LINUX – Move MySQL data directory

LinuxIn newer versions of Linux it’s not easily possible to just move the MySQL data directory to another location and modify my.cnf or create a symbolic link. There is a secutity/protection “daemon” running in background checking which locations is some process trying to access. If it’s allowed, then access is granted, otherwise the process is unable to read/write the required data. This guardian is called “APPARMOR” Continue reading

GIT – Change author or committer

If you want to change author’s and/or committer’s name and/or email in given GIT revisions, you can use the following script:

git filter-branch -f --commit-filter '
  if [ "$GIT_AUTHOR_NAME" = "Old Author" ];
  then
    export GIT_AUTHOR_NAME    = "New Author";
    export GIT_AUTHOR_EMAIL   = "new_author@example.com";
    export GIT_COMMITTER_NAME  = "New Author";
    export GIT_COMMITTER_EMAIL = "new_author@example.com";
  fi;
  git commit-tree "$@"'

Now update the remote (bare) repository

git push --force --tags origin 'refs/heads/*'

ABAP – Convert numbers on input and output

SAPI’m affraid there might be a standard function module already available to achieve the same what I’m going to write myself, but I believe it is good to know that the number format can be different when different user settings is used in SAP.
If you forget about this during your development you might start fighting serious problems in the future.
Therefore I’ve written two short code snippets for numbers conversion for INPUT (save to database) and OUTPUT (display to the user) Continue reading

Excel – Ignore blanks and duplicates in Validation list

I faced a problem where I had a worksheet where in column A there were items I wanted to use as source for validation list in another column. But these items were not unique, therefore they appeared in the validation list not just once. So I used the solution presented below to automatically create a unique list in a spare column and assign that list as the source of data validation drop down list for a specified cell range Continue reading

Best programmer replies when something is wrong

  1. That’s weird…
  2. It’s never done that before.
  3. It worked yesterday.
  4. How is that possible?
  5. It must be a hardware problem.
  6. What did you type in wrong to get it crash?
  7. There is something funky in your data
  8. I haven’t touched that part in weeks!
  9. You must have the wrong version
  10. It’s just some unlucky coincidence
  11. I can’t test everything!
  12. THIS can’t be the source of THAT
  13. It works, but is hasn’t been tested
  14. Someone must have changed my code
  15. Did you check for a virus on your system?
  16. Even though it doesn’t work, how does it feel?
  17. You can’t use that version on your system
  18. Why do you want to do it that way?
  19. Where were you when the program blew up?

And the Number One reply by programmer when their programs don’t work:

  1. It works on my machine

MySQL Master Slave replication

MySQLSometimes it might be usefull or even needed to replicate data from one place to another. If you have data you want to replicate in MySQL database, you are lucky, because replication is integrated in MySQL by default and you just have to set it up. Continue reading

Install Subversion and WebSvn on Ubuntu Server

UbuntuVersion control of your documents and code should be one of your first and major TO-DOs if you intend to develop application or website and you plan to maintain it during time with possibility to view changes made during it’s life cycle. Continue reading

Ruby on Rails on Ubuntu 12.04 LTS

About Ruby on Rails


Ruby on Rails is an application stack that provides developers with a framework to quickly create a variety of web applications.

Ruby on Rails does take a little while to install on a virtual server, but luckily there are a lot of helpful tools to make this process as easy as possible. Continue reading

How to Install and Configure Dropbox on Ubuntu Server 12.04

Dropbox is the best free cloud service and extremely easy-to-use tool for sharing files and syncing them between computers, and you can also use Dropbox to back up files and access them from other computers and devices (including from your Android Smartphone, android tablets and iPad or iPhone, with dedicated Client apps for each of those devices). How to make dropbox features and services available on ubuntu server?

in this post I would like to show you step by step How to Install Dropbox on Ubuntu Server 12.04 and Sync up to your Dropbox Account. Lets start it. Continue reading