PHP from CLI using Curl Multi Exec - php

In the code below from http://php.net/manual/en/function.curl-multi-init.php
How can I add code before the second request is made (ie sleep(5)) before curl makes the request to twitter)
Regards
<?php
// create both cURL resources
$ch1 = curl_init();
$ch2 = curl_init();
// set URL and other appropriate options
curl_setopt($ch1, CURLOPT_URL, "https://www.google.com");
curl_setopt($ch1, CURLOPT_HEADER, 0);
curl_setopt($ch2, CURLOPT_URL, "https://twitter.com");
curl_setopt($ch2, CURLOPT_HEADER, 0);
//create the multiple cURL handle
$mh = curl_multi_init();
//add the two handles
curl_multi_add_handle($mh,$ch1);
curl_multi_add_handle($mh,$ch2);
$active = null;
//execute the handles
do {
$mrc = curl_multi_exec($mh, $active);
} while ($mrc == CURLM_CALL_MULTI_PERFORM);
while ($active && $mrc == CURLM_OK) {
if (curl_multi_select($mh) != -1) {
do {
$mrc = curl_multi_exec($mh, $active);
} while ($mrc == CURLM_CALL_MULTI_PERFORM);
}
}
//close the handles
curl_multi_remove_handle($mh, $ch1);
curl_multi_remove_handle($mh, $ch2);
curl_multi_close($mh);
?>

I'm no PHP guy or competent programmer for that matter :D Now that disclaimer is out there, here's my solution.
There's probably a much cleaner way to do this but I have limited knowledge of PHP and how to extend classes. For that reason, I decided to use the built-in process control extensions and create a helper function to handle the curl process. I'm sure there are much better programmers out there ready to provide a much cleaner solution though.
<?php
// Helper function
function async_curl($url,$delay){
sleep($delay);
echo "FORK: Getting $url after $delay seconds\n";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_FRESH_CONNECT, true);
// Mute the return for demonstration purposes.
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_exec($ch);
curl_close($ch);
}
$urls = array("http://google.com","http://twitter.com","http://www.facebook.com");
foreach($urls as $url){
// Generate random timeout for demonstration purposes.
$delay = rand(1,20);
// Create a forked child process for each URL
$pid = pcntl_fork();
// Exit if fork failed
if ($pid == -1) {
exit("Error, failed to create a child process for the URL: $url");
// Create a single child process to call the helper function
} else if ($pid == 0) {
echo "MAIN: Forking process for $url\nPID: " .getmypid() . "\tDelay: $delay\n";
async_curl($url,$delay);
exit();
}
}
// Wait for all forked processes to complete before exiting.
while (($pid = pcntl_waitpid(0, $status)) > 0) {
echo "MAIN: Process $pid completed\n";
}
?>

Related

How to execute a PHP script in background?

I have a little question:
public function backend()
{
$form = $_POST;
// execute this code in another thread (don't wait to finish)
SearchOnGoogle($form);
// redirect instantly (and function "SearchOnGoogle" works in background);
return redirect('/');
}
How can I do this thing? I tried a lot of things, and the function redirect is executed when SearchOnGoogle finishies execution.
If you want to do this within PHP then you can use curl_multi-exec(). This does does not execute "in the background" - but most of the time a client is retrieving content over HTTP, it is simply waiting for data to pass across the network. The curl_multi_select() function deals with checking the task(s) to see if if the local machine needs to do anything or if any data has arrived from the remote system.
The documentation for curl_multi_exec() in the PHP manual is (IMHO) not on a par with the writeups for other functions. There is a deeper dive here, briefly....
$ch1 = curl_init();
$ch2 = curl_init();
// set URL and other appropriate options
curl_setopt($ch1, CURLOPT_URL, "http://example.com/");
curl_setopt($ch1, CURLOPT_HEADER, 0);
curl_setopt($ch2, CURLOPT_URL, "http://www.php.net/");
curl_setopt($ch2, CURLOPT_HEADER, 0);
$requests=array($ch1, $ch2);
//create the multiple cURL handle
$mh = curl_multi_init();
//add the two handles
curl_multi_add_handle($mh,$ch1);
curl_multi_add_handle($mh,$ch2);
$active=count($requests);
$started=microtime(true);
for ($x=0; $x<=4 && $active; $x++) {
curl_multi_exec($mh, $active);
// we wait for a bit to allow stuff TCP handshakes to complete and so forth...
curl_mutli_select($mh, 0.02)
}
do_something_useful();
do {
// wait for everything to finish...
curl_multi_exec($mh, $active);
if ($active) {
curl_mutli_select($mh, 0.05);
use_some_spare_cpu_cuycles_here();
}
// until all the results are in or a timeout occurs
} while ($active > 0 && (MAX_RUNTIME<microtime(true)=$started);

