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problem with System()

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  • J jsulm
    24 Jun 2016, 08:29

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

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    AlvaroS
    wrote on 24 Jun 2016, 08:31 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

    J A 2 Replies Last reply 24 Jun 2016, 08:33
    0
    • A AlvaroS
      24 Jun 2016, 08:31

      @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

      J Offline
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      jsulm
      Lifetime Qt Champion
      wrote on 24 Jun 2016, 08:33 last edited by jsulm
      #21

      @AlvaroS Then try what @mrjj suggested

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

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      • M mrjj
        24 Jun 2016, 08:30

        @AlvaroS

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

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        AlvaroS
        wrote on 24 Jun 2016, 08:38 last edited by
        #22
        This post is deleted!
        M 1 Reply Last reply 24 Jun 2016, 08:40
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        • A AlvaroS
          24 Jun 2016, 08:31

          @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

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          AlvaroS
          wrote on 24 Jun 2016, 08:39 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

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          • A AlvaroS
            24 Jun 2016, 08:38

            This post is deleted!

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            mrjj
            Lifetime Qt Champion
            wrote on 24 Jun 2016, 08:40 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

            A 1 Reply Last reply 24 Jun 2016, 08:42
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            • M mrjj
              24 Jun 2016, 08:40

              @AlvaroS

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

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

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              AlvaroS
              wrote on 24 Jun 2016, 08:42 last edited by
              #25

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

              M 1 Reply Last reply 24 Jun 2016, 08:43
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              • A AlvaroS
                24 Jun 2016, 08:42

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

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                mrjj
                Lifetime Qt Champion
                wrote on 24 Jun 2016, 08:43 last edited by
                #26

                @AlvaroS

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

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

                A 1 Reply Last reply 24 Jun 2016, 08:44
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                • M mrjj
                  24 Jun 2016, 08:43

                  @AlvaroS

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

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

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                  AlvaroS
                  wrote on 24 Jun 2016, 08:44 last edited by
                  #27

                  @mrjj Yes:

                      myProcess->start(program, arguments);
                  
                      QProcess::ProcessError error = myProcess->error();
                  
                  M 1 Reply Last reply 24 Jun 2016, 08:46
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                  • A AlvaroS
                    24 Jun 2016, 08:44

                    @mrjj Yes:

                        myProcess->start(program, arguments);
                    
                        QProcess::ProcessError error = myProcess->error();
                    
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                    mrjj
                    Lifetime Qt Champion
                    wrote on 24 Jun 2016, 08:46 last edited by
                    #28

                    @AlvaroS
                    hmm really odd then
                    it should say FailedToStart

                    Just to be 100% clear.

                    princi is never run ?

                    A 1 Reply Last reply 24 Jun 2016, 08:48
                    1
                    • M mrjj
                      24 Jun 2016, 08:46

                      @AlvaroS
                      hmm really odd then
                      it should say FailedToStart

                      Just to be 100% clear.

                      princi is never run ?

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                      AlvaroS
                      wrote on 24 Jun 2016, 08:48 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.

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                      • M Offline
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                        mrjj
                        Lifetime Qt Champion
                        wrote on 24 Jun 2016, 08:49 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.

                        A 1 Reply Last reply 24 Jun 2016, 08:54
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                        • M mrjj
                          24 Jun 2016, 08:49

                          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.

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                          AlvaroS
                          wrote on 24 Jun 2016, 08:54 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
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                            mrjj
                            Lifetime Qt Champion
                            wrote on 24 Jun 2016, 09:11 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 ?

                            A 2 Replies Last reply 24 Jun 2016, 09:22
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                            • M mrjj
                              24 Jun 2016, 09:11

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

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                              AlvaroS
                              wrote on 24 Jun 2016, 09:22 last edited by
                              #33

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

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                              • M mrjj
                                24 Jun 2016, 09:11

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

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                                AlvaroS
                                wrote on 24 Jun 2016, 09:31 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...

                                M 1 Reply Last reply 24 Jun 2016, 09:43
                                0
                                • S Offline
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                                  SGaist
                                  Lifetime Qt Champion
                                  wrote on 24 Jun 2016, 09:32 last edited by
                                  #35

                                  What is that + sign doing as parameter ?

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

                                  A 1 Reply Last reply 24 Jun 2016, 09:32
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                                  • S SGaist
                                    24 Jun 2016, 09:32

                                    What is that + sign doing as parameter ?

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                                    AlvaroS
                                    wrote on 24 Jun 2016, 09:32 last edited by
                                    #36

                                    @SGaist + is just and argument that i have to pass to princi

                                    1 Reply Last reply
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                                    • A AlvaroS
                                      24 Jun 2016, 09:31

                                      @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...

                                      M Offline
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                                      mrjj
                                      Lifetime Qt Champion
                                      wrote on 24 Jun 2016, 09:43 last edited by
                                      #37

                                      @AlvaroS
                                      well you must debug it then.
                                      Try to qDebug inside princi what you read and compare that to what u read for
                                      system ("./princi 0 5 10 0 7 8 prueba_princi.bmp 0 0 +")

                                      Sadly We cannot guess why you crash from the code shown.

                                      Also you dump the arguments to qDebug before u
                                      call start, just to see what u are sending also.

                                      and then take it from there.

                                      1 Reply Last reply
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