Split OS.execute into blocking and non-blocking method

[mhilbrunner]

See #19056

[akien-mga]

Duplicate of #18919.

[neikeq]

Is this really a duplicate of #18919. It doesn't look like to me.

[akien-mga]

Well it seemed to me that what is described in #18919 basically implies what this issue here suggests, and as such I had mentioned in #19056 that we could use #18919 to keep track of this proposal.

But if you prefer to use this issue for that, I'm fine with it. It likely needs some more context in the OP though.

[romeojulietthotel]

I see mention of breaking compatibility but why would fixing this break compatibility?

[akien-mga]

Because unless we write two new methods and keep the old OS.execute() unmodified (and thus still broken as it is now), we would need to modify the OS.execute() API (remove it or change its behaviour), and thus break the compatibility.

[romeojulietthotel]

But why do you think OS.execute would need to be modified in a way that would make it incompatible? Your assertions are unclear.

Using posix_spawn should provide a suitable fix for this. I played with it and it would even provide some extra functionality if we wanted.

[neikeq]

@romeojulietthotel This is the method signature for OS.execute: http://docs.godotengine.org/en/3.0/classes/class_os.html#class-os-execute
The bool blocking argument would need to be removed, which breaks compatibility.

[SubSage]

I have a pr that could be helpful with all of this, if anyone wants to double check the pr and make sure it works, feel free : #26462