Automatic check for updates
[cc]sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate AutomaticCheckEnabled -bool TRUE[/cc]
Automatic download new updates when available
[cc]sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate AutomaticDownload -boolean TRUE[/cc]
Install macOS updates
[cc]sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate AutomaticallyInstallMacOSUpdates -boolean TRUE[/cc]
Install app updates from the App Store
[cc]sudo defaults write /Library/Preferences/com.apple.commerce AutoUpdate -bool TRUE[/cc]
Install System Data Files and Security Updates (both writes required)
[cc]sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate CriticalUpdateInstall -boolean TRUE[/cc]
[cc]sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate ConfigDataInstall -boolean TRUE[/cc]