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)) {
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 ATTRIBUTE_UNUSED, 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);
1268 * Nlinks is the number of possible entries of type directory in the
1269 * directory if we're cheating on stat calls, 0 if we're not doing
1270 * any stat calls at all, (nlink_t) -1 if we're statting everything.
1272 if (type == BNAMES) {
1274 /* Be quiet about nostat, GCC. */
1276 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) {
1277 nlinks = (cur->fts_statp->st_nlink
1278 - (ISSET(FTS_SEEDOT) ? 0 : 2));
1286 * If we're going to need to stat anything or we want to descend
1287 * and stay in the directory, chdir. If this fails we keep going,
1288 * but set a flag so we don't chdir after the post-order visit.
1289 * We won't be able to stat anything, but we can still return the
1290 * names themselves. Note, that since fts_read won't be able to
1291 * chdir into the directory, it will have to return different file
1292 * names than before, i.e. "a/b" instead of "b". Since the node
1293 * has already been visited in pre-order, have to wait until the
1294 * post-order visit to return the error. There is a special case
1295 * here, if there was nothing to stat then it's not an error to
1296 * not be able to stat. This is all fairly nasty. If a program
1297 * needed sorted entries or stat information, they had better be
1298 * checking FTS_NS on the returned nodes.
1300 if (nlinks || type == BREAD) {
1301 int dir_fd = dirfd(dirp);
1302 if (ISSET(FTS_CWDFD) && 0 <= dir_fd)
1303 dir_fd = dup (dir_fd);
1304 if (dir_fd < 0 || fts_safe_changedir(sp, cur, dir_fd, NULL)) {
1305 if (nlinks && type == BREAD)
1306 cur->fts_errno = errno;
1307 cur->fts_flags |= FTS_DONTCHDIR;
1310 if (ISSET(FTS_CWDFD) && 0 <= dir_fd)
1319 * Figure out the max file name length that can be stored in the
1320 * current buffer -- the inner loop allocates more space as necessary.
1321 * We really wouldn't have to do the maxlen calculations here, we
1322 * could do them in fts_read before returning the name, but it's a
1323 * lot easier here since the length is part of the dirent structure.
1325 * If not changing directories set a pointer so that can just append
1326 * each new component into the file name.
1329 if (ISSET(FTS_NOCHDIR)) {
1330 cp = sp->fts_path + len;
1333 /* GCC, you're too verbose. */
1337 maxlen = sp->fts_pathlen - len;
1339 level = cur->fts_level + 1;
1341 /* Read the directory, attaching each entry to the `link' pointer. */
1343 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
1346 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
1349 if ((p = fts_alloc (sp, dp->d_name,
1350 _D_EXACT_NAMLEN (dp))) == NULL)
1352 if (_D_EXACT_NAMLEN (dp) >= maxlen) {
1353 /* include space for NUL */
1354 oldaddr = sp->fts_path;
1355 if (! fts_palloc(sp, _D_EXACT_NAMLEN (dp) + len + 1)) {
1357 * No more memory. Save
1358 * errno, free up the current structure and the
1359 * structures already allocated.
1361 mem1: saved_errno = errno;
1365 cur->fts_info = FTS_ERR;
1367 __set_errno (saved_errno);
1370 /* Did realloc() change the pointer? */
1371 if (oldaddr != sp->fts_path) {
1373 if (ISSET(FTS_NOCHDIR))
1374 cp = sp->fts_path + len;
1376 maxlen = sp->fts_pathlen - len;
1379 new_len = len + _D_EXACT_NAMLEN (dp);
1380 if (new_len < len) {
1382 * In the unlikely event that we would end up
1383 * with a file name longer than SIZE_MAX, free up
1384 * the current structure and the structures already
1385 * allocated, then error out with ENAMETOOLONG.
