i found out it is under
"usr/lib/systemd/system/acpid.service"
Are you trying to use a service coming from System:D?On Obarun, really?! it was a good joke XD.
About acpid, try this
# pacman -S acpid-s6serv
# s6opts enable acpid
About difference between xxx-s6rcserv and xxx-s6serv service package. s6rcserv are for s6-rc service and s6serv are for s6 service.
Well when you need to start/create a daemon after or before an another daemon , use s6-rc service. This is exactly the purpose of those service, handling dependencies between services. When you need to handle some stuff like the creation of a directory use s6-rc (in particular oneshot service). The boot (i talk about the boot process) of Obarun is entirely made by a collection of s6-rc services; so you have a lot of example of different type of s6rc service in e.g. /etc/s6/rc directory.(the majorities are oneshot service execpt for udevd part which is longrun)
When you need to simply start/create a daemon like e.g. acpid which do not require e.g the creation of directory or starting an other service before it, use s6 service. I call this kind of service "classic" service (arbitrary name here for Obarun). For example the tty service is a classic service.
cups-s6service and cups-s6rcservice
no difference between the daemon/service itself but the manner to use.
for s6serv
# s6opts enable cups
for s6rcserv
# s6opts update cups-s6rcserv
this is an ergonomic choice. For example you can have a bundle containing the service to use a printer like the cups daemon and maybe some server daemon if you use shared printer. So you can use/start the bundle when you need it and stop it right after your use. Well, just an ergonomic choice to provide the same package in both format, nothing more.
An s6serv format can be converted to s6rcserv format but the contrary is not true(or with a ton of difficultly depending of the daemon to convert)
Permit a depedency tree? Do I need both?
no, use one of them
Do I need the alsa rc service to use my mic and playback simultaneously?
coming from alsactl manpage
DESCRIPTION
alsactl is used to control advanced settings for the ALSA soundcard
drivers. It supports multiple soundcards. If your card has features
that you can't seem to control from a mixer application, you have come
to the right place.
So, what do you think? ;)