Which init System?

[Trevor]

Systemd is the init system used by the great majority of modern Linux 
distributions - certainly is the case with Red Hat Enterprise Linux (RHEL).

There are various ways (commands) to discover if systemd is the init
system being used on a RHEL system.  So commands that will display 
that information are:

#  ps  -p  1  -o  comm=                ->  I really like this one

#  pstree  -p  1

#  cat   /proc/1/comm

#  systemctl  --version

Are there any other COMMANDS that will show that systemd is the
init system being used on the system?

[Chetan_Tiwary_]

@Trevor you have given the most frequently used ones. Anyways, trying to do the same from reverse engineering method :

[Chetan_Tiwary_]

one more : from /sbin/init itself :)D

and ofcourse TOP command :

[Trevor]

I'll disclose even one more on Wednesday - if no one delivers before then!