CODEWITHSUNDEEP
delphisize
Sky
Sky

Reputation: 4370

How do I get the size of a download when a HEAD request doesn't report ContentLength?

Using this code in Delphi for getting a web page size: (I mean page source size)

uses
  IdHTTP

function URLsize(const URL : string) : integer;
var
  Http: TIdHTTP;
begin
  Http := TIdHTTP.Create(nil);
  try
    Http.Head(URL);    
    result := round(Http.Response.ContentLength / 1048576);   //MB   
  finally
    Http.Free;
  end;
end;

I can get file size easily for some URLs like http://sample.com/test.exe. It returns the size in MB.

But I cannot get URL size using this code for a URL like http://stackoverflow.com/; it returns 0 or -1.

How can I get the size in that case?

Upvotes: 3

Views: 2023

Answers (2)

Jerry Dodge
Jerry Dodge

Reputation: 27286

Even if a web server does return the proper content length, you're dividing it by 1048576 to get the megabyte value. Since http://stackoverflow.com/ is much less than a single megabyte, it is returning 0. I'm still stumped however where your -1 came from - because http://stackoverflow.com/ returns 194569 for me, without dividing. Did you get a -1 from another website? And are your results the divided value or the raw value from Http.Response.ContentLength?

Upvotes: 3

David Heffernan
David Heffernan

Reputation: 613332

Not all HTTP HEAD responses contain content-length. So, what you are trying to do is impossible in general. If you encounter a response that does not contain the content length you need to download the contents in order to find the length.

Upvotes: 8

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