I just added a note about how to reset Mac OS X v10.7 Lion to factory defaults. Thanks to Adam and Adrian for the hints (and Mark for the actual work-around on the Apple forum -> unverified, feedback welcome!).
In the Unix/Linux/Mac OS X world, less is more. Literally, in that ‘less‘ fully emulates ‘more‘, and figuratively, as it provides useful additional functionality like backwards scrolling. So, you really want to use ‘less’ instead of ‘more’ for paging another command’s output, e.g.
cat a_long_document.txt|less
When used to page the output of colordiff however, ‘less’ displays a mess instead of properly displaying colored output like ‘more’.
The trick is to use ‘less’ with either the -r or -R option (which both repaint the screen), i.e.
colordiff -u file_old.py file_new.py|less -r
or
colordiff -u file_old.py file_new.py|less -R
(try which one works better with your system and terminal)
When deleting a file, most operating systems just delete the reference to this file, not its actual content. For illustration, that’s like removing a chapter from a book’s table of contents without actually removing (and shredding) the according pages in the book.
So, in order to really (securely) delete a file on a hard disk, there are basically two methods (simplified; from a technical point of view it’s both the same):
For the second method, here’s how to do it using Mac OS X:
Note that overwriting free space like this takes quite some time depending on the amount of free space there is and how many passes you need (e.g. use “2″ for a US DoD 7-pass secure erase or “3″ for a Gutmann 35-pass secure erase). For more information about diskutil and its options, see “man diskutils”.
Thanks to a hint from Macs R We, I’ve updated the list of steps required to take a Mac OS X installation back to its initial state. Now it’s also valid for Mac OS X 10.5 ‘Leopard’. Please take a look at the updated post:
I’ve just installed the free (as in ‘free beer’) Jingproject client by that allows to capture screenshots or screen videos and store or upload and share them (e.g. on screencast.com). It’s amazing, how easy and convenient it is to use – good job! There are clients for both Windows and Mac OS X (which will likely be important for me very soon as I intend to buy a new MacBook Pro with LED backlit display and a Penryn Core 2 Duo processor). The only thing missing is a Linux client (but we’re used to that, aren’t we? ;). Jingproject is provided by TechSmith, the creators of the well-known (and also great) SnagIt screen capture application.
Here’s an example of a screencast I just recorded (no sound, though):
Logitech G9 Laser Mouse SetPoint 5.0 German
It shows the great variety of configuration options you have for customizing your Logitech G9 Laser Mouse using SetPoint 5.0. The Logitech G9 Laser Mouse is Logitech’s latest “gamer” mouse and the best and most accurate mouse I ever used. I bought it though I’m not much of a “gamer” actually, but the form factor, features and its high quality convinced me. It’s quite a small mouse compared to other mice, but that’s intentional as you move it with your fingers rather than with your wrist or arm. This makes it a very user friendly (and particularly gamer friendly) pointing device as you’re much quicker in pointing and clicking while using less energy. The small form factor however might be a problem for you if you have really big hands (check it out in the next hardware store before you buy!).
Further, it’s a mouse with a cord, so you don’t need to worry about batteries, lag or interferences. So in short, I highly recommend the Logitech G9 Laser Mouse. For me, the only minuses are its rather high price and the fact that there is no SetPoint for Mac OS X (let’s hope Logitech will port it soon).
9 out of 10 points from me.
Here’s how to “reset” an installed Mac OS X and virtually return to a “virgin” state with a welcome screen prompting the user to setup and customize his Mac OS X installation:
0. To reset a Mac OS X v10.7 Lion installation to factory default, check Mark’s comment @ Apple forum (basically, deleting users before booting into single user mode seems to do the trick). For Mac OS X v10.6 Snow Leopard and older, follow the procedure below.
1. Press Command-S during startup to get into single user mode
2. Check the filesystem:
# /sbin/fsck -fy
3. Mount the root partition as writable:
# /sbin/mount -uw /
4. Remove the hidden .AppleSetupDone file:
# rm /var/db/.AppleSetupDone
5. a) For Mac OS X 10.5 ‘Leopard’ and newer, do:
# launchctl load /System/Library/LaunchDaemons/com.apple.DirectoryServices.plist
Repeat for every user previously defined on the machine (replace {username} with the real user name):
# dscl . -delete /Users/{username}
# dscl . -delete /Groups/admin GroupMembership {username}
5. b) For older versions of Mac OS X, do:
# rm -rf /var/db/netinfo/local.nidb
6. Remove the home directories of users. For every user do (replace {username} with the real user name):
# rm -rf /Users/{username}
7. If applicable, remove already created files in root’s home directory, e.g.
# rm /root/.bash_history
8. Shutdown (or reboot to verify the procedure worked):
# shutdown -h now
-or-
# reboot
That’s it! :)
[Update 20081106]: Thanks to Macs R We for the update 5 a) regarding Mac OS X Leopard! See the comments below for more information.
[Update 20090429]: Added “dscl . -delete /Groups/admin GroupMembership {username}” to 5b) as suggested by rello (see rello’s comment below)
[Update 20110731]: Some updates about resetting Mac OS X v10.7 Lion (unverified) and a clarification that rebooting at the end isn’t strictly necessary (just to verify the procedure worked). Thanks to David, Adrien and Adam for the hints.