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(SOLVED) Read everything after an specific keyword

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qstringfileqfilereadqt4qt4.8
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  • J Offline
    J Offline
    jjan
    wrote on 16 May 2015, 19:09 last edited by
    #6

    I fixed it, here is the solution!

    QFile rootFile(*p_path + "/Project.arden");
    				if (rootFile.open(QIODevice::ReadOnly))
    				{
    					QTextStream in(&rootFile);
    					while (!in.atEnd())
    					{
    						QString line = in.readAll();
    						/* lets get the track name */
    						QString trackName("name =");
    						int pos = line.indexOf(trackName);
    						QString theTrackName = line.right(pos + trackName.length());
    						printf(theTrackName.toStdString().c_str());
    					}
    				}
    
    K 1 Reply Last reply 16 May 2015, 19:19
    0
    • J jjan
      16 May 2015, 19:09

      I fixed it, here is the solution!

      QFile rootFile(*p_path + "/Project.arden");
      				if (rootFile.open(QIODevice::ReadOnly))
      				{
      					QTextStream in(&rootFile);
      					while (!in.atEnd())
      					{
      						QString line = in.readAll();
      						/* lets get the track name */
      						QString trackName("name =");
      						int pos = line.indexOf(trackName);
      						QString theTrackName = line.right(pos + trackName.length());
      						printf(theTrackName.toStdString().c_str());
      					}
      				}
      
      K Offline
      K Offline
      koahnig
      wrote on 16 May 2015, 19:19 last edited by
      #7

      @jjan
      I guess you have changed also this line to something else

              QString trackName("name = ");
      

      because your file does not contain any "name =" and this cannot be found then.

      ALso you are mixing c and c++ which is possible, but not the prefered way. With Qt typically one uses QDebug for a fast debugging output.

      #include <QDebug>
      
      QFile rootFile(*p_path + "/Project.arden");
      if (rootFile.open(QIODevice::ReadOnly))
      {
            QTextStream in(&rootFile);
            while (!in.atEnd())
            {
                  QString line = in.readAll();
                 /* lets get the track name */
                  QString trackName("name =");
                  int pos = line.indexOf(trackName);
                  QString theTrackName = line.right(pos + trackName.length());
                  // printf(theTrackName.toStdString().c_str());
                  qDebug() << theTrackName;
            }
      }
      

      Vote the answer(s) that helped you to solve your issue(s)

      1 Reply Last reply
      0
      • J Offline
        J Offline
        jjan
        wrote on 16 May 2015, 19:30 last edited by
        #8

        @koahnig

        The problem now is that it returns not that what I want. However when I change it to name = it gives me everything what behind author = is. Its a bit confusing :/

        K 1 Reply Last reply 16 May 2015, 20:05
        0
        • J jjan
          16 May 2015, 19:30

          @koahnig

          The problem now is that it returns not that what I want. However when I change it to name = it gives me everything what behind author = is. Its a bit confusing :/

          K Offline
          K Offline
          koahnig
          wrote on 16 May 2015, 20:05 last edited by
          #9

          @jjan
          ???

          If you have "name =" the indexOf is exactly searching search for "name =" it cannot match anythingelse. It looks exactly for the same sequence of characters. Also the blanks have to match exactly. Your file contains "spec =", "includes =", "title =" and "author =". Therefore, you have to use those strings for searching. With QRegExp you can gain more flexibility of course. However, this is typically a bit confusing in the beginnng.

          Vote the answer(s) that helped you to solve your issue(s)

          J 1 Reply Last reply 17 May 2015, 11:26
          0
          • K koahnig
            16 May 2015, 20:05

            @jjan
            ???

            If you have "name =" the indexOf is exactly searching search for "name =" it cannot match anythingelse. It looks exactly for the same sequence of characters. Also the blanks have to match exactly. Your file contains "spec =", "includes =", "title =" and "author =". Therefore, you have to use those strings for searching. With QRegExp you can gain more flexibility of course. However, this is typically a bit confusing in the beginnng.

            J Offline
            J Offline
            jjan
            wrote on 17 May 2015, 11:26 last edited by jjan
            #10

            @koahnig

            What I get is:

             untitled
            author = none
            

            With code:

            QString trackName("title =");
            				            int pos = line.indexOf(trackName);
            				            if (pos >= 0)
            				            {
            					            QString theTrackName = line.mid(pos + trackName.length());
            					            qDebug() << theTrackName;
            				        	}
            
            K 1 Reply Last reply 17 May 2015, 12:14
            0
            • J jjan
              17 May 2015, 11:26

              @koahnig

              What I get is:

               untitled
              author = none
              

              With code:

              QString trackName("title =");
              				            int pos = line.indexOf(trackName);
              				            if (pos >= 0)
              				            {
              					            QString theTrackName = line.mid(pos + trackName.length());
              					            qDebug() << theTrackName;
              				        	}
              
              K Offline
              K Offline
              koahnig
              wrote on 17 May 2015, 12:14 last edited by
              #11

              @jjan
              This is completely correct with what you wrote in your program.

              QString line = in.readAll();
              

              reads the complete file into the string called line. You are searching for the start of text of "title =" in this complete string. You get a position greater than 0 because the string somewhere later.

              QString theTrackName = line.mid(pos + trackName.length());
              

              will copy the content starting after pos (begin of presence of search string) plus the length of search string. Therefore theTrackName will contain " untitled" followed by the remainder of the content.

              You can replace your readAll (reading the complete file into the string at once) with readLine.
              This should work for your case also.

              When you use Qt creator or another IDE you should use the debugger. This allows you normally to go through the program step by step.
              Further it allows you also to inspect the different vairiables and their actual content after each line.

