own http_response_code method

http_response_code.php

<?php
/**
 * if there is no http_response_code function (PHP 5 >= 5.4)
 * define own http_response_code function.
 * refs. http://www.php.net/manual/ja/function.http-response-code.php#107261
 */
if (!function_exists('http_response_code')) {
	/**
	 * @param string $code   http response code
	 */
	function http_response_code($code = NULL) {
		if ($code !== NULL) {
			switch ($code) {
				case 100: $text = 'Continue'; break;
				case 101: $text = 'Switching Protocols'; break;
				case 200: $text = 'OK'; break;
				case 201: $text = 'Created'; break;
				case 202: $text = 'Accepted'; break;
				case 203: $text = 'Non-Authoritative Information'; break;
				case 204: $text = 'No Content'; break;
				case 205: $text = 'Reset Content'; break;
				case 206: $text = 'Partial Content'; break;
				case 300: $text = 'Multiple Choices'; break;
				case 301: $text = 'Moved Permanently'; break;
				case 302: $text = 'Moved Temporarily'; break;
				case 303: $text = 'See Other'; break;
				case 304: $text = 'Not Modified'; break;
				case 305: $text = 'Use Proxy'; break;
				case 400: $text = 'Bad Request'; break;
				case 401: $text = 'Unauthorized'; break;
				case 402: $text = 'Payment Required'; break;
				case 403: $text = 'Forbidden'; break;
				case 404: $text = 'Not Found'; break;
				case 405: $text = 'Method Not Allowed'; break;
				case 406: $text = 'Not Acceptable'; break;
				case 407: $text = 'Proxy Authentication Required'; break;
				case 408: $text = 'Request Time-out'; break;
				case 409: $text = 'Conflict'; break;
				case 410: $text = 'Gone'; break;
				case 411: $text = 'Length Required'; break;
				case 412: $text = 'Precondition Failed'; break;
				case 413: $text = 'Request Entity Too Large'; break;
				case 414: $text = 'Request-URI Too Large'; break;
				case 415: $text = 'Unsupported Media Type'; break;
				case 500: $text = 'Internal Server Error'; break;
				case 501: $text = 'Not Implemented'; break;
				case 502: $text = 'Bad Gateway'; break;
				case 503: $text = 'Service Unavailable'; break;
				case 504: $text = 'Gateway Time-out'; break;
				case 505: $text = 'HTTP Version not supported'; break;
				default:
					exit('Unknown http status code "' . htmlentities($code) . '"');
					break;
			}
			
			$protocol = (isset($_SERVER['SERVER_PROTOCOL']) ? $_SERVER['SERVER_PROTOCOL'] : 'HTTP/1.0');
			header($protocol . ' ' . $code . ' ' . $text);
			$GLOBALS['http_response_code'] = $code;
		} else {
			$code = (isset($GLOBALS['http_response_code']) ? $GLOBALS['http_response_code'] : 200);
		}

		return $code;
	}
}