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today's howtos
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Linux Capable ☛ How to Install QSpeakers on Ubuntu 26.04, 24.04 and 22.04
Install QSpeakers on Ubuntu 26.04, 24.04, and 22.04, then turn driver measurements into a practical enclosure comparison. Select a known or custom loudspeaker, compare sealed, ported, and bandpass response curves, and save a baseline before changing the design.
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Linuxize ☛ How to Convert MP4 to MP3 with ffmpeg
Convert MP4 video to MP3 audio from the GNU/Linux command line with ffmpeg, including quality settings, lossless extraction, trimming, and batch conversion.
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ID Root ☛ How To Install Yarn on Fedora 44
Every few months, a developer on my team pings me with some variation of the same message: “Yarn is broken on my new Fedora box.”
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Andreas ☛ Parasitic computing with ICMP: making routers do arithmetic | Anagogistis
When a router throws a packet away because its TTL hit zero, it will often send back an ICMP Time Exceeded message to inform us about it. That reply quotes the original IPv4 header and at least the first eight bytes of the payload, and the ICMP checksum is computed over all of it, quoted bytes included. So part of the checksum’s input is whatever we chose to put in that payload.
The rest of that input is not ours to set, being the ICMP header the router writes and the copy of our own IPv4 header. Both can be made to cancel out, as we will show, and what is then left in the reply is the Internet checksum of 48 bits we picked ourselves. The router has done a piece of arithmetic for us while only trying to tell us that our packet expired, and it never finds out that it helped.
This is in the spirit of parasitic computing, the idea of using protocol machinery for work that has nothing to do with its purpose. The classic version of the trick abuses TCP checksum validation to answer yes-or-no questions. Here the checksum field is not a test but the result itself, and with some chaining it is enough to build addition, subtraction and multiplication out of nothing but expired packets.
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[Old] Leah Rowe ☛ How to self-host servers in your living room on static IPs
Most people assume that a router is a piece of hardware, but that’s not true. The router is actually software, and the hardware is just what that software runs on. Almost anything can be a router, just like anything can be on a cob in that one episode of Rick and Morty. The laptop in the photo is my router, configured in exactly the way this guide describes.
Have you ever wanted to host a server at home or in your office, but you can’t because the ISP won’t give you static IPs? Are you behind a CGNAT? This guide is for you. It will teach you how to route static IPv4 and (native) IPv6 addresses to your network, with hosts directly pingable on the internet and all ports open. With this guide, you won’t need to host your software project on github anymore, because you can instead install gitea/cgit with a mailing list on your raspberry pi and host it in your basement or living room!
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HowTo Geek ☛ 5 command-line apps I install on every new Linux PC
Any serious Linux user will have their list of favorite command-line apps that they immediately install on any new machine. I am no exception. It seems I'm finding more apps that I want to install. Here are some more of my go-to terminal apps.