From: Carsten Gronski <cgronski@...>
Date: 2002-06-16T07:39:05+09:00
Subject: Re: Question: how to  do (repeated) bidirectional communication with another process via stdin/stdout ?

ruby-talk@ruby-lang.org schrieb am 15.06.02 19:59:55:
> On 2002.06.16, Carsten Gronski <cgronski@web.de> wrote:
> > My problem is, that the standard Ruby IO class seems not to allow this
> > type of repeated bidirectional communication dialog with another
> > process.  Something like ke = IO.popen("ke.exe", "r+") would give me a
> > bidirectional communication channel, but unfortunatly it is not
> > possible to read from the I/O stream  until the write end of the I/O
> > stream is closed.
> 
> Remember to flush after writing.  Or, set the IO to auto-flush.
> 
> -- Dossy
> 
> -- 
> Dossy Shiobara                       mail: dossy@panoptic.com 
> Panoptic Computer Network             web: http://www.panoptic.com/ 
>   "He realized the fastest way to change is to laugh at your own
>     folly -- then you can let go and quickly move on." (p. 70)


Thanks, but flushing won' t help. Something like this does not work. 
the program hangs, when trying the second write. 
.. 
if (ke != nil)
    ke.syswrite(loginCall)
    ke.flush()
    ke.each("\n") { |line| puts(line) }
    # we get until here
    # this does not get through
    ke.syswrite(sysInfoCall)
    ke.flush()
    # we never get here -- program hangs !!
    ke.close_write
    ke.each("\n") { |line| puts(line) }
    ke.close
end

-- Carsten

______________________________________________________________________________
FreeMail in der Premiumversion! Mit mehr Speicher, mehr Leistung, mehr 
Erlebnis und mehr Pramie. Jetzt unter http://club.web.de/?mc=021105