Can't this be achieved just using ssh instead of setting up a process that listens to the network?
from remote machine:
ssh me@macbook pbcopy < foo.txtfrom remote machine:
ssh me@macbook pbcopy < foo.txtFor me, #1, #2, and #3 are false. #4 is unknown. A VPN would make 1,2,3 easier, though.
S
mac$ ssh user@remote "some command" | pbcopy