Author: Tomas Rutkauskas

How can I extract a FileName from a URL?  For example 
http://www.domain.com/file.zip -> file.zip

Answer:

Solve 1:

1   function ExtractUrlFileName(const AUrl: string): string;
2   var
3     I: Integer;
4   begin
5     I := LastDelimiter('\:/', AUrl);
6     Result := Copy(AUrl, I + 1, MaxInt);
7   end;



Solve 2:

You will just have to parse the string manually, ie:

8   Filename := '../../afolder/anotherfolder/aFilename.ext';
9   Pos := LastDelimiter('/\', Filename);
10  if (Pos > 0) then
11    Filename := Copy(Pos + 1, Length(Filename) - Pos, Filename);



Solve 3:

12  Filename := '../../afolder/anotherfolder/aFilename.ext';
13  Filename := StringReplace(Filename, '/', '\', [rfReplaceAll]);
14  Filename := ExtractFileName(Filename);



Solve 4:

You can treat a string as an array of characters and index individual characters in 
it with array notation. That allows you to write a loop that checks characters 
starting from the end of the string and walking backwards. Once you find the start 
of the filename you can use the Copy function to isolate it.

15  function GetFilenameFromUrl(const url: string): string;
16  var
17    i: Integer;
18  begin
19    Result := EmptyStr; // be a realist, assume failure
20    i := Length(url);
21    while (i > 0) and (url[i] <> '.') do
22      dec(i);
23  
24    if i = 0 then
25      Exit; // no filename separator found
26  
27    if AnsiCompareText(Copy(url, i, maxint), '.exe') <> 0 then
28      Exit; // no .exe at end of url
29  
30    // find next '.' before current position
31    dec(i);
32    while (i > 0) and (url[i] <> '.') do
33      dec(i);
34  
35    if i = 0 then
36      Exit; // no filename separator found
37    Result := Copy(url, i + 1, maxint);
38  end;