use File::Basename;

my $url = "http://google.com/folder/1234.html?session=4247110815";

                               print "Native: ",basename($url,'.html'),"\n";
fileparse_set_fstype('Unix');  print "Unix: ",  basename($url,'.html'),"\n";
fileparse_set_fstype('MacOS'); print "MacOS: ", basename($url,'.html'),"\n";