Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. Copying the file content
Forum Updated to NodeBB v4.3 + New Features

Copying the file content

Scheduled Pinned Locked Moved Solved General and Desktop
copyfileqt5file readfile write
32 Posts 6 Posters 8.7k Views 2 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • jsulmJ jsulm

    @suslucoder This copies a file (doesn't matter what it contains).
    If you want us to tell you why it does not work then please provide more information: what exactly is the old and the new paths?

    D Offline
    D Offline
    deleted286
    wrote on last edited by
    #4

    @jsulm ```

    "C:/Users/user/Documents/MyThread/deneme.txt"
    
    
    This is my old file path, the new one is in different name
    jsulmJ 1 Reply Last reply
    0
    • D deleted286

      @jsulm ```

      "C:/Users/user/Documents/MyThread/deneme.txt"
      
      
      This is my old file path, the new one is in different name
      jsulmJ Offline
      jsulmJ Offline
      jsulm
      Lifetime Qt Champion
      wrote on last edited by jsulm
      #5

      @suslucoder And what exactly does not work: it does not copy the file?
      Please post the new apth also, so we can make sure it is not wrong.
      Does the old file exist?
      Also, what does copy return (true/false)?

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

      D 1 Reply Last reply
      0
      • jsulmJ jsulm

        @suslucoder And what exactly does not work: it does not copy the file?
        Please post the new apth also, so we can make sure it is not wrong.
        Does the old file exist?
        Also, what does copy return (true/false)?

        D Offline
        D Offline
        deleted286
        wrote on last edited by deleted286
        #6

        @jsulm It does not copy the file. It is in my thread.

        void MyThread::writeData()
        {
        
            QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");
            if(!file.open(QIODevice::ReadOnly))
            {
                QTextStream in(&file2);
                while(!in.atEnd())
                {
                    QString line2=in.readAll();
                    QStringList list = line2.split(QLatin1Char(' '), Qt::SkipEmptyParts);
                    for(const QString &entry : list)
                    {
                        double num = entry.toDouble();
                        queue.enqueue(num);
                        qDebug() << num;
                    }
                }
            }
            qDebug() << "im working in writing thread";
        
            emit writingDone();
        

        }

        qDebug does not give anytghing on the secreen. And yes the old file exist. I can read its contents

        jsulmJ sierdzioS 2 Replies Last reply
        0
        • D deleted286

          @jsulm It does not copy the file. It is in my thread.

          void MyThread::writeData()
          {
          
              QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");
              if(!file.open(QIODevice::ReadOnly))
              {
                  QTextStream in(&file2);
                  while(!in.atEnd())
                  {
                      QString line2=in.readAll();
                      QStringList list = line2.split(QLatin1Char(' '), Qt::SkipEmptyParts);
                      for(const QString &entry : list)
                      {
                          double num = entry.toDouble();
                          queue.enqueue(num);
                          qDebug() << num;
                      }
                  }
              }
              qDebug() << "im working in writing thread";
          
              emit writingDone();
          

          }

          qDebug does not give anytghing on the secreen. And yes the old file exist. I can read its contents

          jsulmJ Offline
          jsulmJ Offline
          jsulm
          Lifetime Qt Champion
          wrote on last edited by
          #7

          @suslucoder said in Copying the fle content:

          It does not copy the file

          That I already understood.
          Again: what does QFile::copy return?

          I also do not understand what how this file copy is related to the other code:

          if(!file.open(QIODevice::ReadOnly)) // What is file here? What file are you trying to pen here?
          

