On Tue, Jun 14, 2016 at 12:13:12PM +0200, Irrwahn wrote:

[cut]

>
> Well, I was thinking about being able to shutdown or
> reboot the machine by sending signals to PID1. I am
> however aware it's debatable if that can still be
> considered a sane concept in the 21st century.
>
> And TBH, starting a shell from init via a call to
> system() is an ugly hack to say the least. Probably
> okay for a proof-of-concept throw-away kludge, but
> nothing more.

And that was exactly my point. Playing with a shell script (or a C
code, for that matter), and making something that calls rc might be
somehow istructive and fun, but it should be clear that this is not
"creating a simple OS initialiser" which can be used outside of a
sandbox.

Before coding an init system, I would probably start with coding a
shell, with basic command execution, environment management,
background processes, a few builtins, I/O redirection, pipes, and
proper signal management. That is a really instructive and fun
exercise, IMHO, but I admit that the definition of "instructive" and
"fun" is quite subjective :)

My2Cents

KatolaZ

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