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

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

$output = file_get_contents('http://www.example.com/');
echo $output;

function curl_post_async($url, $params)
{
    foreach ($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/1.1rn";
    $out.= "Host: ".$parts['host']."rn";
    $out.= "Content-Type: application/x-www-form-urlencodedrn";
    $out.= "Content-Length: ".strlen($post_string)."rn";
    $out.= "Connection: Closernrn";
    if (isset($post_string)) $out.= $post_string;

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

// $type must equal 'GET' or 'POST'
  function curl_request_async($url, $params, $type='POST')
  {
      foreach ($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);

      // Data goes in the path for a GET request
      if('GET' == $type) $parts['path'] .= '?'.$post_string;

      $out = "$type ".$parts['path']." HTTP/1.1rn";
      $out.= "Host: ".$parts['host']."rn";
      $out.= "Content-Type: application/x-www-form-urlencodedrn";
      $out.= "Content-Length: ".strlen($post_string)."rn";
      $out.= "Connection: Closernrn";
      // Data goes in the request body for a POST request
      if ('POST' == $type && isset($post_string)) $out.= $post_string;

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

<?php
$request = new cURLRequest('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 (cURLEvent $event) {
    $response = $event->response;
    $content = $response->getContent();
    echo $content;
});

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

function make_request($url, $waitResult=true){
    $cmi = curl_multi_init();

    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

    curl_multi_add_handle($cmi, $curl);

    $running = null;
    do {
        curl_multi_exec($cmi, $running);
        sleep(.1);
        if(!$waitResult)
        break;
    } while ($running > 0);
    curl_multi_remove_handle($cmi, $curl);
    if($waitResult){
        $curlInfos = curl_getinfo($curl);
        if((int) $curlInfos['http_code'] == 200){
            curl_multi_close($cmi);
            return curl_multi_getcontent($curl);
        }
    }
    curl_multi_close($cmi);
}

<?
$urls = array_fill(0, 100, 'http://google.com/blank.html');

function execinbackground($cmd) {
    if (substr(php_uname(), 0, 7) == "Windows"){
        pclose(popen("start /B ". $cmd, "r"));
    }
    else {
        exec($cmd . " > /dev/null &");
    }
}
fwite(fopen("urls.txt","w"),implode("n",$urls);
execinbackground("nodejs urlscript.js urls.txt");
// { do your work while get requests being executed.. }
?>

var https = require('https');
var url = require('url');
var http = require('http');
var fs = require('fs');
var dosya = process.argv[2];
var logdosya = 'log.txt';
var count=0;
http.globalAgent.maxSockets = 300;
https.globalAgent.maxSockets = 300;

setTimeout(timeout,100000); // maximum execution time (in ms)

function trim(string) {
    return string.replace(/^s*|s*$/g, '')
}

fs.readFile(process.argv[2], 'utf8', function (err, data) {
    if (err) {
        throw err;
    }
    parcala(data);
});

function parcala(data) {
    var data = data.split("n");
    count=''+data.length+'-'+data[1];
    data.forEach(function (d) {
        req(trim(d));
    });
    /*
    fs.unlink(dosya, function d() {
        console.log('<%s> file deleted', dosya);
    });
    */
}


function req(link) {
    var linkinfo = url.parse(link);
    if (linkinfo.protocol == 'https:') {
        var options = {
        host: linkinfo.host,
        port: 443,
        path: linkinfo.path,
        method: 'GET'
    };
https.get(options, function(res) {res.on('data', function(d) {});}).on('error', function(e) {console.error(e);});
    } else {
    var options = {
        host: linkinfo.host,
        port: 80,
        path: linkinfo.path,
        method: 'GET'
    };
http.get(options, function(res) {res.on('data', function(d) {});}).on('error', function(e) {console.error(e);});
    }
}


process.on('exit', onExit);

function onExit() {
    log();
}

function timeout()
{
console.log("i am too far gone");process.exit();
}

function log()
{
    var fd = fs.openSync(logdosya, 'a+');
    fs.writeSync(fd, dosya + '-'+count+'n');
    fs.closeSync(fd);
}

function _async_http_post($url, $json_string) {
  $run = "curl -X POST -H 'Content-Type: application/json'";
  $run.= " -d '" .$json_string. "' " . "'" . $url . "'";
  $run.= " > /dev/null 2>&1 &";
  exec($run, $output, $exit);
  return $exit == 0;
}

// Build the multi-curl handle, adding both $ch
$mh = curl_multi_init();

// Build the individual requests, but do not execute them
$chs = [];
$chs['ID0001'] = curl_init('http://webservice.example.com/?method=say&word=Hello');
$chs['ID0002'] = curl_init('http://webservice.example.com/?method=say&word=World');
// $chs[] = ...
foreach ($chs as $ch) {
    curl_setopt_array($ch, [
        CURLOPT_RETURNTRANSFER => true,  // Return requested content as string
        CURLOPT_HEADER => false,         // Don't save returned headers to result
        CURLOPT_CONNECTTIMEOUT => 10,    // Max seconds wait for connect
        CURLOPT_TIMEOUT => 20,           // Max seconds on all of request
        CURLOPT_USERAGENT => 'Robot YetAnotherRobo 1.0',
    ]);

    // Well, with a little more of code you can use POST queries too
    // Also, useful options above can be  CURLOPT_SSL_VERIFYHOST => 0
    // and  CURLOPT_SSL_VERIFYPEER => false ...

