Programming By Stealth

In this special tidbit installment of Programming By Stealth, Helma van der Linden joins Allison to walk through how she solved a real-world problem using jq. The problem to be solved was a need to analyze the installed applications on her Intel-based Mac before migrating to her new Apple Silicon Mac. She used a built-in Terminal command to access System Information to create a JSON file, and then used a series of jq filters to remove data she didn't need, and format what she kept into human-readable form. Helma walks us through every step of the way as she built up her jq script file to massage the data to her needs. At the end Allison explains how to take Helma's final CSV output and analyze the data in a spreadsheet using a pivot table. You can find _Helma's_ fabulous tutorial shownotes at pbs.bartificer.net. Read an unedited, auto-generated transcript with chapter marks: PBS_2024_07_20 Join our Slack at podfeet.com/slack and look for the #pbs channel, and check out our pbs-student GitHub Organizat

In this second (and final) installment about YAML, Bart teaches us who to write multi-line strings and how not to write multi-line strings. He teaches us about String Blocks which is a bit head-bendy but allows you to write human-readable strings and also tell YAML what to do with empty lines and white space. After that slightly heavy lift, we learn about how to write much simpler-looking Sequences and Mappings than the way we learned in our introduction to YAML in PBS 168. It's really nifty how you can write them in compact, sensible forms, and even easily combine separate YAML documents into the same sequence or mapping. Finally we learn how to use the `yq` language to query JSON, CSV, and XML files using a language that uses `jq` syntax so you'll feel right at home. Read an unedited, auto-generated transcript with chapter marks: PBS_2024_07_06

In Programming By Stealth, we've completed our series on the jq language and now Bart Busschots brings us a two-part miniseries about the YAML data format. He takes us through the history of data formats we've "enjoyed" such as fixed-width text files, Comma Separated Value files, through to JSON and XML. All of them had their place in history but also had their downsides. YAML promises to be human-readable (yay) and computer-readable (also yay.) Once we're bought into how YAML is the data format of our dreams, Bart explains that there are only two kinds of data, scalar,s and collections, and that collections can be sequences or mapping and all of these data types go into a document. Luckily this is all of the jargon we'll have to learn and there are useful synonyms from other languages (e.g. sequences are really just arrays). I found this lesson enjoyable and not too hard on my little brain so I suspect you'll enjoy it as much as I did. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.ne

It was actually bittersweet for Bart and me this week as he taught the final installment in our series of Programming By Stealth about jq. As Bart says partway through our recording, he thought this would just be a few episodes but it took 13 episodes to go through everything Bart thought was fun about this deceptively simple programming language. This final installment in the jq series covers querying nested data structures with the `recurse` command. One of the really fun parts of the episode is when he teaches us how to dramatically simplify our code, a concept that's often called syntactic sugar. We get to do `if` statements for the first time, where I wondered why he didn't let us have them earlier! I was cross with him for holding out on us with `try-catch` too because it would have made our coding so much easier. But that was the real theme of this installment – we had to learn the way everything works before learning the shortcuts. In the finale, he gives us a few of what he calls "honourable menti

In this penultimate jq episode of Programming By Stealth, Bart introduces us to three new ways to process arrays and dictionaries without exploding them first. I know that sounds crazy – we've always exploded our arrays first. He teaches us how to use the `reduce` operator which lets us take an entire array or dictionary and reduce it down to one thing. The `map` function lets us process every element in an array (or or values in a dictionary) and return a new array. Finally, `map_values` lets us apply a function against all of the values in a dictionary (or an array). It was a bitter sweet ending to the primary series on `jq` for Bart, but next time he'll do the epilogue where he'll introduce us to some rarely needed but still very useful things you can do with jq. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net. Read an unedited, auto-generated transcript with chapter marks: CCATP_2024_05_25

In this installment of Programming By Stealth, Bart explains why jq is uniquely designed not to need variables (most of the time) and then explains how to use them in the few instances when there's no other way. It's really a fairly straightforward lesson as Bart sets up some clear examples and solves them with some simple variables. It's one of my favorite episodes because the problem is clear and the solutions are clear. It really shows off how clean jq is as a language. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net. Read an unedited, auto-generated transcript with chapter marks: CCATP_2024_05_11

In our previous episode of Programming By Stealth, Bart Busschots taught us how to create lookup tables with jq from JSON data using the `from_entries` command. Just when we have that conquered, this time he teaches us how to do the exact opposite – disassemble lookup tables. I think this was a really fun lesson because taking data apart, reassembling it the way you want and then putting it back together again is a great way to really understand what we're doing with jq. I got much more comfortable as I started to recognize the patterns in what Bart was doing. We also get to play with a new data set, the Have I Been Pwned data gathered by Troy Hunt. If you're a data nerd, and really who amongst us isn't, you'll love this episode too. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net.

