QProcess with External script that kills the main process.

f3tz3r

So for my job i'm implementing an automatic update ability to the application.

Our application versions are controlled via the RPM system. When i run the RPM update command ("rpm -U {rpm file}"), the RPM file kills the current running application process, corrects the applications files / directories / configuration, and moves the new executable and an autostart script restarts the application.

My current implementation is the following:

MainWindow.cpp:

Receives message that an update is needed
Waits for the application to be idle before updating
Once idle, sanity checks where the new code is, and that it is applicable
Emits a signal caught by a controller to execute the file when idle

Controller.cpp:

Receives the signal for update
Start script to do the update.

Controller.cpp:
@
//Function to call the update script
void Controller::updateCode(){
DEBUG("CTRL UPDATE CODE");

/*
system("/home/app/updateScript.sh");
*/

QProcess *process = new QProcess(this);

QString file = "/home/app/updateScript.sh";

// bool x = process->startDetached(file, QStringList());
// bool x = process->startDetached(file);
int x = process->execute(file);

DEBUG("START (%d)", x);

QObject::connect(process, SIGNAL(error(QProcess::ProcessError)), this, SLOT(processError(QProcess::ProcessError)));

DEBUG("PROCESS STATE (%d)", process->state());

}
@

updateScript.sh:

@
if [ ! -d "/home/app/installedCode" ];
then
echo "Creating /home/app/installedCode directory"
mkdir /home/app/installedCode
fi

FILE="$(ls -G /home/app/newCode/)"
echo $FILE

if [ -f "/home/app/newCode/$FILE" ];
then

    MYPATH="$(readlink -f newCode/$FILE)"

    echo $MYPATH

    eval "rpm -U " $MYPATH

    mv "/home/app/newCode/$FILE" "/home/app/installedCode/"

else
echo "No file to update"
fi
@

Here is the log for the currently attempted process:
@
01-19 12:31:07.079 - [controller.cpp:2240] - Simulating SC Update Message
01-19 12:31:07.079 - [mainwindow.cpp:521] - Got request to update code. Waiting for idle
01-19 12:31:10.978 - [mainwindow.cpp:514] - System optimal for update
01-19 12:31:10.979 - [mainwindow.cpp:477] - System idle. Updating code
01-19 12:31:10.979 - [controller.cpp:1211] - CTRL UPDATE CODE
01-19 12:31:11.163 - [controller.cpp:1223] - START (0)
01-19 12:31:11.163 - [controller.cpp:1227] - PROCESS STATE (0)
@

The .rpm file is moved from the newCode/ directory to the installedCode/ directory, so i know the script is getting called. But the running application is not getting killed like it should be.

If i call the updateScript.sh file from the command line on the unit instead of the application, it does exactly what i expect.

I also tried the process->startDetached() function as you can see where it is commented out. It does the same thing that execute() does.

Any help is appreciated, thanks!

p3c0

Hi,

If I understood you correctly, you can emit a custom signal from Controller.cpp once the process completes, catch it in MainWindow.cpp and call close() of MainWindow.cpp.

SGaist

Hi,

Depending on the application connecting to QApplication::quit will ensure that the application is closing. The quitOnLastWindowClosed flag might be unset so closing windows might not be enough