creates a name at
(the containing directory must already exist).
Each write to
appends the written data up to a maximum of
bytes; subsequent writes erase the existing
data in a circular fashion. A read from
will return any currently stored data, if any;
if there is none, then it will block until more
data becomes available.
Multiple readers will receive the data independently
of one another. If a writing process is consistently
producing data faster than a reading process, then
the data read will have some bytes elided; a write
is never blocked.