Kill a process with its processID - c++

Question

I'm trying to display all the running process along with their memory usage and provide a kill option, i've used the OpenProcess method to get the memory used by the current process. How do I kill a process with a processID?
Here is the code:
BOOL GetProcessList( )
{
HANDLE hProcessSnap;
HANDLE hProcess;
HANDLE hToken;
PROCESSENTRY32 pe32;
DWORD dwPriorityClass;
PROCESS_MEMORY_COUNTERS pmc;
hProcessSnap = CreateToolhelp32Snapshot( TH32CS_SNAPPROCESS, 0 );
if( hProcessSnap == INVALID_HANDLE_VALUE )
{
printError( TEXT("CreateToolhelp32Snapshot (of processes)") );
return( FALSE );
}
pe32.dwSize = sizeof( PROCESSENTRY32 );
if( !Process32First( hProcessSnap, &pe32 ) )
{
printError( TEXT("Process32First") ); // show cause of failure
CloseHandle( hProcessSnap ); // clean the snapshot object
return( FALSE );
}
if(!OpenThreadToken(GetCurrentThread(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, FALSE, &hToken))
{
if (GetLastError() == ERROR_NO_TOKEN)
{
if (!ImpersonateSelf(SecurityImpersonation))
return FALSE;
if(!OpenThreadToken(GetCurrentThread(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, FALSE, &hToken)){
printError( TEXT("OpenThreadToken") );
return FALSE;
}
}
else
return FALSE;
}
SetPrivilege(hToken, SE_DEBUG_NAME, FALSE);
do
{
printf( TEXT("\nPROCESS NAME: %s"), pe32.szExeFile );
dwPriorityClass = 0;
SIZE_T dwMin, dwMax;
hProcess = OpenProcess( PROCESS_QUERY_LIMITED_INFORMATION , FALSE, pe32.th32ProcessID );
if(GetProcessMemoryInfo( hProcess, (PROCESS_MEMORY_COUNTERS *)&pmc, sizeof(pmc)))
{
printf( "\nPagefileUsage: %d KB", pmc.PagefileUsage/1024);
} else{
printError( TEXT("GetProcessMemoryInfo") );
}
CloseHandle(hProcess);
}while( Process32Next( hProcessSnap, &pe32 ) );
CloseHandle( hProcessSnap );
return( TRUE );
}

Answer 1

Since you have an hProcess to hand, you can just use that:
BOOL ok = TerminateProcess (hProcess, exit_code);
Where exit_code can be anything you like (try to make it meaningful, in case anything is waiting on the process and would like to know why it exited).
If you don't want to do it that way, you can use OpenProcess:
HANDLE hProcess = OpenProcess (PROCESS_TERMINATE, FALSE, process_id);
if (hProcess)
{
BOOL ok = TerminateProcess (hProcess, exit_code);
CloseHandle (hProcess);
}
else
{
DWORD err = GetLastError ();
...
}
You need to check that OpenProcess() succeeded because (amongst other things), you might not have sufficient access rights, and you need to close hProcess after you're done with it, even though you've killed the process itself.
Documentation for TerminateProcess() here.