1 /* Traverse a file hierarchy.
3 Copyright (C) 2004, 2005, 2006 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 2, or (at your option)
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, write to the Free Software Foundation,
17 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
20 * Copyright (c) 1989, 1993
21 * The Regents of the University of California. All rights reserved.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
26 * 1. Redistributions of source code must retain the above copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 4. Neither the name of the University nor the names of its contributors
32 * may be used to endorse or promote products derived from this software
33 * without specific prior written permission.
35 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
36 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
38 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
39 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
40 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
41 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
42 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
43 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
44 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47 * @(#)fts.h 8.3 (Berkeley) 8/14/94
54 # include <features.h>
55 # define _LGPL_PACKAGE 1
60 # define __BEGIN_DECLS
66 # include <sys/types.h>
67 # include <sys/stat.h>
71 struct _ftsent *fts_cur; /* current node */
72 struct _ftsent *fts_child; /* linked list of children */
73 struct _ftsent **fts_array; /* sort array */
74 dev_t fts_dev; /* starting device # */
75 char *fts_path; /* file name for this descent */
76 int fts_rfd; /* fd for root */
77 int fts_cwd_fd; /* the file descriptor on which the
78 virtual cwd is open, or AT_FDCWD */
79 size_t fts_pathlen; /* sizeof(path) */
80 size_t fts_nitems; /* elements in the sort array */
81 int (*fts_compar) (struct _ftsent const **, struct _ftsent const **);
84 # define FTS_COMFOLLOW 0x0001 /* follow command line symlinks */
85 # define FTS_LOGICAL 0x0002 /* logical walk */
86 # define FTS_NOCHDIR 0x0004 /* don't change directories */
87 # define FTS_NOSTAT 0x0008 /* don't get stat info */
88 # define FTS_PHYSICAL 0x0010 /* physical walk */
89 # define FTS_SEEDOT 0x0020 /* return dot and dot-dot */
90 # define FTS_XDEV 0x0040 /* don't cross devices */
91 # define FTS_WHITEOUT 0x0080 /* return whiteout information */
93 /* There are two ways to detect cycles.
94 The lazy way (which works only with FTS_PHYSICAL),
95 with which one may process a directory that is a
96 part of the cycle several times before detecting the cycle.
97 The `tight' way, whereby fts uses more memory (proportional
98 to number of `active' directories, aka distance from root
99 of current tree to current directory -- see active_dir_ht)
100 to detect any cycle right away. For example, du must use
101 this option to avoid counting disk space in a cycle multiple
102 times, but chown -R need not.
103 The default is to use the constant-memory lazy way, when possible
106 However, with FTS_LOGICAL (when following symlinks, e.g., chown -L)
107 using lazy cycle detection is inadequate. For example, traversing
108 a directory containing a symbolic link to a peer directory, it is
109 possible to encounter the same directory twice even though there
114 So, when FTS_LOGICAL is selected, we have to use a different
115 mode of cycle detection: FTS_TIGHT_CYCLE_CHECK. */
116 # define FTS_TIGHT_CYCLE_CHECK 0x0100
118 /* Use this flag to enable semantics with which the parent
119 application may be made both more efficient and more robust.
120 Whereas the default is to visit each directory in a recursive
121 traversal (via chdir), using this flag makes it so the initial
122 working directory is never changed. Instead, these functions
123 perform the traversal via a virtual working directory, maintained
124 through the file descriptor member, fts_cwd_fd. */
125 # define FTS_CWDFD 0x0200
127 /* Historically, for each directory that fts initially encounters, it would
128 open it, read all entries, and stat each entry, storing the results, and
129 then it would process the first entry. But that behavior is bad for
130 locality of reference, and also causes trouble with inode-simulating
131 file systems like FAT, CIFS, FUSE-based ones, etc., when entries from
132 their name/inode cache are flushed too early.
