| /* 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 */ |
