odr-dabmux fifo output creates normal file instead of fifo

[paraenggu]

If running odr-dabmux with a fifo:// (named pipe) output, a normal file (which grows indefinitely) instead of a fifo will be created.

Example configuration:

; [...]

outputs {
    ; Output RAW ETI NI to a FIFO
    stdout "fifo:///tmp/example.fifo?type=raw"

    ; Throttle output to real-time (one ETI frame every 24ms)
    ; Required for all real-time outputs except stdout
    throttle "simul://"
}

After starting odr-dabmux a normal file will be created:

ls -la /tmp/example.fifo 

-rw-r--r--. 1 odr-dabmux odr-dabmux 2512896 11. Sep 13:54 /tmp/example.fifo
^                                   ^^^^^^^

Manually pre-create the fifo helps as a workaround

mkfifo /tmp/example.fifo
ls -la /tmp/example.fifo

prw-r--r--. 1 odr-dabmux odr-dabmux  0 11. Sep 14:07 /tmp/example.fifo
^                                    ^

[DavidLutton]

#19 Attempt to create FIFO before open, no checks

[mpbraendli]

Should work in 407603c