Hello!

I want my application to know, in the main(...) method preferentially even before starting the QApplication, if an instance of the same application is already running.

Till now I have being doing this by using the following method:

Qt Code: 
  1. /*!
  2.  * \brief getOthermShare tells if there is another mShare opened in this machine.
  3.  * \return
  4.  */
  5. bool getOthermShare()
  6. {
  7.     bool mshare_detectado = false;
  8.     // Get the list of process identifiers
  9.     DWORD aProcesses[1024], cbNeeded, cProcesses;
  10.  
  11.     //Tenta 10 vezes capturar os processos; se nao conseguir, fecha (rever isso aqui!)
  12.     for (int aaa = 0; aaa < 10; aaa++)
  13.     {
  14.         if (EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded ) )
  15.             break;
  16.         else if (aaa == 9)
  17.         {
  18.             QMessageBox::warning(NULL,QMessageBox::tr("Error"),QMessageBox::tr("A fatal error ocurred. Please close down your application and try again.\nIf the problem persists, enter in contact with "
  19.                                  "the support team."));
  20.             return false;
  21.         }
  22.     }
  23.  
  24.     // Calculate how many process identifiers were returned.
  25.     cProcesses = cbNeeded / sizeof(DWORD);
  26.  
  27.     // Discover the name and process identifier for each process.
  28.     for (unsigned int i = 0; i < cProcesses; i++ )
  29.     {
  30.         if( aProcesses[i] != 0 )
  31.         {
  32.             TCHAR szProcessName[MAX_PATH] = TEXT("<unknown>");
  33.  
  34.             // Get a handle to the process.
  35.             HANDLE hProcess = OpenProcess( PROCESS_QUERY_INFORMATION | PROCESS_ALL_ACCESS | READ_CONTROL |
  36.                                            PROCESS_VM_READ,
  37.                                            FALSE, aProcesses[i] );
  38.  
  39.             // Get the process name.
  40.             if (NULL != hProcess )
  41.             {
  42.                 HMODULE hMod;
  43.                 DWORD cbNeeded;
  44.  
  45.                 if ( EnumProcessModules( hProcess, &hMod, sizeof(hMod),
  46.                      &cbNeeded) )
  47.                 {
  48.                     GetModuleBaseName( hProcess, hMod, szProcessName,
  49.                                        sizeof(szProcessName)/sizeof(TCHAR) );
  50.                 }
  51.  
  52. #ifdef Q_OS_WIN
  53. #ifdef UNICODE
  54.  
  55.                 if (QString::fromUtf16((ushort*)szProcessName).section(".",0,0) == "mShare")
  56.                 {
  57.                     if (!mshare_detectado)
  58.                         mshare_detectado = true;
  59.                     else
  60.                     {
  61.                         CloseHandle( hProcess );
  62.                         return true;
  63.                     }
  64.                 }
  65. #endif
  66. #endif
  67.                 // Release the handle to the process.
  68.                 CloseHandle( hProcess );
  69.             }
  70.         }
  71.     }
  72.  
  73.     return false;
  74. }
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which obviously have two problems: first, it works only for Windows, and second, its kinda akward :P

So I'ld like to know if there is a "Qt way" of doing the same thing with the advantage of being platform independent. I noticed the solution shown at [http://www.qtcentre.org/wiki/index.p...leApplication], but I must say I didn't like that way :P Is there another solution? (and one that don't use anything extern to the application, such as a file that is written with "1" when the software is opened or the like)


Thanks,

Momergil