Welcome to HPR, the Community Podcast

We started producing shows as Today with a Techie on 2005-09-19, 19 years, 1 months, 3 days ago. Our shows are produced by listeners like you and can be on any topics that "are of interest to hackers". If you listen to HPR then please consider contributing one show a year. If you record your show now it could be released in 6 days.

Call for shows

We are running very low on shows at the moment. Have a look at the hosts page and if you don't see "2024-??-??" next to your name, or if your name is not listed, you might consider sending us in something.

Latest Shows

hpr4232 :: Replacing backup batteries in my Kenwood TS940S HF Radio Part 6

Part 6 is the final episode it deals with fitting the new replacement PLL backup battery.

Hosted by MrX on 2024-10-22 is flagged as Explicit and released under a CC-BY-SA license.
Tags: Amateur, Radio, DIY, repair, electronics, soldering. Series: HAM radio. Comments: (Be the first).

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Duration: 00:22:13

Picture 1

Shows me attaching the leg of a resistor to the new backup battery. This is to extend the battery terminal length so that it can be soldered between the two connecting battery posts of the radio Printed Circuit Board.

Picture 2

Shows the newly fitted PLL backup battery with it’s extended terminal fitted directly below the EPROM labelled JAF7.

Picture 3

Shows the speaker sitting within a metal box. This box sits on top of the screened metal box housing the PLL backup battery. When I was refitting the speaker box I discovered there were extra badly soldered grey wires attached to the speaker terminals. The other end of the wires was covered with black electrical insulating tape. I removed these extra grey wires from the speaker to prevent them from coming adrift and or causing a short circuit within the radio.

I mention the trick of using blue-tak to hold a difficult screw when inserting it into a tight recess. Wikipedia article about Blu Tack

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hpr4231 :: Duplicating Multiple USB Flash Drives with DD and Tmux on FreeBSD

Claudio describes his process for mass USB flash drive duplication with FreeBSD, tmux, and dd.

Hosted by Claudio Miranda on 2024-10-21 is flagged as Clean and released under a CC-BY-SA license.
Tags: freebsd, tmux, dd, windows, usb, diskduplication, duplication. Series: general. Comments: (Be the first).

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Duration: 00:15:52

Pre-planning and creating your image:

Create your image with your preferred disk image creation tool. I used USB Image Tool to create an image from my "golden master" Windows 11 installation thumb drive A. USB Image Tool: https://www.alexpage.de/usb-image-tool

Prepare your Tmux session on your Linux or BSD-based system.

'tmux new -s $sessionName' to create a new Tmux session window with a session name of your choice.
'Ctrl-B-"' to create a horizontal split, putting one pane over the other.
'Ctrl-B-%' to create a vertical split, putting one pane next to the other.
'Ctrl-B-UpArrow' or 'Ctrl-B-DownArrow' to move to the pane you want to split if you split the window with a horizontal line.
'Ctrl-B-LeftArrow' or 'Ctrl-B-RightArrow' to move to the pane you want to split if you split the window with a vertical line.

https://tmuxcheatsheet.com/

Duplicate 4 USB thumb drives from a disk image within your new, split-paned Tmux session:

CHECK DMESG FOR THE CORRECT DEVICE NAME AND WRITE IT DOWN!!!
- FreeBSD will show dmesg output on TTYv0, or you can use the dmesg command on Linux or BSD. You don't want to end up wiping your system drive!
Within your Tmux session:
- Pane 1: 'dd if=$diskImageName of=/dev/da0 bs=1M status=progress' to begin imaging USB thumb drive #1.
- Pane 2: 'dd if=$diskImageName of=/dev/da1 bs=1M status=progress' to begin imaging USB thumb drive #2.
- Pane 3: 'dd if=$diskImageName of=/dev/da2 bs=1M status=progress' to begin imaging USB thumb drive #3.
- Pane 4: 'dd if=$diskImageName of=/dev/da3 bs=1M status=progress' to begin imaging USB thumb drive #4.
- 'Ctrl-B-:' to call the Tmux command prompt, followed by 'setw synchronize-panes' to sync the 4 panes to your commands. The primary pane will be highlighted in red, and the secondary panes will copy whatever command it typed into that primary pane.
- Hit Enter to begin the process on all 4 panes.
- When the image finishes, you can remove the USB thumbs drives, pop in 4 more, hit the Up arrow on the primary pane to pull up the previous commands on their respective panes, and hit Enter. When in doubt, refer to Step 0!!
- Repeat as needed.

