Re: Faking a TTY on a pipe/socketpair

On 2024-12-10, Muttley@DastardlyHQ.org <Muttley@DastardlyHQ.org> wrote:

On Tue, 10 Dec 2024 08:50:20 +0000
Richard Kettlewell <invalid@invalid.invalid> wibbled:

Jim Jackson <jj@franjam.org.uk> writes:

On 2024-12-05, Lawrence D'Oliveiro <ldo@nz.invalid> wrote:

What ???single task??? did init do?
>
* Mount filesystems
* Spawn syslog, cron
* Spawn terminal login processes (getty)
* Respawn terminated getty processes
* Monitor other special stuff in inittab
* Spawn random other services, without monitoring their state
* Act as a general catch-all for orphaned processes when they terminate
>
This was all before systemd came on the scene.

>
Actually traditional Unix "init" didn't do ALL those things. Most
tended to have the inittab config file. Even busybox's init has.

>
Depends if you mean init=/sbin/init or init=the entire sysvinit system.
If you(plural) are going talk about init systems then you need to agree
terms.

Yes of course. But he did mention "init" which I take to mean pid 1.

Its probably fair to say that because the traditional init system uses
shell scripts and hence can do anything you like they often did. But the
core part should really just be limited to starting the machine and getting
enough things running for a user to log on (or if its a black box to do its
task).

Doesn't have to be shell scripts - init just launched programs, e.g.
getty on serial lines, etc.

I think Android init does quite a bit more.