HPR

Posted at 2026-07-12 03:20:02 relating to the show hpr4677 which was released on 2026-07-07 by Vance entitled UNIX Curio #10 - Checksums and Hashes

Oops, I was switching between tabs when editing my comment and forgot who I was replying to. My apologies for misidentifying you!

Posted at 2026-07-09 22:48:47 relating to the show hpr4678 which was released on 2026-07-08 by Whiskeyjack entitled High Resolution Elapsed Time in Shell Scripts

I'm glad that you found this episode interesting.

I wasn't aware that you could use DEBUG to measure the time that an episode took to run.

Perhaps you could do an episode on this to tell us how to do it? I am sure that a lot of people would find that very interesting.

Posted at 2026-07-09 14:38:32 relating to the show hpr4678 which was released on 2026-07-08 by Whiskeyjack entitled High Resolution Elapsed Time in Shell Scripts

I didn't know there were so many ways to measure the exact time, I just usually use $EPOCHREALTIME for stuff.

Did you know you can also catch DEBUG on bash to implement a "time last command took" field to your prompt? It's a bit of a hacky solution but it works pretty well.

Posted at 2026-07-09 01:50:23 relating to the show hpr4677 which was released on 2026-07-07 by Vance entitled UNIX Curio #10 - Checksums and Hashes

Whiskeyjack, I appreciate your support on this and past episodes. There's another UNIX Curio coming, life got in the way of me recording it but things have settled down now. Another episode is mostly written, and I have two more solid ideas. However, these will require more research than usual so it will likely take me longer to get them out.

Agreed that systemd is a great topic, but I am not the person to explain it. I have not adapted to it well and need to look up man pages most times I want to do some basic thing. However, this makes me think that the subject of UNIX init systems over the years might be up my alley (though would also require significant research). Will give that idea some consideration, thanks!

Posted at 2026-07-08 11:32:04 relating to the show hpr4677 which was released on 2026-07-07 by Vance entitled UNIX Curio #10 - Checksums and Hashes

cksum seems pretty useful! seems like a useful cross-platform way to make hashes, and its age does sort of work for its advantage there!

also, you can use comm to pretty easily check a list of chksums :)

im still most likely going to still just use md5sum, but its nice to know that theres a UNIX alternative ^^

also, for topics you could cover busybox or apropos maybe?

Posted at 2026-07-08 09:46:44 relating to the show hpr4672 which was released on 2026-06-30 by Ken Fallon entitled Hey Mum, I'm on Spotify !

Hi Ken,

Great show, and also laughed at 'Look at this great thing I did'

I get the same response in my household :-)

Cheers,
Archer72

Posted at 2026-07-07 21:17:41 relating to the show hpr4677 which was released on 2026-07-07 by Vance entitled UNIX Curio #10 - Checksums and Hashes

Really happy with this series. At the end, you asked about ideas for further episodes. Perhaps a brief introduction to systemctl and journalctl commands (in the systemd world) would be a good topic. As a greybeard, I was reluctant to embrace systemd, but eventually came around as it seemed nearly inevitable. Both are very useful for tracking down system problems, especially journalctl.

Thanks again for a great episode!

Posted at 2026-07-06 15:07:47 relating to the show hpr4644 which was released on 2026-05-21 by Archer72 entitled Response to comments on HPR4424: Newsboat...

Ken shows a safer way to get episodes from HPR

https://www.hackerpublicradio.com/eps/hpr3962/index.html

Posted at 2026-07-06 13:48:39 relating to the show hpr4644 which was released on 2026-05-21 by Archer72 entitled Response to comments on HPR4424: Newsboat...

Hi Ken,

I believe that you did sign up for a show about using XML Starlet for feeds.

;-)

Cheers,
Archer72

Posted at 2026-07-02 10:50:38 relating to the show hpr4674 which was released on 2026-07-02 by Ahuka entitled Audiobooks

Ook !

