This
#emacs tip of the week: M-x eshell then type ls -lh >> #<foo> and see the command output be appended to the "foo" buffer!
— Stathis Sideris (@stathissideris) October 18, 2016
is kind of cute but, of course, there are more direct ways of getting an external command’s output into an Emacs buffer. Still, one can imagine where something like this might be useful. It shows, once again, how powerful the Emacs environment is and serves as an another example of why many of us never want to leave Emacs.