[Interest] QProcess unbuffered

Björn Schäpers qt-maillist at hazardy.de
Mon Mar 6 21:17:39 CET 2023

Am 06.03.2023 um 02:11 schrieb Scott Bloom:
> I have an external executable (mkvalidator from 
> https://www.matroska.org/downloads/mkvalidator.html
> It never flushes the output, and it uses linefeed without carriage returns to 
> overwrite existing text on the output.
> The problem is, when I run it via QProcess (on windows, Qt 5.15.10), I get 
> zero output until the process ends.  As if it was buffered, and the output was 
> finally flushed
> When running from the command line, I do get output continuously during the 
> processing.
> I setup a timer to waitForRead, didn’t do anything. I cant seem to force the 
> QProcess to read all stdout or stderror info.
> Any thoughts?
> Scott
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I had the exact same problem (but without QProcess). You have to use a trick to 
disable the buffering, I don't know if its possible with QProcess, you will have 
to use QProcess::CreateProcessArgumentModifier or most likely CreateProcess 

If there is interest I can copy some of my data, but currently I can't access it.

Kind regards,
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