Linux-Fu: Running Commands

July 7, 2017 by Al Williams 26 Comments

One of the things that makes Linux and Unix-like systems both powerful and frustrating is that there are many ways to accomplish any particular goal. Take something simple like running a bunch of commands in sequence as an example. The obvious way is to write a shell script which offers a tremendous amount of flexibility. But what if you just want some set of commands to run? It sounds simple, but there are a lot of ways to issue a sequence of commands ranging from just typing them in, to scheduling them, to monitoring them the way a mainframe computer might monitor batch jobs.

Let’s jump in and take a look at a few ways you can execute sequences from bash (and many other Linux shells). This is cover the cron and at commands along with a batch processing system called task spooler. Like most things in Linux, this isn’t even close to a complete list, but it should give you some ideas on ways to control sequences of execution.

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DEF CON Badgelife: The Puffy That Runs Linux

July 7, 2017 by Brian Benchoff 9 Comments

DEF CON is canceled again this year, and this time that statement is at least partially true. There will be no special official badges this year. There is no challenge or mystery embedded in the official DC badge. This is the year that unofficial badges from villages and random attendees finally supersedes the official offering. This is badgelife, and for the next few weeks, we’re going to be taking a look at some of the unofficial badges of DEF CON.

The idea for [dorkengine]’s Puffy badge began last year with the so-called Bender badges from AND!XOR. Chalk this up to a story that ends with, ‘but you had to have been there’, but the Bender badges were wildly popular, sold like hotcakes, and were an astonishing success of independent badge craft at DC. [dorkengine] decided to get in on the action and build his own badge for DC 25.

The design of the Puffy badges is based on a highly stylized rendering of the OpenBSD logo and mascot. Why a pufferfish with Kardashian lips? [dorkengine] has a bunch of boxes in a closet running OpenBSD, and that’s a good enough reason for us.

An electronic badge must do something, and the feature list [dorkengine] came up with included some sort of wireless connectivity, hackability, a serial console, blinkenlights, and some sort of *nix-ish OS. OpenBSD didn’t make the cut, but [dorkengine] eventually stumbled upon the VoCore2, a tiny System on Module that runs Linux, has WiFi and a few GPIOs, and is barely an inch on a side.

After getting a good deal on a large order of VoCores, [dorkengine] started on the PCB. The circuit was simple enough with just a VoCore attached to a USB port, power adapter, and a few LEDs. The Puffy rendering translated beautifully into soldermask and silkscreen, and after a prototype from ITEAD Studio, [dorkengine] had 40 PCBs that worked perfectly.

So, what is [dorkengine] going to do with a box full of Puffy badges? He’ll be selling them for $40 around the con. That’s surprisingly inexpensive for a large PCB soldered to a $17 SoC. If you want to get your grubby mitts on one, you could email him or ping him on Twitter. Of course, if you want to make your own, [dorkengine] has the KiCad files and software available, but at this point, you’re looking at a very fast turnaround for a board house.

Tetris On A Soldering Iron

July 7, 2017 by Elliot Williams 20 Comments

Our commenteers have all said good things about the open-source TS100 soldering iron pencil: things like “it solders well”. But we’ve all got soldering irons that solder well. What possible extra value does having open-source firmware on a soldering iron bring? [Joric] answered that question for us — it can play Tetris. (Video embedded below.)

While that’s cool and all, it wasn’t until we were reading through the README over at GitHub that the funniest part of this hack hit us. Every time you lose a game, the iron tip temperature increases by 10 degrees. Tetris for masochists? The makings of some horrible bar bets? We’re just glad that it’s open-source, because we’re not that good and it would get too hot to handle fast.

We haven’t tried out a TS100 yet, but this hack is almost pushing us to impulse purchase. There are alternative versions of the firmware if you just don’t like the font, for instance. And now, Tetris. Will this become the hot new gaming platform that you’ve been waiting for? Let us know in the comments.

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