(PHP 5 >= 5.4.0, PHP 7, PHP 
http_response_code — Get or Set the HTTP response code
Description
http_response_code(int $response_code = 0): int|bool
Parameters
-
response_code -
The optional
response_codewill set the response code.
Return Values
If response_code is provided, then the previous
status code will be returned. If response_code is not
provided, then the current status code will be returned. Both of these
values will default to a 200 status code if used in a web
server environment.
false will be returned if response_code is not
provided and it is not invoked in a web server environment (such as from a
CLI application). true will be returned if
response_code is provided and it is not invoked in a
web server environment (but only when no previous response status has been
set).
Examples
Example #1 Using http_response_code() in a web server environment
<?php// Get the current response code and set a new one
var_dump(http_response_code(404));// Get the new response code
var_dump(http_response_code());
?>
The above example will output:
Example #2 Using http_response_code() in a CLI environment
<?php// Get the current default response code
var_dump(http_response_code());// Set a response code
var_dump(http_response_code(201));// Get the new response code
var_dump(http_response_code());
?>
The above example will output:
bool(false) bool(true) int(201)
See Also
- header() — Send a raw HTTP header
- headers_list() — Returns a list of response headers sent (or ready to send)
craig at craigfrancis dot co dot uk ¶
11 years ago
If your version of PHP does not include this function:
<?phpif (!function_exists('http_response_code')) {
function http_response_code($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;
}
}
?>
In this example I am using $GLOBALS, but you can use whatever storage mechanism you like... I don't think there is a way to return the current status code:
https://bugs.php.net/bug.php?id=52555
For reference the error codes I got from PHP's source code:
http://lxr.php.net/opengrok/xref/PHP_5_4/sapi/cgi/cgi_main.c#354
And how the current http header is sent, with the variables it uses:
http://lxr.php.net/opengrok/xref/PHP_5_4/main/SAPI.c#856
Stefan W ¶
9 years ago
Note that you can NOT set arbitrary response codes with this function, only those that are known to PHP (or the SAPI PHP is running on).
The following codes currently work as expected (with PHP running as Apache module):
200 – 208, 226
300 – 305, 307, 308
400 – 417, 422 – 424, 426, 428 – 429, 431
500 – 508, 510 – 511
Codes 0, 100, 101, and 102 will be sent as "200 OK".
Everything else will result in "500 Internal Server Error".
If you want to send responses with a freestyle status line, you need to use the `header()` function:
<?php header("HTTP/1.0 418 I'm A Teapot"); ?>
Thomas A. P. ¶
7 years ago
When setting the response code to non-standard ones like 420, Apache outputs 500 Internal Server Error.
This happens when using header(0,0,420) and http_response_code(420).
Use header('HTTP/1.1 420 Enhance Your Calm') instead.
Note that the response code in the string IS interpreted and used in the access log and output via http_response_code().
Anonymous ¶
9 years ago
Status codes as an array:
<?php
$http_status_codes = array(100 => "Continue", 101 => "Switching Protocols", 102 => "Processing", 200 => "OK", 201 => "Created", 202 => "Accepted", 203 => "Non-Authoritative Information", 204 => "No Content", 205 => "Reset Content", 206 => "Partial Content", 207 => "Multi-Status", 300 => "Multiple Choices", 301 => "Moved Permanently", 302 => "Found", 303 => "See Other", 304 => "Not Modified", 305 => "Use Proxy", 306 => "(Unused)", 307 => "Temporary Redirect", 308 => "Permanent Redirect", 400 => "Bad Request", 401 => "Unauthorized", 402 => "Payment Required", 403 => "Forbidden", 404 => "Not Found", 405 => "Method Not Allowed", 406 => "Not