How to make multiple parallel cURL requests in PHP?

To make multiple parallel cURL requests in PHP, you can use multi-cURL functionality, which allows you to execute multiple requests simultaneously. Here is an example code snippet that demonstrates how to achieve this:

// Create array of cURL handles
$curlHandles = array();

// Create multi-cURL handle
$multiCurlHandle = curl_multi_init();

// URLs to make requests to
$urls = array(
    'https://example.com/1',
    'https://example.com/2',
    'https://example.com/3',
    // Add more URLs as needed
);

// Loop through URLs and create cURL handles
foreach ($urls as $url) {
    $curlHandle = curl_init($url);
    
    // Configure cURL options
    curl_setopt($curlHandle, CURLOPT_RETURNTRANSFER, true);
    // Add additional options as needed
    
    // Add cURL handle to array
    $curlHandles[] = $curlHandle;
    
    // Add cURL handle to the multi-cURL handle
    curl_multi_add_handle($multiCurlHandle, $curlHandle);
}

// Execute the multi-cURL requests
do {
    $multiCurlResult = curl_multi_exec($multiCurlHandle, $running);
} while ($multiCurlResult == CURLM_CALL_MULTI_PERFORM);

// Loop through the cURL handles and process their responses
foreach ($curlHandles as $curlHandle) {
    // Wait for the cURL handle to finish
    curl_multi_select($multiCurlHandle);
    
    // Get the cURL handle's result
    $result = curl_multi_getcontent($curlHandle);

    // Process the result as needed
    
    // Remove the cURL handle from the multi-cURL handle
    curl_multi_remove_handle($multiCurlHandle, $curlHandle);
}

// Close the multi-cURL handle
curl_multi_close($multiCurlHandle);

This code uses a loop to create multiple cURL handles, each configured with its own URL and options. These handles are then added to the multi-cURL handle using the curl_multi_add_handle function. The requests are executed using the curl_multi_exec function, and the results are processed in a separate loop.

Note that this is a basic example, and you may need to adjust it based on your specific requirements, such as handling errors, setting request headers, or parsing the responses.