File::Directory::Bubble

A file-removal tool that

• optionally bubbles deletion up the directory tree until it hits a non-empty directory;

• allows for dry runs, only showing you what *would* be deleted.

Installation

With zef:

• just running zef install File::Directory::Bubble should work once the module has been indexed;

• or clone this repo and issue zef install <path-to-cloned-repo>;

• or clone, cd into the repo, and zef install ..

Usage

The module provides the executable bin/bbrm for access to (what I believe would be) the most common functionality.

First, you can run bbrm --help for a quick breakdown of the usage. For the examples, I will assume access to the tree utility in order to visualize the directory structure that bbrm is meant to alter.

Throughout, assume you're in a directory with the following structure:

$ tree .
.
├── a
│   ├── b
│   │   └── c
│   ├── b1
│   │   └── c
│   │       └── d
│   └── b2
│       └── c
│           └── d
└── foo.txt

9 directories, 1 file

I will run the bbrm command with the --dry option, so it only shows us what it would remove.

$ bbrm a/b* --dry

Would remove:
<fully-expanded path>/a/b/c
<fully-expanded path>/a/b
<fully-expanded path>/a/b1/c/d
<fully-expanded path>/a/b1/c
<fully-expanded path>/a/b1
<fully-expanded path>/a/b2/c/d
<fully-expanded path>/a/b2/c
<fully-expanded path>/a/b2   

As expected, that would remove everything under the directories ./a/b*. On the other hand, the --up flag would also remove the ./a directory, because it would become empty upon removing the other ones:

$ bbrm a/b* --dry --up

Would remove:
<fully-expanded path>/a/b2/c/d
<fully-expanded path>/a/b2/c
<fully-expanded path>/a/b2
<fully-expanded path>/a/b1/c/d
<fully-expanded path>/a/b1/c
<fully-expanded path>/a/b1
<fully-expanded path>/a/b/c
<fully-expanded path>/a/b
<fully-expanded path>/a

In fact, the same would happen if you were to first remove everything at lower levels: empty-directory deletion would still bubble up.

$ bbrm a/b*/c --dry --up

Would remove:
<fully-expanded path>/a/b2/c/d
<fully-expanded path>/a/b2/c
<fully-expanded path>/a/b2
<fully-expanded path>/a/b1/c/d
<fully-expanded path>/a/b1/c
<fully-expanded path>/a/b1
<fully-expanded path>/a/b/c
<fully-expanded path>/a/b
<fully-expanded path>/a

Though again, that only happens with the --up flag. Without it you're only deleting down the directory tree.

$ bbrm a/b*/c --dry

Would remove:
<fully-expanded path>/a/b/c
<fully-expanded path>/a/b1/c/d
<fully-expanded path>/a/b1/c
<fully-expanded path>/a/b2/c/d
<fully-expanded path>/a/b2/c

Other modules in the Raku ecosystem

There's of course File::Directory::Tree, but because it deletes files/directories recursively using unlink and rmdir, it's not easy to build a --dry option on top of it:

If you're doing a dry run you're not actually emptying directories, so rmdir doesn't know what it would remove if you were..

Module functions

The library lib/File/Directory/Bubble.rakumod exports a number of functions, some of which are used by the bbrm utility discussed above.

A summary follows.

Starting with the $file you pass in, it builds the increasingly longer lists of ancestors, as in

• $file, parent

• $file, parent, parent-of-parent

• etc.

The predicate &cond is called on these lists, so there's quite a bit of generality built into the kinds of conditions you can check for.

The iteration stops when &cond first returns false, giving you back the last list of parents before that happened.

This is a utility function, for use with &bbUpWith above to produce &bbUpEmpty below.

This function allows the bbrm script to list what it would remove upon passing the --up flag, even during a --dry run.

You can presumably build your own more complicated examples using the more general callback-driven &bbUpWith above.