What is the object that contains data in PHP multi cURL

From the PHP manual a multi curl is performed like this:
// create both cURL resources
$ch1 = curl_init();
$ch2 = curl_init();
// set URL and other appropriate options
curl_setopt($ch1, CURLOPT_URL, "http://lxr.php.net/");
curl_setopt($ch1, CURLOPT_HEADER, 0);
curl_setopt($ch2, CURLOPT_URL, "http://www.php.net/");
curl_setopt($ch2, CURLOPT_HEADER, 0);
//create the multiple cURL handle
$mh = curl_multi_init();
//add the two handles
curl_multi_add_handle($mh,$ch1);
curl_multi_add_handle($mh,$ch2);
$active = null;
//execute the handles
do {
$mrc = curl_multi_exec($mh, $active);
} while ($mrc == CURLM_CALL_MULTI_PERFORM);
while ($active && $mrc == CURLM_OK) {
if (curl_multi_select($mh) != -1) {
do {
$mrc = curl_multi_exec($mh, $active);
} while ($mrc == CURLM_CALL_MULTI_PERFORM);
//---------
Link:http://php.net
I can copy paste the code as is and it would get me the content. Notice how I don't "echo" anything, so it works without echoing.
So my question is, where does the data come from? What is the object holding the data? I know you have to set CURLOPT_RETURNTRANSFER to true and then get the content with curl_multi_getcontent() but as I stated the script retrieves content, but where is the object?
Both curl_exec and curl_multi_exec output the response by default. You need to set CURLOPT_RETURNTRANSFER option to true to disable the output and make those functions return the response instead.

PHP hold request until finish

I have an API written in PHP that sends 10 requests with CURL.
The problem is that when I send a HTTP request to the API, I get the response right away, although the server hasn't finished working( getting the response for all of the 10 requests).
I can't use ignore_user_abort() because I need to know exactly the time that the API finished.
How can I notify the connection "hey, wait for the script to finish working"?
Important note: if I use sleep() the connection holds.
Here's my code: gist
This is just a example to show how ob_start works.
echo "hello";
ob_start(); // output buffering starts here
echo "hello1";
//all curl requests
if(all curl requests completed)
{
ob_end_flush() ;
}
With no code to refer, I can only show implementation of ob_start. You have to change this code according to your requirement.
$handlers = [];
$mh = curl_multi_init();
ob_start(); // output buffering starts here
foreach($query->fetchAll() as $domain){
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'http://'.$domain['name']);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $DEFAULT_REQUEST_TIMEOUT);
curl_setopt($ch, CURLOPT_TIMEOUT, $DEFAULT_REQUEST_TIMEOUT);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_MAXREDIRS, 2);
curl_multi_add_handle($mh, $ch);
$handlers[] = ['ch'=>$ch, 'domain_id'=>$domain['domain_id']];
echo $domain['name'];
}
// Execute the handles
$active = null;
do {
$mrc = curl_multi_exec($mh, $active);
} while ($mrc == CURLM_CALL_MULTI_PERFORM);
while ($active && $mrc == CURLM_OK) {
// Wait for activity on any curl-connection
if (curl_multi_select($mh) == -1) {
usleep(1);
}
// Continue to exec until curl is ready to
// give us more data
do {
$mrc = curl_multi_exec($mh, $active);
} while ($mrc == CURLM_CALL_MULTI_PERFORM);
}
// Extract the content
$values = [];
foreach($handlers as $key => $handle){
// Check for errors
echo $key.'. result: ';
$curlError = curl_error($handle['ch']);
if($curlError == ""){
$res = curl_multi_getcontent($handle['ch']);
echo 'done';
}
else {
echo "Curl error on handle $key: $curlError".' <br />';
}
// Remove and close the handle
curl_multi_remove_handle($mh, $handle['ch']);
curl_close($handle['ch']);
}
// Clean up the curl_multi handle
curl_multi_close($mh);
ob_end_flush() ; // output flushed here
Source - http://php.net/manual/en/function.ob-start.php
I use this code for my website
ob_start("unique_identifier");
// your header script
// your page script
// your footer script
ob_end_flush("unique_identifier");
ob_end_clean("unique_identifier");
I use "unique_identifier" because inside my script also exists another
ob_start()

