[mg]

I had a nice surprise and learning experience, when I discovered that the output of

     (echo red; echo green 1>&2) | echo blue

is indeterministic:

http://www.gibney.de/the_output_of_linux_pipes_can_be_indete...

As it turns out, this short line and its behavior nicely demonstrate a bunch of aspects that happen under the hood when you use a pipe.