feat(win): process.kill / kill_with - add /t to kill tree (inc child …

[YOU54F]

…processes)

See related thread pact-foundation/pact-plugins#73 (comment)

We use sysinfo to kill child processes (plugins invoked from our framework written in rust), across platforms.

plugins on windows may use a batch script to invoke the plugin (my case in reference was a java project). When using this project and process.kill, only the parent process is removed, and not any child processes invoked from the batch script

Taskkill has an option /t

/t : Specifies to terminate all child processes along with the parent process, commonly known as a tree kill.

https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-xp/bb491009(v=technet.10)?redirectedfrom=MSDN

Passing this flag, allows child processes to also be killed and doesn't appear to have any detrimental effect on existing behaviour (if there are no child processes)

[GuillaumeGomez]

This is exactly the wanted behaviour. However, we can extend the API to make it kill children as well. Adding a kill_children: bool argument to both functions should be enough. But then on non-windows platforms, it'll require to go through processes recursively and kill them all one by one.

[YOU54F]

This is exactly the wanted behaviour.

Thanks for confirming 👍🏾

However, we can extend the API to make it kill children as well.

🙏🏾

kill_children: bool argument to both functions should be enough.

That sounds like a sensible proposal

But then on non-windows platforms, it'll require to go through processes recursively and kill them all one by one.

Ahhh, I didn't actually realise that unix based systems doesn't kill child processes, the reason why I hadn't noticed in my testing, is the particular java plugin uses https://github.com/sbt/sbt-native-packager which creates native wrapper scripts. In the bash script wrapper, they use exec to call the java process invoked in the script, which gets the parent PID, when this is killed, the script releases from the exec, grabs the exit code from that process and exits with that code. They even have a note on the exec command in the wrapper script

execRunner () {
  # print the arguments one to a line, quoting any containing spaces
  [[ $verbose || $debug ]] && echo "# Executing command line:" && {
    for arg; do
      if printf "%s\n" "$arg" | grep -q ' '; then
        printf "\"%s\"\n" "$arg"
      else
        printf "%s\n" "$arg"
      fi
    done
    echo ""
  }

  # we use "exec" here for our pids to be accurate.
  exec "$@"
}

I'll look to make the changes tomorrow