majiayu000 Configuring macOS
How to configure macOS programmatically. Don't document specific commands here - use training knowledge or web search for those. This skill is about the process.
Responding to "Configure my X"
When the user asks to configure something:
- Training knowledge - Try what you know first
- Search references - Check macos-defaults.com or mathiasbynens/.macos
- Last resort: Discovery - Use the diff technique below
- After writing - Tell user what restart is needed (see table)
- Generating script? - Use the script template
Discovering Unknown Settings (Last Resort)
When training and references don't have the answer:
# 1. Snapshot current state
defaults read > /tmp/before.plist
# 2. User changes setting in System Settings GUI
# 3. Diff to find what changed
defaults read > /tmp/after.plist
diff /tmp/before.plist /tmp/after.plist
For app-specific: defaults read com.apple.APPNAME > /tmp/before.plist
To find an app's domain:
osascript -e 'id of app "Photos"' # Returns bundle ID
ls ~/Library/Preferences/ | grep -i photos # Or check filesystem
defaults domains | tr ',' '\n' | grep -i photos
Applying Changes
Settings require process restart. Never auto-logout or auto-restart - tell the user what they need to do.
| What Changed | How to Apply |
|---|---|
| Dock, hot corners, Spaces | killall Dock (safe to run) |
| Finder, desktop | killall Finder (safe to run) |
| Menu bar items | killall SystemUIServer (safe to run) |
| Keyboard, fn key, input | Tell user: "Logout and log back in" |
| Login window | Tell user: "Restart your Mac" |
| Uncertain | Try killall cfprefsd, then tell user to logout |
Script Template
#!/usr/bin/env bash
set -euo pipefail
echo "Configuring [category]..."
defaults write DOMAIN KEY -TYPE VALUE
killall PROCESS 2>/dev/null || true
echo "Done."
Troubleshooting
| Problem | Cause & Fix |
|---|---|
| Setting reverts | App overwrote on quit. Close app first. |
| No effect | Wrong domain (defaults find KEYWORD), or needs logout not killall |
| Cached values | killall cfprefsd flushes preference cache |
| Permission denied | May need sudo, or protected by SIP |
Quick Reference
defaults write DOMAIN KEY -TYPE VALUE # Set
defaults read DOMAIN KEY # Get
defaults delete DOMAIN KEY # Remove
defaults find KEYWORD # Search all domains
Types: -string, -int, -float, -bool, -array, -dict
Resources
- macos-defaults.com - Searchable database of known settings
- mathiasbynens/.macos - Comprehensive example script