Re: [Chicken-users] Controlling output of processes

[Lasse Kliemann]

* Message by -Peter Bex- from Fri 2010-03-12:
> On Fri, Mar 12, 2010 at 05:14:02PM +0100, Lasse Kliemann wrote:
> > How can I start a process and control where it sends its stdout 
> > or stderr? I know that I can do:
> > 
> > (receive
> >    (p-stdout p-stdin p-pid p-stderr)
> >    (process* command args)
> >    (...))
> > 
> > This gives input and output ports connected to the process. But 
> > how can I express, e.g.: "everything available on port p-stdout 
> > should go to (current-output-port)"?
> > 
> > Can you give me some suggestions?
> 
> (receive
>    (p-stdout p-stdin p-pid p-stderr)
>    (process* command args)
>    (with-input-from-port p-stdin (lambda () ....)))
> 
> See http://chicken.wiki.br/man/4/Unit%20ports
 
Hello Peter, thank you for the answer. I tried it out, but it 
does not work like the thing I wanted. Here is an example:

(receive
   (p-stdout p-stdin p-pid p-stderr)
   (process* "ls" '("-l"))
   (with-input-from-port p-stdout (lambda () (process-wait p-pid))))

When I run this, I receive no output. The goal was that my 
program hands the output of "ls -l" through. So this program was 
supposed to give exactly the output of "ls -l". You know what I 
mean?

(I replaced "p-stdin" by "p-stdout" in the call to 
"with-input-from-port" because this looked more appropriate to 
me, but it also does not work when I use "p-stdin" there, as your 
example suggested.)

I hope there is a way to do it.

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