1/* Traverse a file hierarchy. 2 3 Copyright (C) 2004-2010 Free Software Foundation, Inc. 4 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. 9 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. 14 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/>. */ 17 18/* 19 * Copyright (c) 1989, 1993 20 * The Regents of the University of California. All rights reserved. 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 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. 33 * 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 44 * SUCH DAMAGE. 45 * 46 * @(#)fts.h 8.3 (Berkeley) 8/14/94 47 */ 48 49#ifndef _FTS_H 50# define _FTS_H 1 51 52# ifdef _LIBC 53# include <features.h> 54# else 55# undef __THROW 56# define __THROW 57# undef __BEGIN_DECLS 58# define __BEGIN_DECLS 59# undef __END_DECLS 60# define __END_DECLS 61# endif 62 63# include <stddef.h> 64# include <sys/types.h> 65# include <sys/stat.h> 66# include "i-ring.h" 67 68typedef struct { 69 struct _ftsent *fts_cur; /* current node */ 70 struct _ftsent *fts_child; /* linked list of children */ 71 struct _ftsent **fts_array; /* sort array */ 72 dev_t fts_dev; /* starting device # */ 73 char *fts_path; /* file name for this descent */ 74 int fts_rfd; /* fd for root */ 75 int fts_cwd_fd; /* the file descriptor on which the 76 virtual cwd is open, or AT_FDCWD */ 77 size_t fts_pathlen; /* sizeof(path) */ 78 size_t fts_nitems; /* elements in the sort array */ 79 int (*fts_compar) (struct _ftsent const **, struct _ftsent const **); 80 /* compare fn */ 81 82# define FTS_COMFOLLOW 0x0001 /* follow command line symlinks */ 83# define FTS_LOGICAL 0x0002 /* logical walk */ 84# define FTS_NOCHDIR 0x0004 /* don't change directories */ 85# define FTS_NOSTAT 0x0008 /* don't get stat info */ 86# define FTS_PHYSICAL 0x0010 /* physical walk */ 87# define FTS_SEEDOT 0x0020 /* return dot and dot-dot */ 88# define FTS_XDEV 0x0040 /* don't cross devices */ 89# define FTS_WHITEOUT 0x0080 /* return whiteout information */ 90 91 /* There are two ways to detect cycles. 92 The lazy way (which works only with FTS_PHYSICAL), 93 with which one may process a directory that is a 94 part of the cycle several times before detecting the cycle. 95 The `tight' way, whereby fts uses more memory (proportional 96 to number of `active' directories, aka distance from root 97 of current tree to current directory -- see active_dir_ht) 98 to detect any cycle right away. For example, du must use 99 this option to avoid counting disk space in a cycle multiple 100 times, but chown -R need not. 101 The default is to use the constant-memory lazy way, when possible 102 (see below). 103 104 However, with FTS_LOGICAL (when following symlinks, e.g., chown -L) 105 using lazy cycle detection is inadequate. For example, traversing 106 a directory containing a symbolic link to a peer directory, it is 107 possible to encounter the same directory twice even though there 108 is no cycle: 109 dir 110 ... 111 slink -> dir 112 So, when FTS_LOGICAL is selected, we have to use a different 113 mode of cycle detection: FTS_TIGHT_CYCLE_CHECK. */ 114# define FTS_TIGHT_CYCLE_CHECK 0x0100 115 116 /* Use this flag to enable semantics with which the parent 117 application may be made both more efficient and more robust. 118 Whereas the default is to visit each directory in a recursive 119 traversal (via chdir), using this flag makes it so the initial 120 working directory is never changed. Instead, these functions 121 perform the traversal via a virtual working directory, maintained 122 through the file descriptor member, fts_cwd_fd. */ 123# define FTS_CWDFD 0x0200 124 125 /* Historically, for each directory that fts initially encounters, it would 126 open it, read all entries, and stat each entry, storing the results, and 127 then it would process the first entry. But that behavior is bad for 128 locality of reference, and also causes trouble with inode-simulating 129 file systems like FAT, CIFS, FUSE-based ones, etc., when entries from 130 their name/inode cache are flushed too early. 131 Use this flag to make fts_open and fts_read defer the stat/lstat/fststat 132 of each entry until it is actually processed. However, note that if you 133 use this option and also specify a comparison function, that function may 134 not examine any data via fts_statp. However, when fts_statp->st_mode is 135 nonzero, the S_IFMT type bits are valid, with mapped dirent.d_type data. 136 Of course, that happens only on file systems that provide useful 137 dirent.d_type data. */ 138# define FTS_DEFER_STAT 0x0400 139 140# define FTS_OPTIONMASK 0x07ff /* valid user option mask */ 141 142# define FTS_NAMEONLY 0x1000 /* (private) child names only */ 143# define FTS_STOP 0x2000 /* (private) unrecoverable error */ 144 int fts_options; /* fts_open options, global flags */ 145 146# if GNULIB_FTS 147 /* Map a directory's device number to a boolean. The boolean is 148 true if for that file system (type determined by a single fstatfs 149 call per FS) st_nlink can be used to calculate the number of 150 sub-directory entries in a directory. 