QFile: Avoid overwriting new data for existing files

Question

Is it possible to do the following?

    QFile file("Test.txt")
    If (file.exists) {
        //Start writing new data at the end of the file and DO NOT overwrite existing data
    } else {
        //Start from the beginning
    }

Answer 1

Try this.

QFile file("Test.txt")
if (file.exists()) {
     if(file.open(QIODevice::WriteOnly | QIODevice::Text | QIODevice::Append))
     {
          QTextStream out(&file);
          out << "new data";
     }
     else
         qDebug() << "file not open";
} else {
}

open() returns bool, so don't forget to check is file was opened correctly.

From documentation:

QIODevice::Append - The device is opened in append mode, so that all data is written to the end of the file.

More information: http://qt-project.org/doc/qt-4.8/qiodevice.html#OpenModeFlag-enum