custom tar -xf replacement as a static binary

What is this

This is a simple Rust program that extracts a list of file from a tar archive. It is meant to be used in ReproZip and is probably not generally useful.

The program takes as argument the archive and a list of null-byte-delimited filenames. Additionally it expects that paths in the archive are prefixed by DATA/ and ignores paths that aren't. It always extracts to the current directory (cwd).

Why is this needed?

tar behaves the way you expect when extracting files over files (replace) or directories over directories (merge), but a problem arise when extracting files over directories. Either it will fail (tar won't be able to remove a directory that's not empty) or you use --recursive-unlink (but then extracting directories over directories will delete too, and not merge).

This is needed by the ReproZip project. The reprounzip component builds virtual machines and unpacks the files needed to reproduce an experiment. In some cases the base image's layout is significantly different from the experiment's files: e.g. /lib might be a directory or a symlink depending on your distribution.

Reprounzip downloads the static binaries from this project's releases page:

https://github.com/remram44/rpztar/releases/download/v1/rpzsudo-{arch}

where {arch} is one of: i686, x86_64 (uname -m).