If I want to add lines to my system's /etc/crontab, what do I have to do to get them to take effect?
Background:
I'm trying to set up a machine with Ubuntu 13.04 so that it automatically locks/unlocks the monitor during the workday (it's hanging on the wall).
I've done this by adding the following to my /etc/crontab:
00 18 * * mon-fri myuser export DISPLAY:=0 && gnome-screensaver-command -a
00 18 * * mon-fri myuser export DISPLAY:=0 && xset dpms force standby
00 08 * * mon-fri myuser export DISPLAY:=0 && gnome-screensaver-command -d
00 08 * * mon-fri myuser export DISPLAY:=0 && xset dpms force on
The individual commands work fine, but I'm trying to test the crontab entries by setting the minute/day to the upcoming minute. For example, at 1:26PM I set the first two columns to 27 13 and waited until the next minute rolled around. But the commands don't appear to be getting executed. I also tried running sudo crontab /etc/crontab
, but it doesn't seem to help.