$du
Typing the above at the prompt gives you a list of directories that exist in the current directory along with their sizes. The last line of the output gives you the total size of the current directory including its subdirectories. The size given includes the sizes of the files and the directories that exist in the current directory as well as all of its subdirectories. Note that by default the sizes given are in kilobytes.
$du -ch | grep total
This would have only one line in its output that displays the total size of the current directory including all the subdirectories.
$du –exculde=doc
The above command would display the size of the current directory along with all its subdirectories, but it would exclude all the files having the given pattern present in their filenames. Thus in the above case if there happens to be any doc files within the current directory or any of its subdirectories, their size would not be included while calculating the total directory size.
$du -ch | sort -rn
Listing the disk space used for a directory and its subdirectories, sorted by disk usage