Education and creativity

Posted by Alberto - 30/11/10 at 01:11:03 am

These days im studying a course about innovation and creativity at UOC (Open University of Catalonia). During this course, we have seen this video about education and creativity. I found it very interesting and I want to share it with all of you.

Solving fake checkouts using ClearCase and Eclipse

Posted by Alberto - 08/11/10 at 01:11:35 am

I’ve been using ClearCase and Eclipse in a Unix environment for the last eight months. One of the most commons problems I had while working with static views is the following: sometimes, Eclipse marked one or more files as checked out, when it was not true. So the situation was:

  • I couldnt edit the file because it wasnt checked out
  • I couldnt check out the file, because for Eclipse, it was checked out
  • I couldnt undo checkout due to there was no checkedout file

This problem is caused by a conflict between Eclipse and the ClearCase plugin. The solution was the following:

  • Close Eclipse
  • Open a terminal window and enter in the directory in where the file is located.
  • Modify the file “.copyarea.db“. This file is used by Eclipse to store some information about the files contained in each directory. It looks like:

    ClearCase CopyAreaDB
    <current directory>
    10:file01.txt|<some metadata (time stamp, checksum..)>
    14:file02.txt|<some metadata (time stamp, checksum..)>
    11:file03.txt|<some metadata (time stamp, checksum..)>

  • Modify the file permissions:

    $> chmod +x .copyarea.db

  • Locate the line containing the information related to our file
  • The most important part: Last digit in that line indicates if the file is checked out or not. It will be “1″ if it is checked out, or “0″ if it isnt. So, if we see the last digit is “1″, we found the problem. Change it to “0″, and save the file. This is how the line looks like before:

    10:file01.txt|<some metadata>|1

    And this is how it will look after:

    10:file01.txt|<some metadata>|0

  • Restore the file permissions:

    $> chmod -x .copyarea.db

    • Now, if you restart Eclipse, the problem should be solved.

    Adding repositories on Ubuntu

    Posted by Alberto - 05/11/10 at 09:11:32 pm

    There are three ways to add new software repositories on Ubuntu:

    1. Using the graphical interface

    Depending on the version of Ubuntu you are using, you will have to look for the “Software Sources” option in a different place. For example:

    • System -> Administration -> Software Sources
    • System -> Administration -> Synaptic Package Manager -> Settings -> Repositories
    • Ubuntu Software Center -> Edit, Software Sources


    2. Editing sources.list file

    Ubuntu uses apt for package management. The list of repositories is stored in the file

    /etc/apt/sources.list

    This file contains lines similar to:

    deb http://us.archive.ubuntu.com/ubuntu/ hardy main restricted
    deb-src http://us.archive.ubuntu.com/ubuntu/ hardy main restricted

    Each repositoy is defined by four elements:

    • Type of packages stored. deb in case of binaries or precompiled packages, or deb-src in case of the source code of the packages.
    • The URL of the repository
    • The name of your Ubuntu version (intrepid, hardy, lucid…)
    • The section name (main, restricted, universe, multiverse, partner…). There can be one or several names.


    3. Using apt-add-repository command

    In Ubuntu 9.10 (Karmic Koala) or later, it is possible to add repositories using Launchpad PPA (Personal Package Archive) addresses using the command apt-add-repository.

    sudo add-apt-repository ppa:<repository-name>

    If you dont have it installed in your computer, you have to install the packet python-software-properties

    sudo apt-get install python-software-properties

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