How do I make an asynchronous GET request in PHP?

Question

I wish to make a simple GET request to another script on a different server. How do I do this?

In one case, I just need to request an external script without the need for any output.

make_request('http://www.externalsite.com/script1.php?variable=45'); //example usage

In the second case, I need to get the text output.

$output = make_request('http://www.externalsite.com/script2.php?variable=45');
echo $output; //string output

To be honest, I do not want to mess around with CURL as this isn't really the job of CURL. I also do not want to make use of http_get as I do not have the PECL extensions.

Would fsockopen work? If so, how do I do this without reading in the contents of the file? Is there no other way?

Thanks all

Update

I should of added, in the first case, I do not want to wait for the script to return anything. As I understand file_get_contents() will wait for the page to load fully etc?

Answer 1

I would recommend you well tested PHP library: curl-easy

<?php
$request = new cURL\Request('http://www.externalsite.com/script2.php?variable=45');
$request->getOptions()
    ->set(CURLOPT_TIMEOUT, 5)
    ->set(CURLOPT_RETURNTRANSFER, true);

// add callback when the request will be completed
$request->addListener('complete', function (cURL\Event $event) {
    $response = $event->response;
    $content = $response->getContent();
    echo $content;
});

while ($request->socketPerform()) {
    // do anything else when the request is processed
}

Answer 2

Just a few corrections on scripts posted above. The following is working for me

function curl_request_async($url, $params, $type='GET')
    {
        $post_params = array();
        foreach ($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);
        echo print_r($parts, TRUE);
        $fp = fsockopen($parts['host'],
            (isset($parts['scheme']) && $parts['scheme'] == 'https')? 443 : 80,
            $errno, $errstr, 30);

        $out = "$type ".$parts['path'] . (isset($parts['query']) ? '?'.$parts['query'] : '') ." 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";
        // Data goes in the request body for a POST request
        if ('POST' == $type && isset($post_string)) $out.= $post_string;
        fwrite($fp, $out);
        fclose($fp);
    }

Answer 3

You don't. While PHP offers lots of ways to call a URL, it doesn't offer out of the box support for doing any kind of asynchronous/threaded processing per request/execution cycle. Any method of sending a request for a URL (or a SQL statement, or a etc.) is going to wait for some kind of response. You'll need some kind of secondary system running on the local machine to achieve this (google around for "php job queue")

Answer 4

Suggestion: format a FRAMESET HTML page which contains, let´s say, 9 frames inside. Each frame will GET a different "instance" of your myapp.php page. There will be 9 different threads running on the Web server, in parallel.

Answer 5

Here is my own PHP function when I do POST to a specific URL of any page....

Sample: * usage of my Function...

<?php
    parse_str("email=[e-mail]&subject=this is just a test");
    $_POST['email']=$email;
    $_POST['subject']=$subject;
    echo HTTP_Post("http://example.com/mail.php",$_POST);***

    exit;
?>
<?php
    /*********HTTP POST using FSOCKOPEN **************/
    // by ArbZ

    function HTTP_Post($URL,$data, $referrer="") {

    // parsing the given URL
    $URL_Info=parse_url($URL);

    // Building referrer
    if($referrer=="") // if not given use this script as referrer
      $referrer=$_SERVER["SCRIPT_URI"];

    // making string from $data
    foreach($data as $key=>$value)
      $values[]="$key=".urlencode($value);
    $data_string=implode("&",$values);

    // Find out which port is needed - if not given use standard (=80)
    if(!isset($URL_Info["port"]))
      $URL_Info["port"]=80;

    // building POST-request: HTTP_HEADERs
    $request.="POST ".$URL_Info["path"]." HTTP/1.1\n";
    $request.="Host: ".$URL_Info["host"]."\n";
    $request.="Referer: $referer\n";
    $request.="Content-type: application/x-www-form-urlencoded\n";
    $request.="Content-length: ".strlen($data_string)."\n";
    $request.="Connection: close\n";
    $request.="\n";
    $request.=$data_string."\n";

    $fp = fsockopen($URL_Info["host"],$URL_Info["port"]);
    fputs($fp, $request);
    while(!feof($fp)) {
        $result .= fgets($fp, 128);
    }
    fclose($fp); //$eco = nl2br();

    function getTextBetweenTags($string, $tagname) {
        $pattern = "/<$tagname ?.*>(.*)<\/$tagname>/";
        preg_match($pattern, $string, $matches);
        return $matches[1]; }
    //STORE THE FETCHED CONTENTS to a VARIABLE, because its way better and fast...
    $str = $result;
    $txt = getTextBetweenTags($str, "span"); $eco = $txt;  $result = explode("&",$result);
    return $result[1];
<span style=background-color:LightYellow;color:blue>".trim($_GET['em'])."</span>
</pre> "; 
}
</pre>

Answer 6

Try this code....

$chu = curl_init();

curl_setopt($chu, CURLOPT_URL, 'http://www.myapp.com/test.php?someprm=xyz');

curl_setopt($chu, CURLOPT_FRESH_CONNECT, true);
curl_setopt($chu, CURLOPT_TIMEOUT, 1);

curl_exec($chu);
curl_close($chu);

Please dont forget to enable CURL php extension.