Help with Popen in 2.2

[Peter Hansen]

Lowel Stern wrote:
> 
> >Do you know about the % operator?
> >
> Yes I do.

But not how to use it properly... <wink>

> You will find that if you use the %s with the popen command you get an
> error:
> TypeError: unsupported operand type(s) for %: 'file' and 'str'

Please post the code that generates this message.  The code 
_can_ be fixed.

-Peter