You have basically two ways
The Easy Way
if you are using Windows Vista or newer try the IFileIsInUse interface
The Hard Way
if you need a method compatible with Windows XP,Vista,7 and so on. then you use the NtQuerySystemInformation, NtQueryInformationFile and NtQueryObject functions.
These are the steps to proceed
- Call the NTQuerySystemInformation passing the undocumented SystemHandleInformation ($10) value to get the list of handles
- then process the list of handles (only for ObjectType = 28) which are files.
- call OpenProcess with
PROCESS_DUP_HANDLE
- then call DuplicateHandle for get a
real handle to the file.
- get the name of the filename asociated to the handle using the NtQueryInformationFile and NtQueryObject functions.
Note 1 : the tricky part of this method is resolve the filename based in a handle. the function NtQueryInformationFile hangs in some scenarios (system handles and others) a workaround to prevent the entire application from hanging is call the function from a separate thread.
Note 2 : exist another functions like GetFileInformationByHandleEx and GetFinalPathNameByHandle to resolve the filename of a handle. but both exist since Windows viste an d in such case is better use IFileIsInUse.
Check this sample application tested in Delphi 2007, XE2 and Windows XP and 7. from here you can take some ideas to resolve your issue.
Note : The function GetProcessIdUsingFile Only compares the name of the files (not the path).
{$APPTYPE CONSOLE}
uses
Windows,
SysUtils;
const
SystemHandleInformation = $10;
STATUS_SUCCESS = $00000000;
FileNameInformation = 9;
ObjectNameInformation = 1;
type
SYSTEM_HANDLE=packed record
uIdProcess:ULONG;
ObjectType:UCHAR;
Flags :UCHAR;
Handle :Word;
pObject :Pointer;
GrantedAccess:ACCESS_MASK;
end;
SYSTEM_HANDLE_ARRAY = Array[0..0] of SYSTEM_HANDLE;
SYSTEM_HANDLE_INFORMATION=packed record
uCount:ULONG;
Handles:SYSTEM_HANDLE_ARRAY;
end;
PSYSTEM_HANDLE_INFORMATION=^SYSTEM_HANDLE_INFORMATION;
NT_STATUS = Cardinal;
PFILE_NAME_INFORMATION = ^FILE_NAME_INFORMATION;
FILE_NAME_INFORMATION = packed record
FileNameLength: ULONG;
FileName: array [0..MAX_PATH - 1] of WideChar;
end;
PUNICODE_STRING = ^TUNICODE_STRING;
TUNICODE_STRING = packed record
Length : WORD;
MaximumLength : WORD;
Buffer : array [0..MAX_PATH - 1] of WideChar;
end;
POBJECT_NAME_INFORMATION = ^TOBJECT_NAME_INFORMATION;
TOBJECT_NAME_INFORMATION = packed record
Name : TUNICODE_STRING;
end;
PIO_STATUS_BLOCK = ^IO_STATUS_BLOCK;
IO_STATUS_BLOCK = packed record
Status: NT_STATUS;
Information: DWORD;
end;
PGetFileNameThreadParam = ^TGetFileNameThreadParam;
TGetFileNameThreadParam = packed record
hFile : THandle;
Result : NT_STATUS;
FileName : array [0..MAX_PATH - 1] of AnsiChar;
end;
function NtQueryInformationFile(FileHandle: THandle;
IoStatusBlock: PIO_STATUS_BLOCK; FileInformation: Pointer;
Length: DWORD; FileInformationClass: DWORD): NT_STATUS;
stdcall; external 'ntdll.dll';
function NtQueryObject(ObjectHandle: THandle;
ObjectInformationClass: DWORD; ObjectInformation: Pointer;
ObjectInformationLength: ULONG;
ReturnLength: PDWORD): NT_STATUS; stdcall; external 'ntdll.dll';
function NtQuerySystemInformation(SystemInformationClass: DWORD; SystemInformation: Pointer; SystemInformationLength: ULONG; ReturnLength: PULONG): NT_STATUS; stdcall; external 'ntdll.dll' name 'NtQuerySystemInformation';
function GetFileNameHandleThr(Data: Pointer): DWORD; stdcall;
var
dwReturn: DWORD;
FileNameInfo: FILE_NAME_INFORMATION;
ObjectNameInfo: TOBJECT_NAME_INFORMATION;
IoStatusBlock: IO_STATUS_BLOCK;
pThreadParam: TGetFileNameThreadParam;
begin
ZeroMemory(@FileNameInfo, SizeOf(FILE_NAME_INFORMATION));
pThreadParam := PGetFileNameThreadParam(Data)^;
Result := NtQueryInformationFile(pThreadParam.hFile, @IoStatusBlock, @FileNameInfo, MAX_PATH * 2, FileNameInformation);
