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problem with System()

Scheduled Pinned Locked Moved Unsolved General and Desktop
system commandsystem
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  • jsulmJ jsulm

    /home is not the full path to your application except it is called home and is located in the root directory.
    So, you can start the program in a shell with /home/princi?
    Did you try it?
    This is quite strange path: in /home you usually have a directory for each user and /home is not writable by normal user.

    AlvaroSA Offline
    AlvaroSA Offline
    AlvaroS
    wrote on last edited by
    #15

    @jsulm sorry yes, it is in /home/user1/ but it does not run as well...

    1 Reply Last reply
    0
    • mrjjM Offline
      mrjjM Offline
      mrjj
      Lifetime Qt Champion
      wrote on last edited by
      #16

      @AlvaroS said:

      QString program = "princi";

      should be

      QString program = "/home/user1/princi";

      ?

      AlvaroSA 1 Reply Last reply
      1
      • mrjjM mrjj

        @AlvaroS said:

        QString program = "princi";

        should be

        QString program = "/home/user1/princi";

        ?

        AlvaroSA Offline
        AlvaroSA Offline
        AlvaroS
        wrote on last edited by
        #17

        @mrjj It works in the same way... :(

        jsulmJ mrjjM 2 Replies Last reply
        0
        • AlvaroSA AlvaroS

          @mrjj It works in the same way... :(

          jsulmJ Offline
          jsulmJ Offline
          jsulm
          Lifetime Qt Champion
          wrote on last edited by
          #18

          @AlvaroS So, if you enter /home/user1/princi in a terminal window and press enter it does not start? What happens? Any error message?

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

          AlvaroSA 1 Reply Last reply
          1
          • AlvaroSA AlvaroS

            @mrjj It works in the same way... :(

            mrjjM Offline
            mrjjM Offline
            mrjj
            Lifetime Qt Champion
            wrote on last edited by
            #19

            @AlvaroS

            Ok, you must debug then
            try to use
            http://doc.qt.io/qt-5/qprocess.html#error
            to see what it thinks.

            AlvaroSA 1 Reply Last reply
            2
            • jsulmJ jsulm

              @AlvaroS So, if you enter /home/user1/princi in a terminal window and press enter it does not start? What happens? Any error message?

              AlvaroSA Offline
              AlvaroSA Offline
              AlvaroS
              wrote on last edited by
              #20

              @jsulm In a terminal if I write

              ./princi 0 747.37 427.68 0 844.37 42.54 prueba_princi.bmp 0 0 +
              

              in /home/user1/ directory it runs good

              jsulmJ AlvaroSA 2 Replies Last reply
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              • AlvaroSA AlvaroS

                @jsulm In a terminal if I write

                ./princi 0 747.37 427.68 0 844.37 42.54 prueba_princi.bmp 0 0 +
                

                in /home/user1/ directory it runs good

                jsulmJ Offline
                jsulmJ Offline
                jsulm
                Lifetime Qt Champion
                wrote on last edited by jsulm
                #21

                @AlvaroS Then try what @mrjj suggested

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

                1 Reply Last reply
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                • mrjjM mrjj

                  @AlvaroS

                  Ok, you must debug then
                  try to use
                  http://doc.qt.io/qt-5/qprocess.html#error
                  to see what it thinks.

                  AlvaroSA Offline
                  AlvaroSA Offline
                  AlvaroS
                  wrote on last edited by
                  #22
                  This post is deleted!
                  mrjjM 1 Reply Last reply
                  0
                  • AlvaroSA AlvaroS

                    @jsulm In a terminal if I write

                    ./princi 0 747.37 427.68 0 844.37 42.54 prueba_princi.bmp 0 0 +
                    

                    in /home/user1/ directory it runs good

                    AlvaroSA Offline
                    AlvaroSA Offline
                    AlvaroS
                    wrote on last edited by AlvaroS
                    #23

                    @AlvaroS said:

                    @jsulm In a terminal if I write

                    ./princi 0 747.37 427.68 0 844.37 42.54 prueba_princi.bmp 0 0 +
                    

                    in /home/user1/ directory it runs good

                    @jsulm said:

                    @AlvaroS Then try what @mrjj suggested

                    okey, it gives me UnknowError.... http://doc.qt.io/qt-5/qprocess.html#ProcessError-enum

                    1 Reply Last reply
                    0
                    • AlvaroSA AlvaroS

                      This post is deleted!

                      mrjjM Offline
                      mrjjM Offline
                      mrjj
                      Lifetime Qt Champion
                      wrote on last edited by
                      #24

                      @AlvaroS

                      well you can use
                      qDebug() "qproc: " << myProcess->error();

                      and check the code in
                      http://doc.qt.io/qt-5/qprocess.html#ProcessError-enum

                      AlvaroSA 1 Reply Last reply
                      1
                      • mrjjM mrjj

                        @AlvaroS

                        well you can use
                        qDebug() "qproc: " << myProcess->error();

                        and check the code in
                        http://doc.qt.io/qt-5/qprocess.html#ProcessError-enum

                        AlvaroSA Offline
                        AlvaroSA Offline
                        AlvaroS
                        wrote on last edited by
                        #25

                        @mrjj Yes thanks!! See my last post. Thanks again. It gives me Unknow error...