If you need to de-synchronize your Tmux panes, just type 'Ctrl-:' to call the Tmux command prompt, followed by 'setw synchronize-panes' to toggle pane synchronization on and off (or you can use the up arrow at the Tmux command prompt to bring up that previously-typed command).

The faster your USB ports and USB thumb drives, the better!

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hpr4230 :: Playing Civilization IV, Part 2

We continue our look at the mechanics of this game

Hosted by Ahuka on 2024-10-18 is flagged as Clean and released under a CC-BY-SA license.
Tags: Computer games, strategy games, Civilization IV. Series: Computer Strategy Games. Comments: (Be the first).

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Duration: 00:12:29

Civilization IV made some changes, and in this episode we look at Build Queues, Research, and Wonders.

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hpr4229 :: Neurodiversity and Hacking

Lee talks to Matthew about the link between neurodiversity and hacking.

Hosted by Lee on 2024-10-17 is flagged as Clean and released under a CC-BY-SA license.
Tags: neurodiversity, hacking. Series: general. Comments: (Be the first).

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Duration: 00:21:29

Lee talks to Matthew about the link between neurodiversity and using systems in ways they were not designed for.

A short biography:

Matthew Bellringer is a neurodiversity and innovation specialist who specialises in supporting work that addresses problems from a unique perspective, co-production, and regenerative working practices. More details on Matthew's website.

Matthew is also Chair and Co-founder of NeurodiverseIT, a group for neurodivergent IT professionals within BCS, the Chartered Institute of IT and the organiser and founder of Curious Being, a community for unconventional people who want to make the world a better place. Matthew is a late-discovery autistic ADHDer.

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hpr4228 :: Auditing Audio Files For Youtube

I detail a technique to ensure all music used on my Youtube channel is free from copyright claims

Hosted by Dave Hingley on 2024-10-16 is flagged as Clean and released under a CC-BY-SA license.
Tags: Audio, Video, Youtube, Abraham Wald, Operational Research. Series: A Little Bit of Python. Comments: (Be the first).

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Duration: 00:04:04

AudioAudit:
https://github.com/anim8or/AudioAuit
My YouTube Channel:
https://www.youtube.com/@TheTitaniumBunker

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hpr4227 :: Introduction to jq - part 3

More filters

Hosted by Dave Morriss on 2024-10-15 is flagged as Explicit and released under a CC-BY-SA license.
Tags: JSON, JavaScript Object Notation, jq, jq filter, jq language. Series: general. Comments: (Be the first).

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Duration: 00:25:53

Overview

In this episode we will continue looking at basic filters. Then we will start looking at the feature that makes jq very powerful, the ability to transform JSON from one form to another. In essence we can read and parse JSON and then construct an alternative form.

More basic filters

Array/String Slice: `.[<number>:<number>]`

This filter allows parts of JSON arrays or strings to be extracted.

The first number is the index of the elements of the array or string, starting from zero. The second number is an ending index, but it means "up to but not including". If the first index is omitted it refers to the start of the string or array. If the second index is blank it refers to the end of the string or array.

This example shows using an array and extracting part of it:

$ x="[$(seq -s, 1 10)]"
$ echo "$x"
[1,2,3,4,5,6,7,8,9,10]
$ echo "$x" | jq -c '.[3:6]'
[4,5,6]

Here we use the seq command to generate the numbers 1-10 separated by commas in a JSON array. Feeding this to jq on its standard input with the slice request '.[3:6]' results in a sub-array from element 3 (containing value 4), up to but not including element 6 (containing 7). Note that using the '-c' option generates compact output, as we discussed in the last episode.

For a string, the idea is similar, as in:

$ echo '"Hacker Public Radio"' | jq '.[7:10]'
"Pub"

Notice that we provide the JSON string quotes inside single quotes following echo. The filter '.[7:10]' starts from element 7 (letter "P") up to but not including element 10 (letter "l").

Both of the numbers may be negative, meaning that they are offsets from the end of the array or string.

So, using '.[-7:-4]' in the array example gives the same result as '.[3:6]', as do '.[3:-4]' and '.[-7:6]'. This example uses the x variable created earlier:

$ for f in '.[-7:-4]' '.[3:6]' '.[3:-4]' '.[-7:6]'; do
> echo "$x" | jq -c  "$f"
> done
[4,5,6]
[4,5,6]
[4,5,6]
[4,5,6]

Similarly, using '.[-12:-9]' gives the same result as '.[7:10]' when used with the string.

$ echo '"Hacker Public Radio"' | jq '.[-12:-9]'
"Pub"

As a point of interest, I wrote a little Bash loop to show the positive and negative offsets of the characters in the test string - just to help me visualise them. See the footnote¹ for details.

