[serbuvlad]

Ok, but there's nothing stopping from writing a "discoverable" GUI or TUI or CLI for this interaction.

To the user it doesn't matter.

To the developer, it makes a difference.

/proc/<pid>/ctl is not any more or less simple or discoverable for the end user than TerminateProcess or kill(2). It's all opaque esoteric stuff.

But for the developer /proc/<pid>/ctl is MORE discoverable than TerminateProcess or kill(2), since it's a file you can list, so you know it exists. Yeah, you still have to read the man page (you always have to read the docs as a developer), but you know there's a ctl file that probably controls some stuff about the process there. And you already know how to interact with it (the same IO interface as everything else).

[calvinmorrison]

Of course. But it's not implemented. The OS is the spec.