Command Line Polling
In an ideal world, we wouldn't have to poll for anything; we would always have events to trigger other functions. This isn't an ideal world, however, so it's important to know how to poll in multiple programming languages. I've covered JavaScript polling (with and without Promises), but what about command line polling? For example, ensuring MYSQL is up before attempting to perform more operations.
Here's the basic syntax:
# while ! (command here); do
while ! mysql -uroot; do
sleep 1
done
The example above performs the mysql -uroot operation (which will fail until mysqld is up) every second. Keep in mind the poll operation you run should be as simple as possible, just enough to know that what you want to use is available!
![39 Shirts – Leaving Mozilla]()
In 2001 I had just graduated from a small town high school and headed off to a small town college. I found myself in the quaint computer lab where the substandard computers featured two browsers: Internet Explorer and Mozilla. It was this lab where I fell...
![9 Mind-Blowing WebGL Demos]()
As much as developers now loathe Flash, we're still playing a bit of catch up to natively duplicate the animation capabilities that Adobe's old technology provided us. Of course we have canvas, an awesome technology, one which I highlighted 9 mind-blowing demos. Another technology available...
![Background Animations Using MooTools]()
One of the sweet effects made easy by JavaScript frameworks like MooTools and jQuery is animation. I ran across this great jQuery tutorial that walks you through animating a background image of a page. Here's a quick MooTools code snippet that...
![Better Pull Quotes with MooTools]()
Chris Coyier authored a post titled Better Pull Quotes: Don't Repeat Markup a while back. In his post he created great-looking pull quotes without repeating any content -- instead he uses jQuery to dynamically create the pull quotes. The following is the...
