The article uses, but does not describe pbcopy and pbpaste on os x.
Feed data to pbcopy, and it goes to the clipboard:
pwd | pbcopy # Copies the working directory to the clipboard
pbpaste outputs the clipboard contents:
cd `pbpaste` # cd to the directory in the clipboard
(I use this to go to the same dir in a second terminal)
(There's Linux equivalent called, xsel does the same.)