1390 cur->fts_info = FTS_ERR;
1392 __set_errno (ENAMETOOLONG);
1395 p->fts_level = level;
1396 p->fts_parent = sp->fts_cur;
1397 p->fts_pathlen = new_len;
1399 #if defined FTS_WHITEOUT && 0
1400 if (dp->d_type == DT_WHT)
1401 p->fts_flags |= FTS_ISW;
1403 /* Store dirent.d_ino, in case we need to sort
1404 entries before processing them. */
1405 p->fts_statp->st_ino = D_INO (dp);
1407 /* Build a file name for fts_stat to stat. */
1408 if (ISSET(FTS_NOCHDIR)) {
1409 p->fts_accpath = p->fts_path;
1410 memmove(cp, p->fts_name, p->fts_namelen + 1);
1412 p->fts_accpath = p->fts_name;
1414 if (sp->fts_compar == NULL || ISSET(FTS_DEFER_STAT)) {
1415 /* Record what fts_read will have to do with this
1416 entry. In many cases, it will simply fts_stat it,
1417 but we can take advantage of any d_type information
1418 to optimize away the unnecessary stat calls. I.e.,
1419 if FTS_NOSTAT is in effect and we're not following
1420 symlinks (FTS_PHYSICAL) and d_type indicates this
1421 is *not* a directory, then we won't have to stat it
1422 at all. If it *is* a directory, then (currently)
1423 we stat it regardless, in order to get device and
1424 inode numbers. Some day we might optimize that
1425 away, too, for directories where d_ino is known to
1427 bool skip_stat = (ISSET(FTS_PHYSICAL)
1428 && ISSET(FTS_NOSTAT)
1430 && ! DT_MUST_BE(dp, DT_DIR));
1431 p->fts_info = FTS_NSOK;
1432 /* Propagate dirent.d_type information back
1433 to caller, when possible. */
1434 set_stat_type (p->fts_statp, D_TYPE (dp));
1435 fts_set_stat_required(p, !skip_stat);
1436 is_dir = (ISSET(FTS_PHYSICAL)
1437 && DT_MUST_BE(dp, DT_DIR));
1439 p->fts_info = fts_stat(sp, p, false);
1440 is_dir = (p->fts_info == FTS_D
1441 || p->fts_info == FTS_DC
1442 || p->fts_info == FTS_DOT);
1445 /* Decrement link count if applicable. */
1446 if (nlinks > 0 && is_dir)
1449 /* We walk in directory order so "ls -f" doesn't get upset. */
1463 * If realloc() changed the address of the file name, adjust the
1464 * addresses for the rest of the tree and the dir list.
1467 fts_padjust(sp, head);
1470 * If not changing directories, reset the file name back to original
1473 if (ISSET(FTS_NOCHDIR)) {
1474 if (len == sp->fts_pathlen || nitems == 0)
1480 * If descended after called from fts_children or after called from
1481 * fts_read and nothing found, get back. At the root level we use
1482 * the saved fd; if one of fts_open()'s arguments is a relative name
1483 * to an empty directory, we wind up here with no other way back. If
1484 * can't get back, we're done.
1486 if (descend && (type == BCHILD || !nitems) &&
1487 (cur->fts_level == FTS_ROOTLEVEL
1488 ? RESTORE_INITIAL_CWD(sp)
1489 : fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
1490 cur->fts_info = FTS_ERR;
1496 /* If didn't find anything, return NULL. */
1499 cur->fts_info = FTS_DP;
1504 /* If there are many entries, no sorting function has been specified,
1505 and this file system is of a type that may be slow with a large
1506 number of entries, then sort the directory entries on increasing
1508 if (nitems > _FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
1510 && ISSET (FTS_CWDFD)
1511 && dirent_inode_sort_may_be_useful (sp->fts_cwd_fd)) {
1512 sp->fts_compar = fts_compare_ino;
1513 head = fts_sort (sp, head, nitems);
1514 sp->fts_compar = NULL;
1517 /* Sort the entries. */
1518 if (sp->fts_compar && nitems > 1)
1519 head = fts_sort(sp, head, nitems);
1525 /* Walk ->fts_parent links starting at E_CURR, until the root of the
1526 current hierarchy. There should be a directory with dev/inode
1527 matching those of AD. If not, print a lot of diagnostics. */
1529 find_matching_ancestor (FTSENT const *e_curr, struct Active_dir const *ad)
1532 for (ent = e_curr; ent->fts_level >= FTS_ROOTLEVEL; ent = ent->fts_parent)
1534 if (ad->ino == ent->fts_statp->st_ino
1535 && ad->dev == ent->fts_statp->st_dev)
1538 printf ("ERROR: tree dir, %s, not active\n", ad->fts_ent->fts_accpath);
1539 printf ("active dirs:\n");
1541 ent->fts_level >= FTS_ROOTLEVEL; ent = ent->fts_parent)
1542 printf (" %s(%"PRIuMAX"/%"PRIuMAX") to %s(%"PRIuMAX"/%"PRIuMAX")...\n",
1543 ad->fts_ent->fts_accpath,
1544 (uintmax_t) ad->dev,
1545 (uintmax_t) ad->ino,
1547 (uintmax_t) ent->fts_statp->st_dev,
1548 (uintmax_t) ent->fts_statp->st_ino);
1552 fts_cross_check (FTS const *sp)
1554 FTSENT const *ent = sp->fts_cur;
1556 if ( ! ISSET (FTS_TIGHT_CYCLE_CHECK))
1559 Dprintf (("fts-cross-check cur=%s\n", ent->fts_path));
1560 /* Make sure every parent dir is in the tree. */
1561 for (t = ent->fts_parent; t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
1563 struct Active_dir ad;
1564 ad.ino = t->fts_statp->st_ino;
1565 ad.dev = t->fts_statp->st_dev;
1566 if ( ! hash_lookup (sp->fts_cycle.ht, &ad))
1567 printf ("ERROR: active dir, %s, not in tree\n", t->fts_path);
1570 /* Make sure every dir in the tree is an active dir.
