contrib/bsdtar/tree.h

   1 /*-
   2  * Copyright (c) 2003-2004 Tim Kientzle
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer
  10  *    in this position and unchanged.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/usr.bin/tar/tree.h,v 1.1 2005/04/24 05:53:37 kientzle Exp $
  27  */
  28
  29 /*-
  30  * A set of routines for traversing directory trees.
  31  * Similar in concept to the fts library, but with a few
  32  * important differences:
  33  *    * Uses less memory.  In particular, fts stores an entire directory
  34  *      in memory at a time.  This package only keeps enough subdirectory
  35  *      information in memory to track the traversal.  Information
  36  *      about non-directories is discarded as soon as possible.
  37  *    * Supports very deep logical traversals.  The fts package
  38  *      uses "non-chdir" approach for logical traversals.  This
  39  *      package does use a chdir approach for logical traversals
  40  *      and can therefore handle pathnames much longer than
  41  *      PATH_MAX.
  42  *    * Supports deep physical traversals "out of the box."
  43  *      Due to the memory optimizations above, there's no need to
  44  *      limit dir names to 32k.
  45  */
  46
  47 #include <sys/stat.h>
  48 #include <stdio.h>
  49
  50 struct tree;
  51
  52 /* Initiate/terminate a tree traversal. */
  53 struct tree *tree_open(const char * /* pathname */);
  54 void tree_close(struct tree *);
  55
  56 /*
  57  * tree_next() returns Zero if there is no next entry, non-zero if there is.
  58  * Note that directories are potentially visited three times.  The first
  59  * time as "regular" file.  If tree_descend() is invoked at that time,
  60  * the directory is added to a work list and will be visited two more
  61  * times:  once just after descending into the directory and again
  62  * just after ascending back to the parent.
  63  *
  64  * TREE_ERROR is returned if the descent failed (because the
  65  * directory couldn't be opened, for instance).  This is returned
  66  * instead of TREE_PREVISIT/TREE_POSTVISIT.
  67  */
  68 #define TREE_REGULAR    1
  69 #define TREE_POSTDESCENT        2
  70 #define TREE_POSTASCENT 3
  71 #define TREE_ERROR      -1
  72 int tree_next(struct tree *);
  73
  74 int tree_errno(struct tree *);
  75
  76 /*
  77  * Request that current entry be visited.  If you invoke it on every
  78  * directory, you'll get a physical traversal.  This is ignored if the
  79  * current entry isn't a directory or a link to a directory.  So, if
  80  * you invoke this on every returned path, you'll get a full logical
  81  * traversal.
  82  */
  83 void tree_descend(struct tree *);
  84
  85 /*
  86  * Return information about the current entry.
  87  */
  88
  89 int tree_current_depth(struct tree *);
  90 /*
  91  * The current full pathname, length of the full pathname,
  92  * and a name that can be used to access the file.
  93  * Because tree does use chdir extensively, the access path is
  94  * almost never the same as the full current path.
  95  */
  96 const char *tree_current_path(struct tree *);
  97 size_t tree_current_pathlen(struct tree *);
  98 const char *tree_current_access_path(struct tree *);
  99 /*
 100  * Request the lstat() or stat() data for the current path.  Since the
 101  * tree package needs to do some of this anyway, and caches the
 102  * results, you should take advantage of it here if you need it rather
 103  * than make a redundant stat() or lstat() call of your own.
 104  */
 105 const struct stat *tree_current_stat(struct tree *);
 106 const struct stat *tree_current_lstat(struct tree *);
 107 /* The following tests may use mechanisms much faster than stat()/lstat(). */
 108 /* "is_physical_dir" is equivalent to S_ISDIR(tree_current_lstat()->st_mode) */
 109 int tree_current_is_physical_dir(struct tree *);
 110 /* "is_physical_link" is equivalent to S_ISLNK(tree_current_lstat()->st_mode) */
 111 int tree_current_is_physical_link(struct tree *);
 112 /* "is_dir" is equivalent to S_ISDIR(tree_current_stat()->st_mode) */
 113 int tree_current_is_dir(struct tree *);
 114
 115 /* For testing/debugging: Dump the internal status to the given filehandle. */
 116 void tree_dump(struct tree *, FILE *);