How to merge result of 2 PHP script outputs

I am getting only the result for the first script. But I want the response for both PHP scripts to be in one output. In my program I am developing, I am querying several remote servers. I have to search information on different servers and return the result in one response.
<?php
// build the individual requests as above, but do not execute them
$ch_1 = curl_init('http://lifesaver.netai.net/example/pharm.php');
$ch_2 = curl_init('http://192.168.1.2/example/pharm.php');
curl_setopt($ch_1, CURLOPT_RETURNTRANSFER, false);
curl_setopt($ch_2, CURLOPT_RETURNTRANSFER, false);
curl_setopt($ch_1, CURLOPT_POST,1);
curl_setopt($ch_2, CURLOPT_POST,1);
curl_setopt($ch_1, CURLOPT_POSTFIELDS, "name=$value");
curl_setopt($ch_2, CURLOPT_POSTFIELDS, "name=$value");
// $_POST["name"]
// build the multi-curl handle, adding both $ch
$mh = curl_multi_init();
curl_multi_add_handle($mh, $ch_1);
curl_multi_add_handle($mh, $ch_2);
// execute all queries simultaneously, and continue when all are complete
$running = null;
do {
curl_multi_exec($mh, $running);
} while ($running);
// all of our requests are done, we can now access the results
$response_1 = curl_multi_getcontent($ch_1);
$response_2 = curl_multi_getcontent($ch_2);
echo $response_1;
echo $response_2;
?>
According to the documentation of curl_multi_getcontent, you need to set CURLOPT_RETURNTRANSFER to true instead of false.
Also, the documentation of curl_multi_init shows an example which is slightly different than yours when it comes to the execution loop:
//execute the handles
$running = null;
do {
$mrc = curl_multi_exec($mh, $running);
} while ($mrc == CURLM_CALL_MULTI_PERFORM);
while ($running && $mrc == CURLM_OK) {
if (curl_multi_select($mh) != -1) {
do {
$mrc = curl_multi_exec($mh, $running);
} while ($mrc == CURLM_CALL_MULTI_PERFORM);
}
}
You could try it that way.

php multi curl problem

i want to get several pages thru curl_exec, first page is come normally, but all others - 302 header, what reason?
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, ROOT_URL);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
$content = curl_exec($curl); // here good content
curl_close($curl);
preg_match_all('/href="(\/users\/[^"]+)"[^>]+>\s*/i', $content, $p);
for ($j=0; $j<count($p[1]); $j++){
$new_curl = curl_init();
curl_setopt($new_curl, CURLOPT_URL, NEW_URL.$p[1][$j]);
curl_setopt($new_curl, CURLOPT_RETURNTRANSFER, 0);
$content = curl_exec($new_curl); // here 302
curl_close($new_curl);
preg_match('/[^#]+#[^"]+/i', $content, $p2);
}
smth like this
You probably want to provide a sample of your code so we can see if you're omitting something.
302 response code typically indicates that the server is redirecting you to a different location (found in the Location response header). Depending on what flags you use, CURL can either retrieve that automatically or you can watch for the 302 response and retrieve it yourself.
Here is how you would get CURL to follow the redirects (where $ch is the handle to your curl connection):
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);// allow redirects
You can use curl multi which is faster and can get data from all the url's in parallel.
You can use it like this
//Initialize
$curlOptions = array(CURLOPT_RETURNTRANSFER => 1);//Add whatever u additionally want.
$curlHandl1 = curl_init($url1);
curl_setopt_array($curlHandl1, $curlOptions);
$curlHandl2 = curl_init($url2);
curl_setopt_array($curlHandl2, $curlOptions);
$multi = curl_multi_init();
curl_multi_add_handle($multi, $curlHandle1);
curl_multi_add_handle($multi, $curlHandle2);
//Run Handles
$running = null;
do {
$status = curl_multi_exec($mh, $running);
} while ($mrc == CURLM_CALL_MULTI_PERFORM);
while ($running && $status == CURLM_OK) {
if (curl_multi_select($mh) != -1) {
do {
$status = curl_multi_exec($mh, $running);
} while ($status == CURLM_CALL_MULTI_PERFORM);
}
}
//Retrieve Results
$response1 = curl_multi_getcontent($curlHandle1);
$status1 = curl_getinfo($curlHandle1);
$response1 = curl_multi_getcontent($curlHandle1);
$status1 = curl_getinfo($curlHandle1);
You can find more information here http://www.php.net/manual/en/function.curl-multi-exec.php
Checkout the Example1

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