[Texmacs-dev] Problem with invoking unix command from TeXmacs experimental plugin

[Krzysztof Retel]

Hello Developers,

I'm writing a plugin in which I invoke external unix command from 
TeXmacs. In the plugin I use  bits of Scheme source code (written 
originally by Henri and/or Chad Brown):

;; UNIX commands. To invoke a command from TeXmacs.
(begin
  (use-modules (ice-9 popen))
  (define (unix-command cmd)
     (let* ((p (open-input-pipe cmd))
           (out (read-delimited "" p)))
       (if (eof-object? out) "" (string-split out #\newline)))))

I use it like that:
(unix-command "dot -Tps temp.mathlang.dra2dg.dot -o 
temp.mathlang.dra2dg.ps")
(unix-command "gv temp.mathlang.dra2dg.ps")

However, I can't do much of the viewed file with gv, e.g. I can't resize 
the gv window, or even go back and work within TeXmacs, unless I close 
the window. 
I guess the problem is with the opened-pipe ((open-input-pipe cmd)) and 
(eof-object? out). I tried to close the pipe with command (close-pipe) 
but it didn't work.

Hope I was clear and somebody could help me with that.

Kind Regards,
Krzysztof Retel