On Tue, 12 Mar 2013 17:18:43 -0400, Lars T. Kyllingstad
<[email protected]> wrote:
On Tuesday, 12 March 2013 at 14:10:34 UTC, Steven Schveighoffer wrote:
On Tue, 12 Mar 2013 03:31:30 -0400, Lars T. Kyllingstad
<[email protected]> wrote:
If you omit the AA parameter altogether, the child inherits the
parent's environment. A null pointer is passed as 'envz' to
spawnProcessImpl(), which in turn passes this straight to
CreateProcess() on Windows and replaces it by 'environ' on POSIX.
If you do specify the AA parameter, it is passed through toEnvz() on
its way to spawnProcessImpl(). If the AA is empty/null, toEnvz() will
create an empty (but non-null) environment block, and the child's
environment will be empty.
I understand that point. I am a little concerned, however, that
passing null as env results in clearing the child environment. These
concerns are simply that the most common desire is to inherit the
environment, and that there is no parameter that simply says "inherit
parent environment," you have to call a different function.
I'd be very interested to hear if you have a suggestion for a better way
to do it, keeping in mind that there needs to be *some* way to clear the
environment too.
Sadly, no I don't. I had hoped [] would allocate an empty AA, but it
fails to compile.
Note that you can "hack" it by setting a single environment variable which
nobody will ever use.
i.e. spawnProcess("blah.exe", ["_____":"_____"]);
But that is really, really ugly.
I suppose it's no different than exec, which you have to call the right
function depending on what you want.
So this sounds fine. The toEnvz still should be fixed to add an extra
null, I'm assuming you're doing that right? :)
Yes. I have some local modifications based on the discussion here,
which I haven't pushed yet. Waiting for you guys to finish debating the
file descriptor issue. ;)
I think all are in agreement at this point that closing the files between
fork and exec is a good solution. Whether or not to ALSO set F_CLOEXEC
wherever Phobos opens a file descriptor is an additional matter.
As a fallback to standard unix behavior, we can have a Config option that
says "don't do the close thing".
-Steve