    // Add every $ch to the multi-curl handle
    curl_multi_add_handle($mh, $ch);
}

// Execute all of queries simultaneously, and continue when ALL OF THEM are complete
$running = null;
do {
    curl_multi_exec($mh, $running);
} while ($running);

// Close the handles
foreach ($chs as $ch) {
    curl_multi_remove_handle($mh, $ch);
}
curl_multi_close($mh);

// All of our requests are done, we can now access the results
// With a help of ids we can understand what response was given
// on every concrete our request
$responses = [];
foreach ($chs as $id => $ch) {
    $responses[$id] = curl_multi_getcontent($ch);
    curl_close($ch);
}
unset($chs); // Finita, no more need any curls :-)

print_r($responses); // output results

//Your Code here
$pid = pcntl_fork();
if ($pid == -1) {
     die('could not fork');
}
else if ($pid)
{
echo("Bye")
}
else
{
     //Do Post Processing
}

/**
   * Performs an async get request (doesn't wait for response)
   * Note: One limitation of this approach is it will not work if server does any URL rewriting
   */
  function async_get($url)
  {
      $parts=parse_url($url);

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

      $out = "GET ".$parts['path']." HTTP/1.1rn";
      $out.= "Host: ".$parts['host']."rn";
      $out.= "Connection: Closernrn";
      fwrite($fp, $out);
      fclose($fp);
  }

class Daemon extends CI_Controller
{
    // Remember to disable CI's csrf-checks for this controller

    function index( )
    {
        ignore_user_abort( 1 );
        try
        {
            if ( strcmp( $_SERVER['REMOTE_ADDR'], $_SERVER['SERVER_ADDR'] ) != 0 && !in_array( $_SERVER['REMOTE_ADDR'], $this->config->item( 'proxy_ips' ) ) )
            {
                log_message( "error", "Daemon called from untrusted IP-address: " . $_SERVER['REMOTE_ADDR'] );
                show_404( '/daemon' );
                return;
            }

            $this->load->library( 'encrypt' );
            $params = unserialize( urldecode( $this->encrypt->decode( $_POST['data'] ) ) );
            unset( $_POST );
            $model = array_shift( $params );
            $method = array_shift( $params );
            $this->load->model( $model );
            if ( call_user_func_array( array( $this->$model, $method ), $params ) === FALSE )
            {
                log_message( "error", "Daemon could not call: " . $model . "::" . $method . "()" );
            }
        }
        catch(Exception $e)
        {
            log_message( "error", "Daemon has error: " . $e->getMessage( ) . $e->getFile( ) . $e->getLine( ) );
        }
    }
}

class Daemon
{
    public function execute_background( /* model, method, params */ )
    {
        $ci = &get_instance( );
        // The callback URL (its ourselves)
        $parts = parse_url( $ci->config->item( 'base_url' ) . "/daemon" );
        if ( strcmp( $parts['scheme'], 'https' ) == 0 )
        {
            $port = 443;
            $host = "ssl://" . $parts['host'];
        }
        else
        {
            $port = 80;
            $host = $parts['host'];
        }
        if ( ( $fp = fsockopen( $host, isset( $parts['port'] ) ? $parts['port'] : $port, $errno, $errstr, 30 ) ) === FALSE )
        {
            throw new Exception( "Internal server error: background process could not be started" );
        }
        $ci->load->library( 'encrypt' );
        $post_string = "data=" . urlencode( $ci->encrypt->encode( serialize( func_get_args( ) ) ) );
        $out = "POST " . $parts['path'] . " HTTP/1.1rn";
        $out .= "Host: " . $host . "rn";
        $out .= "Content-Type: application/x-www-form-urlencodedrn";
        $out .= "Content-Length: " . strlen( $post_string ) . "rn";
        $out .= "Connection: Closernrn";
        $out .= $post_string;
        fwrite( $fp, $out );
        fclose( $fp );
    }
}

$this->load->library('daemon');
$this->daemon->execute_background( 'model', 'method', $arg1, $arg2, ... );

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/1.1rn";
        $out.= "Host: ".$parts['host']."rn";
        $out.= "Content-Type: application/x-www-form-urlencodedrn";
        $out.= "Content-Length: ".strlen($post_string)."rn";
        $out.= "Connection: Closernrn";
        // Data goes in the request body for a POST request
        if ('POST' == $type && isset($post_string)) $out.= $post_string;
        fwrite($fp, $out);
        fclose($fp);
    }

/-----------GET HTML  /--GET IMAGE.........
       /                     /
[Start] GET HTML..............----------------GET IMAGE [Finish]
                            /                      /
        -----GET HTML....../  -----GET IMAGE....../

/-----------GET HTML--GET IMAGE
       /
[Start] GET HTML----------------GET IMAGE [Finish]
                                       /
        -----GET HTML-----GET IMAGE.../

$client = new GuzzleHttpClient();
$promise = $client->requestAsync('GET', 'http://httpbin.org/get');
$promise->then(
    function (ResponseInterface $res) {
        echo $res->getStatusCode() . "n";
    },
    function (RequestException $e) {
        echo $e->getMessage() . "n";
        echo $e->getRequest()->getMethod();
    }
);

<?php
    parse_str("email=myemail@ehehehahaha.com&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/1.1n";
    $request.="Host: ".$URL_Info["host"]."n";
    $request.="Referer: $referern";
    $request.="Content-type: application/x-www-form-urlencodedn";
    $request.="Content-length: ".strlen($data_string)."n";
    $request.="Connection: closen";
    $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>

$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);

<?php
header("http://mahwebsite.net/myapp.php?var=dsafs");
?>