Linux add a scheduled task

archlinux install cron

# pacman -S cronie

 

Example:

CentOS system restart want to 3:00 every day

Open the / etc / crontab add

# vi /etc/crontab

==================================

0  3 * * *  root   reboot

Then restart the crond service

# systemctl restart crond.service

 

1. * represent all the values that match the rules 
2.   1 -4 4 represents an integer of 1, 2 , 3 , 4 
3, a series of spaced specify a list of example values: 1 , 6 , 3 , 7 
4 / can be defined frequency interval, included 0- 59 every two minutes, can also use * / / 2 represents 2 once every two months later run command says if the month