151 Using this table is an optimization that permits us to look up 152 file system type on a per-inode basis at the minimal cost of 153 calling fstatfs only once per traversed device. */ 154 struct hash_table *fts_leaf_optimization_works_ht; 155 156 union { 157 /* This data structure is used if FTS_TIGHT_CYCLE_CHECK is 158 specified. It records the directories between a starting 159 point and the current directory. I.e., a directory is 160 recorded here IFF we have visited it once, but we have not 161 yet completed processing of all its entries. Every time we 162 visit a new directory, we add that directory to this set. 163 When we finish with a directory (usually by visiting it a 164 second time), we remove it from this set. Each entry in 165 this data structure is a device/inode pair. This data 166 structure is used to detect directory cycles efficiently and 167 promptly even when the depth of a hierarchy is in the tens 168 of thousands. */ 169 struct hash_table *ht; 170 171 /* FIXME: rename these two members to have the fts_ prefix */ 172 /* This data structure uses a lazy cycle-detection algorithm, 173 as done by rm via cycle-check.c. It's the default, 174 but it's not appropriate for programs like du. */ 175 struct cycle_check_state *state; 176 } fts_cycle; 177 178# endif 179 /* A stack of the file descriptors corresponding to the 180 most-recently traversed parent directories. 181 Currently used only in FTS_CWDFD mode. */ 182 I_ring fts_fd_ring; 183} FTS; 184 185typedef struct _ftsent { 186 struct _ftsent *fts_cycle; /* cycle node */ 187 struct _ftsent *fts_parent; /* parent directory */ 188 struct _ftsent *fts_link; /* next file in directory */ 189 long fts_number; /* local numeric value */ 190 void *fts_pointer; /* local address value */ 191 char *fts_accpath; /* access file name */ 192 char *fts_path; /* root name; == fts_fts->fts_path */ 193 int fts_errno; /* errno for this node */ 194 int fts_symfd; /* fd for symlink */ 195 size_t fts_pathlen; /* strlen(fts_path) */ 196 197 FTS *fts_fts; /* the file hierarchy itself */ 198 199# define FTS_ROOTPARENTLEVEL (-1) 200# define FTS_ROOTLEVEL 0 201 ptrdiff_t fts_level; /* depth (-1 to N) */ 202 203 size_t fts_namelen; /* strlen(fts_name) */ 204 nlink_t fts_n_dirs_remaining; /* count down from st_nlink */ 205 206# define FTS_D 1 /* preorder directory */ 207# define FTS_DC 2 /* directory that causes cycles */ 208# define FTS_DEFAULT 3 /* none of the above */ 209# define FTS_DNR 4 /* unreadable directory */ 210# define FTS_DOT 5 /* dot or dot-dot */ 211# define FTS_DP 6 /* postorder directory */ 212# define FTS_ERR 7 /* error; errno is set */ 213# define FTS_F 8 /* regular file */ 214# define FTS_INIT 9 /* initialized only */ 215# define FTS_NS 10 /* stat(2) failed */ 216# define FTS_NSOK 11 /* no stat(2) requested */ 217# define FTS_SL 12 /* symbolic link */ 218# define FTS_SLNONE 13 /* symbolic link without target */ 219# define FTS_W 14 /* whiteout object */ 220 unsigned short int fts_info; /* user flags for FTSENT structure */ 221 222# define FTS_DONTCHDIR 0x01 /* don't chdir .. to the parent */ 223# define FTS_SYMFOLLOW 0x02 /* followed a symlink to get here */ 224 unsigned short int fts_flags; /* private flags for FTSENT structure */ 225 226# define FTS_AGAIN 1 /* read node again */ 227# define FTS_FOLLOW 2 /* follow symbolic link */ 228# define FTS_NOINSTR 3 /* no instructions */ 229# define FTS_SKIP 4 /* discard node */ 230 unsigned short int fts_instr; /* fts_set() instructions */ 231 232 struct stat fts_statp[1]; /* stat(2) information */ 233 char fts_name[1]; /* file name */ 234} FTSENT; 235 236#ifndef __GNUC_PREREQ 237# if defined __GNUC__ && defined __GNUC_MINOR__ 238# define __GNUC_PREREQ(maj, min) \ 239 ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min)) 240# else 241# define __GNUC_PREREQ(maj, min) 0 242# endif 243#endif 244 245#if __GNUC_PREREQ (3,4) 246# undef __attribute_warn_unused_result__ 247# define __attribute_warn_unused_result__ \ 248 __attribute__ ((__warn_unused_result__)) 249#else 250# define __attribute_warn_unused_result__ /* empty */ 251#endif 252 253__BEGIN_DECLS 254FTSENT *fts_children (FTS *, int) __THROW __attribute_warn_unused_result__; 255int fts_close (FTS *) __THROW __attribute_warn_unused_result__; 256FTS *fts_open (char * const *, int, 257 int (*)(const FTSENT **, const FTSENT **)) 258 __THROW __attribute_warn_unused_result__; 259FTSENT *fts_read (FTS *) __THROW __attribute_warn_unused_result__; 260int fts_set (FTS *, FTSENT *, int) __THROW; 261__END_DECLS 262 263#endif /* fts.h */ 264