Use the PDF toolkit: sudo apt-get install pdftk To rotate page 1 by 90 degrees clockwise: pdftk in.pdf cat...
Linux provides a fix number of filesystem watches. If you have some greedy daemon (like dropbox) running, chances are it...
Do you wonder which databases are actually taking up how much space but only have one huge ibdata1 in your...
Grep prints one line per match. To return the number if matches, use the -c switch: grep -c "something" filename...
If you use Amazon AWS cloud services you definitively want to utilize software raid for IO intensive stuff such as...
Whenever you deploy using Capistrano, a new folder is created within the releases directory on the remote server containing the...
Under the same origin policy, a web page served from server1.example.com cannot normally connect to or communicate with a server...
This is now part of geordi. Please don't follow the instructions below, if you use geordi. Inspired by the...
When you have a program running in a hidden X screen (like with Xvfb for Selenium tests) you may want...
Resque comes with its own dashboard (Resque server) that you can mount inside your Rails 3 application with #config/routes.rb:
Note: While the solution in this card should still work, we prefer another solution now: Hide your Selenium browser window...
Note: If you are currently working with Ruby 1.8.7 or 1.9.3, we recommend to upgrade to Ruby 2.1 first. From...
Ubuntu comes with keyboard layouts like "Germany Eliminate Dead Keys", which are practical for programming. If you need to type...
Sometimes you need a file of some size (possibly for testing purposes). On Linux, you can use dd to create...
Some folks have started to keep their linux configuration in a git repository called "dotfiles". This sounds like a good...
VirtualBox does not offer anything for this task -- you need to do it yourself. It's not that hard:
When you do a bitwise copy using the dd tool you will not see any output until it completes or...
When you generate a URL in a mailer view, ActionMailer will raise an error unless you previously configured it which...
cpulimit is a simple program which attempts to limit the cpu usage of a process (expressed in percentage, not in...
I've recently encountered a weird problem with specs making lots of SOLR queries using the acts_as_solr plugin...
Here are some popular mistakes when using nested forms: You are using fields_for instead of form.fields_for.
We're adding a script console-for to open a remote Rails console with one command. Also have a look...
If you are exchanging files with a client via Dropbox you do not need to access the Web page every...
If you stub a method or set expectations with should_receive these stubbed methods may also yield blocks. This is...