popen4 doesn't block?
hancock at anansispaceworks.com
Wed Jan 29 15:15:19 CET 2003
Dennis Lee Bieber wrote:
> Strike that... based upon other posters it does look like you need
> do all the writes first, /then/ do a read which blocks until the
> process ends.
Yeah, that's the right answer, it worked very well (thought I should cap
this, since I left it a little vague before -- the remaining bug was a
trivial typo). Thanks a lot for the suggestions!
Of course I realized as soon as I tried it that popen can't block for
obvious logical reasons, but I hadn't thought it through to a solution.
In fact, I've used popen before, but I always closed it right away, so I
never really thought about how it worked. That .read() blocks is very
sensible (I suppose .readline() would not, though). Of course, once I read
the data, I'm free to close it right away, too, so things work out very
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