[AppleJack][1] is one of those indispensable programs. It’s now up to version 1.4.2, go get it. I run it every time I have to restart my Mac and I have it running on every Mac I own.
> AppleJack runs in Single User Mode and is menu-based for ease of use.
> Using AppleJack, you can repair your disk, repair permissions, validate the system’s preference files, and get rid of possibly corrupted cache files. In most cases, these operations can help get your machine back on track. The important thing is that you don’t need another startup disk with you. All you need to do is restart in Single User Mode (SUM), by holding down the command and s keys at startup…
[1]:http://applejack.sourceforge.net/