[Feature Request] Partial extract by pattern

[VHSgunzo]

Thanks for the great project!
Is it possible to add a partial extract by pattern, as it is done in unsquashfs?

For example:

unsquashfs squashfs-image '*.desktop'

or:

unsquashfs squashfs-image 'path/in/squashfs/image/*.png'

[mhx]

Something like this would certainly be possible to add.

Rather than implementing yet another file selection logic (a quick look at the manpage suggests that it's also possible to exclude paths, use regexes, ...), I'd probably use the same logic that is currently used to filter files in mkdwarfs. For convenience, I'd probably also add simple globbing.

It's going to take a while before I'll get around to implementing any of this, though.

[VHSgunzo]

Thanks again! That would be great. I'll be waiting for the news.

[mhx]

I thought I'd let ChatGPT come up with the glob implementation, but after iterating on its malfunctioning and over-complicated "solution" for way too long, I just implemented it myself... :)

Rather than implementing yet another file selection logic (a quick look at the manpage suggests that it's also possible to exclude paths, use regexes, ...), I'd probably use the same logic that is currently used to filter files in mkdwarfs. For convenience, I'd probably also add simple globbing.

I actually went a different route: I changed the code that implements filters in mkdwarfs to also use the new (much more capable) globbing code. This allows for much more flexible filters in addition to supporting partial extraction using one or more patterns. Win-win.

$ dwarfsextract -i data.dwarfs -o tmp2 '**/*.sh' '*.py' '{foo,bar}/**/[i-k]'
I 20:52:30.837724 extraction finished without errors
$ find tmp2
tmp2
tmp2/foo
tmp2/foo/1
tmp2/foo/1/2
tmp2/foo/1/2/3
tmp2/foo/1/2/3/4
tmp2/foo/1/2/3/4/5
tmp2/foo/1/2/3/4/5/6
tmp2/foo/1/2/3/4/5/6/7
tmp2/foo/1/2/3/4/5/6/7/8
tmp2/foo/1/2/3/4/5/6/7/8/9
tmp2/foo/1/2/3/4/5/6/7/8/9/i
tmp2/foo/1/2/3/4/5/6/7/8/9/j
tmp2/foo/1/2/3/4/5/6/7/8/9/k
tmp2/foo/1/2/3/copy.sh
tmp2/foo/1/2/xxx.sh
tmp2/foo/1/fmt.sh
tmp2/foo/bla.sh
tmp2/bench.sh
tmp2/format.sh
tmp2/perl-exec.sh
tmp2/test.py

This should make it into the next release. If you want to play with it, you can try using the artifacts produced by the CI pipeline.

[VHSgunzo]

Thank you for adding this feature, it works better than I even expected ;-)