if Result = STATUS_SUCCESS then
begin
Result := NtQueryObject(pThreadParam.hFile, ObjectNameInformation, @ObjectNameInfo, MAX_PATH * 2, @dwReturn);
if Result = STATUS_SUCCESS then
begin
pThreadParam.Result := Result;
WideCharToMultiByte(CP_ACP, 0, @ObjectNameInfo.Name.Buffer[ObjectNameInfo.Name.MaximumLength - ObjectNameInfo.Name.Length], ObjectNameInfo.Name.Length, @pThreadParam.FileName[0], MAX_PATH, nil, nil);
end
else
begin
pThreadParam.Result := STATUS_SUCCESS;
Result := STATUS_SUCCESS;
WideCharToMultiByte(CP_ACP, 0, @FileNameInfo.FileName[0], IoStatusBlock.Information, @pThreadParam.FileName[0], MAX_PATH, nil, nil);
end;
end;
PGetFileNameThreadParam(Data)^ := pThreadParam;
ExitThread(Result);
end;
function GetFileNameHandle(hFile: THandle): String;
var
lpExitCode: DWORD;
pThreadParam: TGetFileNameThreadParam;
hThread: THandle;
begin
Result := '';
ZeroMemory(@pThreadParam, SizeOf(TGetFileNameThreadParam));
pThreadParam.hFile := hFile;
hThread := CreateThread(nil, 0, @GetFileNameHandleThr, @pThreadParam, 0, PDWORD(nil)^);
if hThread <> 0 then
try
case WaitForSingleObject(hThread, 100) of
WAIT_OBJECT_0:
begin
GetExitCodeThread(hThread, lpExitCode);
if lpExitCode = STATUS_SUCCESS then
Result := pThreadParam.FileName;
end;
WAIT_TIMEOUT:
TerminateThread(hThread, 0);
end;
finally
CloseHandle(hThread);
end;
end;
//get the pid of the process which had open the specified file
function GetProcessIdUsingFile(const TargetFileName:string): DWORD;
var
hProcess : THandle;
hFile : THandle;
ReturnLength: DWORD;
SystemInformationLength : DWORD;
Index : Integer;
pHandleInfo : PSYSTEM_HANDLE_INFORMATION;
hQuery : THandle;
FileName : string;
begin
Result:=0;
pHandleInfo := nil;
ReturnLength := 1024;
pHandleInfo := AllocMem(ReturnLength);
hQuery := NTQuerySystemInformation(DWORD(SystemHandleInformation), pHandleInfo, 1024, @ReturnLength);
if ReturnLength<>0 then
begin
FreeMem(pHandleInfo);
SystemInformationLength := ReturnLength;
pHandleInfo := AllocMem(ReturnLength+1024);
hQuery := NTQuerySystemInformation(DWORD(SystemHandleInformation), pHandleInfo, SystemInformationLength, @ReturnLength);//Get the list of handles
end
else
RaiseLastOSError;
try
if(hQuery = STATUS_SUCCESS) then
begin
for Index:=0 to pHandleInfo^.uCount-1 do
if pHandleInfo.Handles[Index].ObjectType=28 then
begin
hProcess := OpenProcess(PROCESS_DUP_HANDLE, FALSE, pHandleInfo.Handles[Index].uIdProcess);
if(hProcess <> INVALID_HANDLE_VALUE) then
begin
try
if not DuplicateHandle(hProcess, pHandleInfo.Handles[Index].Handle,GetCurrentProcess(), @hFile, 0 ,FALSE, DUPLICATE_SAME_ACCESS) then
hFile := INVALID_HANDLE_VALUE;
finally
CloseHandle(hProcess);
end;
if (hFile<>INVALID_HANDLE_VALUE) then
begin
try
FileName:=GetFileNameHandle(hFile);
finally
CloseHandle(hFile);
end;
end
else
FileName:='';
//Writeln(FileName);
if CompareText(ExtractFileName(FileName), TargetFileName)=0 then
Result:=pHandleInfo.Handles[Index].uIdProcess;
end;
end;
end;
finally
if pHandleInfo<>nil then
FreeMem(pHandleInfo);
end;
end;
function SetDebugPrivilege: Boolean;
var
TokenHandle: THandle;
TokenPrivileges : TTokenPrivileges;
begin
Result := false;
if OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES or TOKEN_QUERY, TokenHandle) then
begin
if LookupPrivilegeValue(nil, PChar('SeDebugPrivilege'), TokenPrivileges.Privileges[0].Luid) then
begin
TokenPrivileges.PrivilegeCount := 1;
TokenPrivileges.Privileges[0].Attributes := SE_PRIVILEGE_ENABLED;
Result := AdjustTokenPrivileges(TokenHandle, False,
TokenPrivileges, 0, PTokenPrivileges(nil)^, PDWord(nil)^);
end;
end;
end;
begin
try
SetDebugPrivilege;
Writeln('Processing');
Writeln(GetProcessIdUsingFile('MyFile.txt'));
Writeln('Done');
except
on E:Exception do
Writeln(E.Classname, ': ', E.Message);
end;
Readln;
end.
