I’ve been experimenting a bit with Software Defined Radio, and specifically the gqrx and gnuradio tools. The I/Q (In-Phase/Quadrature components) recorder in gqrx can record .raw files, which handily record the entire spectrum visible in the waterfall window. In this blog post, I will show how to load data from those files, extract a subset of the recording, and save that into a new file. Unlike .wav files (for which a plethora of tools exist), I found little documentation on how to work with these files outside gnuradio/MATLAB/Octave.
In this post I’ll discuss how Bison’s GLR-parser feature can be used to solve a Facebook Hacker cup parsing problem. The problem at hand requires parsing text that is ambiguous, i.e. there exist multiple correct interpretations.