Because the Debian system strives to maintain standardization, it can accommodate other types of packaged applications. Of course, source code for the programs can always be compiled, but you also can use pre-compiled packages such as RPM and tar.
The Red Hat Package Management (RPM) system was developed by Red Hat for their package. Since then, many other distributions have begun to use this package manager. The one thing RPM lacks is the customization scripts that are installed after a package is installed with the Debian system.
Debian can, however, receive RPM packages. To install an RPM package, you need to first install the rpm tool from the Debian archive. Once installed, you can install the RPM package. RPM can operate in several modes, although the two important ones for most cases involve querying and maintaining.
To query an RPM file, you list the content information about that file. This is similar to getting information about a Debian package using the -i option. Maintaining an RPM package includes installing, uninstalling, freshening, and verifying. The syntax listings for these modes are as follows:
Querying: rpm [--query] [queryoptions] rpm [--querytags]
Maintaining installed packages: rpm [--install] [installoptions] [package_file]+ rpm [--freshen|-F] [installoptions] [package_file]+ rpm [--uninstall|-e] [uninstalloptions] [package]+ rpm [--verify|-V] [verifyoptions] [package]+
- Querying packages—To query a package using the -q option, you will see the package name, the version, and release information about any RPM installed package.
- Installing packages—This lets you actually install the package onto the file system. RPM packages generally end in .rpm and include a platform description for which they are built, such as an i386.
- Uninstalling packages—This is for removing unwanted packages. It requires only that you know the name of the package, and not the original package file name.
- Freshening packages—Reinstalling a package using just the install options will generate an error that this package is already installed. You will need to replace the packages instead.
- Verifying packages—If you want to verify a package against the original RPM package file, use -Vp. This lets you know if any of the installed files have changed.
There is much more you can do with the Red Hat Package Management System. The most important thing is installing applications found in the RPM format. The preceding list of commands should get you started installing packages you find along the way.
Not all program creators take the time to create customized packages for different distributions. Some venders, on the other hand, have gone to great lengths to make their applications universal. Tar files are the universal packaging format for all UNIX systems. Often referred to as tarballs, these packages remain trusted and true.
A tar file contains the package, including any subdirectory structure. Tarballs are very easy to work with, which is why many people prefer to use them to distribute software. Here is an example of using tar to extract the files contained in a tarball:
tar xvf filename.tar tar zxvf filename.tar.gz
The first example shows a straightforward tar file. The second example shows a tar file that was compressed after the file was created. The z option decompresses the file before the x option extracts the files. The v indicates verbose mode, for displaying all the files as they extract.
The f option specifies that it uses the accompanying archive file. After a package has been extracted, follow the instructions that accompany the tar package. Usually, those instructions reside in the first directory that the extraction created. From this point on, every application installation varies.