haliphax

Edit: Now that I'm more familiar with the Linux command line, I realize that I was trying to reinvent the wheel. I don't know if I missed this part of the du manpage or what, but the functionality I was looking for is baked in:

du -hd 1

The h flag is for "human-readable format", and d 1 tells the program to go "no deeper than 1 level from the given folder". (With no folder specified, the current directory is used.)

The following string of commands can be used to not only list the immediate sub-directories of the current directory, but also print their size in human-readable format (kilobytes):

du -sh `ls -l | grep '^d' | awk '{print $9}'`

Here's how it works:

• du is the main command, which is used to list the size of the current directory tree. The -sh flags state that only the current-level sub-directories are to be listed, and that they should be listed in kilobytes (K).
• The "back-ticks" (`) execute commands inline, within the context of the current command. This means that everything inside these back-ticks will be used on the command-line parameters for du.
• ls -l lists files and directories with additional information (security flags, size, owner, group, etc.). This is the main command of the inline command string delineated by the back-ticks.
• grep is a command-line utility for parsing text using regular expressions. The '^d' parameter passed to it is a regular expression pattern that only matches lines beginning with "d" (which are directories, given the output of ls -l).
• awk is a different sort of parsing/formatting tool. '{print $9}' sends it a command to print the 9th column of output it receives (from grep).

Put them all together, and they work like a well-oiled machine to produce a new, specific utility. The utility can become a part of your regular Linux command-line arsenal by creating a text file out of it and flagging it as executable.

Update: EspadaV8 posted a wonderful suggestion for trimming the fat from this command by avoiding the use of awk and piping altogether. Give it a try yourself:

du -sh `ls -d */`