Defaults

A collection - and explanation - of the OS X defaults in CLIX.

Get It Try It

Users on other platforms wish they had it so good: the NeXTSTEP/OS X defaults system. It's the perfect way to get modular fine tuned settings for every user with no risk of conflicts.

Settings on Windows

Windows users are constantly plagued by the hodgepodge of confusion on that platform: settings are found in 'INI files' and in obscure places in the 'Registry'. And the Registry is an unfathomable mess which also constitutes a systematic Achilles heel: it's binary and complete gobbledegook unless the user dares trying a 'Registry editor'.

And even then it's a 'no go' for most people. Built on the same principles as Multics, Windows today wants to 'broadcast' the existence of support modules, and this results in a Registry even a seasoned admin will think twice about using.

And there's no 'save or not save' with the Windows Registry: all changes are immediate and there is no 'undo'. Make a mistake and you're screwed - and your system might not boot next time either.

But unbelievably enough it gets worse, for file associations are stored in the Registry on a per machine basis - not on a per user basis. Which of course leads to inevitable recurring conflicts.

Instead of uprooting the danged thing and doing it right, Microsoft instead choose to create a special 'Documents and Settings' folder which is supposed to contain user specific settings. Good luck.

Settings on Linux

Instead of following a good example, many Linux distributions use a sycophantic copy of the Microsoft 'INI file' system.

The 'INI file' system is like the OS X defaults system with all the good stuff ripped out: there is no hierarchy and data can only be stored as text - meaning 'raw' (binary) data cannot be stored and for that matter developers have to roll their own code to store numerical values.

Settings on OS X

In contrast the system used on OS X is a breath of fresh air - like Harrison Ford emerging into the sunlight at the end of the studio cut of Bladerunner. The system is immediately elegant, simple, and powerful.

OS X settings - the 'defaults' - happen in one or more so-called 'domains'. The domains are inspected in a strict order. Settings found in subsequent domains override those found previously.

Note that the above means you can mostly override any application's default settings by changing them on the command line.

Defaults & Cocoa

Native OS X (Cocoa) applications 'register' their settings on startup, usually through their controlling code class and before any instance of that class has been created. They're registered with the Cocoa NSUserDefaults class which accompanies every Cocoa application.

These become the settings that can subsequently be overridden: they're the 'factory defaults'. As the application initialises, NSUserDefaults will start to look around for overrides - and most often will find them in the user's own preferences directory ~/Library/Preferences. If a preferences file for the application is not found, NSUserDefaults will revert to those previously registered as 'factory defaults'.

When the application finally initialises, it will query NSUserDefaults to get the settings the user wants.

It is thus possible - and even desirable - to alter the default behaviour of software by accessing their preferences files. And even if the syntax of OS X preferences files - so called 'property list files' - is rather easy and straightforward, there is another way to do it: the NeXTSTEP command 'defaults'.

The three most common defaults commands are the following.

defaults read   [-g] <target> <key>
defaults delete [-g] <target> <key>
defaults write  [-g] <target> <key>

Where 'target' is a 'bundle identifier' such as 'com.rixstep.CLIX'. Which normally will mean accessing a file with the name com.rixstep.CLIX.plist. The file extension plist is short for 'property list'.

Property Lists

Before delving into the 'defaults' command it can be good to look at bit at property list files themselves.

Property list files for OS X (as opposed to NeXTSTEP) are in XML format. XML - extended markup language - is a simple way to define 'keys' and 'values'. That is, for any one given key - or setting - establish a corresponding value.

Finder might want to know if it's to show so called hidden files; it checks for the existence of the key 'AppleShowAllFiles' and if found and if its value is non-zero, it shows them. Otherwise it reverts to its default which is to not show them.

[In terms of boolean (logical) values, anything non-zero is 'yes' or true and zero is 'no' or false.]

Property lists do not only have boolean yes/no values - and that's their beauty: they can contain almost anything and they can also 'nest' almost anything.

<key>Subscriptions</key>
<array>
    <dict>
        <key>home</key>
        <string>http://appledefects.com/</string>
        <key>name</key>
        <string>AppleDefects</string>
        <key>rss</key>
        <string>http://appledefects.com/?feed=rss2</string>
    </dict>
</array>

The above key 'Subscriptions' has an array (a series of items) as its value. But inside this array is a series of 'dictionaries' - in effect further nested key/value pairs. For each of the keys found in the dictionary there is a corresponding (character) string.

Property lists can contain arrays, boolean values, calendar dates, further dictionaries, floating point numbers, integer numbers, character strings, and 'raw data'.

