Detecting if a process is still runnning

Question

I need to check if a process with a given HANDLE is still runnning, I tried to do it using the following code however it always returns at the second return false, even if the process is running.

bool isProcessRunning(HANDLE process)
{
    if(process == INVALID_HANDLE_VALUE)return false;

    DWORD exitCode;
    if(GetExitCodeProcess(process, &exitCode) != 0)
        return false;//always returns here

    return GetLastError() == STILL_ACTIVE;//still running
}

Answer 1

You can test the process life by using

bool isProcessRunning(HANDLE process)
{
   return WaitForSingleObject( process, 0 ) == WAIT_TIMEOUT;
}

Answer 2

http://msdn.microsoft.com/en-us/library/ms683189%28VS.85%29.aspx

Return Value

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Answer 3

You can use EnumProcesses() to get all processes running on Windows. Something like:

bool IsProcessRunning(int pid)
{
unsigned long processes[2048];
unsigned long num_proc = 0;
unsigned long needed = 0;

// assume that 2048 processes are enought
if (EnumProcesses(processes, sizeof(processes), &needed))
num_proc = needed / sizeof(DWORD);

for (int i = 0; i < num_proc; i++)
if (processes[i] == pid)
return true;

return false;
}