HTTP requests with file_get_contents, getting the response code

Question

I'm trying to use file_get_contents together with stream_context_create to make POST requests. My code so far:

    $options = array('http' => array(
        'method'  => 'POST',
        'content' => $data,
        'header'  => 
            "Content-Type: text/plain\r\n" .
            "Content-Length: " . strlen($data) . "\r\n"
    ));
    $context  = stream_context_create($options);
    $response = file_get_contents($url, false, $context);

It works fine, however, when an HTTP error occurs, it spits out a warning:

file_get_contents(...): failed to open stream: HTTP request failed! HTTP/1.0 400 Bad Request

and returns false. Is there a way to:

• 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

Extemporize

Answer 1

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);

Variscite

For those wondering, the answer to the first question is to add 'ignore_errors' => TRUE to $options. – Extemporize

Answer 2

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.

Lamoree

That's great! But I wonder: isn't there a less-hacky way to directly get the status code as an integer value? – Pogonia

@Pogonia not with file_get_contents, that's how it was designed (back in the deep, dark ages of PHP) but in my own client I ended up using fopen instead, which avoids this weird, magical API - you can see here how to do that. – Lamoree

Documentation for $http_response_header, which does indeed materialize itself after the call to file_get_contents(). – Duet

Answer 3

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 @)

Internationalize

it's wrong idea to "prefer @". ignore_errors = true suppresses only HTTP errors, while @ gags ALL possible errors that will prevent a programmer from learning why their code doesn't work. When HTTP wrapper is not configured for example, or parameters are not i order. Using @ is a VERY, VERY bad practice. I wish there was less such misinformation on Stack Overflow – Jeroldjeroma

I suggest @ but I said that you can use both @YourCommonSense , I can agree with you about placing @ in other php functions, but in file_get_contents..., if it doesnt work, you just have to remove the @ to check what is happening. – Internationalize

Answer 4

To capture the error message when file_get_contents returns FALSE, write a function which uses ob_start and ob_get_contents to capture the error message that file_get_contents writes to stderr.

function fileGetContents( $fileName )
{
  $errmsg = '' ;
  ob_start( ) ;
  $contents = file_get_contents( $fileName );
  if ( $contents === FALSE )
  {
    $errmsg = ob_get_contents( ) ;
    $errmsg .= "\nfile name:$fileName";
    $contents = '' ;
  }
  ob_end_clean( ) ;
  return (object)[ 'errmsg' => $errmsg, 'contents' => $contents ];
}

Riccio

Answer 5

I go to this page with kind of a different issue, so posting my answer. My problem was that I was just trying to suppress the warning notification and display a customized warning message for the user, so this simple and obvious fix helped me:

// Suppress the warning messages
error_reporting(0);

$contents = file_get_contents($url);
if ($contents === false) {
  print 'My warning message';
}

And if needed, turn back error reporting after that:

// Enable warning messages again
error_reporting(-1);

Fibrin

Answer 6

@file_get_contents and ignore_errors = true are not the same: the first doesn't return anything; the second suppresses error messages, but returns server response (e.g. 400 Bad request).

I use a function like this:

$result = file_get_contents(
  $url_of_API, 
  false, 
  stream_context_create([
    'http' => [
      'content' => json_encode(['value1' => $value1, 'value2' => $value2]), 
      'header' => 'Authorization: Basic XXXXXXXXXXXXXXX', 
      'ignore_errors' => 1, 
      'method' => 'POST', 
      'timeout' => 10
    ]
  ])
);

return json_decode($result)->status;

It returns 200 (Ok) or 400 (Bad request).

It works perfectly and it's easier than cURL.

Dumond

And how does this solve the question? Can you explain how to get the response code? – Pickaninny

It's still a bad one, as you parse a JSON result not and read a random field named status - it has no connection to the HTTP status code for the API call – Pickaninny

It's obvious that the RESTful API I connect to returns a JSON response and that what I need to know for my purpose (200 or 400) is contained in the "status" field. That's all I need and that's all I get. If you need to know the HTTP status code, just do this: return $http_response_header[0]; But note that it doesn't work with @file_get_contents. – Dumond

And how does this answer the original question? Why do you think that $http_response_header[0], a highly upvoted answer, does not work with file_get_contents? – Pickaninny

It doesn't work with @file_get_contents (NOT with file_get_contents). Just try it! – Dumond

@Dumond the ->status is not always an option as it's not part of the spec. That is a property being exposed by whatever stream you are tapping as a courtesy (which is nice) but not standard. If the stream does not explicitly define this property your answer does not provide a viable solution. – Seductress