The problem is the open of the pipe hangs until data is sent into the pipe.

The open of the FIFO file blocks until another process opens the file for writing, not until data is available (which blocks read/sysreads).

In alternative to previous suggestions, you can sysopen using the O_NONBLOCK flag provided in Fcntl. Update: I see only now that Fletch already gave you this suggestion, apologies for the repetition.