curl_multi_info_read - PHP code example

How to Use the PHP Function Curl_Multi_Info_Read

The cURL library helps developers rapidly and firmly fetch data from the webpages. It has a lot of features that make it an extremely popular extension for web applications. It can be used for various purposes including fetching page contents, improving security, and sending and receiving cookies, among others.

To use cURL, you will need to know some basic syntax. Here are some steps that you should take to get started:

First, you will need to create a function. A function is a piece of code that is executed whenever someone calls it. A function must have a name and an argument list. The argument list is a list of values that the function can be called with. The function names must be separated by commas and the arguments must be in order.

If you do not set a default argument value, PHP will assume that the default is -1. This is why it is important to set the argument type when you declare a function. In addition, you must also set the return type. Using a default value can result in a fatal error when the function is called.

The php function curl_multi_info_read is a multi-handle cURL function that returns information about the transfer status of individual handles. It stores the number of handles that still have transfers in progress into the second argument's integer-pointer msgs_in_queue. When this function is called, it will wait until all of the transfers have completed successfully and then return an array of relevant information. Otherwise, it will return FALSE.

curl_multi_info_read example

do {
            $active = 0;

            do {
                $status = curl_multi_exec($multihandle, $active);
            } while ($status === CURLM_CALL_MULTI_PERFORM);

            $to_process = [];

            // Read the information as needed             while ($done = curl_multi_info_read($multihandle)) {
                $key = array_search($done['handle'], $subhandles, true);
                if (!isset($to_process[$key])) {
                    $to_process[$key] = $done;
                }
            }

            // Parse the finished requests before we start getting the new ones             foreach ($to_process as $key => $done) {
                $options = $requests[$key]['options'];
                if ($done['result'] !== CURLE_OK) {
                    //get error string for handle.

$handle = $this->handles[$id]['easy']->handle;
        unset($this->delays[$id], $this->handles[$id]);
        \curl_multi_remove_handle($this->_mh, $handle);
        \curl_close($handle);

        return true;
    }

    private function processMessages(): void
    {
        while ($done = \curl_multi_info_read($this->_mh)) {
            if ($done['msg'] !== \CURLMSG_DONE) {
                // if it's not done, then it would be premature to remove the handle. ref https://github.com/guzzle/guzzle/pull/2892#issuecomment-945150216                 continue;
            }
            $id = (int) $done['handle'];
            \curl_multi_remove_handle($this->_mh, $done['handle']);

            if (!isset($this->handles[$id])) {
                // Probably was cancelled.                 continue;
            }

try {
            $multi->performing = true;
            ++$multi->execCounter;
            $active = 0;
            while (\CURLM_CALL_MULTI_PERFORM === ($err = curl_multi_exec($multi->handle, $active))) {
            }

            if (\CURLM_OK !== $err) {
                throw new TransportException(curl_multi_strerror($err));
            }

            while ($info = curl_multi_info_read($multi->handle)) {
                if (\CURLMSG_DONE !== $info['msg']) {
                    continue;
                }
                $result = $info['result'];
                $id = (int) $ch = $info['handle'];
                $waitFor = @curl_getinfo($ch, \CURLINFO_PRIVATE) ?: '_0';

                if (\in_array($result, [\CURLE_SEND_ERROR, \CURLE_RECV_ERROR, /* CURLE_HTTP2 */ 16, /* CURLE_HTTP2_STREAM */ 92], true) && $waitFor[1] && 'C' !== $waitFor[0]) {
                    curl_multi_remove_handle($multi->handle, $ch);
                    $waitFor[1] = (string) ((int) $waitFor[1] - 1); // decrement the retry counter                     curl_setopt($ch, \CURLOPT_PRIVATE, $waitFor);