Finally, here is how to get the last character of the example string using positive and negative offsets:

$ echo '"Hacker Public Radio"' | jq '.[18:]'
"o"
$ echo '"Hacker Public Radio"' | jq '.[-1:]'
"o"

Array/Object Value Iterator: `.[]`

This filter generates values from iterating through an array or an object. It is similar to the .[index] syntax we have already seen, but it returns all of the array elements:

$ arr='["Kohinoor","plastered","downloadable"]'
$ echo "$arr" | jq '.[]'
"Kohinoor"
"plastered"
"downloadable"

The strings in the array are returned separately, not as an array. This is because this is an iterator, and its output can be linked to other filters.

It can also be used to iterate over values in an object:

$ obj='{"name": "Hacker Public Radio", "type": "Podcast"}'
$ echo "$obj" | jq '.[]'
"Hacker Public Radio"
"Podcast"

This iterator does not work on other data types, just arrays and objects.

An alternative iterator .[]? exists which ignores errors:

$ echo "true" | jq '.[]'
jq: error (at <stdin>:1): Cannot iterate over boolean (true)

Ignoring errors:

$ echo "true" | jq '.[]?'

Using multiple filters

There are two operators that can be placed between filters to combine their effects: the comma (',') and the pipe ('|').

Comma operator

The comma (',') operator allows you to chain together multiple filters. As we already know, the jq program feeds the input it receives on standard input or from a file into whatever filter it is given. So far we have only seen a single filter being used.

With the comma operator the input to jq is fed to all of the filters separated by commas in left to right order. The result is a concatenation of the output of all of these filters.

For example, if we take the output from the HPR stats page which was mentioned in part 1 of this series of shows, and store it in a file called stats.json we can view two separate parts of the JSON like this:

$ curl -s https://hub.hackerpublicradio.org/stats.json -O

$ jq '.shows , .queue' stats.json
{
  "total": 4756,
  "twat": 300,
  "hpr": 4456,
  "duration": 7640311,
  "human_duration": "0 Years, 2 months, 29 days, 10 hours, 18 minutes and 31 seconds"
}
{
  "number_future_hosts": 6,
  "number_future_shows": 18,
  "unprocessed_comments": 0,
  "submitted_shows": 0,
  "shows_in_workflow": 51,
  "reserve": 20
}

This applies the filter .shows (an object identifier-index filter, see part 2) which returns the contents of the object with that name, then it applies filter .queue which returns the relevant JSON object.

Pipe operator

The pipe ('|') operator combines filters by feeding the output of the first (left-most) filter of a pair into the second (right-most) filter of a pair. This is analogous to the way the same symbol works in the Unix shell.

For example, if we extract the 'shows' object from stats.json, we can then extract the value of the total' key' as follows:

$ jq '.shows | .total' stats.json
4756

Interestingly, chaining two object identifier-index filters gives the same output:

$ jq '.shows.total' stats.json
4756

(Note: to answer the question in the audio, the two filters shown can also be written as '.shows .total' with intervening spaces.)

We will see the pipe operator being used in many instances in upcoming episodes.

Parentheses

It is possible to use parentheses in filter expressions in a similar way to using them in arithmetic, where they group parts together and can change the normal order of operations. They can be used in other contexts too. The example is a simple arithmetic one:

$ jq '.shows.total + 2 / 2' stats.json
4757
$ jq '(.shows.total + 2) / 2' stats.json
2379

Examples

Finding country data #1

Here we are using a file called countries.json obtained from the GitHub project listed below. This file is around 39,000 lines long so it is not being distributed with the show. However, it's quite interesting and you are encouraged to grab a copy and experiment with it.

I will show ways in which the structure can be examined and reported with jq in a later show, but for now I will show an example of extracting data:

$ jq '.[42] | .name.common , .capital.[]' countries.json
"Switzerland"
"Bern"

The file contains an array of country objects; the one with index 42 is Switzerland.
The name of the country is in an object called "name", with the common name in a keyed field called "common", thus the filter .name.common.
In this country object is an object called "capital" holding an array containing the name (or names) of the capital city (or cities). The filter .capital.[] obtains and displays the contents of the array.
Note that we used a comma operator between the filters.

Finding country data #2

Another search of the countries.json file, this time looking at the languages spoken. There is an object called "languages" which contains abbreviated language names as keys and full names as the values:

$ jq '.[42] | .name.common , .capital.[] , .languages' countries.json
"Switzerland"
"Bern"
{
  "fra": "French",
  "gsw": "Swiss German",
  "ita": "Italian",
  "roh": "Romansh"
}

Using the filter .languages we get the whole object, however, using the iterator .[] we get just the values.

