Inspired by https://utcc.utoronto.ca/~cks/space/blog/unix/ShellPipelineIndeterminate
( echo red ; echo green 1>&2 ) | echo blue
Quoting Hackaday:
You’d like to think it prints three lines: red, green, and blue. But
would you be surprised to find out that it can sometimes output
“blue green” and sometimes just output blue. The first surprise is
that it isn’t deterministic. But the second thing that is surprising
is the sometimes the entire left-hand part of the line doesn’t do
anything.
Recommended test can be found in test.sh
.
source test.sh