alien

A Rust port of alien, a tool that converts software packages to work from one package manager to the next.

Currently, the tool supports converting between:

• .deb packages — used by dpkg, prevalent in Linux distributions (distros) derived from Debian and Ubuntu;
• .rpm packages — used by rpm, found in Red Hat-derived distros such as RHEL, CentOS, openSUSE, Fedora and more;
• LSB packages — used by Linux Standard Base and are basicaly .rpm packages
• .tgz packages — used by Slackware Linux
• .pkg packages — used by Solaris

Please note that support for .slp packages — once used by Stampede Linux — will not be present in the Rust version. Due to lack of available documentation online caused by lack of interest in Stampede Linux over the last 20 years after its cancellation, and a potential endianness mismatch present in original Perl version, I don't have enough information or incentive to write a Rust port that functions correctly on all architectures.

Motivation

The main goal for this port is to enhance the original alien's performance, error handling and versatility, which were all hindered by the language alien was originally written in, Perl. With Rust, there are a lot more opportunities for offering the end user parallel processing, more robust error messages, and potentially portability to other operating systems.

Code-wise, the original alien's control flow was not entirely clear, and sometimes the program does duplicate work thanks to the use of implicit but overridable accessors. In comparison, the Rust version minimizes duplicate work, cleanly seperates source packages and target packages for better readability and comprehension, and overall the code is just laid out more explicitly which helps users and developers to better debug problems.

In conclusion, I believe rewriting alien in Rust aids users and developers alike, and the benefit far outweighs the cost of my time and my sanity, and so this project was born.

Known Issues

• Names need to be mapped from .rpm to .deb - in particular, .deb package names cannot contain uppercase letters, whereas .rpm packages have no such restriction.

• Currently dependencies from .deb files are not processed, which means .rpm packages converted from .deb packages may not install correctly.

• You can't install the package yet, and alien currently doesn't clean things up.

From the original alien's 8.95 release (which is to my knowledge the latest), on top of which this port is based:

• Handling postinst script when converting to/from .slp packages.

• Alien needs to handle relocatable conffiles, partially relocatable packages, and packages that have multiple parts that relocate differently.

• RPM ghost file support. On conversion, make preinst move file out of the way, postinst put it back. Thus emulating the behavior of rpm.

• Seems slackware packages may now incliude an install/slack-desc with a description in it

License

alien is licensed under the GNU General Public License, version 2, or (at your option) any later version.

© 2023 Leah "pluie" Chen