====== Ubuntu - Packages - Search Packages ======

Search for packages with "foo" in the name:

<code bash>
aptitude search foo
</code>

Search for **installed** packages with "foot" in the name:

<code bash>
aptitude search '~foo'
</code>


Search for packages from the section "foo" that are not installed:

<code bash>
aptitude search \!~i~sfoo
</code>


Pipelines allow complex searches:

<code bash>
aptitude search '~i' | grep -ie 'x11\|xorg' | less
</code>


Looking for packages installed from anything else than stable:

<code bash>
aptitude search '?narrow(?installed, !?archive(stable))'
</code>


Looking for packages installed from testing (assuming you have sources lists with stable and testing repositories):

<code bash>
aptitude search '?narrow(?installed, ?archive(testing) !?archive(stable))'
</code>


Shows all packages which are installed on your system because some other package recommends it, but they are not actually dependencies of packages:

<code bash>
aptitude search '?and( ?automatic(?reverse-recommends(?installed)), ?not(?automatic(?reverse-depends(?installed))) )' 
</code>

can give something like this:

<code bash>
i A apt-xapian-index    -   maintenance and search tools for a Xapian index of Debian packages 
i A exim4               -   metapackage to ease Exim MTA (v4) installation 
i A file                -   Determines file type using "magic" numbers 
i A heirloom-mailx      -   feature-rich BSD mail(1)  
</code>

To determine why an automatically installed package is present on the system:

<code bash>
aptitude why python-debian
</code>

Returns something like:

<code bash>
i   aptitude         Recommends apt-xapian-index         
i A apt-xapian-index Depends    python-debian (>= 0.1.15)
</code>

----

===== Package Column Information =====

The first column of information displayed in the package list in the top pane, when actually viewing packages lists the current state of the package, and uses the following key to describe the state of the package:

  * i: Installed package
  * c: Package not installed, but package configuration remains on system
  * p: Purged from system
  * v: Virtual package
  * B: Broken package
  * u: Unpacked files, but package not yet configured
  * C: Half-configured - Configuration failed and requires fix
  * H: Half-installed - Removal failed and requires fix


**NOTE**:  **aptitude search foo** is slower than using **apt-cache search foo** to perform a search.

The output is also a bit different from **apt-cache**.

Use whichever method is preferred.