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STL functors, scoped handles and how we can use them in Windows programming - example of usage

  • Article

#include "stdafx.h"

#include <iostream>

#include "scoped_handle.h"

using namespace std;

// Implementation of "countof" obtained from https://blogs.msdn.com/the1/archive/2004/05/07/128242.aspx

template <typename T, size_t N>

char (&_ArraySizeHelper(T (&array)[N]))[N];

#define countof(array) (sizeof(_ArraySizeHelper(array)))

int _tmain(int argc, _TCHAR* argv[])

{

    DWORD rProcessIds[256];

    DWORD cbReturned;

    if (0 == ::EnumProcesses(rProcessIds, sizeof(rProcessIds), &cbReturned) || cbReturned == sizeof(rProcessIds))

    {

        cout << "EnumProcesses failed" << endl;

        return 1;

    }

    DWORD cProcesses = cbReturned / sizeof(DWORD);

    char szName[256];

    for (DWORD i = 0; i < cProcesses; ++i)

    {

        DWORD dwProcessId = rProcessIds[i];

        // Skip process ID 0.

        if (0 == dwProcessId)

            continue;

        scoped_handle<HANDLE, NULL> handle(NULL, ::CloseHandle);

        handle = ::OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION | PROCESS_VM_READ, FALSE, dwProcessId);

        if (!handle)

        {

            DWORD dwError = ::GetLastError();

            // Skip inaccessible processes.

            if (ERROR_ACCESS_DENIED == dwError)

                continue;

            cout << "OpenProcess failed with " << dwError << endl;

            return 1;

        }

        DWORD cchName = countof(szName);

        if (0 == ::QueryFullProcessImageNameA(handle, 0, szName, &cchName))

        {

            cout << "QueryFullProcessImageName failed with " << ::GetLastError() << endl;

      continue;

        }

        cout << szName << endl;

    }

    return 0;

}

 

ExampleOfUsage.cpp

Comments

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    November 04, 2008
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