Re: [Expectperl-discuss] pipeline question (fwd)

[<gl...@ma...>]

> 
> > Since you're interested, this is the guts of what I am trying to do:
> > 
> > spawn("rsh machine dump_cmd various args... mount-point |cat -|dd bs=64k of=tape-device");
> > 
> > then use expect to catch the message:
> > "End of tape reached.  Press RETURN when new tape loaded ..."
> > (message varies depending on the dump software - yes, I'm doing this
> > from multiple machines/OSes/dump commands, each with different
> > idiosyncrasies, arguments, etc...)
> > 
> > When I get the expect message, I call a sub to change tapes using the
> > tape robot.  That's the plan anyway.  :)
> 
> Oh, OK, that's a perfectly valid use for Expect... :-)
> 
> BTW, what's the use of that noop-cat inside that pipe?  'dd' already does
> all the buffering you need...

No, unfortunately not.  After a great deal of experimenting, we found
we needed to do this to get the blocking right.  Something to do with
buffering and rsh lags perhaps?

> Good luck with that project!

Thanks.  Believe me, I need it!

I tried the change to the exec in Expect.  Didn't help.  Currently
I am getting this:

Reached end of medium for /dev/nrmt1h; Please wait for file closing
Cannot prompt (can't open /dev/tty): No such device or address

expect is catching the "Press RETURN ..." message, and happily changing
tapes, but the 

print $bakupcmdobj "\r";

which I do after the tape is ready is evidently failing.
The script just hangs - I see this:

# ps -fu root | grep ...
root       3661    198  0.0 -        ??           0:00.00 <defunct>
root        198  12213  0.0 11:14:41 ttyra        0:00.38 perl /usr/local/sbin/bakup_master ....

Any thoughts?


thanks
Glen

-- 
Glen Davison			gl...@ma...
Computer System Administrator	phone: +61 2 9385 7018
Maths, UNSW			fax:   +61 2 9385 7123