Cron Job

Check whether cron daemon is running:

pgrep cron

If you see no number, then cron is not running. sudo /etc/init.d/cron start can be used to start cron.

Rather than invoking init scripts through /etc/init.d, use the service utility, e.g.

sudo service cron start

Launch cron daemon

First check whether cron is running. Launch it if not.

re='^[0-9]+$'
cronpid=`pgrep cron`
if ! [[ $cronpid =~ $re ]] ; then
   service cron start > /dev/null 2>&1
fi