Apple’s never been one for long-lived support of their word processing applications, but they stooped to new lows with their word processing application, Pages.

The latest version of Pages, version 5, released in 2013, cannot read documents created from version 3, last released in 2008.

Imagine if all the important papers in your filing cabinet were unreadable after 5 years. It’s dumbfounding.

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If you have a machine behind a NAT that you don’t want to directly expose to the internet, but want access to it, you can use autossh to create a tunnel.

Assuming the hostname of the machine behind the NAT is pi, and the host you can access is server, do the following steps:

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Tired of your headless Raspberry Pi corrupting itself because it never gets to shut down properly?

If you use a USB wifi dongle, you can use the act of unplugging the dongle to tell your Pi to shut down gracefully. Run lsusb and look for your wireless adapter:

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Update 2015/08/01: The broken cloudprint package that these instructions used to reference have been replaced with Google’s new connector.

There are several articles that proclaim how easy it is to set up a Chromium on a $35 Raspberry Pi to let you print to your printer with your Chromebook or mobile devices.

One unfortunate problem; none of those instructions work anymore.

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The Problem

Incremental feature development against existing systems frequently involves rethinking and rebuilding existing components. If it’s possible, the easiest way to add support for your new feature is to introduce a new, optional attribute on a model (or in the case of a relational database, adding a NULLable column to an existing table, or adding a new table). Sometimes, though, that either isn’t possible, or wouldn’t be the best design going forward, given your new knowledge of the feature set of the product at hand. You’re left with the uncomfortable realization that the best design would be something completely different that isn’t backward-compatible with current systems.

When there are multiple systems that consume a given data model (say, a front-end webserver, an API, tons of cron jobs, and many backend daemons, like in the case of Twitter’s Ads systems), you can’t just “stop the world,” ALTER your tables, and deploy all the new code. That’s fine if it’s you and another nerd in a garage, but when you’ve got paying customers, you don’t want to give them an excuse to spend their money elsewhere.

What to do?

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Travis CI is an awesome continuous integration service that’s free for open-source projects.

If you’d like to test your app against multiple database engines, it’s fairly simple.
For these examples, I’m testing my app against SQLite, MySQL, and PostgreSQL.

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