HPR4221: HPR Community News for September 2024

Civilization IV made some changes, and in this episode we look at Build Queues, Research, and Wonders. Links: https://www.palain.com/gaming/civilization-iv/playing-civilization-iv-part-2/

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: HPR Statistics Random User Generator API Github project mledoze/countries 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! ↩︎

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

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."

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

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.

Picture 1 Shows the EPROM (Erasable Programmable Read Only Memory) fitted with a label marked JAF7. EPROM's can be erased by removing the sticker and exposing the device to strong ultraviolet light. I incorrectly refer to it as a PROM (Programmable Read Only Memory. Below it is the old leaking PLL backup battery. Wikipedia article about EPROM’s (Erasable Programmable Read Only Memory) Link / example of a Fluke 77 DMM (Digital Multi Meter) I mention that I used it to check the battery voltage of the original PLL backup battery which I think was manufactured around 1984. I was very surprised to find that the battery which is likely 40 years old had a battery voltage of 3.2V which is a healthy voltage. The battery still needed changed due to liquid (probably acid) which can be seen in picture 1 being present on the top surface of the battery. Picture 2 Shows me extending the new battery terminal using the leg of a 1.8 kilo ohm resistor. Note that the resistor leg is shiny because this time I scraped away the surface oxidation using pliers prior to soldering it in place. This improves the final solder joint. I mention I have an EC2000 Weller Electronically controlled soldering station. Here is a link to an example I found

table td.shrink { white-space:nowrap } hr.thin { border: 0; height: 0; border-top: 1px solid rgba(0, 0, 0, 0.1); border-bottom: 1px solid rgba(255, 255, 255, 0.3); } New hosts Welcome to our new host: hairylarry. Last Month's Shows Id Day Date Title Host 4196 Mon 2024-09-02 HPR Community News for August 2024 HPR Volunteers 4197 Tue 2024-09-03 After 5 years away, OggCamp is back in 2024! Ken Fallon 4198 Wed 2024-09-04 Are hobbies pathological? Lee 4199 Thu 2024-09-05 HPR New Years Eve Show 2023 - 24 ep 7 Honkeymagoo 4200 Fri 2024-09-06 Intro to Doctor Who Ahuka 4201 Mon 2024-09-09 Today I learnt (2024-08-23) Dave Morriss 4202 Tue 2024-09-10 Replacing backup batteries in my Kenwood HF Radio Part 3 MrX 4203 Wed 2024-09-11 Setup DuckDNS on a Raspberry Pi Kevie 4204 Thu 2024-09-12 LibreOffice Importing External Data gemlog 4205 Fri 2024-09-13 Trollercoasting almost getting a heart attack Trollercoaster 4206 Mon 2024-09-16 New to GNU/Linux resources. Some Guy On The Internet 4207 Tue 2024-09-17 Re: The Kindle/Kobo Open Reader (KOReader) dnt 4208 Wed 2024-09-18 01 Plain Text Programs hairylarry 4209 Thu 2024-09-19 HPR New Years Eve Show 2023 - 24 ep 8 Honkeymagoo 4210 Fri 2024-09-20 Playing Civilization IV, Part 1 Ahuka 4211 Mon 2024-09-23 Rapid Fire 1 operat0r 4212 Tue 2024-09-24 Replacing backup batteries in my Kenwood TS940S HF Radio Part 4 MrX 4213 Wed 2024-09-25 Making Waves Day 1 Ken Fallon 4214 Thu 2024-09-26 Making Waves Day 2 Ken Fallon 4215 Fri 2024-09-27 My home lab Lee 4216 Mon 2024-09-30 Down the rabbit hole. Some Guy On The Internet Comments this month These are comments which have been made during the past month, either to shows released during the month or to past shows. There are 23 comments in total. Past shows There are 6 comments on 6 previous shows: hpr4109 (2024-05-02) "The future of HPR " by knightwise. Comment 9: Ken Fallon on 2024-09-13: "Interesting post by Alan Pope" hpr4156 (2024-07-08) "Badger 2040" by Kevie. Comment 2: Ken Fallon on 2024-09-12: "Heading to spectrum24" hpr4175 (2024-08-02) "what's in my bag part 2" by operat0r. Comment 1: operator on 2024-09-11: "operator" hpr4177 (2024-08-06) "Blender 3D Tutorial #1" by Deltaray. Comment 3: Some Guy On The Internet on 2024-09-09: "Great show." hpr4182 (2024-08-13) "Replacing backup batteries in my Kenwood TS940S HF Radio Part 1" by MrX. Comment 2: MrX on 2024-09-11: "Re Thank you for the reminder" hpr4195 (2024-08-30) "Hacking HPR Hosts" by Ken Fallon. Comment 1: dnt on 2024-09-01: "Scheduling and the reserve queue" This month's shows There are 17 comments on 8 of this month's shows: hpr4196 (2024-09-02) "HPR Community News for August 2024" by HPR Volunteers. Comment 1: Trollercoaster on 2024-09-03: "Why!?"Comment 2: brian-in-ohio on 2024-09-03: "single board computer"Comment 3: Ken Fallon on 2024-09-03: "@Brian" hpr4198 (2024-09-04) "Are hobbies pathological?" by Lee. Comment 1: dnt on 2024-09-10: "Pathologies" hpr4200 (2024-09-06) "Intro to Doctor Who" by Ahuka. Comment 1: hammerron on 2024-09-06: "Streaming Doctor Who"Comment 2: brian-in-ohio on 2024-09-08: "Shows"Comment 3: dnt on 2024-09-10: "Dr Who"Comment 4: Dave Morriss on 2024-09-16: "Excellent start!" hpr4207 (2024-09-17) "Re: The Kindle/Kobo Open Reader (KOReader)" by dnt. Comment 1: Dave Morriss on 2024-09-18: "How to say "Calibre"" hpr4208 (2024-09-18) "01 Plain Text Programs" by hairylarry. Comment 1: ClaudioM on 2024-09-18: "Hello there, fellow SDFer! Great Episode!"Comment 2: brian-in-ohio on 2024-09-18: "The hook"Comment 3: Beeza on 2024-10-03: "Plaintext Programs"Comment 4: Dave Morriss on 2024-10-04: "Regarding VMS and indexed files" hpr4212 (2024-09-24) "Replacing backup batteries in my Kenwood TS940S HF Radio Part 4" by MrX. Comment 1: Henrik Hemrin on 2024-09-30: "Engineering"Comment 2: MrX on 2024-09-30: "Re Engineering" hpr4214 (2024-09-26) "Making Waves Day 2" by Ken Fallon. Comment 1: Trey on 2024-09-26: "Love these!" hpr4216 (2024-09-30) "Down the rabbit hole." by Some Guy On The Internet. Comment 1: Beeza on 2024-10-03: "Good Samaritans" Mailing List discussions Policy decisions surrounding HPR are taken by the community as a whole. This discussion takes place on the Mail List which is open to all HPR listeners and contributors. The discussions are open and available on the HPR server under Mailman. The threaded discussions this month can be found here: https://lists.hackerpublicradio.com/pipermail/hpr/2024-September/thread.html Events Calendar With the kind permission of LWN.net we are linking to The LWN.net Community Calendar. Quoting the site: This is the LWN.net community event calendar, where we track events of interest to people using and developing Linux and free software. Clicking on individual events will take you to the appropriate web page. Any other business Repairing shows where external files have been lost The further back in time we go with these repairs, the more challenging they tend to become because of the variations in the way shows were put together. It has been difficult to process more than five a day, and there have been a few breaks along the way! The current state of the project is that it has been completed: +------------+------------+--------------+------------------+ | date | repairable | repair_count | unrepaired_count | +------------+------------+--------------+------------------+ | 2024-10-03 | 352 | 352 | 0 | +------------+------------+--------------+------------------+ All of the processed shows have access to their transcripts, which are held on archive.org. However, there remains the need to make transcripts available to the older shows which have no external files.

