Sometimes, Mac technologies just work. But then sometimes, they don’t. In that spirit, we offer the following three tips for taking greater control of Time Machine backups, program preferences, and RSS feeds.

Between the three of them, we're confident you'll find something that caters for your personal needs.

Manage Time Machine
For most Leopard users, Time Machine simply works: switch it on and it will back up your hard drive every hour. But you can, if you wish, take a more proactive approach.

For example, you can make sure you’ve backed up only the latest version of a file. To do so, first prune its old backups. In the Time Machine interface, select the item, and choose Delete All Backups Of from the Action menu (denoted with a gear icon). Then select the Time Machine icon in the menu bar and choose Back Up Now. You can also prune a single snapshot: navigate to the desired time and date and then choose Delete Backup.

If you want to find out if you have unnecessary backups of a file, Time Machine Perspective ( – a hacked version of the utility GrandPerspective – can help. This version makes it easier to spot large files that change more often than your backup schedule can handle (such as mailbox databases; this is particularly helpful if you also prune snapshots).

Using this utility, you can see which files on your Time Machine backups are taking up too much hard drive space

Finally, if you want some really powerful Time Machine backup management, try the command-line tool tms ( Want to know how many different versions of artsyPhotos.ivc you have backed up? The tms log command tells you. Other useful options are tms snapshots, which lists all your snapshots; tms snaplog, which reveals extensive information logged while making a snapshot; and our favourite, tms delta, which tells you what files in a snapshot differ from those in the previous snapshot (and therefore occupy actual backup space).

Explore defaults
Much of the time, you can use a program’s Preferences dialog box to change its settings. But the defaults command can give you access to preferences that are not available from the GUI. Here are some general guidelines for using defaults.

The generalised format for any default command is defaults write preferencefile key newvalue. So, for example, the command defaults write mcx-disabled -boolean YES means “In Dashboard’s preference file (, change the Boolean key mcx-disabled to YES” – or in plain English, turn Dashboard off. (You’ll need to type killall Dock for the command to take effect.)

All ‘modern’ preference files – meaning those in XML format that follow Apple’s guidelines – can, in theory, be changed using the defaults system. (There are still lots of programs that have their own binary preference files.) Most of these files reside in the youruserfolder/Library/Preferences folder. To see inside these files, you can use the defaults read command. For example, to see what’s in Safari’s preferences file, type defaults read -app Safari.

Theoretically, you can change any key you find in an XML preferences file. Standard preferences, such as those found in a program’s Preferences window, frequently are documented. But lots of programs contain lots of undocumented preferences.

With the defaults read command, you can see which preferences can be changed with the defaults write command

Most of the switches for these keys are Boolean: on/off, true/false, or 0/1. Some use a -boolean flag followed by YES or NO, or a -bool flag followed by TRUE or FALSE. And most are reversible. For example, you can turn the Dock back on by issuing the command defaults write mcx-disabled -boolean NO (followed by another killall Dock).

Changing hidden preferences can lead to undesired consequences, so don’t start typing randomly just to see what happens. But at least now you know what you’re doing next time someone suggests you start a command line with defaults.

Import RSS feeds
NetNewsWire ( is a fantastic RSS reader, but some people prefer the convenience of having their email and news feeds in a single application. Even though the Leopard version of Mail supports RSS, it can import existing feeds from Safari only. If you previously used NetNewsWire (or another news reader), here’s how to import your subscriptions into Mail.

The only thing you need is a text editor that supports grep-based pattern matching. Bare Bones Software’s free TextWrangler and its $125 (£81) BBEdit ( both do; Apple’s own TextEdit, unfortunately, does not.

To start, in NetNewsWire choose File?Export Subscriptions. Next to Export, select All from the Format pop-up menu. You can choose either export format, OPML (Flat) or OPML (With Groups). Leave the default name (MySubscriptions) and destination (Desktop), and click on Save.

Next, open the MySubscriptions file you’ve just created in TextWrangler or BBEdit. Choose Search?Find. At the top of the Find & Replace window, select Use Grep. Now enter the following, with no spaces, in the search field (at the top of the window): ^\s*<[^\n]*?xmlUrl=”(.+)“?/>\r(\s*\r*)*. In the replace field (near the bottom of the window), enter \1\r. Make sure to select the Start At Top checkbox, and click on Replace All.

Still in your text editor, select all the text and choose Edit?Copy. Switch to Mail and choose File?Add RSS Feeds; make sure Specify A Custom Feed URL is selected. Click in the text field and choose Edit?Paste. Then click on Add. That’s it – your feeds should now appear in the RSS section of your Mail window.

We do have two caveats about this trick. First, whatever folder structure you had in NetNewsWire won’t survive this transfer; you’ll have to recreate your folders manually. To do so, choose Mailbox?New Mailbox. From the pop-up Location menu, choose RSS. Type in the name of a folder and click on OK. You can then drag feeds into your new folders. Second, though this technique should work when you export OPML files from other news readers, we can’t guarantee that it will work with every other RSS program.

See also: How do I restore my Mac using Time Machine