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

          1 Reply Last reply
          0
          • D deleted286

            @jsulm It does not copy the file. It is in my thread.

            void MyThread::writeData()
            {
            
                QFile::copy("C:/Users/user/Documents/MyThread/deneme.txt", "C:/Users/user/Documents/MyThread/new.txt");
                if(!file.open(QIODevice::ReadOnly))
                {
                    QTextStream in(&file2);
                    while(!in.atEnd())
                    {
                        QString line2=in.readAll();
                        QStringList list = line2.split(QLatin1Char(' '), Qt::SkipEmptyParts);
                        for(const QString &entry : list)
                        {
                            double num = entry.toDouble();
                            queue.enqueue(num);
                            qDebug() << num;
                        }
                    }
                }
                qDebug() << "im working in writing thread";
            
                emit writingDone();
            

            }

            qDebug does not give anytghing on the secreen. And yes the old file exist. I can read its contents

            sierdzioS Online
            sierdzioS Online
            sierdzio
            Moderators
            wrote on last edited by
            #8

            @suslucoder said in Copying the fle content:

            qDebug does not give anytghing on the secreen

            This means that MyThread::writeData() function is not called at all! And that implies the problem lies somewhere else (not in QFile::copy()).

            (Z(:^

            D 1 Reply Last reply
            3
            • sierdzioS sierdzio

              @suslucoder said in Copying the fle content:

              qDebug does not give anytghing on the secreen

              This means that MyThread::writeData() function is not called at all! And that implies the problem lies somewhere else (not in QFile::copy()).

              D Offline
              D Offline
              deleted286
              wrote on last edited by
              #9

              @sierdzio I've already called it with start() function. Doesnt it started the thread?

              1 Reply Last reply
              0
              • sierdzioS Online
                sierdzioS Online
                sierdzio
                Moderators
                wrote on last edited by
                #10

                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.

                (Z(:^

                D 1 Reply Last reply
                0
                • sierdzioS sierdzio

                  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.

                  D Offline
                  D Offline
                  deleted286
                  wrote on last edited by deleted286
                  #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
                  0
                  • sierdzioS Online
                    sierdzioS Online
                    sierdzio
                    Moderators
                    wrote on 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
                    0
                    • sierdzioS sierdzio

                      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

                      D Offline
                      D Offline
                      deleted286
                      wrote on last edited by
                      #13

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

                      J.HilkJ 1 Reply Last reply
                      0
                      • D deleted286

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

                        J.HilkJ Offline
                        J.HilkJ Offline
                        J.Hilk
                        Moderators
                        wrote on last edited by J.Hilk
                        #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
                        3
                        • J.HilkJ J.Hilk

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

                          D Offline
                          D Offline
                          deleted286
                          wrote on last edited by
                          #15

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

                          jsulmJ 1 Reply Last reply
                          0
                          • D deleted286

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

                            jsulmJ Offline
                            jsulmJ Offline
                            jsulm
                            Lifetime Qt Champion
                            wrote on 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
                            1
                            • jsulmJ jsulm

                              @suslucoder So, what does copy() return?

                              D Offline
                              D Offline
                              deleted286
                              wrote on last edited by
                              #17

                              @jsulm it returns nothing, Either true or false

                              jsulmJ J.HilkJ 2 Replies Last reply
                              0
                              • D deleted286

                                @jsulm it returns nothing, Either true or false

                                jsulmJ Offline
                                jsulmJ Offline
                                jsulm
                                Lifetime Qt Champion
                                wrote on 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
                                0
                                • D deleted286

                                  @jsulm it returns nothing, Either true or false

                                  J.HilkJ Offline
                                  J.HilkJ Offline
                                  J.Hilk
                                  Moderators
                                  wrote on 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
                                  0
                                  • jsulmJ jsulm

                                    @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");
                                    
                                    D Offline
                                    D Offline
                                    deleted286
                                    wrote on 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
                                    
                                    JonBJ SGaistS 2 Replies Last reply
                                    0
                                    • sierdzioS Online
                                      sierdzioS Online
                                      sierdzio
                                      Moderators
                                      wrote on 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
                                      1
                                      • D deleted286

                                        @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
                                        
                                        JonBJ Offline
                                        JonBJ Offline
                                        JonB
                                        wrote on 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

                                          @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
                                          
                                          SGaistS Offline
                                          SGaistS Offline
                                          SGaist
                                          Lifetime Qt Champion
                                          wrote on 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
                                          4

                                          • Login

                                          • Login or register to search.
                                          • First post
                                            Last post
                                          0
                                          • Categories
                                          • Recent
                                          • Tags
                                          • Popular
                                          • Users
                                          • Groups
                                          • Search
                                          • Get Qt Extensions
                                          • Unsolved