/*-

 * 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.

 *

 * $FreeBSD$

 */

/*-

 * 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 potentially visited three times.  The first

 * time as "regular" file.  If tree_descend() is invoked at that time,

 * the directory is added to a work list and will be visited two more

 * times:  once just after descending into the directory and again

 * just after ascending back to the parent.

 *

 * TREE_ERROR is returned if the descent failed (because the

 * directory couldn't be opened, for instance).  This is returned

 * instead of TREE_PREVISIT/TREE_POSTVISIT.

 */

#define	TREE_REGULAR	1

#define	TREE_POSTDESCENT	2

#define	TREE_POSTASCENT	3

#define	TREE_ERROR_DIR	-1

int tree_next(struct tree *);

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.

 */

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.

 */

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 tests may use mechanisms much faster than stat()/lstat(). */

/* "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 *);