On 23 Aug 2007, at 14:59, Eric Blake wrote:
Bruno also had the idea of letting -delete operate
without -depth, by letting -delete swap the traversal of that
subtree to
depth-first while the rest of the traversal is breadth-first prior to
encountering the -delete action.
Actually, not quite. My proposal amounted to exactly the following:
--- findutils-4.3.8/find/parser.c 2007-06-09 14:12:06.000000000
+0200
+++ findutils-mod/find/parser.c 2007-08-24 12:08:07.000000000 +0200
@@ -724,7 +724,7 @@
our_pred = insert_primary (entry);
our_pred->side_effects = our_pred->no_default_print = true;
- /* -delete implies -depth */
- options.do_dir_first = false;
/* We do not need stat information because we check for the case
* (errno==EISDIR) in pred_delete.
The idea is to have a very straightforward -delete: the action will
try to delete the nodes in order, the traversal is not modified in
any way. The main benefit over other proposals is that -delete can be
combined with normal traversal (and thus with pruning). For example,
consider:
$ ../findutils-mod/find/find
.
./aa
./aa/.svn
./aa/.svn/foo
./aa/foo
./bb
./bb/foo
./.svn
./.svn/foo
$ ../findutils-mod/find/find -not "(" -name .svn -prune ")" -name foo
-delete
$ ../findutils-mod/find/find
.
./aa
./aa/.svn
./aa/.svn/foo
./bb
./.svn
./.svn/foo
The user will have to make sure that nodes can actually be deleted
during the traversal, otherwise he will receive an error. When
deleting directories, this means that the directory must be empty. If
he wants to delete an entire directory tree as a part of one and the
same traversal, he will need to use -depth, but at least he will
knowingly change the traversal order then.
Also, after deleting a directory in a normal traversal, find should
not try to visit this directory anymore, because it's gone. The user
could accomplish this by including a -prune after the -delete, or
find could do it automatically, with a change like this:
--- findutils-4.3.8/find/pred.c 2007-06-09 14:12:35.000000000 +0200
+++ findutils-mod/find/pred.c 2007-08-26 19:30:45.000000000 +0200
@@ -392,6 +392,8 @@
flags |= AT_REMOVEDIR;
if (perform_delete(flags))
{
+ if (options.do_dir_first == true && (flags & AT_REMOVEDIR))
+ state.stop_at_current_level = true;
return true;
}
else
@@ -403,7 +405,11 @@
/* unlink() operation failed because we should
have done rmdir(). */
flags |= AT_REMOVEDIR;
if (perform_delete(flags))
+ {
+ if (options.do_dir_first == true && (flags &
AT_REMOVEDIR))
+ state.stop_at_current_level = true;
return true;
+ }
}
}
}
As such it is possible to -delete empty directories in a normal
traversal. For example, consider the following to clean empty
subdirectories in a tree:
$ ../findutils-mod/find/find
.
./aa
./aa/foo
./bb
./cc
$ ../findutils-mod/find/find -type d
.
./aa
./aa/foo
./cc
$ ../findutils-mod/find/find -type d -empty -delete
$ ../findutils-mod/find/find
.
./aa
./bb
Regards,
Bruno De Fraine
