Comments
Windigo says: Nice to meet you
RE: hpr4666::2026-06-22 How I got into tech by Lennart Benschopfrom the series How I got into tech.00:19:00 Listen in ogg, opus, or mp3 format.
Thank you for the introduction episode, Lennart! I really enjoyed hearing about your path through computing.
I thought it was very amusing that you thought you arrived to computing "late", as you predated my own introduction to computing by a decade.
Looking forward to hearing your next episode!
xmanmonk says: Another great show!
RE: hpr4667::2026-06-23 UNIX Curio #9 - printf by Vance00:20:39 Listen in ogg, opus, or mp3 format.
Thanks again for all your work on these episodes. Lots of good info about printf. I usually futz around with echo to get it to work on my machine, but may not work on others. There are good reasons here to use printf instead.
Whiskeyjack says: HPR4667 - printf
RE: hpr4667::2026-06-23 UNIX Curio #9 - printf by Vance00:20:39 Listen in ogg, opus, or mp3 format.
This is a very interesting series, and I hope that you continue with it.
Here's a few other very useful things that you can do with printf that have made use of.
In a previous episode I mentioned that if you wish to concatenate several audio files into one using ffmpeg you need to create a file containing the names of the files plus some additional text.
You could write a loop writing out each line of the file one at a time.
Or you could do this with a single printf command as follows:
printf "file '%s'\n" *.flac > podseglist.txt
This will create a file consisting of multiple lines of text, each in the form of the word "file" followed by the name of the file and then a line feed. No loop is necessary.
Another example came up with something that I was working on yesterday. I needed to print a floating point time value by combining separate seconds and microsecond numbers.
However the microsecond number is not zero padded on the left and so would give an incorrect value if used it as is. This was readily solved however by using printf to zero pad the number.
padusec=$( printf '%06d' $timeusec )
I was then able to take this result and append it to a string containing the time in seconds followed by a decimal separator and then the zero padded time in microseconds.
It is things like these that make shell scripting fun to use.
candycanearter07 says: learned something new :)
RE: hpr4667::2026-06-23 UNIX Curio #9 - printf by Vance00:20:39 Listen in ogg, opus, or mp3 format.
I had no idea that you could use %s and multiple arguments to repeat the same line multiple times! That would definitely be useful for some bash scripts
i personally moved to using ruby for my own scripts but its still really cool to know :D
Jim DeVore says: Geeks are lazy, too
RE: hpr4655::2026-06-05 Tips for Glasses by norrist00:09:50 Listen in ogg, opus, or mp3 format.
After years of experiments, I settled out on clean 100% cotton washcloths and shampoo.
Before I shower each day, I put a bit of shampoo on my glasses, wash them in the shower as it warms up, then dry with the fresh washcloth. I use it after cleaning my glasses to shower and after drying it goes into the laundry hamper on the next cycle.
Cheap, fast, easy, and i'm not managing any small microfiber cloths or fancy eyeglass cleaner chemicals.
ClaudioM says: Thanks! (In reply to candycanearter & xmanmonk)
RE: hpr4661::2026-06-15 Laptop Computer Woes, or How I Learned to Love My Tech Hoarding by Claudio Miranda00:26:10 Listen in ogg, opus, or mp3 format.
Thanks for the comments! Feels good to be able to use what I have left over in parts to repair devices still in action. BTW, an update on the Evoo laptop: My son's grandfather was able to find the problem, a shorted MOSFET caused by the blown cap. He tested with one he had on hand and it turned on and booted. Once he finds a MOSFET with the correct rating, it should be back in action!
xmanmonk says: Great show!
RE: hpr4661::2026-06-15 Laptop Computer Woes, or How I Learned to Love My Tech Hoarding by Claudio Miranda00:26:10 Listen in ogg, opus, or mp3 format.
Hey Claudio, great show! Enjoy hearing about BSD, even if it's hardware-related! Thanks!
candycanearter07 says: uses :)
RE: hpr4661::2026-06-15 Laptop Computer Woes, or How I Learned to Love My Tech Hoarding by Claudio Miranda00:26:10 Listen in ogg, opus, or mp3 format.
