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. executing cmd.exe with some console application
Forum Updated to NodeBB v4.3 + New Features

executing cmd.exe with some console application

Scheduled Pinned Locked Moved Unsolved General and Desktop
20 Posts 4 Posters 3.6k Views
  • 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.
  • R Robert M.

    I know how to do it in Linux, my solution works fine in Linux. I do not know how to do it in Windows.

    JonBJ Offline
    JonBJ Offline
    JonB
    wrote on last edited by
    #6

    @Robert-M
    What is your solution which works in Linux then?

    I suggested the ways you can do it in Windows. Sorry if that's not what you wanted to hear or if Windows/cmd does not work the way you would like it to.

    R 1 Reply Last reply
    0
    • R Robert M.

      I know how to do it in Linux, my solution works fine in Linux. I do not know how to do it in Windows.

      JonBJ Offline
      JonBJ Offline
      JonB
      wrote on last edited by JonB
      #7

      @Robert-M
      There may be a way to get Qt's QProcess to control the arguments being passed to Windows CreateProcess, which I said you will need to do in order to have it create a new console for the sub-process. Have a look at void QProcess::setCreateProcessArgumentsModifier(QProcess::CreateProcessArgumentModifier modifier) and the discussion at typedef QProcess::CreateProcessArgumentModifier. I have not tried it, but in the sample code there I see

      args->flags |= CREATE_NEW_CONSOLE;
      

      Try that, and then try it for your pause command. You may, or may not, need the cmd /k it shows there rather than cmd /c, depending what you want to happen about the console when your command finishes.

      Note that what you will want/expect to happen to the console after your command executes will depend on what command you are issuing. Likely not the same for echo versus pause.

      1 Reply Last reply
      1
      • R Offline
        R Offline
        Robert M.
        wrote on last edited by
        #8

        I tried (according to Qt documentation):

        QProcess process;
        process.setCreateProcessArgumentsModifier([] (QProcess::CreateProcessArguments *args)
           {
               args->flags |= CREATE_NEW_CONSOLE;
               args->startupInfo->dwFlags &= ~STARTF_USESTDHANDLES;
               args->startupInfo->dwFlags |= STARTF_USEFILLATTRIBUTE;
               args->startupInfo->dwFillAttribute = BACKGROUND_BLUE | FOREGROUND_RED
                                                  | FOREGROUND_INTENSITY;
           });
        process.start("C:\\Windows\\System32\\cmd.exe", QStringList() << "/c" << "pause");
        

        but it does not display console window. Using /k instead of /c does not help.

        1 Reply Last reply
        0
        • JonBJ JonB

          @Robert-M
          What is your solution which works in Linux then?

          I suggested the ways you can do it in Windows. Sorry if that's not what you wanted to hear or if Windows/cmd does not work the way you would like it to.

          R Offline
          R Offline
          Robert M.
          wrote on last edited by
          #9

          In Linux I call process->start(...) with xterm.

          R 1 Reply Last reply
          0
          • VRoninV Offline
            VRoninV Offline
            VRonin
            wrote on last edited by
            #10

            Did you try using startDetached instead of start?

            "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
            ~Napoleon Bonaparte

            On a crusade to banish setIndexWidget() from the holy land of Qt

            R JonBJ 2 Replies Last reply
            2
            • VRoninV VRonin

              Did you try using startDetached instead of start?

              R Offline
              R Offline
              Robert M.
              wrote on last edited by
              #11

              You are great! Thanks a lot!

              process.setProgram("C:\\Windows\\System32\\cmd.exe");
              process.setArguments({"/k", "pause"});
              qint64 pid;
              process.startDetached(&pid);
              

              displays console with pause text.

              1 Reply Last reply
              0
              • VRoninV VRonin

                Did you try using startDetached instead of start?

                JonBJ Offline
                JonBJ Offline
                JonB
                wrote on last edited by
                #12

                @VRonin said in executing cmd.exe with some console application:

                Did you try using startDetached instead of start?

                Interesting. But why does that allow the new console where start does not? :)

                1 Reply Last reply
                0
                • VRoninV Offline
                  VRoninV Offline
                  VRonin
                  wrote on last edited by VRonin
                  #13

                  start is designed explicitly to avoid popping new consoles up, see the comment block in https://code.woboq.org/qt5/qtbase/src/corelib/io/qprocess_win.cpp.html#550

                  we [...] do not want console tools launched from a GUI app to create new console windows (behavior consistent with UNIX).

                  "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
                  ~Napoleon Bonaparte

                  On a crusade to banish setIndexWidget() from the holy land of Qt

                  JonBJ 2 Replies Last reply
                  2
                  • VRoninV VRonin

                    start is designed explicitly to avoid popping new consoles up, see the comment block in https://code.woboq.org/qt5/qtbase/src/corelib/io/qprocess_win.cpp.html#550

                    we [...] do not want console tools launched from a GUI app to create new console windows (behavior consistent with UNIX).

                    JonBJ Offline
                    JonBJ Offline
                    JonB
                    wrote on last edited by JonB
                    #14

                    @VRonin said in executing cmd.exe with some console application:

                    see the comment block in https://code.woboq.org/qt5/qtbase/src/corelib/io/qprocess_win.cpp.html#550

                    // However, we also do not want console tools launched from a GUI app to
                    // create new console windows (behavior consistent with UNIX).
                    DWORD dwCreationFlags = (GetConsoleWindow() ? 0 : CREATE_NO_WINDOW);
                    

                    Well no wonder then :) But we don't get told this is a difference from startDetached() :) I will try to remember this for the future.

