How to extract a tarball?

Question

Background

I have a release file inside a tarball. However I want the final release to have some additional files and to move things around, for the convenience of the user.

This means I need to do 3 things:

1. Extract the contents of the tarball into a folder
2. Add the extra files to said folder and move some items around
3. compress everything again and call it a day

Problem

While I have it clear on how to execute step 2, using File and friends, I have tried several ways to do steps 1 and 3 and I failed.

I have tried using :zip, but it returns a bad encoding error, probably because the file is not a zip but tar instead.

I am also aware of File.open("path", :read, :compressed), but I don't want to read anything, I want to extract it into a new folder.

I also checked Unzip but it does not fit my use case.

Question

How can I extract a tar file into a folder and compress a folder into a tar file?

Answer 1

I was able to extract the file using:

:ok = :erl_tar.extract("tar_path", [{:cwd, "tmp"}, :compressed])

This will extract the tar file into the tmp folder. Once there I can do the rest !