Re: CLOEXEC safety

[Sean Conner <sean@...>]

It was thus said that the Great Daurnimator once stated:
> Hi all,
> 
> I've been thinking about safely spawning processes in a multithreaded
> program lately.
> The opinion of POSIX seems to be that `closefrom` is wrong, and that
> well-written programs and libraries should always open fd with
> O_CLOEXEC set from the start.
> To aid this, the "e" specifier to fopen (currently a gnu extension) is
> to be featured in the next POSIX standard.
> This "e" flag has been widely supported by libcs on posix systems for
> many years.
> This same feature is available on windows as the "N" flag to fopen.
> 
> To prevent issues in multi-threaded applications that use lua,
> I suggest that lua automatically append the relevant flag to the fopen 'mode'.
> i.e. "e" on POSIX systems and "N" on windows.

  And what if I *want* to pass an open file to a child process?  How do I
specify to Lua that I *don't* want this behavior?

  -spc (or is stdin, stdout and stderr only allowed to remain open in a
	child process?)