如何异步运行PHP代码

Question

How can I run PHP code asynchronously without waiting? I have a long run (almost infinite) that should run while server starts and should process asynchronously without waiting.

The possible options I guess are:

1. Running the code in a web page and keep it open to do that task
2. Calling the script from some command line utility (I am not sure how) which would process in the background.

I am running the PHP scripts on my local server which will send emails when certain events occur, eg birthday reminders.

Please suggest how can I achieve this without opening the page in a browser.

Answer 1

If you wanted to run it from the browser (perhaps you're not familiar with the command line) you could still do it. I researched many solutions for this a few months ago and the most reliable and simplest to implement was the following from How to post an asynchronous HTTP request in PHP

<?php


$params['my_param'] = $a_value;
post_async('http:://localhost/batch/myjob.php', $params);

/*
 * Executes a PHP page asynchronously so the current page does not have to wait for it to     finish running.
 *  
 */
function post_async($url, array $params)
{
    foreach ($params as $key => &$val) {
      if (is_array($val)) $val = implode(',', $val);
        $post_params[] = $key.'='.urlencode($val);  
    }
    $post_string = implode('&', $post_params);

    $parts=parse_url($url);

    $fp = fsockopen($parts['host'],
        isset($parts['port'])?$parts['port']:80,
        $errno, $errstr, 30);

    $out = "POST ".$parts['path']." HTTP/1.1\r\n";
    $out.= "Host: ".$parts['host']."\r\n";
    $out.= "Content-Type: application/x-www-form-urlencoded\r\n";
    $out.= "Content-Length: ".strlen($post_string)."\r\n";
    $out.= "Connection: Close\r\n\r\n";
    if (isset($post_string)) $out.= $post_string;

    fwrite($fp, $out);
    fclose($fp);
}

Let's say the file above is in your web root directory ( /var/www ) for example and is called runjobs.php. By visiting http://localhost/runjobs.php your myjob.php file would start to run. You'd probably want to add some output to the browser to let you know it was submitted successfully and it wouldn't hurt to add some security if your web server is open to the rest of the world. One nice thing about this solution if you add some security is that you can start the job anywhere you can find a browser.

Answer 2

Definitely sounds like a job for a cron task. You can set up a php script to do your task once and have the cron run as often as you like. Here's a good writeup on how to have a php script run as a cron task; it's very easy to do.

Answer 3

thanks Todd Chaffee but it is not working for me so i edited your code i hope you will not mind and may be it will also help others with this technique

cornjobpage.php //mainpage

     <?php
//if you want to call page for multiples time w.r.t array 
//then uncomment loop start & end)
?>

<?php
//foreach ($inputkeywordsArr as $singleKeyword) {
    $url="http://localhost/projectname/testpage.php";
        $params['Keywordname'] = "testValue";//$singleKeyword 
        post_async($url, $params);

        //}//foreach ($inputkeywordsArr end
        ?>
        <?php

        /*
         * Executes a PHP page asynchronously so the current page does not have to wait for it to     finish running.
         *  
         */
        function post_async($url, array $params)
        {
            foreach ($params as $key => &$val) {
              if (is_array($val)) $val = implode(',', $val);
                $post_params[] = $key.'='.urlencode($val);  
            }
            $post_string = implode('&', $post_params);

            $parts=parse_url($url);

            $fp = fsockopen($parts['host'],
                isset($parts['port'])?$parts['port']:80,
                $errno, $errstr, 30);

            $out = "GET ".$parts['path']."?$post_string"." HTTP/1.1\r\n";//you can use POST instead of GET if you like
            $out.= "Host: ".$parts['host']."\r\n";
            $out.= "Content-Type: application/x-www-form-urlencoded\r\n";
            $out.= "Content-Length: ".strlen($post_string)."\r\n";
            $out.= "Connection: Close\r\n\r\n";
            fwrite($fp, $out);
            fclose($fp);
        }
        ?>

testpage.php

    <?
    echo $_REQUEST["Keywordname"];//Output > testValue
    ?>

Answer 4

This isn't really what PHP is designed for. You have to use the PECL threading library to spin off threads that run asynchronously, and I don't recommend it. The new hotness in the async department is node.js - I recommend you look into that and see if you can utilize it. It's designed for light weight, asynchronous network operations, and can be used to fire PHP scripts.

Answer 5

How Can I run PHP code asynchronously without waiting. I have a long run (almost inifinite) that should run while server starts and should process asynchrously without waiting.

Assuming a typical LAMP system, you can start a PHP daemon from the command line with

root# php yourscript.php &

where yourscript.php contains something similar to

<?php

$log = fopen('/var/log/yourscript.log', 'a+');
// ### check if we are running already omitted
while(true) {
    // do interesting stuff and log it.

    // don't be a CPU hog
    sleep(1);
}
?>

Embellishments: To make your script directly executable: chmod +x yourscript.php and add #!/usr/bin/php to the beginning of yourscript

To start with apache, you should add that command to your apache startup script (usually apachectl) and be sure to add code to kill it when apache stops.

The check if you are already running involves a file with your PID in /var/locks/ and something like system('/bin/ps '.$thePID); It also makes the kill instruction easier to write.