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. problem with System()
Forum Updated to NodeBB v4.3 + New Features

problem with System()

Scheduled Pinned Locked Moved Unsolved General and Desktop
system commandsystem
37 Posts 5 Posters 12.7k 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.
  • 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

    A Offline
    A Offline
    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
    0
    • A AlvaroS
      24 Jun 2016, 08:42

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

      M Offline
      M Offline
      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
      1
      • 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); ?

        A Offline
        A Offline
        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
        0
        • A AlvaroS
          24 Jun 2016, 08:44

          @mrjj Yes:

              myProcess->start(program, arguments);
          
              QProcess::ProcessError error = myProcess->error();
          
          M Offline
          M Offline
          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 ?

            A Offline
            A Offline
            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.

            1 Reply Last reply
            0
            • M Offline
              M Offline
              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
              0
              • 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.

                A Offline
                A Offline
                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
                0
                • M Offline
                  M Offline
                  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
                  0
                  • 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 ?

                    A Offline
                    A Offline
                    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...

                    1 Reply Last reply
                    0
                    • 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 ?

                      A Offline
                      A Offline
                      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
                        S Offline
                        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
                        1
                        • S SGaist
                          24 Jun 2016, 09:32

                          What is that + sign doing as parameter ?

                          A Offline
                          A Offline
                          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
                          0
                          • 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
                            M Offline
                            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
                            1

                            34/37

                            24 Jun 2016, 09:31

                            • Login

                            • Login or register to search.
                            34 out of 37
                            • First post
                              34/37
                              Last post
                            0
                            • Categories
                            • Recent
                            • Tags
                            • Popular
                            • Users
                            • Groups
                            • Search
                            • Get Qt Extensions
                            • Unsolved