Showing packages installed on the system: show-installed

[FlorianFesti]

Hi everyone!

During Richard Hughes' "Linux and application installing" thread[1] I 
had argued that just showing a list of packages won't cut it for most 
use cases around package handling. One of those use cases is showing 
which packages are installed on a system. For getting an idea about a 
machine a list of about 1500 packages is not really helping. In a side 
note I came up with the following idea [2]:

> Generate a packages section as found in a kickstart file and showthis as
> "Installed Packages". Remove all packages required by others and reduce
> packages to groups whenever possible. May be even to a group with some
> packages missing. Minimizing the number of lines should get pretty good
> results."

This is now implemented as "show-installed" which is part of 
yum-utils-1.1.29-2.fc15 found in Fedora devel. It supports three 
different output formats: kickstart %packages, yum cli and human 
readable. It also supports a number of options for controlling the 
output and whether it should consider excludes to make use of even more 
groups. See "man show-installed" or "show-installed --help" for details. 
As the script also takes a list of package names it can be used to 
create a package list on/for a newer release. As it has not seen too 
many real world use suggestions and bug reports are welcome.

While show-installed might be a useful tool I primarily see it as part 
of the package handing UI discussion. Tools like gpk-application or 
yumex could offer this as a condensed view. May be even the list of 
available packages could presented like this. I separated the logic from 
the actual formatting code so it should be easy to toy around with the 
Python class or to translate the pretty simple algorithm to another 
programming language. Feel free to ask me on #yum if you have question 
or need help with that.

Florian

[1] 
http://lists.fedoraproject.org/pipermail/devel/2010-September/thread.html#142599
[2] 
http://lists.fedoraproject.org/pipermail/devel/2010-September/143349.html