unbuffer sh -c 'echo -n test; sleep 1; echo; sleep 1; echo -n hello; sleep 1; echo' | grep .
The above command should immediately print
test, then after on second print
hello, and after one more second end. Instead, I get a one-second delay, only then
test, then, after a two-second delay,
hello with command exit.
Note that here I'm trying to completely get rid of buffering, and
--line-buffered option of
grep won't help. So, how do I truly unbuffer this pipeline?