logoalt Hacker News

dcrazytoday at 6:46 PM1 replyview on HN

It’s such a bad idea that every OS except Linux implements it? On macOS it’s posix_spawn, on Windows it’s NtCreateProcess.


Replies

jerftoday at 7:01 PM

Who said anything about it being a "bad idea"?

I also explicitly said this wasn't unsolvable. My point isn't about technical implementations or code, my point is that the casual "I want to share nothing about the parent process" thought in sanderj's mind, and presumably a lot others, is much more ill-defined than they realize. There's a lot more state that a process has than what file descriptors are open in a modern system.

Moreover, as things like "in which container is this running" demonstrate, those are also not "create a process that has nothing to do with this process", because, again, there's a lot more to "having to do with this process" than "what file descriptors are open".

Also, as the name might have been a clue, Linux has posix_spawn: https://linux.die.net/man/3/posix_spawn. It also has a thing called "clone": https://www.man7.org/linux/man-pages/man2/clone.2.html Nor do I claim this paragraph is an entire overview of all the ways of starting a process in Linux. If you want to understand what I mean by "lots of details in a modern OS", your assignment is to carefully read the entire "clone" man page, and you'll start to see what I mean, though I'm not sure even that is all the state associated with a process nowadays.

show 2 replies