Curl Multi and Return Transfer - php

Question

I need to make a number of curl requests to the same domain one after the other, but cannot make them in parallel.
I found the following code sample at http://technosophos.com/
which does work well in speeding up the repeated curl calls.
function get2($url) {
// Create a handle.
$handle = curl_init($url);
// Set options...
// Do the request.
$ret = curlExecWithMulti($handle);
// Do stuff with the results...
// Destroy the handle.
curl_close($handle);
}
function curlExecWithMulti($handle) {
// In real life this is a class variable.
static $multi = NULL;
// Create a multi if necessary.
if (empty($multi)) {
$multi = curl_multi_init();
}
// Add the handle to be processed.
curl_multi_add_handle($multi, $handle);
// Do all the processing.
$active = NULL;
do {
$ret = curl_multi_exec($multi, $active);
} while ($ret == CURLM_CALL_MULTI_PERFORM);
while ($active && $ret == CURLM_OK) {
if (curl_multi_select($multi) != -1) {
do {
$mrc = curl_multi_exec($multi, $active);
} while ($mrc == CURLM_CALL_MULTI_PERFORM);
}
}
// Remove the handle from the multi processor.
curl_multi_remove_handle($multi, $handle);
return TRUE;
}
I have tried multiple times by setting the curl options to get function curlExecWithMulti($handle) to return the results of the curl as a variable, but with no success so far.
Can this be done?

Answer 1

Perhaps this will be of interest, very easy to understand. It will do your curl multi requests and then return an array of results, it also does curl POST.
<?php
//demo receiver
if($_SERVER['REQUEST_METHOD']=='POST'){
echo $_POST['post_var'];
die;
}
/**
* CURL GET|POST Multi
*/
function curl_multi($data, $options = array()) {
$curly = array();
$result = array();
$mh = curl_multi_init();
foreach ($data as $id=>$d) {
$curly[$id] = curl_init();
$url = (is_array($d) && !empty($d['url'])) ? $d['url'] : $d;
$header[0]="Accept: text/xml,application/xml,application/xhtml+xml,application/json";
$header[0].="text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5";
$header[]="Cache-Control: max-age=0";
$header[]="Connection: keep-alive";
$header[]="Keep-Alive: 2";
$header[]="Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7";
$header[]="Accept-Language: en-us,en;q=0.5";
$header[]="Pragma: ";
curl_setopt($curly[$id], CURLOPT_URL, $url);
curl_setopt($curly[$id], CURLOPT_HEADER, 0);
curl_setopt($curly[$id], CURLOPT_RETURNTRANSFER, true);
curl_setopt($curly[$id], CURLOPT_TIMEOUT, 30);
curl_setopt($curly[$id], CURLOPT_USERAGENT, "cURL (http://".$_SERVER['SERVER_NAME'].")");
curl_setopt($curly[$id], CURLOPT_HTTPHEADER, $header);
curl_setopt($curly[$id], CURLOPT_REFERER, $url);
curl_setopt($curly[$id], CURLOPT_ENCODING, 'gzip,deflate');
curl_setopt($curly[$id], CURLOPT_AUTOREFERER, true);
curl_setopt($curly[$id], CURLOPT_RETURNTRANSFER, true);
// post?
if (is_array($d)) {
if (!empty($d['post'])) {
curl_setopt($curly[$id], CURLOPT_POST, 1);
curl_setopt($curly[$id], CURLOPT_POSTFIELDS, $d['post']);
}
}
// extra options?
if (!empty($options)) {
curl_setopt_array($curly[$id], $options);
}
curl_multi_add_handle($mh, $curly[$id]);
}
$running = null;
do {
curl_multi_exec($mh, $running);
} while($running > 0);
foreach($curly as $id => $c) {
$result[$id] = curl_multi_getcontent($c);
curl_multi_remove_handle($mh, $c);
}
curl_multi_close($mh);
return $result;
}
$request = array(
array('url'=>'http://localhost:8080/testing.php','post'=>array('post_var'=>'a')),
array('url'=>'http://localhost:8080/testing.php','post'=>array('post_var'=>'b')),
array('url'=>'http://localhost:8080/testing.php','post'=>array('post_var'=>'c')),
);
$curl_result = curl_multi($request);
/*
Array
(
[0] => a
[1] => b
[2] => c
)
*/
echo '<pre>'.print_r($curl_result, true).'</pre>';
?>