It's always nice seeing a repair win, especially if its done with reused parts! Makes me feel justified for refusing to get rid of any of my devices...
Whiskeyjack says: Reply to Vance on awk in HPR4657
RE: hpr4657::2026-06-09 UNIX Curio #8 - Comparing Files by Vance00:14:20 Listen in ogg, opus, or mp3 format.
Awk is another extremely useful command to know in terms of improving performance in cases where you might otherwise need to use a loop.
I don't have any relative numbers to hand in this instance, but I know that I have increased performance very significantly by structuring an algorithm to allow use of awk.
The history of awk may be a good subject for a Unix Curio episode.
"Expect" would be a good command to cover as well. I have used this for scripted log-ins to test VMs over SSH in cases where SSH keys wouldn't work for some reason.
Whiskeyjack says: Reply to candycanearter07 on HPR4659
RE: hpr4659::2026-06-11 Command Line Fun - Recording a show by Keviefrom the series Podcasting HowTo.00:13:19 Listen in ogg, opus, or mp3 format.
When concatenating audio files using FFMPEG, you can create the text file listing the audio files with the following command.
printf "file '%s'\n" *.flac > podseglist.txt
ffmpeg -f concat -safe 0 -i podseglist.txt fullpod.flac
If you are using Sox, you can concatenate the files using the following:
sox *.flac fullpod.flac
I covered concatenating audio files using FFMPEG in HPR4608 in my series on Simple Podcasting and these examples are in the show notes as reference for anyone who is interested.
The FFMPEG list file is probably useful for cases where you want to order the files manually rather than using shell globbing order.
(If there turns out to be a double post from me on this subject, the electric power went out just as I was attempting to send it the first time so I didn't think the first one went through.)
candycanearter07 says: ffmpeg concatenation
RE: hpr4659::2026-06-11 Command Line Fun - Recording a show by Keviefrom the series Podcasting HowTo.00:13:19 Listen in ogg, opus, or mp3 format.
Concatenation is frustratingly confusing in ffmpeg, but according to the wiki https://trac.ffmpeg.org/wiki/Concatenate you can just use
ffmpeg -f concat -i listoffilenames.txt output.flac
for some reason it forces you to use a file thats a list of filenames instead of being able to use a glob, but it works pretty ok
Vance says: Appreciate the comments
RE: hpr4657::2026-06-09 UNIX Curio #8 - Comparing Files by Vance00:14:20 Listen in ogg, opus, or mp3 format.
When I was uploading this episode, I started to feel like maybe I was selling "comm" short a bit. Nice to hear that it's been useful for you, Whiskeyjack. While its functionality can't be easily replicated with "cut" or "awk", those utilities can certainly make good use of the output from "comm".
Interesting to read about your experience in terms of runtime. I have taken to using a single call to "awk" in situations where I might otherwise call on several utilities in a pipeline. Your comment is a good reminder that if something will be used repeatedly, it's best to measure its runtime instead of automatically assuming that one tool or set of tools will be faster than another.
Archer72 says: EyeD3
RE: hpr4644::2026-05-21 Response to comments on HPR4424: Newsboat... by Archer7200:07:08 Listen in ogg, opus, or mp3 format.
Hi WhiskeyJack,
Cool!
Can't wait to hear it. :)
Whiskeyjack says: HPR4657 - use of comm
RE: hpr4657::2026-06-09 UNIX Curio #8 - Comparing Files by Vance00:14:20 Listen in ogg, opus, or mp3 format.
comm is actually a very, very, useful program in scripts if you know how to make good use of it.
For example, bash can be fairly slow when used in a classic looping algorithm over a large amount of data.
However, if you can reformat the data so that it can be compared with comm, then you can use comm as a filter without any loops.
As an example, in one application a simple loop took 3.7 seconds to work its way through the data, which was far too long.
