systemd detection does not work on Arch Linux

[blueyed]

I have noticed that HAVE_SYSTEMD=$(shell grep -q systemd /proc/1/cmdline && echo "y") from the Makefile does not work on Arch Linux, where it contains /sbin/init, which then is a symlink:

/sbin/init -> ../lib/systemd/systemd*

The following would work:
[[ $(readlink -f $(cat /proc/1/cmdline)) == *systemd* ]]

A better method (from http://unix.stackexchange.com/a/164092/1920) might be [[systemctl=~ -\.mount ]] or something similar though.

[phillipberndt]

IMO, your solution is the cleaner one. AFAIK, =~ is bash specific. Also, it is not clear to me what systemctl would output if systemd was not actually in use? For now, I'll apply your fix.