[SOLVED]Detect that file is on server with fphttpclient?
lazarus / 38-Networking and Web Programming

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Robert W.B. · 2017-02-13 13:09

Hi. Is there a way to detect, if a file exists on the server, with
fphttpclient?  

Thanks in advance
Bob

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rvk · 2017-02-13 13:36

You could use HEAD to see if the page (or file) exists.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
Project1;uses fphttpclient, Classes;var  Fp: TFPHttpClient;begin  Fp
:= TFPHttpClient.Create(nil);  try     Fp.HTTPMethod('HEAD',
'http://www.microsoft.com/I_DO_NOT_EXIST.html', nil, []);   
Writeln(Fp.ResponseStatusCode); // will give 404    
Fp.HTTPMethod('HEAD', 'http://www.microsoft.com/nl-nl/windows', nil,
[]);    Writeln(Fp.ResponseStatusCode); // will give 200   finally   
Fp.Free;  end;  readln;end.

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Thaddy · 2017-02-13 13:47

That is correct.

Note ONLY for files that are in the public part of your server.
That code can not detect if a file exists anywhere outside of the
serve-able space on that server disk.
In other words, you can not detect the presence of a specific file if
it is not serve-able.

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rvk · 2017-02-13 13:57

It also doesn't account for redirection. Lot's of file-services use
redirection for files. In that case you will always get a 3xx redirect
on every possible filename. So if that's the purpose you need to do
some manual work to follow the redirection to its final source and see
if it throws an error-page.

So, if you need more information you will also need to provide us with
more information.

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Robert W.B. · 2017-02-13 13:59

This is what I was looking for.
Have a great day.
/Bob