[erlang-questions] How to get pid number in NIF code?

Jovi Zhang <>
Wed Sep 28 11:04:20 CEST 2011

On Wed, Sep 28, 2011 at 4:48 PM, Tony Rogvall <> wrote:
> I do not think there is a way to extract that number (except for a small
> hack, of course)
> Care to tell the reason behind why you need it ?
> /Tony

Hmm, I'm writing a NIF library to let erlang process communicate with
external hand. we call that as "hand", it is similar with erlang
process, but with different number reference, hand is range from

So in this NIF library I must remember the mapping of
"process<->hand", actually I only run this in one node, with process
like <0.X.0>,
which I only care about process number, that's why I want to get
process number, not whole pid structure.

Of course I can store all "ErlNifPid<->hand index", but that will
consume a lot of memory.

I think erts should provide API or macro for get process number for
some use case.

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