285 lines
13 KiB
C
285 lines
13 KiB
C
/* Traverse a file hierarchy.
|
|
|
|
Copyright (C) 2004-2020 Free Software Foundation, Inc.
|
|
|
|
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 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
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
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, see <https://www.gnu.org/licenses/>. */
|
|
|
|
/*
|
|
* Copyright (c) 1989, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* @(#)fts.h 8.3 (Berkeley) 8/14/94
|
|
*/
|
|
|
|
#ifndef _FTS_H
|
|
# define _FTS_H 1
|
|
|
|
# ifdef _LIBC
|
|
# include <features.h>
|
|
# if __STDC_VERSION__ < 199901L
|
|
# define __FLEXIBLE_ARRAY_MEMBER 1
|
|
# else
|
|
# define __FLEXIBLE_ARRAY_MEMBER
|
|
# endif
|
|
# else
|
|
# define __FLEXIBLE_ARRAY_MEMBER FLEXIBLE_ARRAY_MEMBER
|
|
# undef __THROW
|
|
# define __THROW
|
|
# undef __BEGIN_DECLS
|
|
# undef __END_DECLS
|
|
# ifdef __cplusplus
|
|
# define __BEGIN_DECLS extern "C" {
|
|
# define __END_DECLS }
|
|
# else
|
|
# define __BEGIN_DECLS
|
|
# define __END_DECLS
|
|
# endif
|
|
# endif
|
|
|
|
# include <stddef.h>
|
|
# include <sys/types.h>
|
|
# include <dirent.h>
|
|
# include <sys/stat.h>
|
|
# include "i-ring.h"
|
|
|
|
typedef struct {
|
|
struct _ftsent *fts_cur; /* current node */
|
|
struct _ftsent *fts_child; /* linked list of children */
|
|
struct _ftsent **fts_array; /* sort array */
|
|
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 */
|
|
int (*fts_compar) (struct _ftsent const **, struct _ftsent const **);
|
|
/* compare fn */
|
|
|
|
# define FTS_COMFOLLOW 0x0001 /* follow command line symlinks */
|
|
# define FTS_LOGICAL 0x0002 /* logical walk */
|
|
# define FTS_NOCHDIR 0x0004 /* don't change directories */
|
|
# define FTS_NOSTAT 0x0008 /* don't get stat info */
|
|
# define FTS_PHYSICAL 0x0010 /* physical walk */
|
|
# define FTS_SEEDOT 0x0020 /* return dot and dot-dot */
|
|
# define FTS_XDEV 0x0040 /* don't cross devices */
|
|
# define FTS_WHITEOUT 0x0080 /* return whiteout information */
|
|
|
|
/* There are two ways to detect cycles.
|
|
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
|
|
of current tree to current directory -- see active_dir_ht)
|
|
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, 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
|
|
|
|
/* 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. However, when fts_statp->st_mode is
|
|
nonzero, the S_IFMT type bits are valid, with mapped dirent.d_type data.
|
|
Of course, that happens only on file systems that provide useful
|
|
dirent.d_type data. */
|
|
# define FTS_DEFER_STAT 0x0400
|
|
|
|
/* Use this flag to disable stripping of trailing slashes
|
|
from input path names during fts_open initialization. */
|
|
# define FTS_VERBATIM 0x0800
|
|
|
|
# define FTS_OPTIONMASK 0x0fff /* 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 */
|
|
|
|
/* Map a directory's device number to a boolean. The boolean is
|
|
true if for that file system (type determined by a single fstatfs
|
|
call per FS) st_nlink can be used to calculate the number of
|
|
sub-directory entries in a directory.
|
|
Using this table is an optimization that permits us to look up
|
|
file system type on a per-inode basis at the minimal cost of
|
|
calling fstatfs only once per traversed device. */
|
|
struct hash_table *fts_leaf_optimization_works_ht;
|
|
|
|
union {
|
|
/* This data structure is used if FTS_TIGHT_CYCLE_CHECK is
|
|
specified. It records the directories between a starting
|
|
point and the current directory. I.e., a directory is
|
|
recorded here IFF we have visited it once, but we have not
|
|
yet completed processing of all its entries. Every time we
|
|
visit a new directory, we add that directory to this set.