$ jq '.[42] | .name.common , .capital.[] , .languages.[]' countries.json
"Switzerland"
"Bern"
"French"
"Swiss German"
"Italian"
"Romansh"

This has some shortcomings, we need the construction capabilities of jq to generate more meaningful output.

Next episode

In the next episode we will look at construction - how new JSON output data can be generated from input data.

Links

jq:
- The jq manual

Test data sources:

Romansh language

Previous episodes:
- Introduction to jq - part 1
- Introduction to jq - part 2

Footnote: A Bash loop to show positive and negative index values relating to an example string:

$ y='Hacker Public Radio'
$ for ((i=0,j=${#y}; i<"${#y}"; i++,j--)); do printf '%02d: -%02d: %s\n' "$i" "$j" "${y:$i:1}"; done
00: -19: H
01: -18: a
02: -17: c
03: -16: k
04: -15: e
05: -14: r
06: -13:
07: -12: P
08: -11: u
09: -10: b
10: -09: l
11: -08: i
12: -07: c
13: -06:
14: -05: R
15: -04: a
16: -03: d
17: -02: i
18: -01: o

Note that variable y doesn't contain a valid JSON string; we are just counting characters here to demonstrate the offsets that can be used when slicing a string! ↩︎

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hpr4226 :: JAMBOREE and Taco Bell!

SOC Fortress CoPilot / Velociraptor / Wazuh and Taco Bell Quesadilla Sauce!

Hosted by operat0r on 2024-10-14 is flagged as Explicit and released under a CC-BY-SA license.
Tags: cooking, hacking. Series: general. Comments: (Be the first).

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Duration: 00:18:42

JAMBOREE.rmccurdy.com : SOCFortress CoPilot / Velociraptor / Wazuh

Copycat Taco Bell Quesadilla Sauce

PREP TIME
5 minutes

TOTAL TIME
5 minutes

Ingredients
½ cup mayonnaise
½ cup sour cream
3 Tablespoons pickled jalapeno juice (from a jar of pickled jalapenos)
3 Tablespoons pickled jalapenos (diced)
2 teaspoon paprika
2 teaspoons ground cumin
1 teaspoon garlic granules
1 teaspoon onion powder
½ teaspoon salt (or to taste)
½ teaspoon chili powder

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hpr4225 :: Chewing the rag with Kristoff and Ken

Kristoff Bonne ON1ARF and Ken Fallon PA7KEN chat about HAM and Hackers

Hosted by Ken Fallon on 2024-10-11 is flagged as Clean and released under a CC-BY-SA license.
Tags: FOSDEM, HAM. Series: HAM radio. Comments: (Be the first).

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Duration: 00:52:55

Known in the Hacker world as the Ham Radio Guy at FOSDEM, Kristoff Bonne ON1ARF, and Ken Fallon PA7KEN/G5KEN sit down to discuss "vergrijzing, changing attitudes, and increasing participation in the Amateur Radio Community."

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hpr4224 :: Auto shop interaction

Archer72 rambles about an experience in a Wal-Mart oil change shop

Hosted by Archer72 on 2024-10-10 is flagged as Clean and released under a CC-BY-SA license.
Tags: AutoMaintenance, AutoShop. Series: general. Comments: 1.

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Duration: 00:06:54

Archer72 rambles about an experience in a Wal-Mart oil change shop, and a positive interaction with a customer there.

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hpr4223 :: Movie review of The Artifice Girl

Sgoti butchers a movie review of The Artifice Girl

Hosted by Some Guy On The Internet on 2024-10-09 is flagged as Clean and released under a CC-BY-SA license.
Tags: MovieReview, LinuxLUGcastz. Series: general. Comments: (Be the first).

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Duration: 00:34:27

Movie review of The Artifice Girl

Sgoti butchers a movie review of The Artifice Girl

Tags: movie review, LinuxLUGcastz

Welcome to Episode 237 the LinuxLUGcastz

The Artifice Girl

The Artifice Girl is a 2022 science fiction psychological thriller written and directed by Franklin Ritch, produced by Aaron B. Koontz and released direct to VOD. It stars Tatum Matthews, Sinda Nichols, David Girard, Lance Henriksen, and Franklin Ritch. NGO agents discover a revolutionary Artificial intelligence (AI) computer program that uses a digital child to catch online predators, it advances far more rapid than they could have imagined, posing unforeseen challenges for the relationship between humans and AI.

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

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Previous five weeks