                    P.S.
                    Isn't just lovely to see UNIX written? :)

                    1 Reply Last reply
                    0
                    • VRoninV VRonin

                      start is designed explicitly to avoid popping new consoles up, see the comment block in https://code.woboq.org/qt5/qtbase/src/corelib/io/qprocess_win.cpp.html#550

                      we [...] do not want console tools launched from a GUI app to create new console windows (behavior consistent with UNIX).

                      JonBJ Offline
                      JonBJ Offline
                      JonB
                      wrote on last edited by JonB
                      #15

                      @VRonin said in executing cmd.exe with some console application:

                      start is designed explicitly to avoid popping new consoles u

                      Not tested, but can't you change this in the same way in your setCreateProcessArgumentsModifier() anyway, just add the first line to whatever you want:

                      args->flags &= ~CREATE_NO_WINDOW;  // switch that *off*
                      args->flags |= CREATE_NEW_CONSOLE;
                      ...
                      

                      ?

                      If this works for start() like the OP says it apparently is working for startDetached() the advantage is you can still wait for sub-process completion, if desired.

                      1 Reply Last reply
                      2
                      • VRoninV Offline
                        VRoninV Offline
                        VRonin
                        wrote on last edited by
                        #16

                        Indeed you can!

                        "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
                        ~Napoleon Bonaparte

                        On a crusade to banish setIndexWidget() from the holy land of Qt

                        1 Reply Last reply
                        1
                        • R Robert M.

                          In Linux I call process->start(...) with xterm.

                          R Offline
                          R Offline
                          Robert M.
                          wrote on last edited by VRonin
                          #17

                          I have one problem in Linux. I invoke xterm with dirtyphp.sh script:

                              QProcess process;
                              QString exec = QString::fromStdString(terminal);
                              QStringList params;
                              params << "-hold" << "-e"; 
                              bool p0 = true;
                              for (std::string s : explode(std::string(" "), dirtyphp_command)) {
                                  if (p0) {
                                      std::string s0 = str_replace("'", "", s) + ".sh";
                                      params << s0.c_str();
                                      p0 = false;
                                  } else {
                                      params << str_replace("'", "", s).c_str();
                                  }
                              }
                              process.start(exec, params);
                              process.waitForFinished();
                          

                          In dirtyphp.sh script I am waiting for CTRL+C at the end:

                          d=`dirname $0`
                          if [ "$d" = "" ]
                          then
                          	d="."
                          fi
                          $d/dirtyphp $@
                          echo 'Hit CTRL+C';
                          while true 
                          do
                          	sleep 1
                          done 
                          

                          The problem is that xterm window is closed automatically without waiting for CTRL+C and the user cannot browse output produced by program dirtyphp in xterm window. I do not understand why - the loop and the end of dirtyphp.sh script should be infinite.

                          JonBJ 1 Reply Last reply
                          0
                          • R Robert M.

                            I have one problem in Linux. I invoke xterm with dirtyphp.sh script:

                                QProcess process;
                                QString exec = QString::fromStdString(terminal);
                                QStringList params;
                                params << "-hold" << "-e"; 
                                bool p0 = true;
                                for (std::string s : explode(std::string(" "), dirtyphp_command)) {
                                    if (p0) {
                                        std::string s0 = str_replace("'", "", s) + ".sh";
                                        params << s0.c_str();
                                        p0 = false;
                                    } else {
                                        params << str_replace("'", "", s).c_str();
                                    }
                                }
                                process.start(exec, params);
                                process.waitForFinished();
                            

                            In dirtyphp.sh script I am waiting for CTRL+C at the end:

                            d=`dirname $0`
                            if [ "$d" = "" ]
                            then
                            	d="."
                            fi
                            $d/dirtyphp $@
                            echo 'Hit CTRL+C';
                            while true 
                            do
                            	sleep 1
                            done 
                            

                            The problem is that xterm window is closed automatically without waiting for CTRL+C and the user cannot browse output produced by program dirtyphp in xterm window. I do not understand why - the loop and the end of dirtyphp.sh script should be infinite.

                            JonBJ Offline
                            JonBJ Offline
                            JonB
                            wrote on last edited by JonB
                            #18

                            @Robert-M
                            If you think it's even executing that script and getting as far as the while true loop (goodness knows), put some debugging into the loop, like an echo or a read.

                            Or maybe put a set -x at the start of the script so you can see what is going on?

                            1 Reply Last reply
                            0
                            • R Offline
                              R Offline
                              Robert M.
                              wrote on last edited by
                              #19

                              I changed the loop to the following:
                              while true
                              do
                              echo -n _
                              done
                              I see no underscores in xterm window.
                              Qt reports:
                              QProcess: Destroyed while process ("xterm") is still running.
                              I modified waitForFinish call:
                              process.waitForFinish(-1);
                              and now I can see underscores.
                              Problem solved.

                              JonBJ 1 Reply Last reply
                              0
                              • R Robert M.

                                I changed the loop to the following:
                                while true
                                do
                                echo -n _
                                done
                                I see no underscores in xterm window.
                                Qt reports:
                                QProcess: Destroyed while process ("xterm") is still running.
                                I modified waitForFinish call:
                                process.waitForFinish(-1);
                                and now I can see underscores.
                                Problem solved.

                                JonBJ Offline
                                JonBJ Offline
                                JonB
                                wrote on last edited by JonB
                                #20

                                @Robert-M
                                bool QProcess::waitForFinished(int msecs = 30000) means that waitForFinished() only waits up to 30 seconds, and then your QProcess process; goes out of scope and causes the error. If your sub-process takes longer that is why you wanted waitForFinished(-1).

                                1 Reply Last reply
                                0

                                • Login

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