Mac OS® X Tiger™ Unleashed

Getting Disk and Directory Information: du, df

The du and df commands are great examples of where a command-line tool really shines. Finding out how much space your files are using, or how much space is left on your various assorted volumes and drives is not a pleasant process under the Finder. Certainly, the display of drive space on a volume that appears in the bottom of every Finder window is a convenient way to keep track of disk usage, but if you want to find out what drive has the most free space, there isn't a good way to see this information without either clicking through every drive and looking at the window, or running an auxiliary disk-monitoring tool like Disk Utility. At the command line, it's two keystrokes:

brezup:~ ray$ df