Linux, Mac, or Windows with Cygwin: If you have ever wanted to show a list of subdirectories underneath the current directory while at the terminal prompt, there's a simple command that can help.
Simply run the following command from the bash terminal prompt, which filters the file listing to only show folders:
ls -l | grep ^d
Since typing that whole command every time you want to show a list of directories might get a little tiring, you can use the alias feature to assign it to something you can more easily remember:
alias lsd="ls -l | grep ^d"
Now when you type "lsd" at the prompt, you will see a list containing only the directories, which can be very useful when you are trying to navigate through a messy set of folders.