what is happening here ? what is MY CODING ERROR ?

Anonymous_Banned275

Here is my under construction code

if (file.open(QIODevice::ReadWrite | QIODevice::Text))
{

                    qDebug()<< "DEBUG   source " << source;
                    qDebug()<< "BEFORE DEBUG  destination " << destination;
                    QTextStream outStream(&destination);
                    outStream << source;
                    qDebug()<< "DEBUG   source " << source;
                    //qDebug()<< "DEBUG  destination r" << destination;
                    qDebug()<< "AFTER DEBUG  destination " << destination;
                    qDebug()<< "AFTER DEBUG  destination " << destination;r
                    return source;
                }
                else
                {
                    qDebug()<<"\033[0;31m ";
                    qDebug()<< "\nDEBUG FAILED to open stream file  ";
                    qDebug()<<"\033[0;30m ";
                    return source;

 and here us my QDebug output         

   Why do I have "source + destination" AFTER 

 **outStream << source;**

my task is to output "source" text line to file @ destination and that is not happening

what am I doing wrong ?

DEBUG source "TEST LINE"
BEFORE DEBUG destination "../../BT_DATABASE/BluetoothComboData.txt"
DEBUG source "TEST LINE"
AFTER DEBUG destination "../../BT_DATABASE/BluetoothComboData.txtTEST LINE"
AFTER DEBUG destination "../../BT_DATABASE/BluetoothComboData.txtTEST LINE"

JonB

@AnneRanch said in what is happening here ? what is MY CODING ERROR ?:

if (file.open(QIODevice::ReadWrite | QIODevice::Text))

QTextStream outStream(&destination);

You show no relationship between file and destination. Show your declaration/initialisation of destination. By the look of it it is a string, your code will not output to a file of that name/your file variable. Maybe you intended QTextStream outStream(&file);, as per https://doc.qt.io/qt-6/qtextstream.html#details ?

ChrisW67

I am going to guess that destination is a QByteArray containing "../../BT_DATABASE/BluetoothComboData.txt".
That QByteArray is associated with a QTextStream using this constructor. Writing to the stream appends to the QByteArray, and that is what you are seeing.

Anonymous_Banned275

@ChrisW67 No, the destination is QString holding the actual text file.

As far as
"You show no relationship between file and destination. "
That statement really does not address the issue.
Compiler would complain without such relations.

I went back to the original example and installed several copies - no problem.
I just cannot see what is wrong with my "bad" code.

Christian Ehrlicher

@AnneRanch said in what is happening here ? what is MY CODING ERROR ?:

"You show no relationship between file and destination. "
That statement really does not address the issue.

lol - simply ignoring the facts seems to be very popular in the us nowadays :D

mchinand

Show the code where you instantiate source and destination (and any assignments before the code you show above). Appending the contents of source to that of destination is the expected result of outStream << source in your code.

JonB

@AnneRanch said in what is happening here ? what is MY CODING ERROR ?:

That statement really does not address the issue.

It is 100% the issue.

I just cannot see what is wrong with my "bad" code.

I already said. Why don't you try

QTextStream outStream(&file);

(instead of QTextStream outStream(&destination);) which is what you want? Can't see how to state it any clearer than that.

In your code the QTextStream outStream(&destination); means that you are putting the output stream into the variable which holds a pathname, not to the file you opened, not what you intended at all. Hence the debug output you see.