[9fans] acme(4) and addr=dot

[Micah Stetson <micah@stetsonnet.org>]

I think this may apply to all versions of acme, but I'm running into
it on p9p.  First, acme(4) claims that a read on a window's addr file
returns the current address as a pair of character offsets m and n, in
'#m,#n' format or just '#m' if m and n are equal.  It looks like it
really returns m and n as two space-padded integer values.

But that's just a documentation bug.  What's really bothering me is
that I can't seem to get the value of dot.  I've tried this:

% echo -n 'addr=dot' | 9p write acme/70/ctl
% 9p read acme/70/addr
          0           0 %

Window 70's dot is somewhere on line 16.  Thinking maybe the ctl file
had to stay open, I tried this:

% {echo 'addr=dot'; 9p read acme/70/addr >[1=2]} | 9p write acme/70/ctl
          0           0 %

No help.  Am I doing something wrong?

Micah