undocumented macOS commands

Seemingly undiscovered miscellaneous stuff.

disable Quick Actions

Hide Mojave's Finder's Quick Actions toolbar.
defaults write com.apple.Finder ShowQuickActionsBar -bool false

disable zoom button popup

Revert Catalina's green window button to its previous unintrusive existence.
defaults write -g NSZoomButtonShowMenu -bool false

read serial from filesystem

Useful if you have a disk (image) but lack access to the machine itself. Run as root and adjust path if necessary. Tested on Yosemite and newer.
find /var/folders -name consolidated.db -exec sqlite3 -batch {} .dump \;

disable iOS Simulator dyld cache

Prevent automatic CPU-heavy generation of multi-gigabyte files in ~/Library/Developer/CoreSimulator/Caches/dyld. Does not break iOS Simulator, but might impact its performance. Tested on Xcode 12 and newer.
defaults write com.apple.CoreSimulator AutomaticallyGenerateDyldShareCache -bool false