TIL: April 2020

Linux

• Press H to toggle user threads in htop
• Click headings in htop to sort processes
• How to check the CPU (core) clock speed

Product[ivity]/development

• Adding an Apple mail/calendar account on an iOS device lets you use it for two-factor authentication
• VATLayer.com can check the VAT status of a company if you’re building a B2B service
• You can switch between linked versions of libraries with brew switch {cask} {version}
• You get more accurate results if you avoid using spaces when fuzzy searching for files in Visual Studio Code
• You can use an X-Robots-Tag header as an alternative to a meta tag
• rails console has a --sandbox argument that rolls back database changes
• ActiveRecord has support for partial indices
• aasm has before_enter and after_enter callbacks for state transitions
• rspec-activejob has a .to_run_at(x) matcher
• You can build Slack apps and CLI utilities with React
• Typescript: You can inherit Props by using React.ComponentProps<typeof ComponentClass>
• Typescript: You can pick fields from a type definition with Type['key']

Random

• If you have muliple displays you can move the macOS task switcher to a specific display by triggering the dock on that display
• A lot of people are doing TILs
• You can fill cells in Excel and revert the formatting changes after filling
• You need to manually wind automatic watches when they’ve stopped
• Gaming headsets work with macOS and can be used for low-latency, wireless monitoring when producing music