Change the 227 response parser to use a more liberal regular

gvanrossum · gvanrossum · commit 70297d3bd4e3 · 2001-08-17T17:24:29.000Z
expression.  This is needed for certain servers that (in violation of
the standard) don't return the parentheses in the response.

This fixes SF bug #441712 by Henrik Weber (not exactly using his
patch).
diff --git a/Lib/ftplib.py b/Lib/ftplib.py
@@ -551,21 +551,23 @@ def parse150(resp):
     return None
 
 
+_227_re = None
+
 def parse227(resp):
     '''Parse the '227' response for a PASV request.
     Raises error_proto if it does not contain '(h1,h2,h3,h4,p1,p2)'
     Return ('host.addr.as.numbers', port#) tuple.'''
 
     if resp[:3] != '227':
         raise error_reply, resp
-    left = resp.find('(')
-    if left < 0: raise error_proto, resp
-    right = resp.find(')', left + 1)
-    if right < 0:
-        raise error_proto, resp # should contain '(h1,h2,h3,h4,p1,p2)'
-    numbers = resp[left+1:right].split(',')
-    if len(numbers) != 6:
+    global _227_re
+    if _227_re is None:
+        import re
+        _227_re = re.compile(r'(\d+),(\d+),(\d+),(\d+),(\d+),(\d+)')
+    m = _227_re.search(resp)
+    if not m:
         raise error_proto, resp
+    numbers = m.groups()
     host = '.'.join(numbers[:4])
     port = (int(numbers[4]) << 8) + int(numbers[5])
     return host, port
