Mike had encountered a problem with Postfix in that it didn’t start after it had been stopped for a reboot. A quick search revealed that a similar problem had been around in 2016 in both the RedHat and Debian versions of Postfix when it had been traced to a file being left in the wrong place. After discussion, it was suggested that Mike write a script which periodically checked that Postfix was running and then started it if it was not.
Brian had hoped to demonstrate Magic-Wormhole which allows command line communication between two computers where the sender enters:
wormhole send <filename>
which generates a code which the receiver can use when prompted by
to receive the file. However, Internet access was down.
Bernard showed us the results of his infra-red photography kit, powered by his Raspberry Pi. We saw, after some image enhancement in VLC media player, a hedgehog wandering past his hide, a crate in his garden [there was some dispute later as to whether the creature was a hedgehog or a rat].
Mike left the explanation of how to configure a server to allow a single IP address to serve four domains, each configured as a subdomain on the server, until next month when Brian will be back and gave a presentation on darktable. He illustrated a variety of effects, how you can organise the right hand pane to reflect your personal workflow and how easy it is to access and work with the history feature.
Mike tried to explain to Brian how he configured his server to allow a single IP address to serve four domains, each configured as a subdomain on his server. It was suggested that Mike prepare a piece on this for a later meeting.
It was noted in passing that the Windows Subsystem for Linux is getting a Linux kernel.
Bernard demonstrated the Python Package Index for which anyone can write packages. He showed how you could set it up and then how you could download a package to a virtual environment with:
python3 -m venv ~/v5
where v5 is a virtual environment in userspace. To activate that virtual environment, you enter
John noted that Maplin is back as an online store. In response to Mike’s account of the problems he had had trying to install Arch on his computer, John suggested that he could delete all the existing partitions on the hard drive except the very first (very small) one by using System Rescue and then start the installation process afresh.
John managed to demonstrate System Rescue on his own computer by turning off UEFI, using Legacy to load it — though it would only work with the VESA drivers on his computer — and then reverting to UEFI. He said that the documentation is excellent but that they have their own way of creating a bootable USB which John had found you could get round by creating the CD version and then copying it to a USB.
The meeting began with a range of chit-chat. John H, commenting on a note about solution focused journalism, remarked that a very good journalist had told him that you always end a piece with something that left the reader thinking, not a neat solution. This led into a discussion of the principles of writing a good article and how, translated into radio, the principle that there should be a new point at least every 90 seconds was well worth following.
Darren reported that he had not been able to download a version of BlueJ which was compatible with the version used by the Open University.
Bernard began by demonstrating Stellarium, the open source planetarium.
John H then asked about created a looping video to run on a display probably using a Raspberry Pi.