Some usefull commands:

To add a broken pgp key

try

# sudo apt-key adv –recv-keys –keyserver keyserver.ubuntu.com 0x0e494dbb2f021ac1
where 0x0e494dbb2f021ac1 is the key that needs to be added

If this is not working then you need to add a step more.

# gpg –keyserver subkeys.pgp.net –recv C71839136CF5CE97
(replace “C71839136CF5CE97” by the code in your error message)

# gpg –export –armor C71839136CF5CE97 | sudo apt-key add –
(here again, replace “C71839136CF5CE97” by the code in your error message)

Uninstall a hidden application (like AIR applications)

 

 

  • Hit the terminal.
  • Enter ‘sudodpkg-S /opt/*’ (without quotes).
  • You will get an output like this:

    adobeair1.0: /opt/Adobe AIR
    boxee: /opt/boxee
    app.destroyflickr.f242b970c206039aa6d597ec43895e3dd9c3cfe0.1: /opt/DestroyFlickr
    app.destroytwitter.23ca2f9b070e2fb8c4472f982f88b1a471f11ae2.1: /opt/DestroyTwitter
    com.friendfeed.friendfeed.e15dd0e93fae91f55000c2534280f7d2e075d241.1: /opt/FriendFeed
    picasa: /opt/google
    com.seesmic.desktop.client.d89f32799270693bef34aaa36e9b2632b59240fa.1: /opt/Seesmic Desktop
    com.nyt.timesreader.78c54164786ade80cb31e1c5d95607d0938c987a.1: /opt/Times Reader
    tweetdeckfast.f9107117265db7542c1a806c8db837742ce14c21.1: /opt/TweetDeck

  • Enter ‘sudo dpkg -P tweetdeckfast.f9107117265db7542c1a806c8db837742ce14c21.1’ for example to uninstall TweetDeck.
  • You will see the output like this:

    (Reading database … 117955 files and directories currently installed.)
    Removing tweetdeckfast.f9107117265db7542c1a806c8db837742ce14c21.1 …

  • That’s it.  Any application can be uninstalled by copy and pasting the required location from the output received in step 3.