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Copying the file content

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  • S sierdzio
    11 Jan 2021, 07:35

    Yes, start() starts the thread, but it does not mean your writeData() is called. If that were true, you would see your qDebug() output, because it is not in any if conditions - it should be printed every time writeData() is called.

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    deleted286
    wrote on 11 Jan 2021, 07:40 last edited by deleted286 1 Nov 2021, 07:43
    #11

    @sierdzio yes you are right. I've called the function. Thread is working now. But copying issue does not work.

    1 Reply Last reply
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      sierdzio
      Moderators
      wrote on 11 Jan 2021, 07:44 last edited by
      #12

      I don't know either, you have not shown any code or stated how you want it all to work... so all I can say is "read the docs" :D QThread has a nice example and detailed description: https://doc.qt.io/qt-5/qthread.html#details

      (Z(:^

      D 1 Reply Last reply 11 Jan 2021, 07:45
      0
      • S sierdzio
        11 Jan 2021, 07:44

        I don't know either, you have not shown any code or stated how you want it all to work... so all I can say is "read the docs" :D QThread has a nice example and detailed description: https://doc.qt.io/qt-5/qthread.html#details

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        deleted286
        wrote on 11 Jan 2021, 07:45 last edited by
        #13

        @sierdzio I just want, when writeData() thread is called, copy the contents into new txt.

        J 1 Reply Last reply 11 Jan 2021, 07:46
        0
        • D deleted286
          11 Jan 2021, 07:45

          @sierdzio I just want, when writeData() thread is called, copy the contents into new txt.

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          J.Hilk
          Moderators
          wrote on 11 Jan 2021, 07:46 last edited by J.Hilk 1 Nov 2021, 07:46
          #14

          @suslucoder
          QThread has a started signal you connect that signal to your slot


          Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


          Q: What's that?
          A: It's blue light.
          Q: What does it do?
          A: It turns blue.

          D 1 Reply Last reply 11 Jan 2021, 08:09
          3
          • J J.Hilk
            11 Jan 2021, 07:46

            @suslucoder
            QThread has a started signal you connect that signal to your slot

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            deleted286
            wrote on 11 Jan 2021, 08:09 last edited by
            #15

            @J-Hilk My thread has working now. But copying does not occur

            J 1 Reply Last reply 11 Jan 2021, 08:10
            0
            • D deleted286
              11 Jan 2021, 08:09

              @J-Hilk My thread has working now. But copying does not occur

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              jsulm
              Lifetime Qt Champion
              wrote on 11 Jan 2021, 08:10 last edited by
              #16

              @suslucoder So, what does copy() return?

              https://forum.qt.io/topic/113070/qt-code-of-conduct

              D 1 Reply Last reply 11 Jan 2021, 08:15
              1
              • J jsulm
                11 Jan 2021, 08:10

                @suslucoder So, what does copy() return?

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                deleted286
                wrote on 11 Jan 2021, 08:15 last edited by
                #17

                @jsulm it returns nothing, Either true or false

                J J 2 Replies Last reply 11 Jan 2021, 08:16
                0
                • D deleted286
                  11 Jan 2021, 08:15

                  @jsulm it returns nothing, Either true or false

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                  jsulm
                  Lifetime Qt Champion
                  wrote on 11 Jan 2021, 08:16 last edited by
                  #18

                  @suslucoder said in Copying the file content:

                  it returns nothing, Either true or false

                  ?
                  It returns a boolean.
                  Again: what does it return?!

                  qDebug() << QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");
                  

                  https://forum.qt.io/topic/113070/qt-code-of-conduct

                  D 1 Reply Last reply 11 Jan 2021, 08:18
                  0
                  • D deleted286
                    11 Jan 2021, 08:15

                    @jsulm it returns nothing, Either true or false

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                    J.Hilk
                    Moderators
                    wrote on 11 Jan 2021, 08:16 last edited by
                    #19

                    @suslucoder then the function isn't called.

                    Please post what you actually have in your code, otherwise no-one will be able to help you


                    Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                    Q: What's that?
                    A: It's blue light.
                    Q: What does it do?
                    A: It turns blue.

