Non-Blocking I/O

[Ruediger Kupper <Ruediger.Kupper(at)Physik.Uni-Marburg.De>]

Hi!

This is a question regarding Inter Process Communication
(IPC) in a UNIX environment:

Is there any way to tell IDL not to wait for the next
incoming data when reading from a file?
Attempting to read from an IPC channel (a pipe or fifo)
using READF or READU will cause IDL to hang until this read
attempt is successful. (Pipes or fifos do not produce an
EOF-signal unless they are explicitely closed by all sending
processes.) This blocking behaviour is undesired if you need
to check more than one IPC channel for any waiting data, or
if you want to incorporate such a check into an event loop.

The only solution I can think of is to provide support for
non-blocking I/O by a set of C-routines which could be
linked to IDL via CALL_EXTAERNAL, but I would prefer using
any "pure IDL" concept.

If anyone out there ran into the same problem, this person
could make a poor, frustrated IDL-programmer very happy by
posting me a little hint...

Best regards,
Ruediger.