Можно например так, с помощью Curl.
<?php
$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_URL => "/ajax.php",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"foo\"\r\n\r\nbar\r\n-----011000010111000001101001--\r\n",
CURLOPT_HTTPHEADER => array(
"content-type: multipart/form-data; boundary=---011000010111000001101001"
),
));
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}
А еще можно вот так, с помощью HTTP v2:
<?php
$client = new http\Client;
$request = new http\Client\Request;
$body = new http\Message\Body;
$body->addForm(array(
'foo' => 'bar'
), NULL);
$request->setRequestUrl('/ajax.php');
$request->setRequestMethod('POST');
$request->setBody($body);
$client->enqueue($request)->send();
$response = $client->getResponse();
echo $response->getBody();
