1. 通过header()方法来实现，
最简单的方法，而且对php的版本没什么限制
<?php
header('HTTP/1.1 404 Not Found');
header("status: 404 Not Found");
?>
当服务器设置了404页面后，访问该php就会自动返回404状态及404页面。
2. 使用http_response_code()方法，
如果你的php版本大于5.4的话，可以使用这个新增的方法
<?php
http_response_code(404);
?>
注意：如果你的版本低于5.4，但是你又非得使用http_response_code(),下面是这个方法的代码
1 <?php 2 3 if (!function_exists('http_response_code')) { 4 function http_response_code($code = NULL) { 5 6 if ($code !== NULL) { 7 8 switch ($code) { 9 case 100: $text = 'Continue'; break; 10 case 101: $text = 'Switching Protocols'; break; 11 case 200: $text = 'OK'; break; 12 case 201: $text = 'Created'; break; 13 case 202: $text = 'Accepted'; break; 14 case 203: $text = 'Non-Authoritative Information'; break; 15 case 204: $text = 'No Content'; break; 16 case 205: $text = 'Reset Content'; break; 17 case 206: $text = 'Partial Content'; break; 18 case 300: $text = 'Multiple Choices'; break; 19 case 301: $text = 'Moved Permanently'; break; 20 case 302: $text = 'Moved Temporarily'; break; 21 case 303: $text = 'See Other'; break; 22 case 304: $text = 'Not Modified'; break; 23 case 305: $text = 'Use Proxy'; break; 24 case 400: $text = 'Bad Request'; break; 25 case 401: $text = 'Unauthorized'; break; 26 case 402: $text = 'Payment Required'; break; 27 case 403: $text = 'Forbidden'; break; 28 case 404: $text = 'Not Found'; break; 29 case 405: $text = 'Method Not Allowed'; break; 30 case 406: $text = 'Not Acceptable'; break; 31 case 407: $text = 'Proxy Authentication Required'; break; 32 case 408: $text = 'Request Time-out'; break; 33 case 409: $text = 'Conflict'; break; 34 case 410: $text = 'Gone'; break; 35 case 411: $text = 'Length Required'; break; 36 case 412: $text = 'Precondition Failed'; break; 37 case 413: $text = 'Request Entity Too Large'; break; 38 case 414: $text = 'Request-URI Too Large'; break; 39 case 415: $text = 'Unsupported Media Type'; break; 40 case 500: $text = 'Internal Server Error'; break; 41 case 501: $text = 'Not Implemented'; break; 42 case 502: $text = 'Bad Gateway'; break; 43 case 503: $text = 'Service Unavailable'; break; 44 case 504: $text = 'Gateway Time-out'; break; 45 case 505: $text = 'HTTP Version not supported'; break; 46 default: 47 exit('Unknown http status code "' . htmlentities($code) . '"'); 48 break; 49 } 50 51 $protocol = (isset($_SERVER['SERVER_PROTOCOL']) ? $_SERVER['SERVER_PROTOCOL'] : 'HTTP/1.0'); 52 53 header($protocol . ' ' . $code . ' ' . $text); 54 55 $GLOBALS['http_response_code'] = $code; 56 57 } else { 58 59 $code = (isset($GLOBALS['http_response_code']) ? $GLOBALS['http_response_code'] : 200); 60 61 } 62 63 return $code; 64 65 } 66 } 67 68 ?>