Today I Learned

This is a repository of things I've learned as I go about my day. TILs are short Markdown documents explaining concepts, syntax, commands, or other developer tips I've recently learned.

This repository is inspired by TILs from Thoughtbot and TILs from jbranchaud.

For new TILs, follow me on Twitter or LinkedIn.

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Categories

• Today I Learned
  • Categories
    • Claude Code
    • Clojure
    • curl
    • diff
    • direnv
    • git
    • Kubernetes
    • SQL
    • Rails
    • tr
    • OAuth
  • License

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Claude Code

• /security-review

Clojure

• Returned from swap!
• Thread -> vs. doto

curl

• data or form

diff

• diff directory contents

direnv

• Automatic Environment Variables with direnv

git

• git update-ref

Kubernetes

• probes

SQL

• HAVING

Rails

• in_batches

tr

• upcase

OAuth

• client_credentials No Refresh Token

License

© 2026 Matthew Boston Distributed under the Creative Commons Attribution 4.0 International license.