Yes you are correct.
the setup is like this

    QFile database("/RDS.csv");
    QTextStream fileOutputStream(&database);
    QString lineData;
    QStringList fileOutput;

And my search condition is

QString condition = ui->comboBox->currentText();

Also i don't need to hunt the end of line markers.
I had this setup when i was reading all data before.
I wanted to take the first column if the row contained a search term.
But for this it works fine with

fileOutput.append(lineData);

BTW, the string returned by QTextStream::readLine() does not contain any end-of-line markers, so there is not need to try to remove them.

  if (database.open(QFile::ReadOnly | QIODevice::Text))
           {
               while(!fileOutputStream.atEnd())
               {
               lineData = fileOutputStream.readLine();
                if (lineData.contains(condition))
                {
                fileOutput.append(lineData.split("\n"));
                }

               }
               database.close();
           }

While reading, no need to load useless data.

So when i read through a file and a line has ex. "orange" i want to save that line to a list.

And what's the exact problem you face? Read the line, check for your condition and add the values to your stringlist.