vi /etc/crontab

SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/

# For details see man 4 crontabs

# Example of job definition:
# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# |  |  |  |  |
# *  *  *  *  * user-name  command to be executed

*/30 * * * * root /usr/bin/python /home/play.py >> /home/log/crontab_`date +\%Y-\%m-\%d_\%H\%M`.log 2>&1
30분마다 실행


*  */1 * * *  1시간마다 실행
*/5  * * * *  5분마다 실행

---------------------------------------------------------------------------------------
/bin/systemctl stop crond.service
/bin/systemctl restart crond.service
/bin/systemctl start crond.service

* 로고정보
cat /var/log/cron


#crontab