How to roll back packages on CentOS 5 / RHEL 5

CentOS 5 / RHEL 5 preferably uses yum as the program to update, install and remove packages.
When you’ve installed/updates packages with yum or rpm, you can quite easily roll back the updates/installations using rpm.
For this, yum and rpm need to save roll back information, which they do not do by default.
To enable the roll back feature, do the following:

Add tsflags=repackage to /etc/yum.conf.
Add %_repackage_all_erasures 1 to /etc/rpm/macros. If /etc/rpm/macros does not exist, just create it.

You can now install, erase and update packages with yum and/or rpm, and they will save roll back information.

When you want to roll back, use rpm to do so.
You do this by specifying the --rollback switch and a date/time, like the examples below:

rpm -Uhv --rollback '19:00'
rpm -Uhv --rollback '8 hours ago'
rpm -Uhv --rollback 'december 31'
rpm -Uhv --rollback 'yesterday'

Source: http://www.vincentverhagen.nl/2007/12/10/how-to-roll-back-packages-on-centos-5-rhel-5/

Telnet under Win7

It’s very rare that I use Telnet these days, so it took a long time for me to notice that by default it was not packaged with Windows 7. I did some research and found out that this was also true for Windows Vista. More than likely this was an attempt to make Windows more secure by default, as Telnet is very insecure and whenever you have the choice you should always use SSH. However, with that being said, you can quickly re-enable Telnet by following these steps:

- Start
- Control Panel
- Programs And Features
- Turn Windows features on or off
- Check Telnet Client
- Hit OK

After that you can start Telnet via Command Prompt.

Source: http://www.fettesps.com/windows-7-enable-telnet/

Version Control for Multiple Agile Teams

If we have several agile development teams working on the same codebase, how do we minimize the risk of stumbling over each other? How do we ensure that there always is a clean, releasable version at the end of each iteration?

http://www.infoq.com/articles/agile-version-control

New PUTTY!

After 4 years there's a new release of the infamous SSH-client: Putty 0.61 is out

Grab your copy here: http://www.chiark.greenend.org.uk/~sgtatham/putty/

Lazy SVN commits

You're a programmer and therefor lazy. You also hate the mandatory commit messages for SVN. Well lucky for you there are a lot of people who feel the same way.
So let's make live a little less boring by automating the commit messages. Let me know after how many commits somebody caught you with this automated commit messages generator.

svn ci -m "`curl -s 'http://whatthecommit.com/' grep '<p>' cut -c4-`"

Shoo flash

I found this excellent article from a decade ago about not using flash _at all_. While we are anticipating on the standard of html in which, hopefully, flash is banned forever, flash designers keep making the same mistakes still.

Link: http://www.useit.com/alertbox/20001029.html

Kill Comic Sans

One of the worst inventions ever is Comic Sans. Lucky I don't stand alone, a lot of websites are dedicated to erase Comic Sans from existence, here's at least one: http://www.agencyfusion.com/intro/index2.html

Source: http://www.theregister.co.uk/2011/01/31/verity_stob_comic_sans/