Spellcheck in Emacs

Recently I am using Emacs for writing a few essays. While writing, I started missing spellcheck feature of Microsoft Word. The fact that feature is also provided my many browser based tools, like in GMail has made me used to it. So, I did a quick lookup to find the shortcut for triggering spellcheck in the current Emacs buffer. The answer was to simply use M-x ispell. Trying that I got the following error in the Messages buffer below the main buffer.

No word lists can be found for the language "en_US"

The shortcut mentioned above uses aspell which I knew is installed on my system. So, looking for aspell errors, I figured I needed to install the package aspell-en to get it fixed. On Arch linux, it can be done using the following.

pacman -S aspell-en

Gem installation fails due to packaged gems

Rake 0.9.6 comes bundled with ruby 2. However, I needed to build ruby-debug-ide 0.4.17.beta16 against rake 0.8.7. I tried uninstalling rake 0.9.6 but there is no way to do it. Using the following command does not list 0.9.6 as an option.

gem uninstall rake

So, now I had to find a way to tell the gem utility to use rake 0.8.7 instead of 0.9.6. A little reading showed that setting the RAKE environment variable could do this.

RAKE=/usr/lib/ruby/gems/2.0.0/gems/rake-0.8.7/bin/rake gem install ruby-debug-ide -v 0.4.17.beta16 --pre

The above  did not work for some reason. After that I tried the following and it worked.

RAKE=`bundle exec rake` gem install ruby-debug-ide -v 0.4.17.beta16 --pre

Checking memory usage for a set of processes

Recently, I had to monitor memory usage of a set of processes. I used pmap to help me out. The following script gave memory usage of each PID I was interested in.

for foo in `ps aux | grep <my_process_identifier> | awk -F ' ' '{print $2}'`
do
echo $foo
pmap $foo | tail -n 1
done

Coherence break in user experience

Why give the option for special characters when they are not accepted?

Set MySql output charset

The character set of the results returned by MySql is controlled by character_set_results variable. When a client connects to a MySql server, this variable is set to the character set of the environment of the client. So, if you connect from a ISO-8859-1 (latin 1) console, the variable is set to latin 1 encoding. The current value can be checked by the following query.

show variables;

To set the variable, the client can be initialized from a console which has its encoding set appropriately or one can run the following query.

set character_set_results = <character_set>;