[Interest] QProcess unbuffered

[Elvis Stansvik]

Den mån 6 mars 2023 kl 21:21 skrev Scott Bloom <scott at towel42.com>:
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> From: Björn Schäpers <qt-maillist at hazardy.de>
> Sent: Monday, March 6, 2023 12:18 PM
> To: Scott Bloom <scott at towel42.com>; interest at qt-project.org
> Subject: Re: [Interest] QProcess unbuffered
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> Am 06.03.2023 um 02:11 schrieb Scott Bloom:
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> I have an external executable (mkvalidator from https://www.matroska.org/downloads/mkvalidator.html
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> It never flushes the output, and it uses linefeed without carriage returns to overwrite existing text on the output.
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> 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
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> When running from the command line, I do get output continuously during the processing.
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> I setup a timer to waitForRead, didn’t do anything. I cant seem to force the QProcess to read all stdout or stderror info.
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> Any thoughts?
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> TIA
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> Scott
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> Hi,
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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 directly.
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> If there is interest I can copy some of my data, but currently I can't access it.
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> Kind regards,
> Björn.
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> I would love any info/data you can provide.  Feel free to email me privately if you want.

If possible, keep it on the list, to not leave us hanging. I think
it's valuable for both Qt devs and users to see other people's
laundry, even if it's a bit dirty :)

Elvis

>
> Thanks
>
> Scott
>
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