/* Traverse a file hierarchy.
- Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2004-2008 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software Foundation,
- Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
/*
* Copyright (c) 1989, 1993
# ifdef _LIBC
# include <features.h>
-# define _LGPL_PACKAGE 1
# else
# undef __THROW
# define __THROW
# include <stddef.h>
# include <sys/types.h>
# include <sys/stat.h>
+# include "i-ring.h"
typedef struct {
struct _ftsent *fts_cur; /* current node */
dev_t fts_dev; /* starting device # */
char *fts_path; /* file name for this descent */
int fts_rfd; /* fd for root */
+ int fts_cwd_fd; /* the file descriptor on which the
+ virtual cwd is open, or AT_FDCWD */
size_t fts_pathlen; /* sizeof(path) */
- size_t fts_nitems; /* elements in the sort array */
+ size_t fts_nitems; /* elements in the sort array */
int (*fts_compar) (struct _ftsent const **, struct _ftsent const **);
/* compare fn */
# define FTS_WHITEOUT 0x0080 /* return whiteout information */
/* There are two ways to detect cycles.
- The lazy way, with which one may process a directory that is a
+ The lazy way (which works only with FTS_PHYSICAL),
+ with which one may process a directory that is a
part of the cycle several times before detecting the cycle.
The `tight' way, whereby fts uses more memory (proportional
to number of `active' directories, aka distance from root
to detect any cycle right away. For example, du must use
this option to avoid counting disk space in a cycle multiple
times, but chown -R need not.
- The default is to use the constant-memory lazy way. */
+ The default is to use the constant-memory lazy way, when possible
+ (see below).
+
+ However, with FTS_LOGICAL (when following symlinks, e.g., chown -L)
+ using lazy cycle detection is inadequate. For example, traversing
+ a directory containing a symbolic link to a peer directory, it is
+ possible to encounter the same directory twice even though there
+ is no cycle:
+ dir
+ ...
+ slink -> dir
+ So, when FTS_LOGICAL is selected, we have to use a different
+ mode of cycle detection: FTS_TIGHT_CYCLE_CHECK. */
# define FTS_TIGHT_CYCLE_CHECK 0x0100
-# define FTS_OPTIONMASK 0x01ff /* valid user option mask */
+ /* Use this flag to enable semantics with which the parent
+ application may be made both more efficient and more robust.
+ Whereas the default is to visit each directory in a recursive
+ traversal (via chdir), using this flag makes it so the initial
+ working directory is never changed. Instead, these functions
+ perform the traversal via a virtual working directory, maintained
+ through the file descriptor member, fts_cwd_fd. */
+# define FTS_CWDFD 0x0200
+
+ /* Historically, for each directory that fts initially encounters, it would
+ open it, read all entries, and stat each entry, storing the results, and
+ then it would process the first entry. But that behavior is bad for
+ locality of reference, and also causes trouble with inode-simulating
+ file systems like FAT, CIFS, FUSE-based ones, etc., when entries from
+ their name/inode cache are flushed too early.
+ Use this flag to make fts_open and fts_read defer the stat/lstat/fststat
+ of each entry until it is actually processed. However, note that if you
+ use this option and also specify a comparison function, that function may
+ not examine any data via fts_statp. */
+# define FTS_DEFER_STAT 0x0400
+
+# define FTS_OPTIONMASK 0x07ff /* valid user option mask */
# define FTS_NAMEONLY 0x1000 /* (private) child names only */
# define FTS_STOP 0x2000 /* (private) unrecoverable error */
int fts_options; /* fts_open options, global flags */
-# if !_LGPL_PACKAGE
+# if GNULIB_FTS
union {
/* This data structure is used if FTS_TIGHT_CYCLE_CHECK is
specified. It records the directories between a starting
of thousands. */
struct hash_table *ht;
- /* This data structure uses lazy checking, as done by rm via
- cycle-check.c. It's the default, but it's not appropriate
- for programs like du. */
+ /* FIXME: rename these two members to have the fts_ prefix */
+ /* This data structure uses a lazy cycle-detection algorithm,
+ as done by rm via cycle-check.c. It's the default,
+ but it's not appropriate for programs like du. */
struct cycle_check_state *state;
} fts_cycle;
+
# endif
+ /* A stack of the file descriptors corresponding to the
+ most-recently traversed parent directories.
+ Currently used only in FTS_CWDFD mode. */
+ I_ring fts_fd_ring;
} FTS;
typedef struct _ftsent {
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