                    1 Reply Last reply
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                    • J jsulm
                      11 Jan 2021, 08:16

                      @suslucoder said in Copying the file content:

                      it returns nothing, Either true or false

                      ?
                      It returns a boolean.
                      Again: what does it return?!

                      qDebug() << QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");
                      
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                      deleted286
                      wrote on 11 Jan 2021, 08:18 last edited by
                      #20

                      @jsulm it returns false. Ekran görüntüsü 2021-01-11 111741.png

                      #include "mythread.h"
                      #include "mainwindow.h"
                      #include <QtCore>
                      #include <QDebug>
                      #include <QFile>
                      #include <QTimer>
                      #include <QThread>
                      #include <QMutex>
                      #include <QQueue>
                      #include <QMessageBox>
                      #include <QApplication>
                      #include <QtWidgets/QApplication>
                      #include <QtWidgets/QMainWindow>
                      #include <QFileDialog>
                      #include <QMainWindow>
                      
                      QFile file("C:/Users/ilknu/Documents/MyThread/deneme.txt");
                      
                      
                      MyThread::MyThread(QObject* parent)
                          : QThread(parent)
                      {
                          writeData();
                      }
                      
                      MyThread::~MyThread()
                      {
                      
                      }
                      
                      void MyThread::writeData()
                      {
                          QFile file2("C:/Users/ilknu/Documents/MyThread/new.txt");
                          QFile::copy("C:/Users/ilknu/Documents/MyThread/deneme.txt","C:/Users/ilknu/Documents/MyThread/new.txt" );
                          qDebug() << QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");
                          qDebug() << "im working in writing thread";
                      
                          emit writingDone();
                      
                      }
                      
                      void MyThread::run()  //Reading file from txt with thread1
                      {
                      
                          if (file.open(QIODevice::ReadOnly))
                          {
                              QTextStream in (&file);
                              while (!in.atEnd())
                              {
                                  QString line = in.readAll();
                                  QStringList list = line.split(QLatin1Char(' '), Qt::SkipEmptyParts);
                                  for(const QString &entry : list)
                                  {
                                      double num = entry.toDouble();
                                      queue.enqueue(num);
                      
                                  }
                      
                      
                                  qDebug()<< "im running on worker thread " <<line;
                      
                              } // for
                          } // while
                          file.close();
                      } // if
                      
                      J S 2 Replies Last reply 11 Jan 2021, 08:21
                      0
                      • S Offline
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                        sierdzio
                        Moderators
                        wrote on 11 Jan 2021, 08:20 last edited by
                        #21

                        Check if it exists:

                        qDebug() << "Source exists?" << QFile::exists("C:/Users/ilknu/Documents/MyThread/deneme.txt");
                        qDebug() << "Destination exists?" << QFile::exists("C:/Users/ilknu/Documents/MyThread/new.txt");
                        

                        You need to check destination because:

                        If a file with the name newName already exists, copy() returns false (i.e., QFile will not overwrite it).

                        (Z(:^

                        D 1 Reply Last reply 11 Jan 2021, 08:24
                        1
                        • D deleted286
                          11 Jan 2021, 08:18

                          @jsulm it returns false. Ekran görüntüsü 2021-01-11 111741.png

                          #include "mythread.h"
                          #include "mainwindow.h"
                          #include <QtCore>
                          #include <QDebug>
                          #include <QFile>
                          #include <QTimer>
                          #include <QThread>
                          #include <QMutex>
                          #include <QQueue>
                          #include <QMessageBox>
                          #include <QApplication>
                          #include <QtWidgets/QApplication>
                          #include <QtWidgets/QMainWindow>
                          #include <QFileDialog>
                          #include <QMainWindow>
                          
                          QFile file("C:/Users/ilknu/Documents/MyThread/deneme.txt");
                          
                          
                          MyThread::MyThread(QObject* parent)
                              : QThread(parent)
                          {
                              writeData();
                          }
                          
                          MyThread::~MyThread()
                          {
                          
                          }
                          
                          void MyThread::writeData()
                          {
                              QFile file2("C:/Users/ilknu/Documents/MyThread/new.txt");
                              QFile::copy("C:/Users/ilknu/Documents/MyThread/deneme.txt","C:/Users/ilknu/Documents/MyThread/new.txt" );
                              qDebug() << QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");
                              qDebug() << "im working in writing thread";
                          
