defaults is a command line utility that manipulates plist files. Introduced in 1998 OPENSTEP, defaults is found in the system's descendants macOS and GNUstep.[1][2]
The name "defaults" derives from OpenStep's name for user preferences, Defaults, or NSUserDefaults in Foundation Kit. Each application had its own defaults plist ("domain"), under ~/Defaults for the user configuration and /Defaults for the system configuration. The lookup system also supports a NSGlobalDomain.plist, where defaults written there will be seen by all applications.[2][3] In macOS, the Defaults part of the path is replaced by the more intuitive Library/Preferences. defaults accesses the plists based on the domain given.[2]
defaults is also able to read and write any plist specified with a path,[1] although Apple plans to phase out this utility in a future version.[2][4]
Common uses of defaults:
$ defaults read DOMAIN # gets all $ defaults read DOMAIN PROPERTY_NAME # gets $ defaults write DOMAIN PROPERTY_NAME VALUE # sets $ defaults delete DOMAIN PROPERTY_NAME # resets a property $ defaults delete DOMAIN # resets preferences
DOMAIN should be replaced by the plist file name sans extension ('.plist'). plist files are named with reverse domain name notation. For example:
$ defaults read com.apple.iTunes # prints all iTunes preference values
plist files store keys and values. The PROPERTY_NAME key is the name of the property to modify. For example, to remove the search field from Safari's address bar:
$ defaults write com.apple.Safari AddressBarIncludesGoogle 0 $ # or $ defaults write com.apple.Safari AddressBarIncludesGoogle -bool NO # case-sensitive!
Using "1", "YES", or "TRUE" instead restores this to the default of including search.
Preferences can at times corrupt applications. To reset Address Book's preferences, either the file ~/Library/Preferences/com.apple.AddressBook.plist must be removed or the following command issued:
$ defaults delete com.apple.AddressBook
defaults prints values in the OpenStep format. It allows the VALUE to be arrays and dicts, as long as they conform to old-style plist syntax.[5]
Some example settings configurable with defaults under macOS:
| Key | OSX Version | Legal Values | Default Value |
|---|---|---|---|
| AppleAquaColorVariant | 10.8 | 1, 6 | 1 |
| AppleHighlightColor | 10.8 | RGB, 3 floats range 0-1.0 | "0.780400 0.815700 0.858800" |
| AppleShowScrollBars[6] | 10.8 | Automatic, WhenScrolling, Always | Automatic |
| NSQuitAlwaysKeepsWindows[7] | 10.8 | bool | false |
| NSAutomaticWindowAnimationsEnabled[8] | 10.8 | bool | true |
| NSNavPanelExpandedStateForSaveMode[9] | 10.8 | bool | false |
| NSWindowResizeTime[8] | 10.8 | float:time in seconds | .2 |
| CGFontDefaultAllowsFontSmoothing[10] | 10.14? | boolean |
SS64 documents a set of other keys that can be changed for each software (not the global domain) in macOS.[11] Other sites also document settings to be changed using defaults.[12] Apple does not publish a complete list of these "secret knobs", but their support site does occasionally provide defaults commands for user to change a certain setting, such as the creation of .DS_Store.[13]
GNUstep documents its defaults more clearly, so that there is no such thing as a "hidden settings" community like there is for macOS.[3]