Formats an attribute string for an HTTP header.
$attributes: An associative array of attributes such as 'rel'.
A ; separated string ready for insertion in a HTTP header. No escaping is performed for HTML entities, so this string is not safe to be printed.
function drupal_http_header_attributes(array $attributes = array()) {
foreach ($attributes as $attribute => &$data) {
if (is_array($data)) {
$data = implode(' ', $data);
}
$data = $attribute . '="' . $data . '"';
}
return $attributes ? ' ' . implode('; ', $attributes) : '';
}