In article <200001121013.CAA17917@bugs.wakawaka.com>,
Paul Sander <paul@wakawaka.com> wrote:
>
>Have you considered writing a daemon that writes to a named pipe?
>Use mknod to create a fifo file, and run a program that writes to
>the pipe, then closes it, then writes to it again.  When a second
>program opens the pipe for reading, it will read the initial content
>from the daemon, then get an EOF when the daemon closes the pipe.
>
>The two programs run in different processes, so setid issues don't
>come into play.  You might put some thought into the permissions on
>the pipe, though.


Most programs check that the file is plain before opening it to avoid
blocking. there was a well known denial of service attack on fingerd's
.plan files.

christos