Sorry, i should have stated this in the original post, but i have tried this as well and it did not work either.
Interactive Elixir (1.7.3) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> System.cmd("mkfifo", ["/tmp/fifo", "-m", "0666"])
{"", 0}
iex(2)> port = :erlang.open_port({:spawn, '/tmp/fifo'}, [:binary])
#Port<0.7>
iex(3)> sh: /tmp/fifo: Permission denied
sh: line 0: exec: /tmp/fifo: cannot execute: Permission denied
and in another terminal, writing to the FIFO just hangs until i send a ctrl+c
echo "hello world" -e > "/tmp/fifo" Thu 24 Jan 2019 10:28:34 AM PST
^CAn error occurred while redirecting file '/tmp/fifo'
open: Interrupted system call
