| 1 | /* Traverse a file hierarchy.
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| 2 |
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| 3 | Copyright (C) 2004-2012 Free Software Foundation, Inc.
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| 4 |
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| 5 | This program is free software: you can redistribute it and/or modify
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| 6 | it under the terms of the GNU General Public License as published by
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| 7 | the Free Software Foundation; either version 3 of the License, or
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| 8 | (at your option) any later version.
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| 9 |
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| 10 | This program is distributed in the hope that it will be useful,
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 13 | GNU General Public License for more details.
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| 14 |
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| 15 | You should have received a copy of the GNU General Public License
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| 16 | along with this program. If not, see <http://www.gnu.org/licenses/>. */
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| 17 |
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| 18 | /*
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| 19 | * Copyright (c) 1989, 1993
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| 20 | * The Regents of the University of California. All rights reserved.
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| 21 | *
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| 22 | * Redistribution and use in source and binary forms, with or without
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| 23 | * modification, are permitted provided that the following conditions
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| 24 | * are met:
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| 25 | * 1. Redistributions of source code must retain the above copyright
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| 26 | * notice, this list of conditions and the following disclaimer.
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| 27 | * 2. Redistributions in binary form must reproduce the above copyright
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| 28 | * notice, this list of conditions and the following disclaimer in the
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| 29 | * documentation and/or other materials provided with the distribution.
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| 30 | * 4. Neither the name of the University nor the names of its contributors
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| 31 | * may be used to endorse or promote products derived from this software
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| 32 | * without specific prior written permission.
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| 33 | *
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| 34 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND
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| 35 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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| 36 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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| 37 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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| 38 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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| 39 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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| 40 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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| 41 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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| 42 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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| 43 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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| 44 | * SUCH DAMAGE.
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| 45 | *
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| 46 | * @(#)fts.h 8.3 (Berkeley) 8/14/94
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| 47 | */
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| 48 |
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| 49 | #ifndef _FTS_H
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| 50 | # define _FTS_H 1
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| 51 |
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| 52 | # ifdef _LIBC
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| 53 | # include <features.h>
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| 54 | # else
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| 55 | # undef __THROW
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| 56 | # define __THROW
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| 57 | # undef __BEGIN_DECLS
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| 58 | # undef __END_DECLS
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| 59 | # ifdef __cplusplus
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| 60 | # define __BEGIN_DECLS extern "C" {
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| 61 | # define __END_DECLS }
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| 62 | # else
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| 63 | # define __BEGIN_DECLS
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| 64 | # define __END_DECLS
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| 65 | # endif
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| 66 | # endif
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| 67 |
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| 68 | # include <stddef.h>
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| 69 | # include <sys/types.h>
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| 70 | # include <dirent.h>
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| 71 | # include <sys/stat.h>
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| 72 | # include "i-ring.h"
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| 73 |
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| 74 | typedef struct {
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| 75 | struct _ftsent *fts_cur; /* current node */
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| 76 | struct _ftsent *fts_child; /* linked list of children */
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| 77 | struct _ftsent **fts_array; /* sort array */
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| 78 | dev_t fts_dev; /* starting device # */
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| 79 | char *fts_path; /* file name for this descent */
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| 80 | int fts_rfd; /* fd for root */
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| 81 | int fts_cwd_fd; /* the file descriptor on which the
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| 82 | virtual cwd is open, or AT_FDCWD */
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| 83 | size_t fts_pathlen; /* sizeof(path) */
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| 84 | size_t fts_nitems; /* elements in the sort array */
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| 85 | int (*fts_compar) (struct _ftsent const **, struct _ftsent const **);
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| 86 | /* compare fn */
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| 87 |
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| 88 | # define FTS_COMFOLLOW 0x0001 /* follow command line symlinks */
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| 89 | # define FTS_LOGICAL 0x0002 /* logical walk */
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| 90 | # define FTS_NOCHDIR 0x0004 /* don't change directories */
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| 91 | # define FTS_NOSTAT 0x0008 /* don't get stat info */
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| 92 | # define FTS_PHYSICAL 0x0010 /* physical walk */
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| 93 | # define FTS_SEEDOT 0x0020 /* return dot and dot-dot */
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| 94 | # define FTS_XDEV 0x0040 /* don't cross devices */
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| 95 | # define FTS_WHITEOUT 0x0080 /* return whiteout information */
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| 96 |
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| 97 | /* There are two ways to detect cycles.
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| 98 | The lazy way (which works only with FTS_PHYSICAL),
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| 99 | with which one may process a directory that is a
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| 100 | part of the cycle several times before detecting the cycle.
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| 101 | The "tight" way, whereby fts uses more memory (proportional
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| 102 | to number of "active" directories, aka distance from root
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| 103 | of current tree to current directory -- see active_dir_ht)
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| 104 | to detect any cycle right away. For example, du must use
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| 105 | this option to avoid counting disk space in a cycle multiple
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| 106 | times, but chown -R need not.
