At 2:06 PM 4/2/95, Charles M. Hannum wrote:
>The FIFO mentioned in your ktrace output is used to communicate with
>the WP print daemon.  When `xwp' tries to open the FIFO for writing
>and fails, it forks another process to start the daemon.  The error is
>displayed because `wpexc60' exits with a status of 1, indicating
>failure.  The reason it fails is that it tries to open the FIFO with
>O_RDWR (which doesn't make sense), apparently expecting it to be
>equivalent to opening it with O_RDONLY|O_NDELAY but leaving the FIFO
>in blocking mode, and instead gets EINVAL.
>
While we are on this... The other unix machines I have worked with
do allow FIFOs to be opened RDWR. It is inconvenient that NetBSD doesn't.

-mark