File Size - Get the Size of a File in Bytes using Delphi

When working with files and folders from a Delphi application you sometimes need to know what is the size of a file (in bytes).

Get File Size

The FileSize function returns the size of a file in bytes, -1 if the file was not found.

// returns file size in bytes or -1 if not found.
function FileSize(fileName : wideString) : Int64;
var
  sr : TSearchRec;
begin
  if FindFirst(fileName, faAnyFile, sr ) = 0 then
     result := Int64(sr.FindData.nFileSizeHigh) shl Int64(32) + Int64(sr.FindData.nFileSizeLow)
  else
     result := -1;

  FindClose(sr) ;
end;

Note: when you have the size of a file in bytes, you might want to format the size for display (Kb, Mb, Gb)

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