[CentOS] Running a command at startup

Thu Dec 13 13:17:24 UTC 2018
Jonathan Billings <billings at negate.org>

On Wed, Dec 12, 2018 at 09:43:56PM -0500, Robert Moskowitz wrote:
> OK....
> I have had problems in the past with crontab parsing a command. Would I use:
> @reboot root echo none | tee /sys/class/leds/blue\:heartbeat/trigger
> ?
> Or do I have to make a script and run that?

Since this is a crontab, you can use normal shell redirection:

@reboot root echo none > /sys/class/leds/blue\:heartbeat/trigger

in a file in /etc/cron.d/

The 'echo foo | sudo tee' thing is what you do for people who are
using sudo to echo output into a file -- so often people think they
can do 'sudo echo none > /some/path' and will be surprised it doesn't

I still think it makes sense to create it as a systemd unit.

Jonathan Billings <billings at negate.org>