replace string split with shlex; show dir listing for /; naming

pier.py

@@ -26,17 +26,23 @@ from io import StringIO
 
 import os
 import sys
+import shlex
 import http.server
 import socketserver
 
 
-HTML_SPACE = "%20"
+URL_SPACE = "%20"
 
 
 class ScriptServer(http.server.SimpleHTTPRequestHandler):
 
     def do_GET(self):
-        args = self.path.lstrip("/").split(HTML_SPACE)
+        args = self.path.lstrip("/").replace(URL_SPACE, " ")
+        args = shlex.split(args)
+
+        if not args:
+            super().do_GET()
+
         scr = args[0]
 
         if not scr.endswith(".py"):