HTTP requests with file_get_contents, getting the response code

None of the answers (including the one accepted by OP) actually satisfy the two requirements:

• suppress a warning (I'm planning to throw my own exception in case of failure)
• obtain the error information (at least, the response code) from the stream

Here's my take:

function fetch(string $method, string $url, string $body, array $headers = []) {
    $context = stream_context_create([
        "http" => [
            // http://docs.php.net/manual/en/context.http.php
            "method"        => $method,
            "header"        => implode("\r\n", $headers),
            "content"       => $body,
            "ignore_errors" => true,
        ],
    ]);

    $response = file_get_contents($url, false, $context);

    /**
     * @var array $http_response_header materializes out of thin air
     */

    $status_line = $http_response_header[0];

    preg_match('{HTTP\/\S*\s(\d{3})}', $status_line, $match);

    $status = $match[1];

    if ($status !== "200") {
        throw new RuntimeException("unexpected response status: {$status_line}\n" . $response);
    }

    return $response;
}

This will throw for a non-200 response, but you can easily work from there, e.g. add a simple Response class and return new Response((int) $status, $response); if that fits your use-case better.

For example, to do a JSON POST to an API endpoint:

$response = fetch(
    "POST",
    "http://example.com/",
    json_encode([
        "foo" => "bar",
    ]),
    [
        "Content-Type: application/json",
        "X-API-Key: 123456789",
    ]
);

Note the use of "ignore_errors" => true in the http context map - this will prevent the function from throwing errors for non-2xx status codes.

This is most likely the "right" amount of error-suppression for most use-cases - I do not recommend using the @ error-suppression operator, as this will also suppress errors like simply passing the wrong arguments, which could inadvertently hide a bug in calling code.

http://php.net/manual/en/reserved.variables.httpresponseheader.php

$context = stream_context_create(['http' => ['ignore_errors' => true]]);
$result = file_get_contents("http://example.com", false, $context);
var_dump($http_response_header);

Adding few more lines to the accepted response to get the http code

function getHttpCode($http_response_header)
{
    if(is_array($http_response_header))
    {
        $parts=explode(' ',$http_response_header[0]);
        if(count($parts)>1) //HTTP/1.0 <code> <text>
            return intval($parts[1]); //Get code
    }
    return 0;
}

@file_get_contents("http://example.com");
$code=getHttpCode($http_response_header);

to hide the error output both comments are ok, ignore_errors = true or @ (I prefer @)