how to know if socket is still connected

[nephish at xit.net]

ok, yeah, thats in my book.
thanks, and no, it isn't enabled.
thanks again for everything
-sk


Grant Edwards wrote:
> On 2006-07-17, nephish at xit.net <nephish at xit.net> wrote:
> >> If the server _application_ crashes or exits, then the OS will
> >> close the socket and recv() will return "".  If somebody powers
> >> down the server without warning, or if the server OS crashes,
> >> or if the Ethernet cable between the Internet and the server is
> >> cut, then the socket will not be closed, and recv() will wait
> >> forever[1].
> >
> > Ok, yes all of the above is what i mean. Actually I am not too
> > concerned about a server os crash, or the cable being cut. But I have
> > had them close the connection on me, after which i just reconnect
> > (whenever i discover that its happened)
> >
> >>[1] Unless you've enabled the TCP Keepalive feature, in which
> >>    case the socket will timeout in a couple hours and recv()
> >>    will return "".
> >
> > if this is something that must be enabled, or is not enabled by
> > default, then it is not enabled.
>
> On all OSes with which I'm familiar it's disabled by default.
> You use a socket object's setsockopt method to enable it:
>
> s.setsockopt(socket.SOL_TCP,socket.SO_KEEPALIVE,True)
>
> --
> Grant Edwards                   grante             Yow!  Wow! Look!! A stray
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