Thunderbird: Upgrade notes

Introduction These are my notes as I upgraded Thunderbird from version 3.0.7 (released September 2010) to 91.10.0 on Linux Mint 19. That’s more than a ten year’s gap, which says something about what I think about upgrading software. What eventually forced me to do this was the need to support OAuth2 in order to send [...]

Run Firefox over X11 over SSH / VNC on a cheap virtual machine

To run over SSH: Not This is how to run a Firefox browser on a cheap VPS machine (e.g. a Google Cloud VM Instance) with an X-server connection. It’s actually not a good idea, because it’s extremely slow. The correct way is to set up a VNC server, because the X server connection exchanges information [...]

Using firejail to throttle network bandwidth for wget and such

Introduction Occasionally, I download / upload huge files, and it kills my internet connection for plain browsing. I don’t want to halt the download or suspend it, but merely calm it down a bit, temporarily, for doing other stuff. And then let it hog as much as it want again. There are many ways to [...]

Octave: Creating images from plots for web page

This should have been a trivial task, but it turned out quite difficult. So these are my notes for the next time. Octave 4.2.2 under Linux Mint 19, using qt5ct plugin with GNU plot (or else I get blank plots). So this is the small function I wrote for creating a plot and a thumbnail: [...]

When dovecot silently stops to deliver mails

After a few days being happy with not getting spam, I started to suspect that something is completely wrong with receiving mail. As I’m using fetchmail to get mail from my own server running dovecot v2.2.13, I’m used to getting notifications when fetchmail is unhappy. But there was no such. Checking up the server’s logs, [...]

Running Xilinx Impact on Linux Mint 19

Introduction This is my short war story as I made Xilinx’ Impact, part of ISE 14.7, work on a Linux Mint 19 machine with a v4.15 Linux kernel. I should mention that I already use Vivado on the same machine, so the whole JTAG programming thing was already sorted out, including loading firmware into the [...]

systemd: Shut down computer at a certain uptime

Motivation Paid-per-time cloud services. I don’t want to forget one of those running, just to get a fat bill at the end of the month. And if the intended use is short sessions anyhow, make sure that the machine shuts down by itself after a given amount of time. Just make sure that a shutdown [...]

Systemd services as cronjobs: No process runs away

But why? Cronjobs typically consists of a single utility which we’re pretty confident about. Even if it takes quite some time to complete (updatedb, for example), there’s always a simple story, a single task to complete with a known beginning and end. If the task involves a shell script that calls a few utilities, that [...]

Decoding email’s quoted-printable with Perl

To make it short, the command at shell prompt is $ perl -MMIME::QuotedPrint -e ‘local $/; $x=<>; print decode_qp($x)’ < quoted.txt > unquoted.html and I needed this to extract an HTML segment of an email.

Creating a tarball for distribution (without user/group information)

A tarball is the common way to convey several files on UNIX systems. But because tar was originally intended for backup, it stores not only the permission information, but also the owner and group of each file. Try listing the content of a tarball with e.g. $ tar -tzvf thestuff.tar.gz Note the “v” flag that [...]