Linux Commands for 99 Bottles of Beer and Disk Space - page 2

99 Bottles of Beer, df command

du shows the total space used by my home directory:

$ du -hs ~
122G    /home/carla

hs means use human-readable numbers and show the total for the whole directory, and ~ is a shortcut for "my own home directory". Use this to get the total size of any directory. If you leave off the s it lists every subdirectory and file. You can also get the size of any individual file:

$ du -h worried-man.wav
18M   worried-man.wav

Or all the same type of files in the current directory:

$ du -h *.jpg
144K    jpgtest1.jpg
132K    jpgtest.jpg
28K     nascarcap.jpg
128K    firefox-win.jpg
48K     funny-pictures-cat-is-grumpy.jpg

This finds the ten biggest directories or files in my home directory:

$ du -a ~ | sort -nr | head -n 10
127353376       /home/carla
122939388       /home/carla/sda1
55389844        /home/carla/sda1/photos
40650788        /home/carla/sda1/Photos
37020884        /home/carla/sda1/photos/2007
23911504        /home/carla/sda1/carla
17702480        /home/carla/sda1/photos/2008
16547200        /home/carla/sda1/Photos/2007-sept-montana
16547200        /home/carla/sda1/photos/2007/2007-sept-montana
5634812 /home/carla/sda1/carla/pictures

If you leave off the a option it only reports directories. I can't use the human-readable option because that does not sort correctly. I'm sure there is some nifty regular expression that knows 1000M is bigger than 1000K, but I haven't figured it out yet. Ace admins script these commands to monitor disk usage, and to send them alerts when disks get too full.

See man df, man du, man bash, man sort, and the excellent book Learning the Bash Shell to learn more.

Carla Schroder is the author of the Linux Cookbook and the Linux Networking Cookbook (O'Reilly Media), the upcoming "Book of Audacity" (NoStarch Press), a lifelong book lover, and the managing editor of LinuxPlanet and Linux Today.