How can I find the process id from the service name/handle in Delphi?

Question

I have the service name for a windows service in delphi, and I know how to get the handle from that as well. What I need to do is stop a service, and if the stop fails for some reason I need to kill the process associated with the service. The problem is that I have multiple services running from the same executable, so I can't use the executable name to kill the process. This means I need the process id to kill the proper associated process. How can I get this id or some way to kill the proper process from the service name or handle?

Answer 1

QueryServiceStatusEx?

Answer 2

Please note I have only accepted this solution so that a full delphi code solution is accepted, all due thanks to Jk though for pointing me on the correct path.

--

Ok, I've been able to figure out how to use the answer by Jk and have come up with this solution in delphi.

For reference, this is the link provided by Jk:

QueryServiceStatusEx

My Solution:

unit Demo;

interface

uses
  Windows, Forms, SysUtils,
  StdCtrls, WinSvc, Controls, Classes;

type

  //Form for basic demo usage
  TForm6 = class(TForm)
    Button1: TButton;
    Memo1: TMemo;
    procedure Button1Click(Sender: TObject);
  end;

  //Record defined for use as return buffer
  _SERVICE_STATUS_PROCESS = record
    dwServiceType: DWORD;
    dwCurrentState: DWORD;
    dwControlsAccepted: DWORD;
    dwWin32ExitCode: DWORD;
    dwServiceSpecificExitCode: DWORD;
    dwCheckPoint: DWORD;
    dwWaitHint: DWORD;
    dwProcessId: DWORD;
    dwServiceFlags: DWORD;
  end;
  //Function Prototype
  function QueryServiceStatusEx(
  SC_HANDLE: SC_Handle;
  SC_STATUS_TYPE: Cardinal;
  out lpBuffer: _SERVICE_STATUS_PROCESS;
  cbBufSize: DWORD;
  out pcbBytesNeeded: LPDWORD
  ): BOOL; stdcall;


  //internal setup function
  function GetPid(sService: String; sMachine: String = '') : Cardinal;
var
  Form6: TForm6;

implementation

{$R *.dfm}
const
  // windows api library
  advapi32 = 'advapi32.dll';
  //define the api call
  function QueryServiceStatusEx;   external advapi32 name 'QueryServiceStatusEx';

//for demo usage
procedure TForm6.Button1Click(Sender: TObject);
begin
  Memo1.Lines.Add(IntToStr(Integer(GetPid('Service'))))
end;


function GetPid(sService: String; sMachine: String = '') : Cardinal;
var
  schm,
  schs: SC_Handle;
  SC_STATUS_TYPE: Cardinal;
  lpBuffer: _SERVICE_STATUS_PROCESS;
  cbBufSize: DWORD;
  pcbBytesNeeded: LPDWORD;
begin
  //open the service manager  (defined in WinSvc)
  schm := OpenSCManager(PChar(sMachine), nil, SC_MANAGER_CONNECT);
  //set the status type to SC_STATUS_PROCESS_INFO
  //this is currently the only value supported
  SC_STATUS_TYPE := $00000000;
  //set the buffer size to the size of the record
  cbBufSize := sizeof(_SERVICE_STATUS_PROCESS);
  if (schm>0) then
  begin
    //grab the service handle
    schs := OpenService(schm, PChar(sService), SERVICE_QUERY_STATUS);
    if (schs>0) then
    begin
      //call the function
      QueryServiceStatusEx(
      schs,
      SC_STATUS_TYPE,
      lpBuffer,
      cbBufSize,
      pcbBytesNeeded);
      CloseServiceHandle(schs);
    end;
    CloseServiceHandle(schm);
  end;
  Result := lpBuffer.dwProcessId;
end;



end.

Please note that not all external naming and other necessities are included.