Hello there,

reading the section about “IO and the file system”, I’ve noticed the following paragraph:

By modeling IO devices with processes, the Erlang VM allows I/O messages to be routed between different nodes running Distributed Erlang or even exchange files to perform read/write operations across nodes. Neat!

I’ve tried opening a file on a remote node using :rpc.call, but the returned pid seems to get closed immediately afterwards:

steffen@sdBookAir ~> iex --sname "b"
Erlang/OTP 23 [erts-11.2] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [dtrace]

Interactive Elixir (1.11.4) - press Ctrl+C to exit (type h() ENTER for help)
iex(b@sdBookAir)1> Node.connect(:"a@sdBookAir")
true
iex(b@sdBookAir)1> {:ok, file} = :rpc.call(:a@sdBookAir, File, :open, ["/tmp/testfile"])
{:ok, #PID<11250.126.0>}
iex(b@sdBookAir)2> :file.read(file, 100)
{:error, :terminated}

Opening the file on the other node and then “transferring” the pid works:

iex(a@sdBookAir)1> {:ok, pid} = File.open("/tmp/testfile")
{:ok, #PID<0.128.0>}
# then on the other node
iex(b@sdBookAir)3> file = pid("11250.128.0")
#PID<11250.128.0>
iex(b@sdBookAir)4> :file.read(file, 100)
{:ok, "hello\n"}

Is there a way to prevent the file opened with :rpc.call from being closed? And if yes, why is it being closed in the first place?

Thanks!