[docs] socket.fileno() documentation
vlado at poti.sk
Thu Oct 10 19:27:35 CEST 2013
I might be wrong but in my opinion the socket library documentation is not
clear enough regarding the behaviour of the fileno() method in a case of a
In the Python 3.2 socket library documentation there is:
A subclass of IOError, this exception is raised for socket-related errors.
Close the socket. All future operations on the socket object will fail.
Return the socket’s file descriptor (a small integer).
Based on the information quoted above, I wrote a test if a socket is active or
if it has been closed already:
But is doesn't work. I have found out that fileno() returns -1 on a closed
socket. Replacing fileno() with e.g. getsockname() fixes the code.
It looks like a fileno's failure - unlike to getsockname's failure - is not
expressed by raising an exception, but by returning -1. However this seems to
be not documented and that's why I'm unsure if I may rely on this.
More information about the docs