1 abstract class FileNamingStrategy{
 2     abstract function createLinkName( $fileName );
 3 }
 4 
 5 class ZipFileNamingStrategy extends FileNamingStrategy{
 6     function createLinkName( $fileName ){
 7         return $fileName . ".zip";
 8     }
 9 }
10 
11 class TarFileNamingStrategy extends FileNamingStrategy{
12     function createLinkName( $fileName ){
13         return $fileName . ".tar.gz";
14     }
15 }
16 
17 if( strstr( $_SERVER['HTTP_USER_AGENT'], 'Win' ) ) {
18     $obj = new ZipFileNamingStrategy();
19 }else {
20     $obj = new TarFileNamingStrategy();
21 }
22 
23 $file1 = $obj->createLinkName( "test1" );
24 $file2 = $obj->createLinkName( "test2" );
25 
26 print <<<EOF
27 <a href="$file1">test1</a>
28 <a href="$file2">test2</a>
29 EOF;