                        mrjjM 1 Reply Last reply
                        0
                        • AlvaroSA AlvaroS

                          @mrjj Yes thanks!! See my last post. Thanks again. It gives me Unknow error...

                          mrjjM Offline
                          mrjjM Offline
                          mrjj
                          Lifetime Qt Champion
                          wrote on last edited by
                          #26

                          @AlvaroS

                          " This is the default return value of error()."

                          You do call it AFTER u call
                          myProcess->start(program,arguments); ?

                          AlvaroSA 1 Reply Last reply
                          1
                          • mrjjM mrjj

                            @AlvaroS

                            " This is the default return value of error()."

                            You do call it AFTER u call
                            myProcess->start(program,arguments); ?

                            AlvaroSA Offline
                            AlvaroSA Offline
                            AlvaroS
                            wrote on last edited by
                            #27

                            @mrjj Yes:

                                myProcess->start(program, arguments);
                            
                                QProcess::ProcessError error = myProcess->error();
                            
                            mrjjM 1 Reply Last reply
                            0
                            • AlvaroSA AlvaroS

                              @mrjj Yes:

                                  myProcess->start(program, arguments);
                              
                                  QProcess::ProcessError error = myProcess->error();
                              
                              mrjjM Offline
                              mrjjM Offline
                              mrjj
                              Lifetime Qt Champion
                              wrote on last edited by
                              #28

                              @AlvaroS
                              hmm really odd then
                              it should say FailedToStart

                              Just to be 100% clear.

                              princi is never run ?

                              AlvaroSA 1 Reply Last reply
                              1
                              • mrjjM mrjj

                                @AlvaroS
                                hmm really odd then
                                it should say FailedToStart

                                Just to be 100% clear.

                                princi is never run ?

                                AlvaroSA Offline
                                AlvaroSA Offline
                                AlvaroS
                                wrote on last edited by
                                #29

                                @mrjj said:

                                @AlvaroS
                                hmm really odd then
                                it should say FailedToStart

                                Just to be 100% clear.

                                princi is never run ?

                                okey look.
                                if I write:

                                    myProcess->start(program, arguments);
                                
                                    myProcess->waitForFinished(3000);
                                
                                    QProcess::ProcessError error = myProcess->error();
                                
                                

                                Now error says:
                                QProcess::Crashed The process crashed some time after starting successfully.

                                1 Reply Last reply
                                0
                                • mrjjM Offline
                                  mrjjM Offline
                                  mrjj
                                  Lifetime Qt Champion
                                  wrote on last edited by mrjj
                                  #30

                                  so it sounds like your princi do run but it crashes?

                                  oh. sorry my bad. start is async so calling error right after was
                                  not correct.

                                  waitForFinished fixed that.

                                  AlvaroSA 1 Reply Last reply
                                  0
                                  • mrjjM mrjj

                                    so it sounds like your princi do run but it crashes?

                                    oh. sorry my bad. start is async so calling error right after was
                                    not correct.

                                    waitForFinished fixed that.

                                    AlvaroSA Offline
                                    AlvaroSA Offline
                                    AlvaroS
                                    wrote on last edited by
                                    #31

                                    @mrjj Yes... I think so...
                                    How should I pass the arguments?

                                    the arguments of princi are:

                                    0 wps.front().x() wps.front().y() 0 wps.back().x() wps.front().y() prueba_princi.bmp 0 0 +
                                    

                                    so my QStringList arguments is:

                                     QStringList arguments;
                                    arguments << "0" << QString::number(wps.front().x()) << QString::number(wps.front().y()) << "0" << QString::number(wps.back().x()) << QString::number(wps.back().y()) << "prueba_princi.bmp" << "0" << "0" << "+" ;
                                    
                                    
                                    1 Reply Last reply
                                    0
                                    • mrjjM Offline
                                      mrjjM Offline
                                      mrjj
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #32

                                      it seems fine
                                      You should look inside princi for how it
                                      reads it. it must be that part that is crashing ?

                                      AlvaroSA 2 Replies Last reply
                                      0
                                      • mrjjM mrjj

                                        it seems fine
                                        You should look inside princi for how it
                                        reads it. it must be that part that is crashing ?

                                        AlvaroSA Offline
                                        AlvaroSA Offline
                                        AlvaroS
                                        wrote on last edited by
                                        #33

                                        @mrjj yes, but it really rare that if I run from terminal princi runs good...

                                        1 Reply Last reply
                                        0
                                        • mrjjM mrjj

                                          it seems fine
                                          You should look inside princi for how it
                                          reads it. it must be that part that is crashing ?

                                          AlvaroSA Offline
                                          AlvaroSA Offline
                                          AlvaroS
                                          wrote on last edited by AlvaroS
                                          #34

                                          @mrjj And if I write:

                                          system ("./princi 0 5 10 0 7 8 prueba_princi.bmp 0 0 +")
                                          where 5,10,7 and 8 are wps.front,wps.back....
                                          it runs well...

                                          mrjjM 1 Reply Last reply
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