QProcess problem to start executable

[cydside]

Hi to all,
it's driving me crazy, trust me. Let me show you the code:

void frmMain::dumpSqliteDatabase()
{
   QString strError;
   QString strPathSqlite;
 
   QString fileName = "Dump.sql";
 
   QProcess p;
 
   strPathSqlite = QDir::toNativeSeparators(QCoreApplication::applicationDirPath() + "/data/sqlite3.exe");
   strPathSqlite.replace("\\","\\\\");
 
   p.start(strPathSqlite + " Scrab.db .dump > " + fileName);
 
   if (!p.waitForStarted() || !p.waitForFinished(-1) || (p.exitStatus() != QProcess::NormalExit))
   {
      switch (p.error())
      {
         case (QProcess::FailedToStart) :
            strError = tr("The process failed to start. Either the invoked "
               "program is missing, or you may have insufficient permissions to invoke the program.");
            break;
         case (QProcess::Crashed) :
            strError = tr("The process crashed some time after starting successfully.");
            break;
         case (QProcess::WriteError) :
            strError = tr("An error occurred when attempting to write to the process. For example, the process may not be running, or it may have closed its input channel.");
            break;
         case (QProcess::ReadError):
            strError = tr("An error occurred when attempting to read from the process. For example, the process may not be running.");
            break;
         default:
            strError = tr("An unknown error occurred.");
      }
 
      QMessageBox msgBox;
      msgBox.setWindowTitle(tr("!!!"));
      msgBox.setIcon(QMessageBox::Warning);
      msgBox.setText(strError);
      msgBox.setStandardButtons(QMessageBox::Ok);
      msgBox.exec();
   }
}

void frmMain::dumpSqliteDatabase()
{
   QString strError;
   QString strPathSqlite;

   QString fileName = "Dump.sql";

   QProcess p;

   strPathSqlite = QDir::toNativeSeparators(QCoreApplication::applicationDirPath() + "/data/sqlite3.exe");
   strPathSqlite.replace("\\","\\\\");

   p.start(strPathSqlite + " Scrab.db .dump > " + fileName);

   if (!p.waitForStarted() || !p.waitForFinished(-1) || (p.exitStatus() != QProcess::NormalExit))
   {
      switch (p.error())
      {
         case (QProcess::FailedToStart) :
            strError = tr("The process failed to start. Either the invoked "
               "program is missing, or you may have insufficient permissions to invoke the program.");
            break;
         case (QProcess::Crashed) :
            strError = tr("The process crashed some time after starting successfully.");
            break;
         case (QProcess::WriteError) :
            strError = tr("An error occurred when attempting to write to the process. For example, the process may not be running, or it may have closed its input channel.");
            break;
         case (QProcess::ReadError):
            strError = tr("An error occurred when attempting to read from the process. For example, the process may not be running.");
            break;
         default:
            strError = tr("An unknown error occurred.");
      }

      QMessageBox msgBox;
      msgBox.setWindowTitle(tr("!!!"));
      msgBox.setIcon(QMessageBox::Warning);
      msgBox.setText(strError);
      msgBox.setStandardButtons(QMessageBox::Ok);
      msgBox.exec();
   }
}

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I've tested the same command(C:\data>sqlite3 Scrab.db .dump > Dump.sql) in the windows 7 shell and it works, but the above code doesn't create the dumped file!

Thanks in advance for yuor help.

[squidge]

QProcess isn't the Windows shell. It doesn't support redirection for example.

[agathiyaa]

Hi,

Try...

p.setStandardOutputFile(fileName);
p.start(strPathSqlite + " Scrab.db .dump ");

p.setStandardOutputFile(fileName);
p.start(strPathSqlite + " Scrab.db .dump ");

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[cydside]

Hi,

Try...

p.setStandardOutputFile(fileName);
p.start(strPathSqlite + " Scrab.db .dump ");

p.setStandardOutputFile(fileName);
p.start(strPathSqlite + " Scrab.db .dump ");

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Thanks, the way is correct!
I just added the setWorkingDirectory to complete the task as follow:

QProcess p;
 
   p.setStandardOutputFile(fileName);
   p.setWorkingDirectory(strWorkingDirectory);

QProcess p;

   p.setStandardOutputFile(fileName);
   p.setWorkingDirectory(strWorkingDirectory);

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It finally works!!!