1571 But ENT is not necessarily a directory. If so, just skip this part. */
1572 if (ent->fts_parent->fts_level >= FTS_ROOTLEVEL
1573 && (ent->fts_info == FTS_DP
1574 || ent->fts_info == FTS_D))
1576 struct Active_dir *ad;
1577 for (ad = hash_get_first (sp->fts_cycle.ht); ad != NULL;
1578 ad = hash_get_next (sp->fts_cycle.ht, ad))
1580 find_matching_ancestor (ent, ad);
1586 same_fd (int fd1, int fd2)
1588 struct stat sb1, sb2;
1589 return (fstat (fd1, &sb1) == 0
1590 && fstat (fd2, &sb2) == 0
1591 && SAME_INODE (sb1, sb2));
1595 fd_ring_print (FTS const *sp, FILE *stream, char const *msg)
1597 I_ring const *fd_ring = &sp->fts_fd_ring;
1598 unsigned int i = fd_ring->fts_front;
1599 char *cwd = getcwdat (sp->fts_cwd_fd, NULL, 0);
1600 fprintf (stream, "=== %s ========== %s\n", msg, cwd);
1602 if (i_ring_empty (fd_ring))
1607 int fd = fd_ring->fts_fd_ring[i];
1609 fprintf (stream, "%d: %d:\n", i, fd);
1612 char *wd = getcwdat (fd, NULL, 0);
1613 fprintf (stream, "%d: %d: %s\n", i, fd, wd);
1616 if (i == fd_ring->fts_back)
1618 i = (i + I_RING_SIZE - 1) % I_RING_SIZE;
1622 /* Ensure that each file descriptor on the fd_ring matches a
1623 parent, grandparent, etc. of the current working directory. */
1625 fd_ring_check (FTS const *sp)
1630 /* Make a writable copy. */
1631 I_ring fd_w = sp->fts_fd_ring;
1633 int cwd_fd = sp->fts_cwd_fd;
1634 cwd_fd = dup (cwd_fd);
1635 char *dot = getcwdat (cwd_fd, NULL, 0);
1636 error (0, 0, "===== check ===== cwd: %s", dot);
1638 while ( ! i_ring_empty (&fd_w))
1640 int fd = i_ring_pop (&fd_w);
1643 int parent_fd = openat (cwd_fd, "..", O_RDONLY);
1649 if (!same_fd (fd, parent_fd))
1651 char *cwd = getcwdat (fd, NULL, 0);
1652 error (0, errno, "ring : %s", cwd);
1653 char *c2 = getcwdat (parent_fd, NULL, 0);
1654 error (0, errno, "parent: %s", c2);
1667 static unsigned short int
1669 fts_stat(FTS *sp, register FTSENT *p, bool follow)
1671 struct stat *sbp = p->fts_statp;
1674 if (p->fts_level == FTS_ROOTLEVEL && ISSET(FTS_COMFOLLOW))
1677 #if defined FTS_WHITEOUT && 0
1678 /* check for whiteout */
1679 if (p->fts_flags & FTS_ISW) {
1680 memset(sbp, '\0', sizeof (*sbp));
1681 sbp->st_mode = S_IFWHT;
1687 * If doing a logical walk, or application requested FTS_FOLLOW, do
1688 * a stat(2). If that fails, check for a non-existent symlink. If
1689 * fail, set the errno from the stat call.
