[Qt-interest] Problems running QProcess under linux

[Scott Aron Bloom]

No reading from the console, only writing.

Scott

-----Original Message-----
From: qt-interest-bounces+scott.bloom=onshorecs.com at qt.nokia.com
[mailto:qt-interest-bounces+scott.bloom=onshorecs.com at qt.nokia.com] On
Behalf Of Thiago Macieira
Sent: Monday, September 26, 2011 11:04 AM
To: qt-interest at qt.nokia.com
Subject: Re: [Qt-interest] Problems running QProcess under linux

On Monday, 26 de September de 2011 13:37:19 Bill Crocker wrote:
> Scott Aron Bloom wrote:
> > Thanks.. the problem here is the crash takes 3-4 hours of running to

> > crash..  and has yet to be reproduced when run with the same command

> > line arguments from the CLI only...  hence my thoughts that it might

> > be a QProcess settings issue...
> 
> Create a small program which dumps all resource limits using 
> getrlimit. Run this from a QProcess and see if the limits differ from 
> a command line run.
> 
> You can also dump its list of env vars and see if there are any 
> differences there.

Usually, the only difference between running from the command line and
using QProcess is stdin, stdout and stderr. From the command-line, they
are connected to a terminal; from QProcess, they are connected to a
pipe.

By default, libc uses line-buffering with stdout when connected to a
terminal, but full buffering when it's a file or pipe,

Also, reading from a terminal respects terminal settings (canonical
mode, for example), whereas reading from a file or pipe is just that:
reading.

It might be that the child process attempts to read a chunk of data
expecting to get at most one line, but it eventually gets more than that
and then falls out of sync.

--
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
   Software Architect - Intel Open Source Technology Center
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