subprocess.Popen() redirecting to TKinter or WXPython textwidget???

Ivo Woltring TheDolphin at
Wed Jan 26 22:56:12 CET 2005

<stewart.midwinter at> wrote in message
news:1106775371.049857.36360 at
> Ivo, my initial thought would be, you need to know how much text you
> will get back from popen.  My Python reference has the following
> example:
> import os
> dir = os.popen('ls -al', 'r')
> while (1):
> line = dir.readline()
> if line:
> print line,
> else:
> break
> that example shows how to capture the process output in a file-type
> object, then bring it into a string with readline().
>[.... snip ....]
> cheers
> S

Thanx for trying Stewart,
 but that is not what I need
The output of mencoder is not readable with readlines (i tried it) because
after the initial informational lines You don't get lines anymore (you get a
linefeed but no newline)
The prints are all on the same line (like a status line)
something like
Pos:   3,1s     96f ( 0%)  42fps Trem:   0min   0mb  A-V:0,038 [171:63]

which is coninually updated while the process runs...

> in your app, you could create a Tkinter stringVar, say myOutput, for
> the process output. In your Tkinter widget, you could then set a
> textvariable=myOutput. also use the wait_variable and watch options

How does this work? wait?? anyone?

> (hope I recall these correctly, don't have my Tkinter ref. at hand) to
> detect when there's been a change to the contents of the StringVar and
> update the contents of the label.
> Hope this helps, if not, write back.

I really like to know how I can catch the output of a subproces.Popen()
command and redirect it to something else (like a textwidget )
and I really like to use the subprocess module (standard in v2.4) to get to
know it.
Another reason to use the subprocess module is I can stop the process
because I know the handle of the thread. The subprocess module knows all


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