Difference between revisions of "Cron Service"
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| − | Dragino supports cron service which you can schedule your task to be executed | + | Dragino supports cron service which you can schedule your task to be executed periodically. |
| + | |||
| + | =Steps to use cron service= | ||
| + | *create file: '''/etc/crontabs/root''' | ||
| + | *modify /etc/crontabs/root for scheduling task, below is the format and example | ||
| + | #run script /root/test at 10 every hour | ||
| + | #format [min] [hour] [day of month] [month] [day of week] [program to be run] | ||
| + | 10 * * * * /bin/sh /root/test | ||
| + | *restart cron service | ||
| + | root@dragino-1a7f76:~# /etc/init.d/cron restart | ||
| + | |||
| + | =Explaination of the time format= | ||
| + | Variable Range: | ||
| + | {| class="wikitable" border="1" align="center" | ||
| + | |- | ||
| + | ! Variable | ||
| + | ! Description | ||
| + | |- | ||
| + | |[min] | ||
| + | |Minutes that program should be executed on. 0-59. Do not set as * or the program will be run once a minute. | ||
| + | |- | ||
| + | |[hour] | ||
| + | |Hour that program should be executed on. 0-23. * for every hour. | ||
| + | |- | ||
| + | |[day of month] | ||
| + | |Day of the month that process should be executed on. 1-31. * for every day. | ||
| + | |- | ||
| + | |[month] | ||
| + | |Month that program whould be executed on. 1-12 * for every month. | ||
| + | |- | ||
| + | |[day of week] | ||
| + | |Day of the week. 0-6 where Sunday = 0, Monday = 1, ...., Saturday = 6. * for every day of the week. | ||
| + | |- | ||
| + | |[program] | ||
| + | |Program to be executed. Include full path information. | ||
| + | |} | ||
| + | |||
| + | Use Operators: | ||
| + | {| class="wikitable" border="1" align="center" | ||
| + | |- | ||
| + | ! Operator | ||
| + | ! Function | ||
| + | |- | ||
| + | | Asterisk (*) | ||
| + | | Specifies all possible values for this field | ||
| + | |- | ||
| + | | Comma (,) | ||
| + | | Specifies a list of value for this field, for example, 1,5,6,8,10 | ||
| + | |- | ||
| + | | Dash (-) | ||
| + | | Specifies a range of value for this field, for example: 1-5 | ||
| + | |- | ||
| + | | Slash(/) | ||
| + | | Per , for example, */5, every 5 (minutes) | ||
| + | |} | ||
| + | |||
| + | =Examples= | ||
| + | * execute script at 8:30am every Monday To Friday | ||
| + | 30 8 * * 1-5 /bin/test | ||
| + | |||
| + | * execute script every 5 minutes | ||
| + | */5 * * * * /bin/test | ||
Latest revision as of 02:47, 2 May 2012
Dragino supports cron service which you can schedule your task to be executed periodically.
Steps to use cron service
- create file: /etc/crontabs/root
- modify /etc/crontabs/root for scheduling task, below is the format and example
#run script /root/test at 10 every hour #format [min] [hour] [day of month] [month] [day of week] [program to be run] 10 * * * * /bin/sh /root/test
- restart cron service
root@dragino-1a7f76:~# /etc/init.d/cron restart
Explaination of the time format
Variable Range:
| Variable | Description |
|---|---|
| [min] | Minutes that program should be executed on. 0-59. Do not set as * or the program will be run once a minute. |
| [hour] | Hour that program should be executed on. 0-23. * for every hour. |
| [day of month] | Day of the month that process should be executed on. 1-31. * for every day. |
| [month] | Month that program whould be executed on. 1-12 * for every month. |
| [day of week] | Day of the week. 0-6 where Sunday = 0, Monday = 1, ...., Saturday = 6. * for every day of the week. |
| [program] | Program to be executed. Include full path information. |
Use Operators:
| Operator | Function |
|---|---|
| Asterisk (*) | Specifies all possible values for this field |
| Comma (,) | Specifies a list of value for this field, for example, 1,5,6,8,10 |
| Dash (-) | Specifies a range of value for this field, for example: 1-5 |
| Slash(/) | Per , for example, */5, every 5 (minutes) |
Examples
- execute script at 8:30am every Monday To Friday
30 8 * * 1-5 /bin/test
- execute script every 5 minutes
*/5 * * * * /bin/test
