No matter what distribution of Linux you have installed, there will come a time when you would like to install a package in one of the other distribution's formats. No one distribution has available every possible package, and the updates to packages often depend on a volunteer's inclination and time constraints.
On a reasonably current and well-maintained Linux system, most of the quality source-code packages will compile without much effort beyond perusal of the README and INSTALL files. In other words, *.rpm and *.deb packages aren't vitally necessary, though the ease of upgrading or removal possible with these packages makes them a time-saving convenience.
But few people have both the time and/or inclination to compile every new program from source. It does take more time than using a precompiled package, and often a package maintainer will have access to patches which haven't yet been incorporated into an official release. One of these patches might be just what it takes to insure a successful installation on your system! Therefore it stands to reason that the more different genera of precompiled packages you have available, the wider the pool of available software.
A year and a half ago I was running a Slackware 3.0 system, but had used Redhat just long enough to appreciate the value of an rpm package. As I remember, there were a few pieces of software which I was unable, no matter what tweaking I did, to successfully compile. The rpm's available for those packages were tempting, but I didn't want to start from scratch and reinstall the Redhat Linux distribution just for a few packages. Poking around the Redhat FTP site, I saw that the source for the then-current version of rpm was available, and after various trials and tribulations I managed to successfully compile and install it. The crucial factor which made it all work was downloading and installing a newer version of cpio, which was right there in the Redhat rpm directory. It wasn't the easiest installation I've ever done, but I don't blame the folks at Redhat for not making it a no-brainer. After all, they evidently worked long and hard developing the rpm package system and they surely wanted to leverage its value in influencing users to buy their distribution. Redhat is to be commended for resisting purely commercial urges and making rpm freely available.
Two distributions later, I never have gotten around to reinstalling rpm, partly because the Debian distribution has a utility called alien, which will convert an *.rpm file into a *.deb file. This is a nice utility, but sometimes I'd just like to poke around inside a package and see what's there without actually installing it. Both rpm and Debian's dpkg utility have command-line switches for just listing the contents, or extracting individual files from a package. These aren't the sort of switches I would use often enough to memorize, and it's a pain to read the man page each time. So I gradually meander my way to the point of this article...
Recently, in nearly daily updates, Kent Robotti has been releasing to the Sunsite archive site a package of programs and scripts which simplify working with these various package formats. UnRpm is most useful when used in conjunction with the Midnight Commander file manager, as one component of the package is a set of entries meant to be appended to the mc user menu.
This is what the package includes:
The earlier versions of UnRpm-Install included statically-linked binaries, no doubt to make them usable by a wider variety of users, but with the disadvantage of large binaries. Since most systems have compatible libc versions installed, which is the only library linked with the binaries, recent versions have included the smaller dynamically-linked versions.
The Midnight Commander in its recent incarnations has excellent support built-in for treating these various archive formats as virtual file-systems, allowing the user to browse through their contents without actually expanding them. The menu entries provided by UnRpm expand upon these capabilities, making it easier than ever to convert one format to another and to see just what an archive will install on your system.
There's nothing in UnRpm-Install which you couldn't gather up yourself, from various FTP sites or distribution cd's. What makes the package valuable is that Kent Robotti has done this for you, and presented these disparate binaries and scripts as a coherent whole, bound together by the Midnight Commander used as archive manager.
Various versions of UnRpm-Install are still in the /pub/Linux/Incoming directory of the Sunsite FTP archive, but the most recent version will eventually make its way into the archive utility directory.