Qt-interest Archive, April 2007
QProcess not starting my program
Message 1 in thread
Hello-
First time using QProcess, seemed easy enuf.
Im in a QT gui, I try launching another QT gui
using QProcess but it never seems to start
and the process falls through the code:
QProcess *proc = new QProcess(this);
QStringList env = QProcess::systemEnvironment();
proc->setEnvironment(env);
proc->setWorkingDirectory(".");
proc->setStandardOutputFile("./out");
QStringList args;
args << " -d directory";
proc->start("mygui", args);
proc->waitForStarted(5000);
printf("Proc state: %d\n",proc->state());
I get one line of output in my 'out' file
and proc state is = 2 (running), however the
GUI never comes up. The GUI works just fine
standalone, so I assume its my use of QProcess
somehow.
Suggestions/advice? This is QT 4.2.2
Thanks,
Jeff
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Message 2 in thread
Hi,
do you have this problem only under linux?
I had the problem that my Qt gui apps only
could be started inside an xterm - when I
tried to start them by another program,
they didn't show up.
Hint: You could try to open an xterm and
provide your app as parameter for xterm -
e.g.: "xterm -e ~/mygui"
ciao,
Chris
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Message 3 in thread
On Thursday 12 April 2007 06:33, Jeff Lacki wrote:
> Hello-
>
> First time using QProcess, seemed easy enuf.
> Im in a QT gui, I try launching another QT gui
> using QProcess but it never seems to start
> and the process falls through the code:
>
> QProcess *proc = new QProcess(this);
> QStringList env = QProcess::systemEnvironment();
> proc->setEnvironment(env);
> proc->setWorkingDirectory(".");
> proc->setStandardOutputFile("./out");
>
> QStringList args;
> args << " -d directory";
>
> proc->start("mygui", args);
> proc->waitForStarted(5000);
> printf("Proc state: %d\n",proc->state());
>
> I get one line of output in my 'out' file
> and proc state is = 2 (running), however the
> GUI never comes up. The GUI works just fine
> standalone, so I assume its my use of QProcess
> somehow.
>
> Suggestions/advice? This is QT 4.2.2
> Thanks,
> Jeff
Your sample code works fine with QT 4.2.3 and proc->start("./mygui", args) or
proc->start("mygui", args) in case mygui is in the path.
I get state = 0 if mygui cannot be found when using proc->start("mygui", args)
without having it in the path. Does the single line in the output file
indicate that the mygui application was actually started? My 'out' file is a
zero length file if the application failed to start.
Regards,
Enar
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Message 4 in thread
Enar VÃikene wrote:
>Your sample code works fine with QT 4.2.3 and proc->start("./mygui", args) or
>proc->start("mygui", args) in case mygui is in the path.
>
>I get state = 0 if mygui cannot be found when using proc->start("mygui", args)
>without having it in the path. Does the single line in the output file
>indicate that the mygui application was actually started? My 'out' file is a
>zero length file if the application failed to start.
>
>
>
>
This is under linux (I dont have it setup under any other OS to try it
there).
Yes Im doing :
proc->start("./mygui", args)
Im sorry, I should have said that it seems to startup
but never actually comes up. I do get one line in my
output file during the main.cpp command line processing right
before my splash screen gets started (which does not come up).
Jeff
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Message 5 in thread
Sorry for the waste of bandwidth. I found my issue. I didnt
do a setProcessChannelMode(QProcess::MergedChannels);
So I wasnt getting my stderr output in the log file telling me I had
a command line argument error.
Thanks for the help and suggestions.
Jeff
>On Thursday 12 April 2007 06:33, Jeff Lacki wrote:
>
>
>>Hello-
>>
>>First time using QProcess, seemed easy enuf.
>>Im in a QT gui, I try launching another QT gui
>>using QProcess but it never seems to start
>>and the process falls through the code:
>>
>> QProcess *proc = new QProcess(this);
>> QStringList env = QProcess::systemEnvironment();
>> proc->setEnvironment(env);
>> proc->setWorkingDirectory(".");
>> proc->setStandardOutputFile("./out");
>>
>> QStringList args;
>> args << " -d directory";
>>
>> proc->start("mygui", args);
>> proc->waitForStarted(5000);
>>printf("Proc state: %d\n",proc->state());
>>
>>I get one line of output in my 'out' file
>>and proc state is = 2 (running), however the
>>GUI never comes up. The GUI works just fine
>>standalone, so I assume its my use of QProcess
>>somehow.
>>
>>Suggestions/advice? This is QT 4.2.2
>>Thanks,
>>Jeff
>>
>>
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