However, by using awk and sort to reformat one file, and a combination of find, cut, sort, uniq, and awk on the directory structure to generate a second file and then comparing them with comm, I was able to filter the information down to just the records that had relevant changes, and then use the slower looping algorithm on those.
This cut that time down to 0.150 seconds, which was more or less instantaneous from a user perspective. Despite this method appearing to have a lot more transformations in it, it was 25 times faster. This is because there are actually far fewer calls to commands in the second algorithm, even though more different commands are involved.
So comm is a very useful command to know, and if you have a lot of information to process it should be one of the tools that you turn to when figuring out the best way to do it.
Whiskeyjack says: Response to Archer72 on HPR4644
RE: hpr4644::2026-05-21 Response to comments on HPR4424: Newsboat... by Archer7200:07:08 Listen in ogg, opus, or mp3 format.
If you want to get the episode title from an HPR podcast episode and use it to modify the name further, then you can do that by extracting the tag information from the MP3 file using "id3v2". On Debian and derivatives, I believe this comes in the eyeD3 package. This hands v1 as well as v2 tags.
I will add this to the episode script that I am currently writing.
Archer72 says: Response to WhiskeyJack
RE: hpr4644::2026-05-21 Response to comments on HPR4424: Newsboat... by Archer7200:07:08 Listen in ogg, opus, or mp3 format.
Hi,
I tend to go down rabbit holes, and this is one such time. After a quick response to أحمد المحمودي, I decided to try a 'fix'. This is further proof that I am not a programmer and should not be asking too many questions of AI. Still, it was a fun endeavor for me, and see it as useful to see where I went wrong.
Thank you for the constructive critique and hope to hear your next episode. :)
P.S. A useful reason to rename the episodes is a project I may talk about later when use Rockbox on an Ipod classic. A titled show as a file name is easier to see what I want to listen to than hpr1234.mp3.
candycanearter07 says: comparisons
RE: hpr4657::2026-06-09 UNIX Curio #8 - Comparing Files by Vance00:14:20 Listen in ogg, opus, or mp3 format.
cmp is, while not as useful as it may have been, still quite useful for testing whether two files are bit copies of each other.
Kevie says: Interesting
RE: hpr4656::2026-06-08 My review of musicozy sleep/exercise bluetooth headband by Swift11000:09:49 Listen in ogg, opus, or mp3 format.
I have never heard of these before but think the concept is great. My wife has recently been asking me to research a set of headphones for her to use at the gym: I will suggest these. Thanks for sharing.
Kevie says: Geeks are ahead of their time
RE: hpr4654::2026-06-04 What's in my component Box? by MrXfrom the series Hobby Electronics.00:27:51 Listen in ogg, opus, or mp3 format.
In an age of recycling and re-purposing items, I find that geeks are always a step ahead as we have been doing this for years. I laughed out loud when you said that you weren't sure why you kept an item and thought: good, it isn't just me.
An excellent show as always MrX; keep up the good work.
Kevie says: Nice episode
RE: hpr4653::2026-06-03 Starting the Habit of Reading by Thaj Sara00:24:59 Listen in ogg, opus, or mp3 format.
Thank you very much for posting this, I've never read any of the Battletech books, but I may keep an eye out for them. I enjoy reading physical books, I've tried ebook readers but I really don't like the experience, although I have found myself listening to audiobooks more, especially in the car or when stuck doing a mundane task.
Thanks for the tip on Openreads, I've never come across it before but I think we will take a look at it for a review on an upcoming episode of TuxJam.
xmanmonk says: Great Show (again)
RE: hpr4657::2026-06-09 UNIX Curio #8 - Comparing Files by Vance00:14:20 Listen in ogg, opus, or mp3 format.
Another great show on these often forgotten commands. Glad to hear you have some more episodes in the works! Looking forward to them!
Whiskeyjack says: Response to hpr4644
RE: hpr4644::2026-05-21 Response to comments on HPR4424: Newsboat... by Archer7200:07:08 Listen in ogg, opus, or mp3 format.
