/*- * Copyright (c) 2003-2007 Tim Kientzle * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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. * * $FreeBSD: src/usr.bin/tar/tree.h,v 1.4 2008/11/27 05:49:52 kientzle Exp $ */ /*- * A set of routines for traversing directory trees. * Similar in concept to the fts library, but with a few * important differences: * * Uses less memory. In particular, fts stores an entire directory * in memory at a time. This package only keeps enough subdirectory * information in memory to track the traversal. Information * about non-directories is discarded as soon as possible. * * Supports very deep logical traversals. The fts package * uses "non-chdir" approach for logical traversals. This * package does use a chdir approach for logical traversals * and can therefore handle pathnames much longer than PATH_MAX. * * Supports deep physical traversals "out of the box." * Due to the memory optimizations above, there's no need to * limit dir names to 32k. */ #include <sys/stat.h> #include <stdio.h> struct tree; /* Initiate/terminate a tree traversal. */ struct tree *tree_open(const char * /* pathname */); void tree_close(struct tree *); /* * tree_next() returns Zero if there is no next entry, non-zero if * there is. Note that directories are visited three times. * Directories are always visited first as part of enumerating their * parent; that is a "regular" visit. If tree_descend() is invoked at * that time, the directory is added to a work list and will * subsequently be visited two more times: once just after descending * into the directory ("postdescent") and again just after ascending * back to the parent ("postascent"). * * TREE_ERROR_DIR is returned if the descent failed (because the * directory couldn't be opened, for instance). This is returned * instead of TREE_POSTDESCENT/TREE_POSTASCENT. TREE_ERROR_DIR is not a * fatal error, but it does imply that the relevant subtree won't be * visited. TREE_ERROR_FATAL is returned for an error that left the * traversal completely hosed. Right now, this is only returned for * chdir() failures during ascent. */ #define TREE_REGULAR 1 #define TREE_POSTDESCENT 2 #define TREE_POSTASCENT 3 #define TREE_ERROR_DIR -1 #define TREE_ERROR_FATAL -2 int tree_next(struct tree *); /* Errno value associated with the last traversal error. */ int tree_errno(struct tree *); /* * Request that current entry be visited. If you invoke it on every * directory, you'll get a physical traversal. This is ignored if the * current entry isn't a directory or a link to a directory. So, if * you invoke this on every returned path, you'll get a full logical * traversal. */ void tree_descend(struct tree *); /* * Return information about the current entry. */ /* Current depth in the traversal. */ int tree_current_depth(struct tree *); /* * The current full pathname, length of the full pathname, and a name * that can be used to access the file. Because tree does use chdir * extensively, the access path is almost never the same as the full * current path. * * TODO: Flesh out this interface to provide other information. In * particular, Windows can provide file size, mode, and some permission * information without invoking stat() at all. * * TODO: On platforms that support it, use openat()-style operations * to eliminate the chdir() operations entirely while still supporting * arbitrarily deep traversals. This makes access_path troublesome to * support, of course, which means we'll need a rich enough interface * that clients can function without it. (In particular, we'll need * tree_current_open() that returns an open file descriptor.) * * TODO: Provide tree_current_archive_entry(). */ const char *tree_current_path(struct tree *); size_t tree_current_pathlen(struct tree *); const char *tree_current_access_path(struct tree *); /* * Request the lstat() or stat() data for the current path. Since the * tree package needs to do some of this anyway, and caches the * results, you should take advantage of it here if you need it rather * than make a redundant stat() or lstat() call of your own. */ const struct stat *tree_current_stat(struct tree *); const struct stat *tree_current_lstat(struct tree *); /* The following functions use tricks to avoid a certain number of * stat()/lstat() calls. */ /* "is_physical_dir" is equivalent to S_ISDIR(tree_current_lstat()->st_mode) */ int tree_current_is_physical_dir(struct tree *); /* "is_physical_link" is equivalent to S_ISLNK(tree_current_lstat()->st_mode) */ int tree_current_is_physical_link(struct tree *); /* "is_dir" is equivalent to S_ISDIR(tree_current_stat()->st_mode) */ int tree_current_is_dir(struct tree *); /* For testing/debugging: Dump the internal status to the given filehandle. */ void tree_dump(struct tree *, FILE *);