Installing the MySQL RubyGem on Ubuntu

I have successfully installed the MySQL driver for Ruby on Windows and Mac OS X but I had not installed it on Ubuntu until today.

I am assuming that you have already installed the MySQL server.  I am using MySQL 5.1.
$ sudo apt-get install mysql-server

Install the MySQL database client library.  I am not certain of this but I believe that the number '15' in 'libmysqlclient15-dev' indicates the version.  This is apparently the most current one and the default version on Ubuntu 10.4 as of today.
$ sudo apt-get install libmysqlclient15-dev

Install RubyGems if you have not done so already.  I am using Ruby 1.9.1.
 $ sudo apt-get install rubygems1.9

If everything was successfuly, then you should be able to use the mysql RubyGem in  your Ruby scripts.

Formatting Hex Strings in Ruby

This method converts a 1 or 2 character string representing a hex number into a 2 character string representing a hex number.

Usage examples:

irb(main):001:0>format("a")
=> "0A"
irb(main):002:0>format("2D")
=> "2D"


Implementation:

def format_hex_string(byte)
    byte.upcase
    byte.to_i(16) >= 16 ? byte : "0" + byte
end