<key>NSRecentDocumentRecords</key>
<array>
    <dict>
        <key>_NSLocator</key>
        <dict>
            <key>_NSAlias</key>
            <data>
            AAAAAAF4AAIAAApSaXhzdGVwIEhEAAAAAAAAAAAAAAAA
            AAAAAADAySU6SCsAAAABu1gKI3Jvcyw5LnJ0eAAAAAAA
            AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
            AAAAAAAAAAAAAAAAAAAAAAG7X8CkCLAAAAAAAAAAAP//
            //8AAAEgAAAAAAAAAAAAAAAAAAAABCNyb3MAEAAIAADA
            yPsKAAAAEQAIAADAo96AAAAAAQAUAAG7WAABu0oAAOvp
            AADr3AAAHDQAAgA3Uml4c3RlcCBIRDpVc2VyczpyaXhz
            dGVwOkRvY3VtZW50czpOZXdzOiNyb3M6I3Jvcyw5LnJ0
            eAAADgAWAAoAIwByAG8AcwAsADkALgByAHQAeAAPABYA
            CgBSAGkAeABzAHQAZQBwACAASABEABIALFVzZXJzL3Jp
            eHN0ZXAvRG9jdW1lbnRzL05ld3MvI3Jvcy8jcm9zLDku
            cnR4ABMAAS8A//8AAA==
            </data>
        </dict>
    </dict>
</array>

It is the ability of property lists to store 'raw' (binary) data which makes them so powerful: keeping to a text format and yet still allowing any kind of data whatsoever to be stored.

The List

Following is the list of current CLIX defaults commands - and then some. Defaults commands are normally grouped in threes: a command to turn a flag on, a command to turn the flag off, and a command to read its current setting.

CLIX commands revert to 'factory defaults' not by changing the value of a flag but by removing the key/value pair entirely.

Some commands will work on all OS X releases; some will work only on one or two; the list is still far from exhaustive.

.Global

Settings in this category are found in the .GlobalPreferences files in both /Library/Preferences and ~/Library/Preferences. As their names imply, these are 'global' rather than application specific settings.

You can read all your '.Global' preferences by running the following two commands from Terminal or CLIX.

defaults read /Library/Preferences/.GlobalPreferences
defaults read ~/Library/Preferences/.GlobalPreferences

Address Book

Note the final command in this block: 'Me'. Reading defaults for 'AddressBookMe' will in effect access the file AddressBookMe.plist in one of the preferences directories.

Clean

A selection of an extensive collection of 'clean/purge' commands in CLIX. These three use the 'defaults' command. (Most do not.)

CLIX

These three commands govern the behaviour of CLIX with respect to the ManOpen application.

Crash Reporter

Three commands which determine the behaviour of the system crash reporter. Default behaviour is to begin with the 'unexpected quit' dialog - 'gee this was really unexpected and nothing's been harmed'. You can either stick with it or not.

Dashboard

Turning the Dashboard widget engine on and off.

Desktop

Use these to control your desktop settings.

Disk Copy

These three commands toggle 'expert mode' and read the current value.

Disk Images

These commands control image verification and how 'Internet enabled' DMG files are treated - default is to toss them into the Trash.

Disk Utility

Toggle the verify burn flag and read its current setting.

Dock

There are a lot more things you can do with your dock than you'd think. Some commands require you restart the program ('killall').

DVD Player

Flip the debug toggle and read its current setting.

Exposé

Finder

Some commands require you restart the program ('killall').

HI Toolbox

HI (human interface) Toolbox settings are stores in the file com.apple.HIToolbox.plist in /Library/Preferences.

iChat

Adjust the user idle timeout and read its current setting.

iDisk

iTunes

Login Window

These commands access the file loginwindow.plist in ~/Library/Preferences. Not to be confused with com.apple.loginwindow.plist in /Library/Preferences.

Mail

The first of these commands is especially useful if you have a hopeless friend who 1) cannot abandon Windows; 2) cannot abandon Outlook; and 3) cannot figure out how to send civilised plain text mail.

Menu Bar Clock

You can read all settings at once by running 'defaults read com.apple.MenuBarClock' from Terminal or CLIX. For that matter, you can do the same for any application or property list file.

Network

Be sure to use the first command if you're connected to a network; be sure to use the fourth command regardless.

Safari

You can read all of Safari's settings by running 'defaults read com.apple.Safari' from Terminal or CLIX. But it's a long list.

Security

So called 'drive by downloads' should be turned off in all possible cases. Check your setting and adjust accordingly. Complement the firewall commands by inspecting your firewall rules by running 'sudo ipfw list' from Terminal or CLIX.

System

The fourth command in effect lists all the property list files in your own preferences directory. The fifth command lists file assocations. The sixth command lists all your 'user' defaults. It'll run for a while!

Terminal

A few command line tricks for the command line.

User Keys

NeXTSTEP/Cocoa 'user key equivalents' override anything in your system, directly binding a menu text string with a keyboard shortcut. Note that user key equivalents are 'universal' - they pertain to all applications.

Xshelf

A member of the ACP, Xshelf is soon to be released as a standalone application.

See Also
CLIX - The #1 Power Tool for OS X

CLIX 1.7d
CLIX Manpage
CLIX 1.7.2(a) 'Ilgaz'
CLIX 1.7.2d 'pk' — Explosive Action!
CLIX 1.7.2e 'lipo'
CLIX 1.7.2f 'f'

Cookie Tin Tips I
Cookie Tin Tips II
Cookie Tin Tips III
Cookie Tin Tips IV
Cookie Tin Tips V

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Cool Clever Stuff with CLIX III

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