/proc/[pid]/comm is available since Linux 2.6.33 so
we should be able to rely on that.
Inside /proc/1/cmdline might end up additional boot options,
e.g. when booting with "nocolor" boot option it ends up as
"/sbin/initnocolor" and then our check breaks.
# Ignore these signals in non-interactive mode: INT, TERM, SEGV
[ -z "$PS1" ] && trap "" 2 3 11
# Ignore these signals in non-interactive mode: INT, TERM, SEGV
[ -z "$PS1" ] && trap "" 2 3 11
-if [[ "$(realpath "$(cat /proc/1/cmdline)")" == "/lib/systemd/systemd" ]] ; then
+if [ "$(cat /proc/1/comm 2>/dev/null)" = "systemd" ] ; then
SYSTEMD=true
else
SYSTEMD=false
SYSTEMD=true
else
SYSTEMD=false