First, add sheel script
1, first create an executive program: vim a.sh
2, editor: #! / bin / the bash
to python3 python.py test2.log >> 2> &. 1
3, add the permission: chmod + x ./a.sh
4, view the execution results: ./a.sh
Second, add regular tasks
Installation: apt-get install cron (default will be installed server environment)
1, crontab -e: Modify crontab file if the file does not exist will be created automatically.
2, crontab -l: Display a crontab file.
3, crontab -r: remove crontab files.
4, crontab -ir: crontab files before deleting alert the user.
6, cron file syntax:
Minute hour day month week command
0-59 0-23 1-31 1-12 0-6 command (range, 0 represents a line generally corresponding to a task on Sunday)
"*" Representatives within the range of numbers,
"/" Stands for "every"
"-" represents the numbers from one to a certain number,
"" Several separate discrete digital
7, / sbin / service crond start // Start Service
/ Sbin / service crond stop // shut down service
/ Sbin / service crond restart // restart the service
/ Sbin / service crond reload // reload the configuration
14 Super practical examples of the use of Crontab
1. 02:00 daily tasks
0 2 * * * /bin/sh backup.sh
5:00 and 17:00 2. day mission
0 5,17 * * * /scripts/script.sh
3. Perform the task once per minute
* * * * * /scripts/script.sh
4. Every Sunday 17:00 mission
0 17 * * sun /scripts/script.sh
5. Each 10min perform a task
*/10 * * * * /scripts/monitor.sh
6. perform tasks in particular a few months
* * * jan,may,aug * /script/script.sh
7. In particular certain days of the mission
0 17 * * sun,fri /script/scripy.sh
Every Friday, Sunday 17:00 to perform tasks
8. perform tasks in the first Sunday of a month
0 2 * * sun [ $(date +%d) -le 07 ] && /script/script.sh
9. every four hours to perform a task
0 */4 * * * /scripts/script.sh
10. Monday, Sunday mission
0 4,17 * * sun,mon /scripts/script.sh
11. Each 30 seconds to perform a task
We have no direct way to perform a similar example of Appeal, since the minimum is 1min. However, we can adopt the following method.
-
* * * * * /scripts/script.sh
-
* * * * * sleep 30; /scripts/script.sh
Arranged in a plurality of tasks 12. The command
* * * * * /scripts/script.sh; /scripts/scrit2.sh
13. perform tasks once a year
@yearly /scripts/script.sh
@yearly like "0011 *." It will be performed within the first minute of each year, usually we can use this to send New Year's greetings.
14. The system performs reboot
@reboot /scripts/script.sh