133 Use this flag to make fts_open and fts_read defer the stat/lstat/fststat
134 of each entry until it actually processed. However, note that if you use
135 this option and also specify a comparison function, that function may not
136 examine any data via fts_statp. */
137 # define FTS_DEFER_STAT 0x0400
139 # define FTS_OPTIONMASK 0x07ff /* valid user option mask */
141 # define FTS_NAMEONLY 0x1000 /* (private) child names only */
142 # define FTS_STOP 0x2000 /* (private) unrecoverable error */
143 int fts_options; /* fts_open options, global flags */
147 /* This data structure is used if FTS_TIGHT_CYCLE_CHECK is
148 specified. It records the directories between a starting
149 point and the current directory. I.e., a directory is
150 recorded here IFF we have visited it once, but we have not
151 yet completed processing of all its entries. Every time we
152 visit a new directory, we add that directory to this set.
153 When we finish with a directory (usually by visiting it a
154 second time), we remove it from this set. Each entry in
155 this data structure is a device/inode pair. This data
156 structure is used to detect directory cycles efficiently and
157 promptly even when the depth of a hierarchy is in the tens
159 struct hash_table *ht;
161 /* FIXME: rename these two members to have the fts_ prefix */
162 /* This data structure uses a lazy cycle-detection algorithm,
163 as done by rm via cycle-check.c. It's the default,
164 but it's not appropriate for programs like du. */
165 struct cycle_check_state *state;
169 /* A stack of the file descriptors corresponding to the
170 most-recently traversed parent directories.
171 Currently used only in FTS_CWDFD mode. */
175 typedef struct _ftsent {
176 struct _ftsent *fts_cycle; /* cycle node */
177 struct _ftsent *fts_parent; /* parent directory */
178 struct _ftsent *fts_link; /* next file in directory */
179 long fts_number; /* local numeric value */
180 void *fts_pointer; /* local address value */
181 char *fts_accpath; /* access file name */
182 char *fts_path; /* root name; == fts_fts->fts_path */
183 int fts_errno; /* errno for this node */
184 int fts_symfd; /* fd for symlink */
185 size_t fts_pathlen; /* strlen(fts_path) */
187 FTS *fts_fts; /* the file hierarchy itself */
189 # define FTS_ROOTPARENTLEVEL (-1)
190 # define FTS_ROOTLEVEL 0
191 ptrdiff_t fts_level; /* depth (-1 to N) */
193 size_t fts_namelen; /* strlen(fts_name) */
195 # define FTS_D 1 /* preorder directory */
196 # define FTS_DC 2 /* directory that causes cycles */
197 # define FTS_DEFAULT 3 /* none of the above */
198 # define FTS_DNR 4 /* unreadable directory */
199 # define FTS_DOT 5 /* dot or dot-dot */
200 # define FTS_DP 6 /* postorder directory */
201 # define FTS_ERR 7 /* error; errno is set */
202 # define FTS_F 8 /* regular file */
203 # define FTS_INIT 9 /* initialized only */
204 # define FTS_NS 10 /* stat(2) failed */
205 # define FTS_NSOK 11 /* no stat(2) requested */
206 # define FTS_SL 12 /* symbolic link */
207 # define FTS_SLNONE 13 /* symbolic link without target */
208 # define FTS_W 14 /* whiteout object */
209 unsigned short int fts_info; /* user flags for FTSENT structure */
211 # define FTS_DONTCHDIR 0x01 /* don't chdir .. to the parent */
212 # define FTS_SYMFOLLOW 0x02 /* followed a symlink to get here */
213 unsigned short int fts_flags; /* private flags for FTSENT structure */
215 # define FTS_AGAIN 1 /* read node again */
216 # define FTS_FOLLOW 2 /* follow symbolic link */
217 # define FTS_NOINSTR 3 /* no instructions */
218 # define FTS_SKIP 4 /* discard node */
219 unsigned short int fts_instr; /* fts_set() instructions */
221 struct stat fts_statp[1]; /* stat(2) information */
222 char fts_name[1]; /* file name */
226 FTSENT *fts_children (FTS *, int) __THROW;
227 int fts_close (FTS *) __THROW;
228 FTS *fts_open (char * const *, int,
229 int (*)(const FTSENT **, const FTSENT **)) __THROW;
230 FTSENT *fts_read (FTS *) __THROW;
231 int fts_set (FTS *, FTSENT *, int) __THROW;