7deeds

I upgraded Ubuntu 9.10 to 10.04. Everything was cool. I tried to work on a Rails project I am involved by issuing the command rake db:migrate to update the database.

I was getting the following error:

Error: uninitialized constant MysqlCompat::MysqlRes

Then I uninstalled the mysql gem and tried to install it again only to get the following error:

Building native extensions. This could take a while...
ERROR: While executing gem ... (Gem::Installer::ExtensionBuildError)
ERROR: Failed to build gem native extension.

Then I issued the following command:

sudo apt-get install libmysqlclient-dev

and then installed mysql gem and it installed with no problems. Finally, rake db:migrate worked again.

If you are using zsh as your terminal in Ubuntu, you can use a built in feature to display version control information at the prompt.

After reading “Zsh Prompt Magic” I created the zsh_vcs_info file which you can download. You place it in your home directory and open .zshrc and add the following line:

source /home/user/.zsh_vcs_info

Notice that I added a . (dot) in the filename because I want it to be hidden. Also, notice that “user” in the path above, is the username of the account you use to log into Ubuntu.

A few months ago, I got a new computer in the office. Instead of Windows I decided I wanted to try out Ubuntu.

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md5sum file.iso > file.iso.md5

In order to turn a CD/DVD into an .iso one can:

sudo umount /dev/cdrom

dd if=/dev/cdrom of=file.iso bs=1024

In order to turn a folder into an .iso one can:

mkisofs -r -o file.iso /location_of_folder/

Related posts:

• How to generate the MD5 checksum of a file

My first computer was an Amstrad CPC 6128, my second an Amiga 500 and my third and Amiga 2000. Then and onward, every computer I owned belonged to the PC category operated through Microsoft products: DOS and later Windows.

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