ubuntu – Rob's Blog

PSA: apt / gpg issue – The following signatures couldn’t be verified because the public key is not available

Posted on Monday, August 16th, 2021Thursday, August 19th, 2021 by Rob Hallam

Not a key?! Context Bob from Root Access ran into this annoyance while installing pixiecore by Dave Anderson, a tool for making PXE (network) booting a cinch. Problem He grabbed the pubkey via curl -L https://packagecloud.io/danderson/pixiecore/gpgkey, saved the output to a file at /usr/share/keyrings/pixiecore-archive-keyring.gpg, and told apt about both the repo and the pubkey: deb […]

Pi-hole and WireGuard on LXC for Phone Ad-Blocking

Posted on Tuesday, November 17th, 2020Saturday, November 21st, 2020 by Rob Hallam

Ads-B-Gone I’ve been getting some quite obnoxious ads on my phone of late. In the past, I used Pi-hole, which blocks ads on the network level via DNS. By combining this with OpenVPN I had ad-blocking on my OnePlus 3. Things have moved on since then; the machine – a laptop ‘server’ – serving Pi-hole […]

Solved: No Files In MPD (eg mpc ls)

Posted on Saturday, July 9th, 2011Thursday, August 18th, 2011 by Rob Hallam

I was doing my initial “is it working?” tests after reinstalling mpc, and mpc ls was not giving me any output. ncmpc was also showing no files. What I didn’t appreciate was that the music database is no populated by default- you have to issue an “update” command manually (or semi-manually by running a client […]

Show Progress Bar During dd Copy

Posted on Wednesday, January 5th, 2011Wednesday, January 5th, 2011 by Rob Hallam

There are a number of ways of showing the progress of a dd copy. The easiest is sending the USER1 signal to the dd process, like: dd if=FILE1 of=FILE2 pkill -USER1 dd But that only gives a current status – eg 12345678 bytes transferred (11.77MB) … [8.56MB/s]. Not that helpful if you want an ongoing […]

Connect to a WPA/WPA2 Secured Network In Linux

Posted on Wednesday, May 19th, 2010 by Rob Hallam

This turned out to be dead easy, although it took a bit of futzing around due to my own slowness. The situation arose during an a failed upgrade of my dad’s machine to Ubuntu 10.04 (aka Lucid Lynx). I’m sensing a pattern here; I don’t think there has been an upgrade that has gone smoothly […]

Ubuntu 9.10 Karmic Upgrade Problem Fixed (mountall/init)

Posted on Wednesday, March 24th, 2010Wednesday, March 24th, 2010 by Rob Hallam

(Jump to the bonus section on sorting a removed Gnome panel) I finally got round to doing the Jaunty->Karmic upgrade on a troublesome machine. Well, re-doing. I made an abortive attempt to install it on this particular exhibit of electronic arthritis back before I left for Barcelona, which ended in me reinstalling 9.04. Anyway, for […]

Count Arguments In A Bash Script

Posted on Thursday, October 1st, 2009 by Rob Hallam

Another useful tip I’m sure most people will be familiar with, but in bash scripts $# stores the number of arguments passed to the script. Eg, combine with $@ (all arguments) for batch processing (what I used it for): foreach $arg in $@; do [stuff] [compare with $# to tell remaining items] done Very basic […]

Batch Rename or Move An Extension In Linux (Eg .JPG to .jpg)

Posted on Wednesday, September 30th, 2009 by Rob Hallam

A short and easy trick, but one that is either not referred to or more complex examples given. I wanted to change a bunch of upper case .JPG images to lower case. Rather than writing a bash script or some such, I just used the ‘rename’ command: rename ‘s/\.JPG$/\.jpg/’ *.JPG It may depend on perl […]

Back to Ubuntu

Posted on Thursday, February 7th, 2008Thursday, February 7th, 2008 by Rob Hallam

So I’m suppose to be revising for the Big Testâ„¢ that I’ve got tomorrow, but instead I decided to reboot in Ubuntu. And by gosh, I’d forgotten how nice it looks. And this is still the 7.04 version! Sounds are nice too – it’s probably just subjective perception, but playing music sounds nicer too, although […]