Ubuntu16 installing cron and using

Https://www.cnblogs.com/intval/p/5763929.html

sudo apt-get install cron

Start cron

sudo service cron start

View all cron services on this computer

Ls-l/ETC/INIT.D

Edit a file: User name +cron

*/2 * * * * Date >>/home/postgres/time.log

Enter the above content,

Then: Wq

Then service cron Restart

In a minute, the current time is printed to the Time.log

# m H Dom Mon Dow command

M min 0-59

H hours 0-23

Dow Day 1-31

Mon month 1-12

Dow Week 1-6 0 indicates Sunday

command is the order to execute.

Example 1: command is executed every 1 minutes
Command:
* * * * * command

Example 2:3rd and 15 minutes per hour of execution
Command:
3,15 * * * command

Example 3: Execution at 3rd and 15 minutes from 8 o'clock in the morning to 11.
Command:
3,15 8-11 * * command

Example 4:3rd and 15 minutes of every two-day 8 o'clock in the morning to 11-point execution
Command:
3,15 8-11 */2 * command

Example 5:3rd and 15 minutes of each Monday from 8 o'clock in the morning to 11.
Command:
3,15 8-11 * * 1 command

Example 6:21:30 restart of SMB per night
Command:
* * * * */ETC/INIT.D/SMB restart

Example 7:4:45 restart SMB per month for 1, 10, 22nd
Command:
4 1,10,22 * */ETC/INIT.D/SMB restart

Example 8:1:10 restart SMB per Saturday, Sunday
Command:
1 * * 6,0/ETC/INIT.D/SMB restart

Example 9: Restart SMB every 30 minutes from 18:00 to 23:00 daily
Command:
0,30 18-23 * * */ETC/INIT.D/SMB restart

Example 10: Every Saturday night at 11:00am restart SMB
Command:
0 * * 6/ETC/INIT.D/SMB restart

Example 11: Restart SMB every hour
Command:
* */1 * * * */ETC/INIT.D/SMB restart

Example 12: Restart SMB every hour from 11 o'clock to 7 in the morning
Command:
* 23-7/1 * * * */ETC/INIT.D/SMB restart

Example 13:4th per month with 11 points per Monday to Wednesday restart SMB
Command:
0 4 * MON-WED/ETC/INIT.D/SMB restart

Example 14:4-point restart of SMB on January 1
Command:
0 4 1 Jan */ETC/INIT.D/SMB restart

Example 15: Execution of scripts within/etc/cron.hourly directory per hour
Command:
* * * * * Root run-parts/etc/cron.hourly
Description
Run-parts This parameter, if you remove this parameter, you can write a script name to run, not the directory name.

Ubuntu16 installing cron and using