                              emit writingDone();
                          
                          }
                          
                          void MyThread::run()  //Reading file from txt with thread1
                          {
                          
                              if (file.open(QIODevice::ReadOnly))
                              {
                                  QTextStream in (&file);
                                  while (!in.atEnd())
                                  {
                                      QString line = in.readAll();
                                      QStringList list = line.split(QLatin1Char(' '), Qt::SkipEmptyParts);
                                      for(const QString &entry : list)
                                      {
                                          double num = entry.toDouble();
                                          queue.enqueue(num);
                          
                                      }
                          
                          
                                      qDebug()<< "im running on worker thread " <<line;
                          
                                  } // for
                              } // while
                              file.close();
                          } // if
                          
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                          JonB
                          wrote on 11 Jan 2021, 08:21 last edited by
                          #22

                          @suslucoder
                          Did you read the documentation of QFile::Copy() for yourself?

                          Note that if a file with the name newName already exists, copy() returns false (i.e. QFile will not overwrite it).

                          So, does the destination file already exist? Does the source file also exist?

                          1 Reply Last reply
                          1
                          • D deleted286
                            11 Jan 2021, 08:18

                            @jsulm it returns false. Ekran görüntüsü 2021-01-11 111741.png

                            #include "mythread.h"
                            #include "mainwindow.h"
                            #include <QtCore>
                            #include <QDebug>
                            #include <QFile>
                            #include <QTimer>
                            #include <QThread>
                            #include <QMutex>
                            #include <QQueue>
                            #include <QMessageBox>
                            #include <QApplication>
                            #include <QtWidgets/QApplication>
                            #include <QtWidgets/QMainWindow>
                            #include <QFileDialog>
                            #include <QMainWindow>
                            
                            QFile file("C:/Users/ilknu/Documents/MyThread/deneme.txt");
                            
                            
                            MyThread::MyThread(QObject* parent)
                                : QThread(parent)
                            {
                                writeData();
                            }
                            
                            MyThread::~MyThread()
                            {
                            
                            }
                            
                            void MyThread::writeData()
                            {
                                QFile file2("C:/Users/ilknu/Documents/MyThread/new.txt");
                                QFile::copy("C:/Users/ilknu/Documents/MyThread/deneme.txt","C:/Users/ilknu/Documents/MyThread/new.txt" );
                                qDebug() << QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");
                                qDebug() << "im working in writing thread";
                            
                                emit writingDone();
                            
                            }
                            
                            void MyThread::run()  //Reading file from txt with thread1
                            {
                            
                                if (file.open(QIODevice::ReadOnly))
                                {
                                    QTextStream in (&file);
                                    while (!in.atEnd())
                                    {
                                        QString line = in.readAll();
                                        QStringList list = line.split(QLatin1Char(' '), Qt::SkipEmptyParts);
                                        for(const QString &entry : list)
                                        {
                                            double num = entry.toDouble();
                                            queue.enqueue(num);
                            
                                        }
                            
                            
                                        qDebug()<< "im running on worker thread " <<line;
                            
                                    } // for
                                } // while
                                file.close();
                            } // if
                            
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                            SGaist
                            Lifetime Qt Champion
                            wrote on 11 Jan 2021, 08:21 last edited by
                            #23

                            Hi,

                            @suslucoder said in Copying the file content:

                            QFile::copy("C:/Users/ilknu/Documents/MyThread/deneme.txt","C:/Users/ilknu/Documents/MyThread/new.txt" );
                            qDebug() << QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");

                            You do not have the same paths in the qDebug and the previous line.
                            You do realise that you are copying it twice ?

                            Interested in AI ? www.idiap.ch
                            Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                            D 1 Reply Last reply 11 Jan 2021, 08:24
                            4
                            • S sierdzio
                              11 Jan 2021, 08:20

                              Check if it exists:

                              qDebug() << "Source exists?" << QFile::exists("C:/Users/ilknu/Documents/MyThread/deneme.txt");
                              qDebug() << "Destination exists?" << QFile::exists("C:/Users/ilknu/Documents/MyThread/new.txt");
                              

                              You need to check destination because:

                              If a file with the name newName already exists, copy() returns false (i.e., QFile will not overwrite it).