1691 if (ISSET(FTS_LOGICAL) || follow) {
1692 if (stat(p->fts_accpath, sbp)) {
1693 saved_errno = errno;
1695 && lstat(p->fts_accpath, sbp) == 0) {
1697 return (FTS_SLNONE);
1699 p->fts_errno = saved_errno;
1702 } else if (fstatat(sp->fts_cwd_fd, p->fts_accpath, sbp,
1703 AT_SYMLINK_NOFOLLOW)) {
1704 p->fts_errno = errno;
1705 err: memset(sbp, 0, sizeof(struct stat));
1709 if (S_ISDIR(sbp->st_mode)) {
1710 p->fts_n_dirs_remaining = (sbp->st_nlink
1711 - (ISSET(FTS_SEEDOT) ? 0 : 2));
1712 if (ISDOT(p->fts_name)) {
1713 /* Command-line "." and ".." are real directories. */
1714 return (p->fts_level == FTS_ROOTLEVEL ? FTS_D : FTS_DOT);
1720 * Cycle detection is done by brute force when the directory
1721 * is first encountered. If the tree gets deep enough or the
1722 * number of symbolic links to directories is high enough,
1723 * something faster might be worthwhile.
1727 for (t = p->fts_parent;
1728 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
1729 if (sbp->st_ino == t->fts_statp->st_ino
1730 && sbp->st_dev == t->fts_statp->st_dev)
1740 if (S_ISLNK(sbp->st_mode))
1742 if (S_ISREG(sbp->st_mode))
1744 return (FTS_DEFAULT);
1748 fts_compar (void const *a, void const *b)
1750 /* Convert A and B to the correct types, to pacify the compiler, and
1751 for portability to bizarre hosts where "void const *" and "FTSENT
1752 const **" differ in runtime representation. The comparison
1753 function cannot modify *a and *b, but there is no compile-time
1755 FTSENT const **pa = (FTSENT const **) a;
1756 FTSENT const **pb = (FTSENT const **) b;
1757 return pa[0]->fts_fts->fts_compar (pa, pb);
1762 fts_sort (FTS *sp, FTSENT *head, register size_t nitems)
1764 register FTSENT **ap, *p;
1766 /* On most modern hosts, void * and FTSENT ** have the same
1767 run-time representation, and one can convert sp->fts_compar to
1768 the type qsort expects without problem. Use the heuristic that
1769 this is OK if the two pointer types are the same size, and if
1770 converting FTSENT ** to long int is the same as converting
1771 FTSENT ** to void * and then to long int. This heuristic isn't
1772 valid in general but we don't know of any counterexamples. */
1774 int (*compare) (void const *, void const *) =
1775 ((sizeof &dummy == sizeof (void *)
1776 && (long int) &dummy == (long int) (void *) &dummy)
1777 ? (int (*) (void const *, void const *)) sp->fts_compar
1781 * Construct an array of pointers to the structures and call qsort(3).
1782 * Reassemble the array in the order returned by qsort. If unable to
1783 * sort for memory reasons, return the directory entries in their
1784 * current order. Allocate enough space for the current needs plus
1785 * 40 so don't realloc one entry at a time.
1787 if (nitems > sp->fts_nitems) {
1790 sp->fts_nitems = nitems + 40;
1791 if (SIZE_MAX / sizeof *a < sp->fts_nitems
1792 || ! (a = realloc (sp->fts_array,
1793 sp->fts_nitems * sizeof *a))) {
1794 free(sp->fts_array);
1795 sp->fts_array = NULL;
1801 for (ap = sp->fts_array, p = head; p; p = p->fts_link)
1803 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), compare);
1804 for (head = *(ap = sp->fts_array); --nitems; ++ap)
1805 ap[0]->fts_link = ap[1];
1806 ap[0]->fts_link = NULL;
1812 fts_alloc (FTS *sp, const char *name, register size_t namelen)
1818 * The file name is a variable length array. Allocate the FTSENT
1819 * structure and the file name in one chunk.
1821 len = sizeof(FTSENT) + namelen;
1822 if ((p = malloc(len)) == NULL)
1825 /* Copy the name and guarantee NUL termination. */
1826 memmove(p->fts_name, name, namelen);
1827 p->fts_name[namelen] = '\0';
1829 p->fts_namelen = namelen;
1831 p->fts_path = sp->fts_path;
1834 p->fts_instr = FTS_NOINSTR;
1836 p->fts_pointer = NULL;
1842 fts_lfree (register FTSENT *head)
1846 /* Free a linked list of structures. */
1847 while ((p = head)) {
1848 head = head->fts_link;
1854 * Allow essentially unlimited file name lengths; find, rm, ls should
1855 * all work on any tree. Most systems will allow creation of file
1856 * names much longer than MAXPATHLEN, even though the kernel won't
1857 * resolve them. Add the size (not just what's needed) plus 256 bytes
1858 * so don't realloc the file name 2 bytes at a time.