Acceptable", 407 => "Proxy Authentication Required", 408 => "Request Timeout", 409 => "Conflict", 410 => "Gone", 411 => "Length Required", 412 => "Precondition Failed", 413 => "Request Entity Too Large", 414 => "Request-URI Too Long", 415 => "Unsupported Media Type", 416 => "Requested Range Not Satisfiable", 417 => "Expectation Failed", 418 => "I'm a teapot", 419 => "Authentication Timeout", 420 => "Enhance Your Calm", 422 => "Unprocessable Entity", 423 => "Locked", 424 => "Failed Dependency", 424 => "Method Failure", 425 => "Unordered Collection", 426 => "Upgrade Required", 428 => "Precondition Required", 429 => "Too Many Requests", 431 => "Request Header Fields Too Large", 444 => "No Response", 449 => "Retry With", 450 => "Blocked by Windows Parental Controls", 451 => "Unavailable For Legal Reasons", 494 => "Request Header Too Large", 495 => "Cert Error", 496 => "No Cert", 497 => "HTTP to HTTPS", 499 => "Client Closed Request", 500 => "Internal Server Error", 501 => "Not Implemented", 502 => "Bad Gateway", 503 => "Service Unavailable", 504 => "Gateway Timeout", 505 => "HTTP Version Not Supported", 506 => "Variant Also Negotiates", 507 => "Insufficient Storage", 508 => "Loop Detected", 509 => "Bandwidth Limit Exceeded", 510 => "Not Extended", 511 => "Network Authentication Required", 598 => "Network read timeout error", 599 => "Network connect timeout error");
?>
Source: Wikipedia "List_of_HTTP_status_codes"
viaujoc at videotron dot ca ¶
2 years ago
Do not mix the use of http_response_code() and manually setting the response code header because the actual HTTP status code being returned by the web server may not end up as expected. http_response_code() does not work if the response code has previously been set using the header() function. Example:
<?php
header('HTTP/1.1 401 Unauthorized');
http_response_code(403);
print(http_response_code());
?>
The raw HTTP response will be (notice the actual status code on the first line does not match the printed http_response_code in the body):
HTTP/1.1 401 Unauthorized
Date: Tue, 24 Nov 2020 13:49:08 GMT
Server: Apache
Connection: Upgrade, Keep-Alive
Keep-Alive: timeout=5, max=100
Transfer-Encoding: chunked
Content-Type: text/html; charset=UTF-8
403
I only tested it on Apache. I am not sure if this behavior is specific to Apache or common to all PHP distributions.
Anonymous ¶
9 years ago
You can also create a enum by extending the SplEnum class.
<?php/** HTTP status codes */
class HttpStatusCode extends SplEnum {
const __default = self::OK;
const
SWITCHING_PROTOCOLS = 101;
const OK = 200;
const CREATED = 201;
const ACCEPTED = 202;
const NONAUTHORITATIVE_INFORMATION = 203;
const NO_CONTENT = 204;
const RESET_CONTENT = 205;
const PARTIAL_CONTENT = 206;
const MULTIPLE_CHOICES = 300;
const MOVED_PERMANENTLY = 301;
const MOVED_TEMPORARILY = 302;
const SEE_OTHER = 303;
const NOT_MODIFIED = 304;
const USE_PROXY = 305;
const BAD_REQUEST = 400;
const UNAUTHORIZED = 401;
const PAYMENT_REQUIRED = 402;
const FORBIDDEN = 403;
const NOT_FOUND = 404;
const METHOD_NOT_ALLOWED = 405;
const NOT_ACCEPTABLE = 406;
const PROXY_AUTHENTICATION_REQUIRED = 407;
const REQUEST_TIMEOUT = 408;
const CONFLICT = 408;
const GONE = 410;
const LENGTH_REQUIRED = 411;
const PRECONDITION_FAILED = 412;
const REQUEST_ENTITY_TOO_LARGE = 413;
const REQUESTURI_TOO_LARGE = 414;
const UNSUPPORTED_MEDIA_TYPE = 415;
const REQUESTED_RANGE_NOT_SATISFIABLE = 416;
const EXPECTATION_FAILED = 417;
const IM_A_TEAPOT = 418;
const INTERNAL_SERVER_ERROR = 500;
const NOT_IMPLEMENTED = 501;
const BAD_GATEWAY = 502;
const SERVICE_UNAVAILABLE = 503;
const GATEWAY_TIMEOUT = 504;
const HTTP_VERSION_NOT_SUPPORTED = 505;
}
Rob Zazueta ¶
10 years ago
The note above from "Anonymous" is wrong. I'm running this behind the AWS Elastic Loadbalancer and trying the header(':'.$error_code...) method mentioned above is treated as invalid HTTP.
