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How to get process id

Jun 24, 2009 at 3:27pm
mathueie (22)
Hi,

How to get process id of any running process by its name in windows.
Jun 24, 2009 at 5:44pm
mackabee (152)
FindWindow() - http://msdn.microsoft.com/en-us/library/ms633499(VS.85).aspx
GetWindowThreadProcessId() - http://msdn.microsoft.com/en-us/library/ms633522(VS.85).aspx

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#include <iostream>
#include <string>
#include <windows.h>

int main()
{
	std::wstring windowName;
	std::getline(std::wcin, windowName);

	HWND windowHandle = FindWindowW(NULL, windowName.c_str());
	DWORD* processID = new DWORD;
	GetWindowThreadProcessId(windowHandle, processID);

	std::wcout << L"Process ID of " << windowName.c_str() << L" is: " << *processID << std::endl;

	system("PAUSE");
}
Edit & run on cpp.sh



Try to use wchar_t when dealing with the Windows API since all the ANSI functions are just wrappers which make copies of the ANSI strings to Unicode strings and recall the function.
Jun 25, 2009 at 7:33am
mathueie (22)

Hi,

Thanks for ur reply..
But its not working.
I gave input to program ------------regedit
Ans is........Process ID of regedit is : 3452816845


Actual process id is ::
regedit.exe process id is.............2536.
Jun 25, 2009 at 10:00am
Duthomhas (13251)
Don't blame the API for user error.

When you execute regedit.exe, notice that the window title is "Registry Editor". You cannot search for a window titled "regedit" and expect a match if no such window exists.

Hope this helps.
Jun 27, 2009 at 5:55pm
mackabee (152)
As Duoas said, the functions I provided require the name of the actual window. If you were looking for how to check against "process.exe" then this should help you

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#include <iostream>
#include <string>
#include <windows.h>
#include <tlhelp32.h>

DWORD FindProcessId(const std::wstring& processName);

int main()
{
	std::wstring processName;

	std::wcout << "Enter the process name: ";
	std::getline(std::wcin, processName);
	
	DWORD processID = FindProcessId(processName);

	if ( processID == 0 )
		std::wcout << "Could not find " << processName.c_str() << std::endl;
	else
		std::wcout << "Process ID is " << processID << std::endl;

	system("PAUSE");
	return 0;
}

DWORD FindProcessId(const std::wstring& processName)
{
	PROCESSENTRY32 processInfo;
	processInfo.dwSize = sizeof(processInfo);

	HANDLE processesSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);
	if ( processesSnapshot == INVALID_HANDLE_VALUE )
		return 0;

	Process32First(processesSnapshot, &processInfo);
	if ( !processName.compare(processInfo.szExeFile) )
	{
		CloseHandle(processesSnapshot);
		return processInfo.th32ProcessID;
	}

	while ( Process32Next(processesSnapshot, &processInfo) )
	{
		if ( !processName.compare(processInfo.szExeFile) )
		{
			CloseHandle(processesSnapshot);
			return processInfo.th32ProcessID;
		}
	}
	
	CloseHandle(processSnapshot);
	return 0;
}
Edit & run on cpp.sh
Last edited on Jun 27, 2009 at 6:09pm
Jun 30, 2009 at 2:37pm
mathueie (22)

Hi,

thanks...
Jul 2, 2009 at 12:06am
Kiana (186)
Found this while helping someone else, hope it helps you. It's written by someone called Irwin.

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#include <psapi.h> 
#define MAX_PROCESSES 1024 

DWORD FindProcess(__in_z LPCTSTR lpcszFileName) 
{ 
  LPDWORD lpdwProcessIds; 
  LPTSTR  lpszBaseName; 
  HANDLE  hProcess; 
  DWORD   i, cdwProcesses, dwProcessId = 0; 

  lpdwProcessIds = (LPDWORD)HeapAlloc(GetProcessHeap(), 0, MAX_PROCESSES*sizeof(DWORD)); 
  if (lpdwProcessIds != NULL) 
  { 
    if (EnumProcesses(lpdwProcessIds, MAX_PROCESSES*sizeof(DWORD), &cdwProcesses)) 
    { 
      lpszBaseName = (LPTSTR)HeapAlloc(GetProcessHeap(), 0, MAX_PATH*sizeof(TCHAR)); 
      if (lpszBaseName != NULL) 
      { 
        cdwProcesses /= sizeof(DWORD); 
        for (i = 0; i < cdwProcesses; i++) 
        { 
          hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, lpdwProcessIds[i]); 
          if (hProcess != NULL) 
          { 
            if (GetModuleBaseName(hProcess, NULL, lpszBaseName, MAX_PATH) > 0) 
            { 
              if (!lstrcmpi(lpszBaseName, lpcszFileName)) 
              { 
                dwProcessId = lpdwProcessIds[i]; 
                CloseHandle(hProcess); 
                break; 
              } 
            } 
            CloseHandle(hProcess); 
          } 
        } 
        HeapFree(GetProcessHeap(), 0, (LPVOID)lpszBaseName); 
      } 
    } 
    HeapFree(GetProcessHeap(), 0, (LPVOID)lpdwProcessIds); 
  } 
  return dwProcessId; 
}
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