Archives for the ‘Linux’ Category

Convert video with subtitles to MP4 for iPhone/iPad (preliminary notes)

By now, we know of a few requirements for viewing video on iOS (iPhone/iPad et al.). The video codec should be H.264 or another “standard” MPEG codec, and the audio should be AAC. AC3, as far as I know, is not supported. That’s all fine and dandy, but subtitles have been one of the trickiest […]

Command-line snippets for processing scans

I originally wrote this in 2009 as a cheatsheet for processing black and white scanned sheet music. It’s a collection of tips for converting and processing scanned images to ultimately get a nice, high-quality PDF that you could archive. The programs convert and mogrify are part of the ImageMagick suite and the program pdfimages is […]

I just installed Ubuntu 10.04

I just installed Ubuntu 10.04 minimal on a server and it’s great. $ less -bash: less: command not found $ man bash -bash: man: command not found $ tree ./ -bash: tree: command not found $ whois google.com -bash: whois: command not found $ curl –help -bash: curl: command not found

Scheme in Javascript

Scheme’s power to simplicity ratio makes it a fun target for implementation. Today, I introduce a couple new ways of running Scheme powered by Javascript. The first is an online Scheme interface that I’ve been working on sporadically for the last few months. Inspired by TryHaskell, it began as a series of patches to jquery-console, […]

Convert PHP to static pages with GNU Make

I recently moved an old website to a new server. For performance reasons, the new server is running nginx instead of Apache, and didn’t have nginx set up to use PHP. (The optimal way, apparently, is to use PHP-FGM, which currently requires you to patch and build PHP yourself, at least until PHP 5.4). That […]

Android emulator temp directories

If you are using the Android SDK on a shared computer, you might run into the awesome “NAND: could not create temp file for system NAND” error. This is because “/tmp/android” is hardcoded into the emulator as the directory to start temporary files during emulation, and somebody else has likely claimed it first. The easiest […]

“usbscale”: read USB scales

I’ve just finished writing the big parts of usbscale, a command-line program written in C that reads and interprets data from USB scales. It was meant as a little hack for the Stamps.com scale, so currently it’s only set up to recognize the Stamps.com 10-lb scale (manufactured by Elane). It should be trivial to add […]

Petite Chez Scheme for Ubuntu

An Ubuntu package of Petite Chez Scheme seems to be a common request among students, given the popularity of Ubuntu among the techno-capable. ¬†Currently, only RPM packages are provided on the Chez Scheme site, and the traditional recommendation was to use alien to convert the RPM into a .deb. There’s no reason to have everybody […]

Reading a USB Stamps.com scale

Update: I now have an improved C version of this program: usbscale. I got suckered into one of those hard-to-cancel Stamps.com trials. The upside is that they give you a $10 USB 5 lb. scale to use with their software. The downside is that they want you to only use it with their software, and […]

GParted stuck on "Scanning all devices"

Ubuntu’s partition editor, GParted, usually scans all the hard drives when it starts. However, in some cases, it will get stuck on this “Scanning all devices” step indefinitely. By knowing what hard drive you want to edit, you can launch GParted specifically for that hard drive. Either go into run or a terminal, and run […]