Binary list pattern maching direction?

Kenji Rikitake <>
Thu Dec 17 03:06:06 CET 2009

I've been using the following Erlang binary list matching pattern for
quite a while.

Actually, this piece of code below as a shell command sequence is
originally from ssh_sftpd.erl in the ssh module of R13B02 (and maybe

My question:

* The variables on the left-hand side of the matching operator (=) match
  from left to right.  Is this guaranteed or documented anywhere in
  Erlang reference manual(s)?
Answers or references appreciated.

-- begin --

2> <<Len:32/unsigned-big-integer, Msg:Len/binary, Rest/binary>> = <<0,0,0,5,10,11,12,13,14,15,16,17>>.
3> Len.
4> Msg.
5> Rest.

-- end --

Kenji Rikitake

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