CODEWITHSUNDEEP
phpcurlbackground
AL-Kateb
AL-Kateb

Reputation: 2962

How do I run cURL request in the background in PHP?

I'm trying to build some kind of web based download manager using PHP and the cURL extension, I am stuck with one problem though, how can I download and save the file with cURL without having to make the user wait, meaning he will make the request and it will be processed in the background.

Now I can't use system calls (exec, system ... etc) as most of the hosts I work with disable these functions, and the other problem is the max execution time for PHP scripts, but I guess this one can be changed in .htaccess or using ini_set or can it not?

I've read somewhere that setting connect_timeout to 1 will work, but does not that terminate the connection?

One solution is to use cronjobs, after the users submits the file he wants to download, a cronjob will check the database and if there is a file in the queue it will start downloading it, but I thought I want to avoid using cron jobs if possible.

So back to the main question, is there a way to tell the php script to run some certain function in the background and delivering the response to the users regardless of the result of that function

Thanks

Upvotes: 8

Views: 24874

Answers (4)

Monkeypox
Monkeypox

Reputation: 61

        function background_curl_request($url, $method, $post_parameters){
            if (is_array($post_parameters)){
                $params = "";
                foreach ($post_parameters as $key=>$value){
                    $params .= $key."=".urlencode($value).'&';
                }
                $params = rtrim($params, "&");
            } else {
                $params = $post_parameters;
            }
            $command = "/usr/bin/curl -X '".$method."' -d '".$params."' --url '".$url."' >> /dev/shm/request.log 2> /dev/null &";
            exec($command);
        }

Upvotes: 5

user5175717
user5175717

Reputation: 101

My experience is to wrap your command correctly.

$time = microtime(true);
$command = '/usr/bin/curl -H \'Content-Type: application/json\' -d \'' . $curlPost . '\' --url \'' . $wholeUrl . '\' >> /dev/shm/request.log 2> /dev/null &';
exec($command);
echo (microtime(true) - $time) * 1000 . ' ms';

Above works well for me, takes only 3ms, but following won't work, takes 1500ms.

$time = microtime(true);
$command = '/usr/bin/curl -H \'Content-Type: application/json\' -d \'' . $curlPost . '\' --url ' . $wholeUrl;
exec($command . ' >> /dev/shm/request.log 2> /dev/null &');
echo (microtime(true) - $time) * 1000 . ' ms';

In total, adding " &> /dev/null &" at the end of your command could makes it running on background and don't hang the php and apache processes, just remember to WRAP your command properly.

Upvotes: 3

Aslam Sayyed
Aslam Sayyed

Reputation: 101

  1. Make simple curl request from php like below or ajax call using javascript

    $curl = curl_init('http://mutant-tech.com/execjob.php');
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
$result = curl_exec($curl);
echo $result; // should get - Closing Curl Request

  2. Close http connection using header at starting, later write php code to execute

    // File - execjob.php START
ob_end_clean();
header("Connection: close");
ignore_user_abort();
ob_start();
echo ('Closing Curl Request');
$size = ob_get_length();
header("Content-Length: $size");
ob_end_flush();
flush();
// BELOW YOUR BACKGROUND JOB/CODE

If you need more exec time / memory, use function accordingly

Upvotes: 4

joerx
joerx

Reputation: 2088

I think there have been other posts exploring the options already. Given your constraints, I see two other approaches:

Upvotes: 5

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