Mac OS X Tech Tips

The Geeky Side of Mac OS X

Here is my personal collection of Mac OS X technical odds & ends. For more specific tech tips under Mac OS X, refer to the following pages.

• Apache
• Audio
• Perl
• NetJuke

Make Hidden Apps Look Hidden

The easiest way to hide an application's windows is to press Command+H. But when you do this, the hidden application's Dock icon doesn't change -- which may lead you to accidentally activate the hidden windows by clicking on the application's icon. With one simple Terminal command, you can command the Dock to differentiate between hidden and nonhidden apps. Just open a new Terminal window, type the following, and then press enter:

$ defaults write com.apple.Dock showhidden -bool yes

Editor's Note:
I believe this setting is now the default in 10.4 "Tiger"

Mac OS X 10.4 "Tiger" Login Window

During the login process, a window pops up with a "phony" progress bar (See Daring Fireball Article)

In addition to the progress bar (what we used to call a "swoosh bar" in the old days of x86 & 68k software development), the window normally displays the machine name. Like many things on Mac OS X, this is customizeable.

From macosxhints.com

Back in the 10.4.3 minor update, Apple silently added a pretty interesting feature to OS X. On the login window, below the large silver Apple logo and the words Mac OS X, you normally see the name of your Mac. While interesting, this isn't necessarily all that useful. After all, you're logging into the machine, sitting right in front of it, so you probably know which Mac it is unless you're one of those surrounded by six Macs all sharing one keyboard and monitor via a KVM switch.

When 10.4.3 came out, that info line was suddenly not quite so useless. You can now click your mouse on your machine's name, and the OS X version number will appear. Click again, you'll see the OS X build number. Keep clicking, and you'll see your Mac's serial number, the Mac's IP address on the network, the status of any network account (directory services), and finally, the current date and time.

This can be very useful for troubleshooting a friend's system, or for tech support folks trying to help others (which is probably why Apple added the info in the first place). I personally find the date to be much more useful to me than I do the name of the machine. Unfortunately, the changes you make won't stick around. Change the display to date, and the next time you login, it will be back to the machine's name. But with a tiny bit of work in Terminal (in /Applications -> Utilities), you can make a permanent change.

Open Terminal, and type this command:

$ defaults write /Library/Preferences/com.apple.loginwindow AdminHostInfo

Do not press Return yet. Instead, press the Space Bar after the last word above, then type one of these words:

• HostName to show the default display.
• SystemVersion to show the OS X version number
• SystemBuild to show the OS X build number
• SerialNumber to show the OS X serial number
• IPAddress to show the Mac’s IP address
• DSStatus to show the networked account info
• Time to show the date and time

After adding the word for the data you wish to display, press Return. To show the date by default, for instance, the full command would look like:

defaults write /Library/Preferences/com.apple.loginwindow AdminHostInfo Time