Posted at 2026-06-29 21:55:12 relating to the show hpr4181 which was released on 2024-08-12 by Bob entitled Downloading out of copyright movies

If you want the subtitle as well

yt-dlp --write-subs --sub-format srt --proxy socks5://localhost:9150

Posted at 2026-06-27 15:04:02 relating to the show hpr4666 which was released on 2026-06-22 by Lennart Benschop entitled How I got into tech

I liked this episode, its nice seeing other peoples introduction to the hobby. I agree with Windigo that its amusing you got into computing "late", since I also got into it very much later :P

Posted at 2026-06-26 18:53:44 relating to the show hpr4655 which was released on 2026-06-05 by norrist entitled Tips for Glasses

I want to say thank you. I am glad the queue was empty because I recently bought new glasses at Costco. I feel like I overpaid for them (which makes sense since I have not worn glasses or contacts in 15 years). My vision is changing as I age (I am now 46). Even with a large 49 ultrawide monitor, I must increase the font size to read comfortably. I ordered 2 monitors today. Wish me luck.

Posted at 2026-06-26 02:24:48 relating to the show hpr4666 which was released on 2026-06-22 by Lennart Benschop entitled How I got into tech

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!

Posted at 2026-06-24 21:15:22 relating to the show hpr4667 which was released on 2026-06-23 by Vance entitled UNIX Curio #9 - printf

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.

Posted at 2026-06-24 03:54:20 relating to the show hpr4667 which was released on 2026-06-23 by Vance entitled UNIX Curio #9 - printf

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.

Posted at 2026-06-23 13:23:06 relating to the show hpr4667 which was released on 2026-06-23 by Vance entitled UNIX Curio #9 - printf

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

Posted at 2026-06-21 00:10:45 relating to the show hpr4655 which was released on 2026-06-05 by norrist entitled Tips for Glasses

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.

Posted at 2026-06-17 14:02:17 relating to the show hpr4661 which was released on 2026-06-15 by Claudio Miranda entitled Laptop Computer Woes, or How I Learned to Love My Tech Hoarding

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!

Posted at 2026-06-17 04:37:48 relating to the show hpr4661 which was released on 2026-06-15 by Claudio Miranda entitled Laptop Computer Woes, or How I Learned to Love My Tech Hoarding

Hey Claudio, great show! Enjoy hearing about BSD, even if it's hardware-related! Thanks!

Posted at 2026-06-16 15:04:20 relating to the show hpr4661 which was released on 2026-06-15 by Claudio Miranda entitled Laptop Computer Woes, or How I Learned to Love My Tech Hoarding

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...

Posted at 2026-06-15 17:02:57 relating to the show hpr4657 which was released on 2026-06-09 by Vance entitled UNIX Curio #8 - Comparing Files

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.

Posted at 2026-06-15 16:53:16 relating to the show hpr4659 which was released on 2026-06-11 by Kevie entitled Command Line Fun - Recording a show

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.)

Posted at 2026-06-15 11:58:49 relating to the show hpr4659 which was released on 2026-06-11 by Kevie entitled Command Line Fun - Recording a show

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

Posted at 2026-06-15 03:16:05 relating to the show hpr4657 which was released on 2026-06-09 by Vance entitled UNIX Curio #8 - Comparing Files

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.

Posted at 2026-06-13 21:10:48 relating to the show hpr4644 which was released on 2026-05-21 by Archer72 entitled Response to comments on HPR4424: Newsboat...

Hi WhiskeyJack,

Cool!

Can't wait to hear it. :)

Posted at 2026-06-13 11:47:53 relating to the show hpr4657 which was released on 2026-06-09 by Vance entitled UNIX Curio #8 - Comparing Files

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.

Posted at 2026-06-13 11:13:49 relating to the show hpr4644 which was released on 2026-05-21 by Archer72 entitled Response to comments on HPR4424: Newsboat...

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.

Posted at 2026-06-12 16:50:42 relating to the show hpr4644 which was released on 2026-05-21 by Archer72 entitled Response to comments on HPR4424: Newsboat...

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.

Posted at 2026-06-11 16:57:57 relating to the show hpr4657 which was released on 2026-06-09 by Vance entitled UNIX Curio #8 - Comparing Files

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.