Crontab注意事项

m h dom mon dow分别代表了：
# m------------ minute (0 - 59)
# h------------ hour (0 - 23)
# dom------------day of month (1 - 31)
# mon----------- month (1 - 12) OR jan,feb,mar,apr ...
# dow------------ day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
#
# * * * * * command to be executed
时间调度表格

Entry	Description	Equivalent To
@reboot	Run once, at startup.	None
@yearly	Run once a year	0 0 1 1 *
@annually	(same as @yearly)	0 0 1 1 *
@monthly	Run once a month	0 0 1 * *
@weekly	Run once a week	0 0 * * 0
@daily	Run once a day	0 0 * * *
@midnight	(same as @daily)	0 0 * * *
@hourly	Run once an hour	0 * * * *

在crontab中直接执行二进制命令，需要在后面添加>/dev/null 2>&1