Raw NIF surface over the Hamlib C API (via the hlx_* C shim and a Rustler crate at native/hamlib_nif).

This is the low-level binding — prefer Hamlib.Rig for a managed, process-owned interface. Every function here corresponds 1:1 to a shim call.

Return shapes

• Operations that don't return data → :ok | {:error, {code, reason}}

• get_freq/1 → {:ok, hz} | {:error, {code, reason}}

• get_mode/1 → {:ok, {mode_string, passband_hz}} | {:error, …}

• get_ptt/1 → {:ok, boolean} | {:error, …}

code is the integer Hamlib error (negative), reason its text. A handle is an opaque resource from init/1; the BEAM frees the underlying rig when the handle is garbage-collected (close + cleanup), even on owner crash.

Lifecycle

{:ok, h} = Hamlib.Nif.init(model)            # allocate (no I/O)
:ok = Hamlib.Nif.set_conf(h, "rig_pathname", path)
:ok = Hamlib.Nif.set_conf(h, "serial_speed", "19200")
:ok = Hamlib.Nif.open(h)                      # opens the port
...
:ok = Hamlib.Nif.close(h)