This is a look at the very first serial of Doctor who, and how the cast was first put in place. It is in many ways an unlikely story for a show that has gone on for 60 years and counting. I find the early stories to be charming and worth a look, and many things from these early stories come back in later stories as well. Links: https://en.wikipedia.org/wiki/Sydney_Newman https://en.wikipedia.org/wiki/The_Avengers_(TV_series) https://en.wikipedia.org/wiki/Diana_Rigg https://en.wikipedia.org/wiki/Verity_Lambert https://en.wikipedia.org/wiki/Doctor_Who_Magazine https://en.wikipedia.org/wiki/Waris_Hussein https://en.wikipedia.org/wiki/William_Hartnell https://en.wikipedia.org/wiki/Carole_Ann_Ford https://en.wikipedia.org/wiki/Jacqueline_Hill https://en.wikipedia.org/wiki/William_Russell_(English_actor) https://en.wikipedia.org/wiki/Sacha_Dhawan https://en.wikipedia.org/wiki/Thirteenth_Doctor https://en.wikipedia.org/wiki/An_Adventure_in_Space_and_Time https://en.wikipedia.org/wiki/An_Unearthly_Child https://doctorwhoconcordance.fandom.com/wiki/100,000_BC https://tardis.fandom.com/wiki/Coal_Hill_School https://en.wikipedia.org/wiki/TARDIS https://en.wikipedia.org/wiki/Control_of_fire_by_early_humans https://www.palain.com/science-fiction/intro-to-doctor-who/how-doctor-who-began/

Black diamond head lamp and other gear. Sgoti talks about using his head lamp and backpack during his day job. Tags: headlamp, backpack black diamond spot 400 headlamp Features Dual-fuel design allows you to power the headlamp with 3 AAA alkaline batteries (included) or the rechargeable BD 1500 lithium-ion battery and charger (not included) Settings include proximity and distance modes, dimming, strobe, red LED night vision, and lock mode White LED outputs up to 400 lumens on max setting, 200 lumens on medium and 6 lumens on low PowerTap™ Technology allows instant adjustment between max output and dimmed power Brightness Memory allows you to turn the light on and off at a chosen brightness setting without it reverting back to the default setting Red LED night vision has dimming and strobe modes, and is quickly activated without cycling through the white mode Multifaceted optical efficiency lens technology Integrated battery meter display shows the percentage of power remaining so you know when to replace the batteries Digital lockout feature prevents accidental use when stored in a pack or pocket IPX8 waterproof protection rated to operate at least 1.1 meters underwater for 30 minutes—perfect should you be caught in a downpour If submerged, water may enter the battery compartment, but it will still operate; it should be completely dried out after use in wet conditions Fieldsmith Lid Pack 28L This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.