poplib for multihomed machines

[Donn Cave]

In article <9418be08.0406280751.6cc50097 at posting.google.com>,
 elbertlev at hotmail.com (Elbert Lev) wrote:

> There no way to tell the classPOP3 which of local interfaces (NICs) to
> use for connections). In most cases it is OK, but requires proper
> routing.
> 
> Here is the __init__ from POP3
> 
> class POP3
>     def __init__(self, host, port = POP3_PORT):
>         self.host = host
>         self.port = port
>         msg = "getaddrinfo returns an empty list"
>         self.sock = None
>         for res in socket.getaddrinfo(self.host, self.port, 0,
> socket.SOCK_STREAM):
>             af, socktype, proto, canonname, sa = res
>             try:
>                 self.sock = socket.socket(af, socktype, proto)
>                 self.sock.connect(sa)
>             except socket.error, msg:
>                 if self.sock:
>                     self.sock.close()
>                 self.sock = None
>                 continue
>             break
>         if not self.sock:
>             raise socket.error, msg
>         self.file = self.sock.makefile('rb')
>         self._debugging = 0
>         self.welcome = self._getresp()
> 
> Can I subclass it in such a way, that derived class takes care of the
> problem?
> 
> def __init__ (self, host, port = POP3_PORT, interface = ""):
> 	POP3.__init..(....)
> 	
> 	will create the socket and there is no way to bind it to local
> interface
> 	
> 
> The problem with POP3 class is: it connects during __init__ and it is
> "hard coded". I do not see any way to change this behavior with no
> rewrite of POP3 class.
> 
> Do you?

Well, no.  It should probably use an open() method like imaplib's.

   Donn Cave, donn at u.washington.edu