|
|
When we finish with a directory (usually by visiting it a
|
|
second time), we remove it from this set. Each entry in
|
|
this data structure is a device/inode pair. This data
|
|
structure is used to detect directory cycles efficiently and
|
|
promptly even when the depth of a hierarchy is in the tens
|
|
of thousands. */
|
|
struct hash_table *ht;
|
|
|
|
/* 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;
|
|
|
|
/* 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 {
|
|
struct _ftsent *fts_cycle; /* cycle node */
|
|
struct _ftsent *fts_parent; /* parent directory */
|
|
struct _ftsent *fts_link; /* next file in directory */
|
|
DIR *fts_dirp; /* Dir pointer for any directory
|
|
containing more entries than we
|
|
read at one time. */
|
|
long fts_number; /* local numeric value */
|
|
void *fts_pointer; /* local address value */
|
|
char *fts_accpath; /* access file name */
|
|
char *fts_path; /* root name; == fts_fts->fts_path */
|
|
int fts_errno; /* errno for this node */
|
|
int fts_symfd; /* fd for symlink */
|
|
size_t fts_pathlen; /* strlen(fts_path) */
|
|
|
|
FTS *fts_fts; /* the file hierarchy itself */
|
|
|
|
# define FTS_ROOTPARENTLEVEL (-1)
|
|
# define FTS_ROOTLEVEL 0
|
|
ptrdiff_t fts_level; /* depth (-1 to N) */
|
|
|
|
size_t fts_namelen; /* strlen(fts_name) */
|
|
|
|
/* If not (nlink_t) -1, an upper bound on the number of
|
|
remaining subdirectories of interest. If this becomes
|
|
zero, some work can be avoided. */
|
|
nlink_t fts_n_dirs_remaining;
|
|
|
|
# define FTS_D 1 /* preorder directory */
|
|
# define FTS_DC 2 /* directory that causes cycles */
|
|
# define FTS_DEFAULT 3 /* none of the above */
|
|
# define FTS_DNR 4 /* unreadable directory */
|
|
# define FTS_DOT 5 /* dot or dot-dot */
|
|
# define FTS_DP 6 /* postorder directory */
|
|
# define FTS_ERR 7 /* error; errno is set */
|
|
# define FTS_F 8 /* regular file */
|
|
# define FTS_INIT 9 /* initialized only */
|
|
# define FTS_NS 10 /* stat(2) failed */
|
|
# define FTS_NSOK 11 /* no stat(2) requested */
|
|
# define FTS_SL 12 /* symbolic link */
|
|
# define FTS_SLNONE 13 /* symbolic link without target */
|
|
# define FTS_W 14 /* whiteout object */
|
|
unsigned short int fts_info; /* user flags for FTSENT structure */
|
|
|
|
# define FTS_DONTCHDIR 0x01 /* don't chdir .. to the parent */
|
|
# define FTS_SYMFOLLOW 0x02 /* followed a symlink to get here */
|
|
unsigned short int fts_flags; /* private flags for FTSENT structure */
|
|
|
|
# define FTS_AGAIN 1 /* read node again */
|
|
# define FTS_FOLLOW 2 /* follow symbolic link */
|
|
# define FTS_NOINSTR 3 /* no instructions */
|
|
# define FTS_SKIP 4 /* discard node */
|
|
unsigned short int fts_instr; /* fts_set() instructions */
|
|
|
|
struct stat fts_statp[1]; /* stat(2) information */
|
|
char fts_name[__FLEXIBLE_ARRAY_MEMBER]; /* file name */
|
|
} FTSENT;
|
|
|
|
#ifndef __GNUC_PREREQ
|
|
# if defined __GNUC__ && defined __GNUC_MINOR__
|
|
# define __GNUC_PREREQ(maj, min) \
|
|
((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
|
|
# else
|
|
# define __GNUC_PREREQ(maj, min) 0
|
|
# endif
|
|
#endif
|
|
|
|
#if __GNUC_PREREQ (3,4)
|
|
# undef __attribute_warn_unused_result__
|
|
# define __attribute_warn_unused_result__ \
|
|
__attribute__ ((__warn_unused_result__))
|
|
#else
|
|
# define __attribute_warn_unused_result__ /* empty */
|
|
#endif
|
|
|
|
__BEGIN_DECLS
|
|
FTSENT *fts_children (FTS *, int) __THROW __attribute_warn_unused_result__;
|
|
int fts_close (FTS *) __THROW __attribute_warn_unused_result__;
|
|
FTS *fts_open (char * const *, int,
|
|
int (*)(const FTSENT **, const FTSENT **))
|
|
__THROW __attribute_warn_unused_result__;
|
|
FTSENT *fts_read (FTS *) __THROW __attribute_warn_unused_result__;
|
|
int fts_set (FTS *, FTSENT *, int) __THROW;
|
|
__END_DECLS
|
|
|
|
#endif /* fts.h */
|