On Wed, Feb 4, 2015 at 10:10 PM, Richard A. O'Keefe wrote:

Given things like sockets, STREAMS, and ptys, I am not sure that it is _possible_ for a Unix system to determine whether two streams are or are not "related" reliably.

It's not. I was not implying that it was, or that it was even a good idea to try to do so. On the other hand, flushing *every* line-buffered FILE is rather overkill but less heinous than highly dubious and untestable assumptions about relationships. -- brandon s allbery kf8nh sine nomine associates allbery.b@gmail.com ballbery@sinenomine.net unix, openafs, kerberos, infrastructure, xmonad http://sinenomine.net