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Diffstat (limited to 'lib/fts_.h')
| -rw-r--r-- | lib/fts_.h | 282 |
1 files changed, 282 insertions, 0 deletions
diff --git a/lib/fts_.h b/lib/fts_.h new file mode 100644 index 0000000..9cd46e2 --- /dev/null +++ b/lib/fts_.h @@ -0,0 +1,282 @@ +/* Traverse a file hierarchy. + + Copyright (C) 2004-2016 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 <http://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 + +# define FTS_NOATIME 0x0800 /* use O_NOATIME during traversal */ + + /* Use this flag to disable stripping of trailing slashes + from input path names during fts_open initialization. */ +# define FTS_VERBATIM 0x1000 + +# define FTS_OPTIONMASK 0x1fff /* valid user option mask */ + +# define FTS_NAMEONLY 0x2000 /* (private) child names only */ +# define FTS_STOP 0x4000 /* (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) */ + nlink_t fts_n_dirs_remaining; /* count down from st_nlink */ + +# 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 */ |