如何发现隐藏的UserDefaults？揭秘终端修改偏好技巧的来源

Great question—these obscure Terminal commands that tweak hidden UserDefaults settings have been a favorite of Apple power users for decades. Let’s unpack your questions one by one:

1. How do people actually find these "hidden" tricks? #

Most discoveries come from a mix of technical sleuthing, community collaboration, and happy accidents:

• Reverse engineering & plist scanning: Developers and tinkerers dig into app bundles (right-click > Show Package Contents) to inspect Info.plist or Settings.bundle files, which often contain default preference keys never exposed in the GUI. Tools like class-dump or Hopper Disassembler also pull hidden preference names directly from app binary files.
• Reading raw defaults output: Running defaults read [domain] (e.g., defaults read com.apple.finder) spits out all preferences for that app or system domain—including hundreds that never appear in System Settings. Power users tweak these values one by one to test effects, then share their findings.
• Developer hints (and rare leaks): Occasionally, WWDC sessions, beta release notes, or internal Apple documentation hint at hidden settings. While former employees have shared bits of internal knowledge over the years, this is far from the primary source of discoveries.
• Community sharing: Forums like MacRumors, old Apple discussion boards, and GitHub repos dedicated to collecting these commands let users trade findings. One person’s random experiment often becomes a widely shared trick overnight.

2. Does Apple document all available preferences? #

Short answer: No.
Apple only formally documents supported preferences—those you can adjust via the GUI or official public APIs. Hidden defaults settings are typically:

• Internal debug flags for testing during development
• Experimental features that never made it to the final GUI
• Legacy settings kept for backward compatibility but no longer promoted

These are intentionally undocumented because Apple doesn’t guarantee they’ll work across macOS/iOS versions, and modifying them can break system stability. You won’t find them in official developer docs.

3. Are these tricks from Apple insiders, or self-discovered? #

The vast majority are self-discovered by the community. While insider leaks happen occasionally, most hidden settings are found by regular power users and developers who enjoy poking around the system. For example, the popular trick to remove the Dock’s autohide delay (defaults write com.apple.dock autohide-delay -float 0; killall Dock) was discovered by someone experimenting with defaults values, not an Apple employee.

A quick heads-up: modifying hidden defaults settings isn’t supported by Apple. If something breaks after a tweak, you’ll likely have to reset preferences (via defaults delete [domain]) or restore from a backup to fix it.

内容的提问来源于stack exchange，提问作者Pro Blaster