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!
![Create a Sheen Logo Effect with CSS]()
I was inspired when I first saw Addy Osmani's original ShineTime blog post. The hover sheen effect is simple but awesome. When I started my blog redesign, I really wanted to use a sheen effect with my logo. Using two HTML elements and...
![Write Better JavaScript with Promises]()
You've probably heard the talk around the water cooler about how promises are the future. All of the cool kids are using them, but you don't see what makes them so special. Can't you just use a callback? What's the big deal? In this article, we'll...
![Create a Clearable TextBox with the Dojo Toolkit]()
Usability is a key feature when creating user interfaces; it's all in the details. I was recently using my iPhone and it dawned on my how awesome the "x" icon is in its input elements. No holding the delete key down. No pressing it a...
![CSS calc]()
CSS is a complete conundrum; we all appreciate CSS because of its simplicity but always yearn for the language to do just a bit more. CSS has evolved to accommodate placeholders, animations, and even click events. One problem we always thought...
