asked on

WaitForSingleObject() Function

I am trying to execute a shell command from VB5.0. I am using the CreateProcess to execute the command and then a WaitForSingleObject to tell me when that process has completed. The problem is that WAIT_OBJECT_0 is returned and execution continues before the process is actually done. It appears the program I am calling (Oracle's SQL*Loader) is initiating another process. I am wondering how to get at that process or what I need to do to get the program to stop executing until the shell program completes. (I substituted notepad.exe for the command and it runs just fine).

galkin

I don't know VB but this is C code

      STARTUPINFO StartupInfo;
PROCESS_INFORMATION ProcessInformation;

      memset(&StartupInfo,0,sizeof(StartupInfo));
StartupInfo.cb = sizeof(StartupInfo);

      memset(&ProcessInformation, sizeof(ProcessInformation));

            if(!::CreateProcess( NULL,
(LPTSTR)(LPCTSTR)strCmdLine,
NULL,
NULL,
TRUE,
CREATE_DEFAULT_ERROR_MODE,
NULL,
NULL,
&StartupInfo,
&ProcessInformation
)
              )
            {
            // failed to create process
            }

::WaitForSingleObject(ProcessInformation.hProcess, INFINITE);

// process has exited
::CloseHandle(ProcessInformation.hProcess);
::CloseHandle(ProcessInformation.hThread);

      }

StangLady92

ASKER

You are doing the same thing in C that I am doing in VB. The problem is that the procedure I am creating and calling must execute another procedure so my WaitForSingleObject retures the Wait_Object_0 because the procedure I fired off actually completes while the procedure fired off by my procedure continues. Is there a way to determine when that 2nd procedure finishes?

galkin

So the simpliest way is add a return type to the second procedure to be handle of the process just created so that the first procedure might use it in WaitForSingleObject

StangLady92

ASKER

I am not executing the call to the second procedure. It is being done from the sqlldr.exe program which is my shell command. Is there a way to get information feedback about that procedure back to my VB program?

ASKER CERTIFIED SOLUTION

mikeblas

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alexo

Also you can use CBT hooks. See documentation on SetWindowsHookEx().

mikeblas

What good would a CBT hook be?

.B ekiM