Is there a way to specify buffering mode
(unbuffered,line-buffered,block-buffered) in spawnShell + friends?
This is very useful to have in many applications, eg for logging where one
wants to view in progress log results without waiting for entire process to
complete or for a 40960-sized block to be written (as is currently the case
it seems)

Do you want to customize buffering in child or parent process?