Getting size of a file in D2010?

Question

Delphi 2010 has a nice set of new file access functions in IOUtils.pas (I especially like the UTC versions of the date-related functions). What I miss so far is something like

TFile.GetSize (const Path : String)

What is the Delphi 2010-way to get the size of a file? Do I have to go back and use FindFirst to access TSearchRec.FindData?

Thanks.

Answer 1

You can use simple workaround API call:

var
  LowCount,
  HighCount: integer;
...

  LowCount := GetCompressedFileSize('c:\test.txt', @HighCount);

The API call GetCompressedFileSize also works well for non-compressed files!

If you need the actual number of bytes of disk storage then you can call API GetCompressedFileSizeTransacted

Answer 2

I'm not sure if there's a "Delphi 2010" way, but there is a Windows way that doesn't involve FindFirst and all that jazz.

I threw together this Delphi conversion of that routine (and in the process modified it to handle > 4GB size files, should you need that).

  function FileSize(const aFilename: String): Int64;
  var
    info: TWin32FileAttributeData;
  begin
    result := -1;

    if NOT GetFileAttributesEx(PWideChar(aFileName), GetFileExInfoStandard, @info) then
      EXIT;

    result := info.nFileSizeLow or (info.nFileSizeHigh shl 32);
  end;

You could actually just use GetFileSize() but this requires a file HANDLE, not just a file name, and similar to the GetCompressedFileSize() suggestion, this requires two variables to call. Both GetFileSize() and GetCompressedFileSize() overload their return value, so testing for success and ensuring a valid result is just that little bit more awkward.

GetFileSize*Ex*() avoids the nitty gritty of handling > 4GB file sizes and detecting valid results, but also requires a file HANDLE, rather than a name, and (as of Delphi 2009 at least, I haven't checked 2010) isn't declared for you in the VCL anywhere, you would have to provide your own import declaration.

Answer 3

You can also use DSiFileSize from DSiWin32. Works in "all" Delphis. Internally it calls CreateFile and GetFileSize.