sp, stderr, "pre-pop");
1969 parent_fd = i_ring_pop (&sp->fts_fd_ring);
1980 if (fd < 0 && (newfd = diropen (sp, dir)) < 0)
1983 /* The following dev/inode check is necessary if we're doing a
1984 `logical' traversal (through symlinks, a la chown -L), if the
1985 system lacks O_NOFOLLOW support, or if we're changing to ".."
1986 (but not via a popped file descriptor). When changing to the
1987 name "..", O_NOFOLLOW can't help. In general, when the target is
1988 not "..", diropen's use of O_NOFOLLOW ensures we don't mistakenly
1989 follow a symlink, so we can avoid the expense of this fstat. */
1990 if (ISSET(FTS_LOGICAL) || ! HAVE_WORKING_O_NOFOLLOW
1991 || (dir && STREQ (dir, "..")))
1994 if (fstat(newfd, &sb))
1999 if (p->fts_statp->st_dev != sb.st_dev
2000 || p->fts_statp->st_ino != sb.st_ino)
2002 __set_errno (ENOENT); /* disinformation */
2008 if (ISSET(FTS_CWDFD))
2010 cwd_advance_fd (sp, newfd, ! is_dotdot);
2014 ret = fchdir(newfd);
2020 __set_errno (oerrno);