1862 fts_palloc (FTS *sp, size_t more)
1865 size_t new_len = sp->fts_pathlen + more + 256;
1868 * See if fts_pathlen would overflow.
1870 if (new_len < sp->fts_pathlen) {
1872 sp->fts_path = NULL;
1873 __set_errno (ENAMETOOLONG);
1876 sp->fts_pathlen = new_len;
1877 p = realloc(sp->fts_path, sp->fts_pathlen);
1880 sp->fts_path = NULL;
1888 * When the file name is realloc'd, have to fix all of the pointers in
1889 * structures already returned.
1893 fts_padjust (FTS *sp, FTSENT *head)
1896 char *addr = sp->fts_path;
1898 #define ADJUST(p) do { \
1899 if ((p)->fts_accpath != (p)->fts_name) { \
1900 (p)->fts_accpath = \
1901 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \
1903 (p)->fts_path = addr; \
1905 /* Adjust the current set of children. */
1906 for (p = sp->fts_child; p; p = p->fts_link)
1909 /* Adjust the rest of the tree, including the current level. */
1910 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
1912 p = p->fts_link ? p->fts_link : p->fts_parent;
1918 fts_maxarglen (char * const *argv)
1922 for (max = 0; *argv; ++argv)
1923 if ((len = strlen(*argv)) > max)
1929 * Change to dir specified by fd or file name without getting
1930 * tricked by someone changing the world out from underneath us.
1931 * Assumes p->fts_statp->st_dev and p->fts_statp->st_ino are filled in.
1932 * If FD is non-negative, expect it to be used after this function returns,
1933 * and to be closed eventually. So don't pass e.g., `dirfd(dirp)' and then
1934 * do closedir(dirp), because that would invalidate the saved FD.
1935 * Upon failure, close FD immediately and return nonzero.
1939 fts_safe_changedir (FTS *sp, FTSENT *p, int fd, char const *dir)
1942 bool is_dotdot = dir && STREQ (dir, "..");
1945 /* This clause handles the unusual case in which FTS_NOCHDIR
1946 is specified, along with FTS_CWDFD. In that case, there is
1947 no need to change even the virtual cwd file descriptor.
1948 However, if FD is non-negative, we do close it here. */
1949 if (ISSET (FTS_NOCHDIR))
1951 if (ISSET (FTS_CWDFD) && 0 <= fd)
1956 if (fd < 0 && is_dotdot && ISSET (FTS_CWDFD))
1958 /* When possible, skip the diropen and subsequent fstat+dev/ino
1959 comparison. I.e., when changing to parent directory
1960 (chdir ("..")), use a file descriptor from the ring and
1961 save the overhead of diropen+fstat, as well as avoiding
1962 failure when we lack "x" access to the virtual cwd. */
1963 if ( ! i_ring_empty (&sp->fts_fd_ring))
1966 fd_ring_print (sp, stderr, "pre-pop");
1967 parent_fd = i_ring_pop (&sp->fts_fd_ring);
1978 if (fd < 0 && (newfd = diropen (sp, dir)) < 0)
1981 /* The following dev/inode check is necessary if we're doing a
1982 `logical' traversal (through symlinks, a la chown -L), if the
1983 system lacks O_NOFOLLOW support, or if we're changing to ".."
1984 (but not via a popped file descriptor). When changing to the
1985 name "..", O_NOFOLLOW can't help. In general, when the target is
1986 not "..", diropen's use of O_NOFOLLOW ensures we don't mistakenly
1987 follow a symlink, so we can avoid the expense of this fstat. */
1988 if (ISSET(FTS_LOGICAL) || ! HAVE_WORKING_O_NOFOLLOW
1989 || (dir && STREQ (dir, "..")))
1992 if (fstat(newfd, &sb))
1997 if (p->fts_statp->st_dev != sb.st_dev
1998 || p->fts_statp->st_ino != sb.st_ino)
2000 __set_errno (ENOENT); /* disinformation */
2006 if (ISSET(FTS_CWDFD))
2008 cwd_advance_fd (sp, newfd, ! is_dotdot);
2012 ret = fchdir(newfd);
2018 __set_errno (oerrno);