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| 107 | The default is to use the constant-memory lazy way, when possible
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| 108 | (see below).
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| 109 |
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| 110 | However, with FTS_LOGICAL (when following symlinks, e.g., chown -L)
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| 111 | using lazy cycle detection is inadequate. For example, traversing
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| 112 | a directory containing a symbolic link to a peer directory, it is
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| 113 | possible to encounter the same directory twice even though there
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| 114 | is no cycle:
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| 115 | dir
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| 116 | ...
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| 117 | slink -> dir
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| 118 | So, when FTS_LOGICAL is selected, we have to use a different
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| 119 | mode of cycle detection: FTS_TIGHT_CYCLE_CHECK. */
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| 120 | # define FTS_TIGHT_CYCLE_CHECK 0x0100
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| 121 |
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| 122 | /* Use this flag to enable semantics with which the parent
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| 123 | application may be made both more efficient and more robust.
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| 124 | Whereas the default is to visit each directory in a recursive
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| 125 | traversal (via chdir), using this flag makes it so the initial
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| 126 | working directory is never changed. Instead, these functions
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| 127 | perform the traversal via a virtual working directory, maintained
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| 128 | through the file descriptor member, fts_cwd_fd. */
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| 129 | # define FTS_CWDFD 0x0200
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| 130 |
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| 131 | /* Historically, for each directory that fts initially encounters, it would
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| 132 | open it, read all entries, and stat each entry, storing the results, and
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| 133 | then it would process the first entry. But that behavior is bad for
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| 134 | locality of reference, and also causes trouble with inode-simulating
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| 135 | file systems like FAT, CIFS, FUSE-based ones, etc., when entries from
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| 136 | their name/inode cache are flushed too early.
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| 137 | Use this flag to make fts_open and fts_read defer the stat/lstat/fststat
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| 138 | of each entry until it is actually processed. However, note that if you
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| 139 | use this option and also specify a comparison function, that function may
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| 140 | not examine any data via fts_statp. However, when fts_statp->st_mode is
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| 141 | nonzero, the S_IFMT type bits are valid, with mapped dirent.d_type data.
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| 142 | Of course, that happens only on file systems that provide useful
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| 143 | dirent.d_type data. */
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| 144 | # define FTS_DEFER_STAT 0x0400
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| 145 |
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| 146 | # define FTS_NOATIME 0x0800 /* use O_NOATIME during traversal */
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| 147 |
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| 148 | # define FTS_OPTIONMASK 0x0fff /* valid user option mask */
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| 149 |
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| 150 | # define FTS_NAMEONLY 0x1000 /* (private) child names only */
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| 151 | # define FTS_STOP 0x2000 /* (private) unrecoverable error */
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| 152 | int fts_options; /* fts_open options, global flags */
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| 153 |
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| 154 | /* Map a directory's device number to a boolean. The boolean is
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| 155 | true if for that file system (type determined by a single fstatfs
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| 156 | call per FS) st_nlink can be used to calculate the number of
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| 157 | sub-directory entries in a directory.
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| 158 | Using this table is an optimization that permits us to look up
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| 159 | file system type on a per-inode basis at the minimal cost of
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| 160 | calling fstatfs only once per traversed device. */
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| 161 | struct hash_table *fts_leaf_optimization_works_ht;
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| 162 |
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| 163 | union {
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| 164 | /* This data structure is used if FTS_TIGHT_CYCLE_CHECK is
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| 165 | specified. It records the directories between a starting
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| 166 | point and the current directory. I.e., a directory is
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| 167 | recorded here IFF we have visited it once, but we have not
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| 168 | yet completed processing of all its entries. Every time we
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| 169 | visit a new directory, we add that directory to this set.
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| 170 | When we finish with a directory (usually by visiting it a
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| 171 | second time), we remove it from this set. Each entry in
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| 172 | this data structure is a device/inode pair. This data
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| 173 | structure is used to detect directory cycles efficiently and
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| 174 | promptly even when the depth of a hierarchy is in the tens
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| 175 | of thousands. */
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| 176 | struct hash_table *ht;
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| 177 |
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| 178 | /* FIXME: rename these two members to have the fts_ prefix */
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| 179 | /* This data structure uses a lazy cycle-detection algorithm,
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| 180 | as done by rm via cycle-check.c. It's the default,
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| 181 | but it's not appropriate for programs like du. */
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| 182 | struct cycle_check_state *state;
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| 183 | } fts_cycle;
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| 184 |
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| 185 | /* A stack of the file descriptors corresponding to the
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| 186 | most-recently traversed parent directories.
