Compdigitec Labs


Epson DS-30 on Ubuntu Linux

Saturday, February 13th, 2021 Use the attached ds-30-bundle, download from Install the deb packages with ./ –dry-run Use simple-scan to run the scan. Insert paper face down above/next tothe little scan marker and press the button

Running a GUI application in Docker

Saturday, January 30th, 2021

Creating a service to run a systemd-nspawn server

Thursday, January 28th, 2021

debootstrap –include=systemd-container –components=main,universe focal myContainer Edit /usr/lib/systemd/system/systemd-nspawn@.service ExecStart= -> remove -UAdd[Exec]PrivateUsers=off sudo systemctl daemon-reloadsudo systemctl restart systemd-nspawn@myContainer

Git refuses to discover new remote branches

Saturday, January 23rd, 2021

In addition to the excellent suggestions at, take a look in .git/config and make sure fetch is specified to only fetch the master branch: [remote “origin”] url = fetch = +refs/heads/master:refs/remotes/origin/master # bad You’ll want to change the fetch line to fetch all branches instead: [remote “origin”] url = fetch = +refs/heads/*:refs/remotes/origin/*

ImageMagick snippet: batch crop, dither, and guillotine

Thursday, November 12th, 2020

Concatenating PDFs while padding/extending odd-length PDFs

Saturday, October 10th, 2020

When concatenating PDFs to consolidate print jobs, it is nice to have single-page or PDFs with odd numbers of pages to not have to share sides with another unrelated document. There is a short script available at ; however, it does not appear to be updated for PyPDF2. So here is an update for […]

Scanning with Brother DCP-7065DN in Ubuntu

Saturday, September 12th, 2020

First, make sure the printer is detected in lsusb: Then, either add a udev rule to ensure that we have permission to access it, or use the following one-time hack: Now, install the correct driver for the printer from For the DCP-7065DN on Ubuntu 64-bit, the following package worked: Check that sane-find-scanner can see […]

Simple recursive DNS server with Unbound DNS

Thursday, July 30th, 2020

This is a simple configuration for running a recursive DNS server (passes DNS requests to another server and caches responses) with the Unbound DNS server. Installation (Ubuntu): Open the config Configuration Replace below with the desired upstream DNS server. Starting the server Debugging / Troubleshooting Query the server Read the DNS server log References: […]

Make fails silently

Tuesday, February 28th, 2017

Run make -d &> log.txt and examine the log. Likely there is some prerequisite which is missing, in the form of “File `foo’ does not exist.”

LaTeX macros ending in numbers

Saturday, February 13th, 2016

Only letters are directly permitted in macro names, but by using csname to create definitions along with a variable command, we can simulate them. First, define the macros with numbers using \csname: Now, create a command which takes in one variable argument, and simply expands it to call the appropriate macro (“xR” + variable) defined […]

« Previous Entries