Re: proced: ppid of process ID 0 can be 0

[Harald Hanche-Olsen <hanche@math.ntnu.no>]

+ Eli Zaretskii <eliz@gnu.org>:

>> I.e. under POSIX, they should treat a "ppid == 0" as meaning that
>> there's no parent (i.e. the data returned to Elisp should never say "the
>> parent is process 0" but should instead say "this process doesn't have
>> a parent").
> 
> [...]
> 
> Btw, is the above really mandated by Posix?  Any references to that?

FWIW, on FreeBSD there is process 0 (the swapper), and various kernel
processes have process 0 as their parent.

; pstree 0
-+= 00000 root [swapper]
 |-+= 00001 root /sbin/init --
 | |--= 00354 _dhcp dhclient: em0 (dhclient)
 | |--= 00623 root /sbin/devd
.... <snip> ....
 |--- 00002 root [g_event]
 |--- 00003 root [g_up]
 |--- 00004 root [g_down]
 |--- 00005 root [system_taskq]
 |--- 00006 root [system_taskq]
 |--- 00007 root [acpi_task_0]
.... <snipetty snip> ....

Of course, it may be that you really don't want emacs to see kernel
processes at all.

- Harald