I have been following this saga on downloaded podcast filenames and am still as confused now as ever when it comes to understanding what this is all about. I still don't understand why Newsboat needs to come into the picture.
I use a cron job to run a bash script to automatically download podcasts, including HPR. They just appear in a directory that I have set aside for holding new podcasts.
While some podcasts have rubbish audio file names in their RSS feed that have to be fixed, HPR isn't one of them. Their URL is just fine.
What you need to do is to extract the audio file name from the RSS feed using something like basename, and then specify that name to wget using the -O option for output file name. This results in a file with a name such as "hpr4644.mp3" being saved. No after the fact file renaming is necessary.
I'll do an episode on a simplified version of what I use that just does HPR podcasts.The next slot I can use is in July, so I will plan to have it for then.
candycanearter07 says: wishlist!
RE: hpr4656::2026-06-08 My review of musicozy sleep/exercise bluetooth headband by Swift11000:09:49 Listen in ogg, opus, or mp3 format.
i often listen to podcasts and stuff when i go to bed so using one of these would be very useful!! the only downside would be figuring out how to use it with my mp3 player since it doenst have bluetooth
Archer72 says: Not quite a complete script
RE: hpr4644::2026-05-21 Response to comments on HPR4424: Newsboat... by Archer7200:07:08 Listen in ogg, opus, or mp3 format.
Ken,
I did some more testing, and the script is not quite ready and breaks on some renamed files, leaving i.e. hpr1234.ogg in Podboat
I'll try again.
Cheers,
Archer72
Trey says: Avoid hand soap
RE: hpr4655::2026-06-05 Tips for Glasses by norrist00:09:50 Listen in ogg, opus, or mp3 format.
Great recommendations. I do avoid hand soaps, as many included a lotion residue.
I may check out those mid-range progressives. I use dedicated computer glasses which are great, but I need to remember to change back to my progressive lenses when I get up to walk around and such.
Antoine says: Reading always has been a life-saver for me, this alone makes this show Very Nice
RE: hpr4653::2026-06-03 Starting the Habit of Reading by Thaj Sara00:24:59 Listen in ogg, opus, or mp3 format.
The books on your list have beautiful covers!
About the Cardio code, I was expecting some sharing of the specifics of the content (so we all could do better cardio!).
Nice to see you accomplishing your audacious (20-a-year) reading goal! Thx 4 'dā' share! \o
Antoine says: #2 Thanks!
RE: hpr4650::2026-05-29 Playing Civilization V, Part 12 by Ahukafrom the series Computer Strategy Games.00:14:30 Listen in ogg, opus, or mp3 format.
Hey, Dear Ahuka, Thanks, Help'd understanding!
candycanearter07 says: Re: Love PHP
RE: hpr4649::2026-05-28 What did I do at work today? Part 3 Section 2 by Lee01:03:49 Listen in ogg, opus, or mp3 format.
I think PHP is ok for what it does, but I really don't like the language that much. I've been considering moving my site to Ruby or Go for a while now...
Lee says: Aerials
RE: hpr4633::2026-05-06 Ham Radio Licence by Leefrom the series HAM radio.00:14:23 Listen in ogg, opus, or mp3 format.
Thankfully the foundation exam is multiple choice, but it is important to recognise the following terms:-
- Pointy signal-spikey bit
- Long wire dangly-doo
- Metal pokey-poke
- Linear wave catch-a-me-bob
- Bendy frequency rubber-stub
- Wire stretchy-poo
- Scoping prong-a-me-jig
RJ says: Very interesting as always
RE: hpr4633::2026-05-06 Ham Radio Licence by Leefrom the series HAM radio.00:14:23 Listen in ogg, opus, or mp3 format.
Very interesting show as always. I love your podcasts (I'm new to HPR (just found it a few weeks ago) and you've been one I know I can always go to for an interesting show).
Is 'uppy downy thing' the technical term in the test for an aerial? ;)
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