Does python use ctypes c_char for Windows 64?

Question

I am trying to load a list of processes and it works correctly on 32-bit python. However, on 64-bit, I cannot get the process name for the list. The code is below. If I changed the structure of szExeFile from c_char to c_int or long, the list of processes is listed, but I do not see that pid belongs to what exe is. How can I make this work on x64?

from ctypes import * from ctypes.wintypes import * import sys # const variable # Establish rights and basic options needed for all process declartion / iteration TH32CS_SNAPPROCESS = 2 STANDARD_RIGHTS_REQUIRED = 0x000F0000 SYNCHRONIZE = 0x00100000 PROCESS_ALL_ACCESS = (STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | 0xFFF) TH32CS_SNAPMODULE = 0x00000008 TH32CS_SNAPTHREAD = 0x00000004 ## Create object definitions to story information in class PROCESSENTRY32(Structure): _fields_ = [ ( 'dwSize' , c_uint ) , ( 'cntUsage' , c_uint) , ( 'th32ProcessID' , c_uint) , ( 'th32DefaultHeapID' , c_uint) , ( 'th32ModuleID' , c_uint) , ( 'cntThreads' , c_uint) , ( 'th32ParentProcessID' , c_uint) , ( 'pcPriClassBase' , c_long) , ( 'dwFlags' , c_uint) , ( 'szExeFile' , c_char * 260 ) ] CreateToolhelp32Snapshot= windll.kernel32.CreateToolhelp32Snapshot Process32First = windll.kernel32.Process32First Process32Next = windll.kernel32.Process32Next GetLastError = windll.kernel32.GetLastError OpenProcess = windll.kernel32.OpenProcess GetPriorityClass = windll.kernel32.GetPriorityClass CloseHandle = windll.kernel32.CloseHandle try: hProcessSnap = c_void_p(0) hProcessSnap = CreateToolhelp32Snapshot( TH32CS_SNAPPROCESS , 0 ) pe32 = PROCESSENTRY32() pe32.dwSize = sizeof( PROCESSENTRY32 ) ret = Process32First( hProcessSnap , pointer( pe32 ) ) global PROGPid PROGPid=False while ret: print pe32.dwSize,pe32.cntUsage,pe32.th32ProcessID,pe32.th32DefaultHeapID,pe32.th32ModuleID,pe32.cntThreads,pe32.th32ParentProcessID,pe32.pcPriClassBase,pe32.dwFlags,pe32.szExeFile hProcess = OpenProcess( PROCESS_ALL_ACCESS , 0 , pe32.th32ProcessID ) dwPriorityClass = GetPriorityClass( hProcess ) if dwPriorityClass == 0 : CloseHandle( hProcess ) PROGPid=pe32.th32ProcessID ret = Process32Next( hProcessSnap, pointer(pe32) ) print PROGPid CloseHandle ( hProcessSnap ) except: print "Error in ListProcessPid" 

Answer 1

Your PROCESSENTRY32 structure is incorrect. This works for me:

 class PROCESSENTRY32(Structure): _fields_ = [ ( 'dwSize' , DWORD ) , ( 'cntUsage' , DWORD) , ( 'th32ProcessID' , DWORD) , ( 'th32DefaultHeapID' , POINTER(ULONG)) , ( 'th32ModuleID' , DWORD) , ( 'cntThreads' , DWORD) , ( 'th32ParentProcessID' , DWORD) , ( 'pcPriClassBase' , LONG) , ( 'dwFlags' , DWORD) , ( 'szExeFile' , c_char * 260 ) ]