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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