How to implement scheduled tasks in PHP?

We introduced to you the implementation principle of php scheduled tasks in our previous article. I believe that everyone understands the principle of php scheduled tasks, so today we will continue to introduce php to you. How to implement scheduled tasks!

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1. Windows plan Task

1. Write a PHP program, named test.php, and the content is as follows

##

<?   
    $fp = fopen("test.txt", "a+");   
    fwrite($fp, date("Y-m-d H:i:s") . " 成功成功了！\n");   
    fclose($fp);   
?>

Write the program boldly, you can use any include\require, no problem

2. Create a new

Bat file and name it test.bat, The content is as follows:

D:\php\php.exe -q D:\website\test.php

3. Create a WINDOWS scheduled task:

Start–>Control Panel–>Task Schedule–>Add Task Plan

Browse the folder and select the above

bat file

Set the time and password (log in to WINDOWS)

Save it.

4. over! You can right-click the scheduled task and click "Run" to try

2. Linux script implementation

1. In

Using PHP to execute scripts in Crontab

is just like calling ordinary shell scripts in Crontab (specific Crontab usage), using PHP programs to call PHP scripts.

Executed every hour

myscript.php is as follows:

# crontab -e  
00 * * * * /usr/local/bin/php /home/john/myscript.php

/usr/local/bin/php is the path of the PHP program.

2. Use URL to execute scripts in Crontab

If your PHP script can be triggered by URL, you can use lynx or curl or wget to configure your Crontab .

The following example uses a Lynx text browser to access a URL to execute a PHP script every hour. Lynx text browser uses conversational mode to open URLs by default. However, as shown below, I use the

-dump option in the lynx command line to convert the URL output to standard output.

00 * * * * lynx -dump http:
//www.centos.bz/myscript.php

The following example is to use CURL to access the URL to execute a PHP script every 5 minutes. Curl displays output on standard output by default. You can also dump the script's output to a temporary file using the "curl -o" option.

*/5 * * * * /usr/bin/curl -o temp.txt http:
//www.centos.bz/myscript.php

The following example uses WGET to access the URL to execute a PHP script every 10 minutes. The -q option indicates quiet mode. "-O temp.txt" means that the output will be sent to a temporary file

*/10 * * * * /usr/bin/wget -q -O temp.txt http:
//www.centos.bz/myscript.php

3. PHP implements scheduled execution of scheduled tasks

Using php to refresh the browser requires solving several problems

1. PHP script execution time limit, the default is

30m Solution: set_time_limit();Or modify PHP.ini settings max_execution_time time (not recommended)

2. If the client browser is closed, the program may be forced to terminate. Solution:

ignore_user_abortEven if the page is closed, it will still execute normally

3. If the program continues to execute, it is likely to consume a lot of resources. The solution is to use

sleepUse the program to sleep for a while. Then when executing the PHP scheduled execution code

<?php   
    ignore_user_abort();//关掉浏览器，PHP脚本也可以继续执行.   
    set_time_limit(3000);// 通过set_time_limit(0)可以让程序无限制的执行下去   
     $interval=5;// 每隔5s运行   
    
     //方法1--死循环   
     do{   
        echo &#39;测试&#39;.time().&#39;<br/>&#39;;    
        sleep($interval);// 等待5s       
    }while(true);   
    
    //方法2---sleep 定时执行   
     require_once &#39;./curlClass.php&#39;;//引入文件   
        
     $curl = new httpCurl();//实例化   
     $stime = $curl->getmicrotime();   
    for($i=0;$i<=10;$i++){   
            
        echo &#39;测试&#39;.time().&#39;<br/>&#39;;    
        sleep($interval);// 等待5s   
            
    }   
    ob_flush();   
    flush();   
    $etime = $curl->getmicrotime();   
    echo &#39;<hr>&#39;;   
    echo round(($etime-stime),4);//程序执行时间

, I found that the efficiency was not very high

Summary:

This article uses Windows scheduled tasks, Linux script implementation, and examples of PHP executing scheduled scheduled tasks, so that friends can have a more direct understanding of PHP scheduled scheduled tasks. I hope it will be helpful to you!

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Principle Analysis of Implementing Planned Tasks

php Scheduled Tasks and Continuous Processes (fsockopen) Example

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