Question

I have an application which sits on a server in the network shared folder. Many users in network, can use that file simultaneously. I would like to perform an update of that EXE file and to do this, I would like to know who in network (besides me) is currently using that file.

Is it possible to check this programmatically? For example: to list all user names who are using that file now? Or atleast to retrieve number of locks on that file?

Thanks.

Answer 1

To list the open shared files in a machine you can use ADSI (Active Directory Service Interfaces).

In order to use these interfaces from delphi you must import the Active DS type library

Then access the IADsFileServiceOperations interface, which contains a method called Resources this method return a collection with all the shared resources opened.

Check this sample code

{$APPTYPE CONSOLE}

uses
  ActiveDs_TLB,
  Variants,
  ActiveX,
  SysUtils;


function ADsGetObject(lpszPathName:WideString; const riid:TGUID; out ppObject):HRESULT; safecall; external 'activeds.dll';


procedure ListSharedResourcesInUse;
var
  FSO           : IADsFileServiceOperations;
  Resources     : IADsCollection;
  Resource      : OleVariant;
  pceltFetched  : Cardinal;
  oEnum         : IEnumvariant;
begin
  //establish the connection to ADSI
  ADsGetObject('WinNT://./lanmanserver', IADsFileServiceOperations, FSO);
  //get the resources interface 
  Resources := FSO.Resources;
  //get the enumerator
  oEnum:= IUnknown(Resources._NewEnum) as IEnumVariant;
  while oEnum.Next(1, Resource, pceltFetched) = 0 do
  begin
    Writeln(Format('Resource %s User %s',[Resource.Path,Resource.User]));
    Resource:=Unassigned;
  end;
end;


begin
 try
    CoInitialize(nil);
    try
      ListSharedResourcesInUse;
    finally
      CoUninitialize;
    end;
 except
    on E:Exception do
        Writeln(E.Classname, ':', E.Message);
 end;
 Writeln('Press Enter to exit');
 Readln;
end.