              Vote the answer(s) that helped you to solve your issue(s)

              J 2 Replies Last reply 17 May 2015, 13:08
              1
              • K koahnig
                17 May 2015, 12:14

                @jjan
                This is completely correct with what you wrote in your program.

                QString line = in.readAll();
                

                reads the complete file into the string called line. You are searching for the start of text of "title =" in this complete string. You get a position greater than 0 because the string somewhere later.

                QString theTrackName = line.mid(pos + trackName.length());
                

                will copy the content starting after pos (begin of presence of search string) plus the length of search string. Therefore theTrackName will contain " untitled" followed by the remainder of the content.

                You can replace your readAll (reading the complete file into the string at once) with readLine.
                This should work for your case also.

                When you use Qt creator or another IDE you should use the debugger. This allows you normally to go through the program step by step.
                Further it allows you also to inspect the different vairiables and their actual content after each line.

                J Offline
                J Offline
                jjan
                wrote on 17 May 2015, 13:08 last edited by
                #12

                @koahnig

                This worked, many thanks!

                1 Reply Last reply
                0
                • T Offline
                  T Offline
                  t3685
                  wrote on 17 May 2015, 14:25 last edited by
                  #13

                  Hi,

                  Is the file you are reading in some sort of settings ini file? If yes, you can use the QSettings class to make things easier and less error-prone.

                  Greetings,

                  t3685

                  J 1 Reply Last reply 17 May 2015, 18:02
                  0
                  • T t3685
                    17 May 2015, 14:25

                    Hi,

                    Is the file you are reading in some sort of settings ini file? If yes, you can use the QSettings class to make things easier and less error-prone.

                    Greetings,

                    t3685

                    J Offline
                    J Offline
                    jjan
                    wrote on 17 May 2015, 18:02 last edited by
                    #14

                    @t3685

                    It looks a little bit like an INI but has different style etc, so no its not a settings file ;) But thanks for the info!

                    1 Reply Last reply
                    0
                    • K koahnig
                      17 May 2015, 12:14

                      @jjan
                      This is completely correct with what you wrote in your program.

                      QString line = in.readAll();
                      

                      reads the complete file into the string called line. You are searching for the start of text of "title =" in this complete string. You get a position greater than 0 because the string somewhere later.

                      QString theTrackName = line.mid(pos + trackName.length());
                      

                      will copy the content starting after pos (begin of presence of search string) plus the length of search string. Therefore theTrackName will contain " untitled" followed by the remainder of the content.

                      You can replace your readAll (reading the complete file into the string at once) with readLine.
                      This should work for your case also.

                      When you use Qt creator or another IDE you should use the debugger. This allows you normally to go through the program step by step.
                      Further it allows you also to inspect the different vairiables and their actual content after each line.

                      J Offline
                      J Offline
                      jjan
                      wrote on 21 May 2015, 15:56 last edited by jjan
                      #15

                      @koahnig
                      Sorry that I am posting here again. My file looks like this:

                      window_color_red = 130

                      The code to get this is:

                      void
                      		Theme::loadTheme(QPalette& palette, QApplication& app, Radon::Ui::MainWindow *window)
                      		{
                      			QString themePath = getTheme();
                      			printf(themePath.toStdString().c_str());
                      			QFile t(themePath);
                      			if (t.open(QIODevice::ReadOnly))
                      			{
                      				QTextStream input(&t);
                      				while (!input.atEnd())
                      				{
                      					QString line = input.readLine();
                      					QString windowRedColorKeyword("window_color_red = ");
                      					int redPos = line.indexOf(windowRedColorKeyword);
                      					if (redPos >= 0)
                      					{
                      						QString windowRedColor = line.mid(redPos + windowRedColorKeyword.length());
                      						printf(windowRedColor.toStdString().c_str());
                      					}
                      				}
                      			}
                      		}
                      

                      but it don't gives me the number 130, it gives me nothing. Is this basically because it only can read text and not numbers or why?

                      EDIT

                      This was as mistake I've made, forgot to remove the " in the path!

                      K 1 Reply Last reply 21 May 2015, 17:03
                      0
                      • J jjan
                        21 May 2015, 15:56

                        @koahnig
                        Sorry that I am posting here again. My file looks like this:

                        window_color_red = 130

                        The code to get this is:

                        void
                        		Theme::loadTheme(QPalette& palette, QApplication& app, Radon::Ui::MainWindow *window)
                        		{
                        			QString themePath = getTheme();
                        			printf(themePath.toStdString().c_str());
                        			QFile t(themePath);
                        			if (t.open(QIODevice::ReadOnly))
                        			{
                        				QTextStream input(&t);
                        				while (!input.atEnd())
                        				{
                        					QString line = input.readLine();
                        					QString windowRedColorKeyword("window_color_red = ");
                        					int redPos = line.indexOf(windowRedColorKeyword);
                        					if (redPos >= 0)
                        					{
                        						QString windowRedColor = line.mid(redPos + windowRedColorKeyword.length());
                        						printf(windowRedColor.toStdString().c_str());
                        					}
                        				}
                        			}
                        		}
                        

                        but it don't gives me the number 130, it gives me nothing. Is this basically because it only can read text and not numbers or why?

                        EDIT

                        This was as mistake I've made, forgot to remove the " in the path!

                        K Offline
                        K Offline
                        koahnig
                        wrote on 21 May 2015, 17:03 last edited by
                        #16

                        @jjan
                        Just for an iteration the code reads line by line. As long as the search text is found, it will provide the remainder of the line. There is real dependency to the content as long as it is displayble (probably also some non-displayable characters). There are some special characters marking the end of lines (line feed (LF) and carriage return (CR) are those at least).

                        Vote the answer(s) that helped you to solve your issue(s)

                        1 Reply Last reply
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                        21 May 2015, 15:56

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