Ubuntu 20.04 getting wrong IP address

Yesterday (early August 2021) my Ubuntu 20.04 installation started configuring all network interfaces (wifi, ethernet) with IPv4 addresses from the wrong network segment block, namely 192.168.0.x. IPv6 still worked fine. I didn't figure out whether that's due to a change in the router or the OS (I suspect the router, because the situation improved when … Continue reading Ubuntu 20.04 getting wrong IP address →

Extracting field with fluentd

While playing around with fluentd the need came up to extract data nested deep into the logging input and add it as a flat field to the output. If you're not familiar with fluentd (I'm not): it's similar to logstash in that it collects logs from a variety of sources, filters, transforms and categorises them … Continue reading Extracting field with fluentd →

Double push-pull amplifier with cross over compensation

Push-pull amplifiers [1] are great for driving heavy loads because they divide work among two transistors and produce a centred output signal that can freely move up or down around the centre. Simple push-pull amplifier When powering the amplifier with a single power source (eg. a 12V battery), then the output signal oscillates around half … Continue reading Double push-pull amplifier with cross over compensation →

Search multiple PDFs in Linux

What user sjr said on https://stackoverflow.com/questions/4643438/how-to-search-contents-of-multiple-pdf-files find /path -name '*.pdf' -exec sh -c 'pdftotext "{}" - | grep --with-filename --label="{}" --color "your pattern"' \;

Death penalty and justice

One of the many reasons to oppose the death penalty is its incompatibility with the goals of justice. As a fan of systems thinking I feel that capital punishment deprives justice of its most valuable functions that make a system work. The functions of justice Due process: we want to know that a dispute is … Continue reading Death penalty and justice →