In this episode of Programming By Stealth, Bart Busschots as usual works through his solution to the challenge from last time, and as usual I learn a lot more about how to use jq to solve problems. He takes a bit of a detour to explain a fun email we got from Jill of Kent in which she explained the vast number of headaches you'll run into when trying to alphabetize names no matter the language. Then we buckle down and learn about how to make tradeoffs between speed and efficiency of resources, and how jq lookups can help us. Bart also helps us understand _when_ lookups can help us with querying JSON files. This episode is more of a lecture, which is fine because he's introducing a new concept and explaining some philosophy. You won't hear me breaking into the conversation very much but it's only because I'm not confused! Don't worry, when we get into the final example you'll hear me get confused! Bart explains it about 3 or 4 times and when you hear why your co-host here was confused, it's kind of ironic

Bart Busschots is back to teach us how to alter arrays and dictionaries in JSON files using jq. Bart went through his challenge solution on cleaning up the Nobel Prize database and I learned a lot from it. Maybe he'd already taught all of it to us before but I sure wouldn't have been able to put the pieces together. For the new content, we learned how to alter arrays. We mastered sorting and reversing, how to add and remove elements, how to deduplicate the values within, and how to flatten even nested arrays. From there we learned how to manipulate dictionaries by adding and removing keys. It's a very focused lesson that continues to show how powerful the jq language is. I think my favorite part though was when Bart made an existential philosophy observation when he said "Everything exists with the value of null." You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net.

In this week's episode of Programming By Stealth, Bart continues to expand our knowledge on how to use jq to query and manipulate JSON files. We learn how to use mathematical operators on data in our JSON files along with fun functions like floor and absolute value. I even contributed some to the learning by showing examples of how `ceil` (for ceiling), `floor`, and `round` produce curiously different results when operating on negative decimal numbers. We move onto learning about both plain assignment and update assignment. It seems like a small deal but the ability to set a parameter using the plain assignment `=` vs the ability to update a value using ` |=` is is actually huge and has lots of subtleties. I think one of my favorite parts was when Bart took us back to our JavaScript lessons and reminded us of how weird it is on one concept but how jq is much more in line with modern programming languages. I felt like a seasoned programmer because I knew the history of what we'd learned. Finally we learned h

In this week's installment of Programming By Stealth, Bart Busschots teaches us how to use jq as a programming language. Before we get into the new stuff, Bart takes us through his solution to the challenge, and I have to say I was pretty chuffed when he said my solution to the extra credit portion was more elegant than his. To be fair, it took a buddy programming session with him for me to get the _first_ part of the challenge figured out. When we got into the programming language part of the lesson, there were so many times that I said, "I needed this last week!" I think finding out these options are available after understanding the problems they solve was fantastic. We learned how to run jq filters from files, which means no more looking at our filters all on one line - we can put line feeds and indents into our filters to make them more readable. We can even add comments. Bart tells us about a couple of handy plugins for VS Code to give us syntax highlighting which will be swell. My favorite thing I

In this very meaty episode of Programming By Stealth, Bart Busschots teaches us how to build data structures using jq with JSON files. We're not just querying existing data, we're rebuilding the data the way we want to see it. We learn how to build strings with interpolation, which I find is a very odd word to describe the process. It's really like concatenation in Excel, but maybe that's just me. We build arrays using jq, and even convert between strings and arrays with the `split` and `join` commands. We build dictionaries in a syntax that is simple and elegant. We also build dictionaries from strings using `capture` with Regular Expressions. We learn not to do string formatting and escaping using `@` – for example `@csv` can automatically create comma-separated values data for us and @uri can escape characters for us in a URL we build using jq. Like I said, it's a meaty episode but Bart and I both enjoyed the lesson quite a bit. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net. And

Two weeks ago, Bart Busschots and I recorded a Programming By Stealth episode covering more queries using the jq language on our JSON files. We spent so much time working through the challenges from the previous installment that we only made it halfway through his tutorial shownotes. So this week we're back with the second half of that episode, Programming By Stealth 158B. Before we got started learning, I alerted the audience to a significant enhancement to the material we create for this show. I use a service called Auphonic to do a lot of things with the audio file when we're done recording, including leveling the audio, adding metadata to it, converting it to an MP3, and FTPing it to the server for the listeners to download. Auphonic has recently added AI-generated transcripts which we've had for a while with Programming By Stealth. The NosillaCast has chapter marks you can use to jump to content in the audio file, but Chit Chat Across the Pond has never had that. Auphonic now adds auto-generated ch

