PHP: get_headers set temporary stream_context - php

Question

I guess PHP's get_headers does not allow for a context, so I have to change the default stream context to only get the HEAD of a request. This causes some issues with other requests on the page. I can't seem to figure out how to reset the default stream context. I'm trying something like:
$default = stream_context_get_default(); //Get default stream context so we can reset it
stream_context_set_default( //Only fetch the HEAD
array(
'http' => array(
'method' => 'HEAD'
)
)
);
$headers = get_headers($url, 1); //Url can be whatever you want it to be
//var_dump($headers);
var_dump($default);
stream_context_set_default($default); //This doesn't work as it expects an array and not a resource pointer
Does anyone know a fix for this?
I know it has been suggested to use Curl, but I would rather not for this one. Thanks!

Answer 1

I ended up using the stream_get_meta_data() function to get the HTTP headers.
This is how I implemented it:
function get_headers_with_stream_context($url, $context, $assoc = 0) {
$fp = fopen($url, 'r', null, $context);
$metaData = stream_get_meta_data($fp);
fclose($fp);
$headerLines = $metaData['wrapper_data'];
if(!$assoc) return $headerLines;
$headers = array();
foreach($headerLines as $line) {
if(strpos($line, 'HTTP') === 0) {
$headers[0] = $line;
continue;
}
list($key, $value) = explode(': ', $line);
$headers[$key] = $value;
}
return $headers;
}
Called like this,
$context = stream_context_create(array('http' => array('method' => 'HEAD')));
$headers = get_headers_with_stream_context($url, $context, 1);
it gives you what you're after while leaving the standard stream_context unmodified.
Please note that this function will fail if passed anything other than an http url.
There seems to be a feature request for an additional argument for get_headers(), but the bug tracker is down as I'm writing this, so I can't check for other solutions there.

Answer 2

I had a similar issue but I just used the file_get_contents function with the custom stream context instead.
Here's how I implemented it:
$options = array(
'http' => array(
'method' => 'HEAD',
'follow_location' => 0
)
);
$context = stream_context_create($options);
#file_get_contents($url, NULL, $context);
var_dump($http_response_header);
Using this context only the headers will be fetched by file_get_contents and will populate the $http_response_header PHP variable.

Answer 3

Instead of the accepted answer, I did the following, which will work in PHP 5.3 and above, though I haven't fully tested it. (There's also a stream_context_get_params($context) but I think this is enough.)
$stream_context_defaults = stream_context_get_options(stream_context_get_default());
stream_context_set_default(
array(
'http' => array(
'method' => 'HEAD'
)
)
);
for ($i = 1; $i <= 10; $i++) {
$headers = get_headers('http://www.example.org');
}
stream_context_set_default($stream_context_defaults); // reset to defaults

Answer 4

As of PHP 7.1.0, get_headers() now accepts a third parameter for context.
$context = stream_context_create(
array(
'http' => array('method' => 'HEAD')
)
);
$headers = get_headers($url, true, $context);