duct.py

Notably, this adds the new pidfd_spawn, pidfd_spawp, and pidfd_getpid functions, which should fix the PID race problem, as discussed here: <https://github.com/oconnor663/duct.py/blob/master/gotchas.md...>

If anyone can suggest an update to https://github.com/oconnor663/duct.py/blob/master/gotchas.md..., please let me know. As far as I'm aware, there's still no reliable way to kill a tree of processes on Unix that's suitable for library code.

I'm going to shamelessly plug my own library here: https://github.com/oconnor663/duct.rs I wanted to solve the same problem, originally in Python (https://github.com/oconnor663/duct.py). It's surprisingly annoying to do pipelines and redirections, compared to how easy they are to do in the shell. Lots of libraries try to address this, but most of them seem do it by emulating shell syntax within the host language, using operator overloading or other magic like that. I think that's a limiting choice. (For example, can you use `cd` to change the working dir for the left half of a pipeline but not the right half? In Bash you would use a "subshell" for this.) Instead, I think it's sufficient to build an API out of regular objects with regular methods. The result doesn't look like shell code, but it's easier to reason about, and more consistent