In Programming By Stealth this week, Bart Busschots and I start off by going through the challenges from our previous installment. Remember how I said I was really digging jq and querying JSON files because at heart I'm a data nerd? Well, I failed completely at accomplishing the homework. It was not for lack of trying though - I worked about 4 hours on just the first challenge. Because of a fundamental building block that wasn't properly in place in my brain, I was never going to succeed. That means that this episode is almost half about the challenges and Bart carefully re-explaining the pieces he'd taught us in the previous installment. We both agree that it's good work because if I was lost, there's a reasonable chance that one other student was as well. Because of my questions, we cut the episode in half, so the shownotes are complete but the second half will be explained in PBS 158B which we'll record in a couple of weeks. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net. Read a

In this week's episode of Programming By Stealth, Bart Busschots continues his instruction on learning more about how to use the jq language to query JSON files. We get into the thick of it as Bart teaches us three important jq concepts: filter chaining, operators, and functions. To get there we learn about the literal values in JSON and jq and how only null and false are false. Armed with that, Bart explains the `not` function and once we put those concepts together, this ridiculous command will make perfect sense: `jq -n 'true and true | not' # false` I got such a kick out of that when I first read it in the shownotes earlier this week that I posted my enjoyment of it on Mastodon, and one of the actual developers of `jq` commented that he was excited to learn we were covering jq in Programming By Stealth! The `any` and `all` functions are nearly as silly sounding but are equally useful. By the end of the episode, we can successfully query the Nobel Prize JSON file to show us all of the prizes won by any

After the last episode of Programming By Stealth where Bart gave us an intro to jq and the problems it can solve, this week we start to get our feet wet by learning how to extract data from JSON files. We learn how to descend into dictionaries and arrays, and how to slice arrays. Learn how jq will output sarcasm about "Bart Busschots" if you don't learn how to ask it for raw output. We even learn how to extract data from multiple files at once and how to extract multiple values from our JSON files. Finally, we learn about exploding arrays and how to suppress errors. I think I really love data manipulation because I loved this episode. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net. Read an unedited, auto-generated transcript: CCATP_2023_11_25 Join our Slack at podfeet.com/slack and look for the #pbs channel, and check out our pbs-student GitHub Organization. It's by invitation only but all you have to do is ask Allison!

After our annual break from Programming By Stealth that happens at an unknown time for an unknown length every single year, Bart and I are back with a new episode of Programming By Stealth. Bart introduces us to a language called jq _and_ a terminal command called `jq` which together are used to help query JSON files, see "pretty versions of them, and also to manipulate them. We don't learn a lot of commands but Bart walks us through a few examples to help illustrate why we care, or shall I say, "the problem to be solved"? I'm sold on the idea having just mucked about in a config files for homebridge this week. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net. Read an unedited, auto-generated transcript: CCATP_2023_11_18 Join our Slack at podfeet.com/slack and look for the #pbs channel, and check out our pbs-student GitHub Organization. It's by invitation only but all you have to do is ask Allison!

Bart Busschots joins us for Programming By Stealth with the final installment of our miniseries on Bash. He explains a few new concepts, but the real value of this installment and especially his fabulous tutorial shownotes is that he compiles a lot of info into some tables for us to use as reference for the future. As with all good programming, Bart is scratching his own itch - he wanted a single place to go to know which brackets mean which and which ones do you have to cuddle vs. not cuddle. He also wanted a table of the order in which Bash processes the seven distinct expansions. We're closing out Bash but Bart has a new miniseries on the horizon to look forward to. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net.

In Programming By Stealth, we've come to the end of our journey with Bash. I'll be sad to have it complete because as I tell Bart in this episode, I've really enjoyed it. Next time he will do a final bow-tying episode where he brings everything we learned together in one set of notes as a handy reference guide. In this episode, he explains how functions work in Bash, and after about the 12th time he repeated it, I understand that functions we create in Bash work just like built-in functions such as `ls` or `cat`. After walking us through some easy-to-follow scripts to illustrate this and show us the syntax, we go into a harder concept: scope. We learn that Bash does scope differently from pretty much every other language, and so he teaches us how to avoid spooky action at a distance because of this different way of dealing with scope. Protecting ourselves isn't actually hard but it is very important to understand why we need to do this. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.

In Programming By Stealth 152A Bart and I decided to hold off on the middle of the lesson he'd written up. That middle bit where he said to "put a pin in it" was about the use of `xargs`. I'm really glad we did skip it in the last installment. It's a pretty useful concept and deserved a lot more attention than it would have if we'd tried to cram it into that episode. The other good news is that Bart learned a bit more about _how_ `xargs` does its magic, so he is better able to explain it, and he updated the shownotes with a lot more detail and a great worked example. As a teaser, the big problem `xargs` was designed to solve is that there are times when we want the data from the standard input stream (STDIN) to be passed to another command as one or more arguments. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net. Read an unedited, auto-generated transcript: CCATP_2023_07_08