Principle of PHP5 scheduled task offline function_PHP tutorial

In order to update a certain file regularly, the program needs to run automatically. I found two methods from the Internet: ignore_user_abort() and crontab

The ignore_user_abort() function can be used with set_time_limit(0) and sleep($interval) to realize automatic program running and updating. Here is an example

ignore_user_abort(); //Even if the Client is disconnected (such as closing the browser), the PHP script can continue to execute.

set_time_limit(0); // The execution time is unlimited. The default execution time of PHP is 30 seconds. Through set_time_limit(0), the program can be executed without limit

$interval=60*5; // Run every 5 minutes

do{

$fp = fopen(test.txt,a);

fwrite($fp,test);

fclose($fp);

sleep($interval); // Wait 5 minutes

}while(true);

?>

As long as you run the page above and then close it, the program will continue to run.

There is a simpler method under Linux, which is the crontab command

The function of the crontab command is to schedule the execution of some commands at a certain time interval.

How to use crontab: crontab [ -e | -l | -r ] file name -e: edit task -l: display task information -r: delete scheduled execution task information

crontab format:

* * * * * Command

Minute Hour Day Month Weekday Command to run

Example of crontab:

*/5 * * * * lynx http://www.BkJia.com

Visit www.2cto.com every 5 minutes

0 8 * * * lynx http://www.BkJia.com

Visit www.2cto.com at 8am every day

0 10 6 * 1-5 lynx http://www.BkJia.com

Visit www.2cto.com on the 6th of every month and every Monday to Friday at 10am

0 5 7 8 * lynx http://www.BkJia.com

Visit www.2cto.com at 5am on August 7

Special meanings of the above:

"*" represents all numbers within the value range, "/" represents every, "*/5" represents every 5 units, "-" represents from a certain number to a certain number,", "Separate several discrete numbers.

http://www.bkjia.com/PHPjc/486034.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/486034.htmlTechArticleIn order to update a certain file regularly, the program needs to run automatically. I found two methods from the Internet: ignore_user_abort() and crontab ignore_user_abort() function with set_time_limit(0) and sleep...