Linux Dummies 9th

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Part IV: Junior Administrator Boot Camp
Consider this example. Start with a simple command. The du command lists
the contents of the directory you’re now in, along with its subdirectories and
how much hard-drive space it takes up, with a total at the end. Try typing
just the du command by itself. You see a long listing of files that looks something
like this:
rich@testbox:~$ du
4 ./.local/share/totem
8 ./.local/share
12 ./.local
4 ./.config/gnome-session/saved-session
8 ./.config/gnome-session
8 ./.config/gtk-2.0
8 ./.config/totem
40 ./.config
44 ./.pulse
That’s neat, but it probably raises more questions than it answers. The
output gives you a long listing of data, but of what? Do those numbers represent
bytes, kilobytes, or messages from outer space? To clarify, try adding a
simple option to your command:
rich@testbox:~$ du -h
4.0K ./.local/share/totem
8.0K ./.local/share
12K ./.local
4.0K ./.config/gnome-session/saved-session
8.0K ./.config/gnome-session
8.0K ./.config/gtk-2.0
8.0K ./.config/totem
40K ./.config
44K ./.pulse
You’re still issuing the same command, but now you’re providing an additional
instruction about what you want displayed. The -h option tells du to
show you the information in terms that humans can read more easily. Now
Ms, Ks, and Gs appear next to the numbers so you can see how big these
numbers actually are. But wait — there’s more. What if you just want to know
the total amount of disk space this directory and its subdirectories are taking
up? That calls for the -s flag:
rich@testbox:~$ du -s
24064 .
rich@testbox:~$
What if you want the total for a different directory? Or just for one of your
subdirectories? The following command shows, in a human-readable way,
how much hard drive space the Music directory takes up:
du -sh ~/Music