In this Tidbit version of Programming By Stealth, Bart Busschots interviews Mattias Wadman, one of the maintainers of the jq project. This was great fun as we just finished learning jq in Programming By Stealth.

Read an unedited, auto-generated transcript with chapter marks: PBS_2024_08_06

You can find out more about Mattias & the various projects he is working on at the links below:

• Follow Mattias on Mastodon: @wader@fosstodon.org

• Mattias’ GitHub Profile which hosts some notable jq-related projects:

  • fq for querying binary files with the jq language: github.com/wader/fq

    • A list of presentations about fq — github.com/…
    • The fork of the Go version of jq that powers fq — github.com/…

  • The language definition file for adding jq support to IDEs like VS Code: github.com/wader/jq-lsp

  • jq implemented in jq: github.com/wader/jqjq

• Some notable jq commits & files mentioned during the interview:

  • The very first commit in Haskel
  • The switch to C
  • jq’s main function which is written in jq — https://github.com/…

• A version of jq implemented in Go: github.com/itchyny/gojq

• A version of jq implemented in Rust by Michael Färber: github.com/01mf02/jaq

  • Michael’s formal specification of the jq language — github.com/…
  • The “Denotational Semantics and a Fast Interpreter for jq” academic paper by Michael

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 Organization. It's by invitation only but all you have to do is ask Allison!

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