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| 187 | Currently used only in FTS_CWDFD mode. */
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| 188 | I_ring fts_fd_ring;
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| 189 | } FTS;
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| 190 |
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| 191 | typedef struct _ftsent {
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| 192 | struct _ftsent *fts_cycle; /* cycle node */
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| 193 | struct _ftsent *fts_parent; /* parent directory */
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| 194 | struct _ftsent *fts_link; /* next file in directory */
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| 195 | DIR *fts_dirp; /* Dir pointer for any directory
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| 196 | containing more entries than we
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| 197 | read at one time. */
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| 198 | long fts_number; /* local numeric value */
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| 199 | void *fts_pointer; /* local address value */
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| 200 | char *fts_accpath; /* access file name */
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| 201 | char *fts_path; /* root name; == fts_fts->fts_path */
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| 202 | int fts_errno; /* errno for this node */
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| 203 | int fts_symfd; /* fd for symlink */
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| 204 | size_t fts_pathlen; /* strlen(fts_path) */
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| 205 |
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| 206 | FTS *fts_fts; /* the file hierarchy itself */
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| 207 |
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| 208 | # define FTS_ROOTPARENTLEVEL (-1)
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| 209 | # define FTS_ROOTLEVEL 0
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| 210 | ptrdiff_t fts_level; /* depth (-1 to N) */
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| 211 |
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| 212 | size_t fts_namelen; /* strlen(fts_name) */
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| 213 | nlink_t fts_n_dirs_remaining; /* count down from st_nlink */
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| 214 |
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| 215 | # define FTS_D 1 /* preorder directory */
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| 216 | # define FTS_DC 2 /* directory that causes cycles */
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| 217 | # define FTS_DEFAULT 3 /* none of the above */
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| 218 | # define FTS_DNR 4 /* unreadable directory */
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| 219 | # define FTS_DOT 5 /* dot or dot-dot */
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| 220 | # define FTS_DP 6 /* postorder directory */
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| 221 | # define FTS_ERR 7 /* error; errno is set */
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| 222 | # define FTS_F 8 /* regular file */
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| 223 | # define FTS_INIT 9 /* initialized only */
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| 224 | # define FTS_NS 10 /* stat(2) failed */
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| 225 | # define FTS_NSOK 11 /* no stat(2) requested */
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| 226 | # define FTS_SL 12 /* symbolic link */
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| 227 | # define FTS_SLNONE 13 /* symbolic link without target */
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| 228 | # define FTS_W 14 /* whiteout object */
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| 229 | unsigned short int fts_info; /* user flags for FTSENT structure */
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| 230 |
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| 231 | # define FTS_DONTCHDIR 0x01 /* don't chdir .. to the parent */
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| 232 | # define FTS_SYMFOLLOW 0x02 /* followed a symlink to get here */
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| 233 | unsigned short int fts_flags; /* private flags for FTSENT structure */
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| 234 |
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| 235 | # define FTS_AGAIN 1 /* read node again */
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| 236 | # define FTS_FOLLOW 2 /* follow symbolic link */
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| 237 | # define FTS_NOINSTR 3 /* no instructions */
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| 238 | # define FTS_SKIP 4 /* discard node */
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| 239 | unsigned short int fts_instr; /* fts_set() instructions */
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| 240 |
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| 241 | struct stat fts_statp[1]; /* stat(2) information */
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| 242 | char fts_name[1]; /* file name */
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| 243 | } FTSENT;
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| 244 |
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| 245 | #ifndef __GNUC_PREREQ
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| 246 | # if defined __GNUC__ && defined __GNUC_MINOR__
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| 247 | # define __GNUC_PREREQ(maj, min) \
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| 248 | ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
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| 249 | # else
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| 250 | # define __GNUC_PREREQ(maj, min) 0
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| 251 | # endif
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| 252 | #endif
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| 253 |
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| 254 | #if __GNUC_PREREQ (3,4)
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| 255 | # undef __attribute_warn_unused_result__
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| 256 | # define __attribute_warn_unused_result__ \
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| 257 | __attribute__ ((__warn_unused_result__))
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| 258 | #else
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| 259 | # define __attribute_warn_unused_result__ /* empty */
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| 260 | #endif
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| 261 |
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| 262 | __BEGIN_DECLS
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| 263 | FTSENT *fts_children (FTS *, int) __THROW __attribute_warn_unused_result__;
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| 264 | int fts_close (FTS *) __THROW __attribute_warn_unused_result__;
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| 265 | FTS *fts_open (char * const *, int,
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| 266 | int (*)(const FTSENT **, const FTSENT **))
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| 267 | __THROW __attribute_warn_unused_result__;
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| 268 | FTSENT *fts_read (FTS *) __THROW __attribute_warn_unused_result__;
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| 269 | int fts_set (FTS *, FTSENT *, int) __THROW;
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| 270 | __END_DECLS
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| 271 |
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| 272 | #endif /* fts.h */
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