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                              deleted286
                              wrote on 11 Jan 2021, 08:24 last edited by
                              #24

                              @sierdzio
                              They exists.

                              Ekran görüntüsü 2021-01-11 112331.png

                              J S 2 Replies Last reply 11 Jan 2021, 08:25
                              0
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                                JonB
                                wrote on 11 Jan 2021, 08:24 last edited by
                                #25

                                @SGaist , @sierdzio , @J-Hilk
                                If QFile::copy() returns false, I don't see anywhere the user can obtain any kind of error message/reason for the failure. Does Qt not supply this by any means?

                                1 Reply Last reply
                                0
                                • S SGaist
                                  11 Jan 2021, 08:21

                                  Hi,

                                  @suslucoder said in Copying the file content:

                                  QFile::copy("C:/Users/ilknu/Documents/MyThread/deneme.txt","C:/Users/ilknu/Documents/MyThread/new.txt" );
                                  qDebug() << QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");

                                  You do not have the same paths in the qDebug and the previous line.
                                  You do realise that you are copying it twice ?

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                                  deleted286
                                  wrote on 11 Jan 2021, 08:24 last edited by
                                  #26

                                  @SGaist I fixed it

                                  1 Reply Last reply
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                                  • D deleted286
                                    11 Jan 2021, 08:24

                                    @sierdzio
                                    They exists.

                                    Ekran görüntüsü 2021-01-11 112331.png

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                                    JonB
                                    wrote on 11 Jan 2021, 08:25 last edited by JonB 1 Nov 2021, 08:26
                                    #27

                                    @suslucoder said in Copying the file content:

                                    They exists.

                                    And? We have all said QFile::copy() says:

                                    Note that if a file with the name newName already exists, copy() returns false (i.e. QFile will not overwrite it).

                                    So you (not we) need to do something about that.

                                    Also, as @SGaist has pointed out, you don't even have the same paths on your two QFile::copy() calls.

                                    D 1 Reply Last reply 11 Jan 2021, 08:29
                                    1
                                    • D deleted286
                                      11 Jan 2021, 08:24

                                      @sierdzio
                                      They exists.

                                      Ekran görüntüsü 2021-01-11 112331.png

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                                      sierdzio
                                      Moderators
                                      wrote on 11 Jan 2021, 08:29 last edited by
                                      #28

                                      @suslucoder

                                      Then the cause is clear: destination exists, so copy() will not overwrite it. You need to remove the destination file first, before calling copy().

                                      (Z(:^

                                      D 1 Reply Last reply 11 Jan 2021, 08:30
                                      1
                                      • J JonB
                                        11 Jan 2021, 08:25

                                        @suslucoder said in Copying the file content:

                                        They exists.

                                        And? We have all said QFile::copy() says:

                                        Note that if a file with the name newName already exists, copy() returns false (i.e. QFile will not overwrite it).

                                        So you (not we) need to do something about that.

                                        Also, as @SGaist has pointed out, you don't even have the same paths on your two QFile::copy() calls.

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                                        deleted286
                                        wrote on 11 Jan 2021, 08:29 last edited by
                                        #29

                                        @JonB said in Copying the file content:

                                        Also, as @SGaist has pointed out, you don't even have the same paths on your two QFile::copy() calls. I've fixed it, it is my mistake.

                                        Even i delete the destination file, for returning true by creating new destination, it returns false.

                                        J 1 Reply Last reply 11 Jan 2021, 08:30
                                        0
                                        • D deleted286
                                          11 Jan 2021, 08:29

                                          @JonB said in Copying the file content:

                                          Also, as @SGaist has pointed out, you don't even have the same paths on your two QFile::copy() calls. I've fixed it, it is my mistake.

                                          Even i delete the destination file, for returning true by creating new destination, it returns false.

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                                          jsulm
                                          Lifetime Qt Champion
                                          wrote on 11 Jan 2021, 08:30 last edited by
                                          #30

                                          @suslucoder Did you check what @SGaist said? Do NOT call copy twice! Call it once like before but put qDebug() in front of it...

                                          https://forum.qt.io/topic/113070/qt-code-of-conduct

                                          1 Reply Last reply
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