Enumerating Process Objects

The example in this topic uses the PDH interface to enumerate the process objects on the system.

#ifdef UNICODE
#ifndef _UNICODE
#define _UNICODE  1
#endif
#define tmain     wmain
#else
#define tmain     main
#endif

// This program needs only the essential Windows header files.
#define WIN32_LEAN_AND_MEAN 1

#include <windows.h>
#include <winperf.h>
#include <malloc.h>
#include <stdio.h>
#include <tchar.h>
#include <pdh.h>

int
tmain ()
{
    PDH_STATUS  pdhStatus               = ERROR_SUCCESS;
    LPTSTR      szCounterListBuffer     = NULL;
    DWORD       dwCounterListSize       = 0;
    LPTSTR      szInstanceListBuffer    = NULL;
    DWORD       dwInstanceListSize      = 0;
    LPTSTR      szThisInstance          = NULL;


// Determine the required buffer size for the data. 

    pdhStatus = PdhEnumObjectItems (
        NULL,                   // reserved
        NULL,                   // local machine
        TEXT("Process"),        // object to enumerate
        szCounterListBuffer,    // pass in NULL buffers
        &dwCounterListSize,     // an 0 length to get
        szInstanceListBuffer,   // required size 
        &dwInstanceListSize,    // of the buffers in chars
        PERF_DETAIL_WIZARD,     // counter detail level
        0); 

    if (pdhStatus == ERROR_SUCCESS) 
    {
    // Allocate the buffers and try the call again.
        szCounterListBuffer = (LPTSTR)malloc (
            (dwCounterListSize * sizeof (TCHAR)));
        szInstanceListBuffer = (LPTSTR)malloc (
            (dwInstanceListSize * sizeof (TCHAR)));
        if ((szCounterListBuffer != NULL) &&
            (szInstanceListBuffer != NULL)) 
        {
            pdhStatus = PdhEnumObjectItems (
                NULL,   // reserved
                NULL,   // local machine
                TEXT("Process"), // object to enumerate
                szCounterListBuffer,    // passing in NULL buffers
                &dwCounterListSize,     // passing in 0
                szInstanceListBuffer,   
                &dwInstanceListSize,    
                PERF_DETAIL_WIZARD,     // counter detail level
                0);     
            if (pdhStatus == ERROR_SUCCESS) 
            {
                _tprintf (TEXT("\nRunning Processes:"));
            // Walk the return instance list.
                for (szThisInstance = szInstanceListBuffer;
                     *szThisInstance != 0;
                     szThisInstance += lstrlen(szThisInstance) + 1) 
                {
                     _tprintf (TEXT("\n  %s"), szThisInstance);
                }
            }
        } 
        else 
        {
            _tprintf (TEXT("\nPROCLIST: unable to allocate buffers"));
        }

        if (szCounterListBuffer != NULL) 
            free (szCounterListBuffer);

        if (szInstanceListBuffer != NULL) 
            free (szInstanceListBuffer);
    } 
    else 
    {
        _tprintf(TEXT("\nUnable to determine required buffer size."));
    }
    return 0;
}