[Python-Dev] PEP 433: Choose the default value of the new cloexec parameter

[Antoine Pitrou]

Le Fri, 25 Jan 2013 12:28:10 +0100,
Victor Stinner <victor.stinner at gmail.com> a écrit :
> > I think the default behaviour needs to be configurable from the
> > environment and the command line, but I don't believe it should be
> > configurable from within the interpreter.
> 
> sys.setdefaultcloexec() is convinient for unit test, but it may also
> be used by modules. A web framework may want to enable close-on-exec
> flag by default.
> 
> The drawback of changing the default value after Python started is
> that Python may have created file descriptors before, so you cannot
> guarantee that all existing file descriptors have the flag set.
> 
> Well, I don't know if sys.setdefaultcloexec() is a good idea or
> not :-)

Both Charles-François and Nick have good points.
sys.setdefaultcloexec() is still useful if you want to force the
policy from a Python script's toplevel (it's more practical than
trying to fit a command-line option in the shebang line).

Regards

Antoine.