The documentation for the header() function has the right way to implement this if you're still on < php 5.4:
<?php
header("HTTP/1.0 404 Not Found");
?>
Anonymous ¶
10 years ago
If you don't have PHP 5.4 and want to change the returned status code, you can simply write:
<?php
header(':', true, $statusCode);
?>
The ':' are mandatory, or it won't work
divinity76 at gmail dot com ¶
3 years ago
if you need a response code not supported by http_response_code(), such as WebDAV / RFC4918's "HTTP 507 Insufficient Storage", try:
<?php
header($_SERVER['SERVER_PROTOCOL'] . ' 507 Insufficient Storage');
?>
result: something like
HTTP/1.1 507 Insufficient Storage
Steven ¶
8 years ago
http_response_code is basically a shorthand way of writing a http status header, with the added bonus that PHP will work out a suitable Reason Phrase to provide by matching your response code to one of the values in an enumeration it maintains within php-src/main/http_status_codes.h. Note that this means your response code must match a response code that PHP knows about. You can't create your own response codes using this method, however you can using the header method.
In summary - The differences between "http_response_code" and "header" for setting response codes:
1. Using http_response_code will cause PHP to match and apply a Reason Phrase from a list of Reason Phrases that are hard-coded into the PHP source code.
2. Because of point 1 above, if you use http_response_code you must set a code that PHP knows about. You can't set your own custom code, however you can set a custom code (and Reason Phrase) if you use the header method.
Richard F. ¶
10 years ago
At least on my side with php-fpm and nginx this method does not change the text in the response, only the code.
<?php// HTTP/1.1 404 Not Found
http_response_code(404);?>
The resulting response is HTTP/1.1 404 OK
stephen at bobs-bits dot com ¶
9 years ago
It's not mentioned explicitly, but the return value when SETTING, is the OLD status code.
e.g.
<?php
$a
= http_response_code();
$b = http_response_code(202);
$c = http_response_code();var_dump($a, $b, $c);// Result:
// int(200)
// int(200)
// int(202)
?>
Chandra Nakka ¶
5 years ago
On PHP 5.3 version, If you want to set HTTP response code. You can try this type of below trick :)
<?php
header
('Temporary-Header: True', true, 404);
header_remove('Temporary-Header');?>
yefremov {dot} sasha () gmail {dot} com ¶
8 years ago
@craig at craigfrancis dot co dot uk@ wrote the function that replaces the original. It is very usefull, but has a bug. The original http_response_code always returns the previous or current code, not the code you are setting now. Here is my fixed version. I also use $GLOBALS to store the current code, but trigger_error() instead of exit. So now, how the function will behave in the case of error lies on the error handler. Or you can change it back to exit().
if (!function_exists('http_response_code')) {
function http_response_code($code = NULL) {
$prev_code = (isset($GLOBALS['http_response_code']) ? $GLOBALS['http_response_code'] : 200);
if ($code === NULL) {
return $prev_code;
}
switch ($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:
trigger_error('Unknown http status code ' . $code, E_USER_ERROR); // exit('Unknown http status code "' . htmlentities($code) . '"');
return $prev_code;
}
$protocol = (isset($_SERVER['SERVER_PROTOCOL']) ? $_SERVER['SERVER_PROTOCOL'] : 'HTTP/1.0');
header($protocol . ' ' . $code . ' ' . $text);
$GLOBALS['http_response_code'] = $code;
// original function always returns the previous or current code
return $prev_code;
}
}
Anonymous ¶
5 years ago
http_response_code() does not actually send HTTP headers, it only prepares the header list to be sent later on.
So you can call http_reponse_code() to set, get and reset the HTTP response code before it gets sent.
Test code:
<php
http_response_code(500); // set the code
var_dump(headers_sent()); // check if headers are sent
http_response_code(200); // avoid a default browser page
Kubo2 ¶
7 years ago
If you want to set a HTTP response code without the need of specifying a protocol version, you can actually do it without http_response_code():
<?php
header
('Status: 404', TRUE, 404);?>
zweibieren at yahoo dot com ¶
8 years ago
The limited list given by Stefan W is out of date. I have just tested 301 and 302 and both work.
divinity76 at gmail dot com ¶
6 years ago
warning, it does not check if headers are already sent (if it is, it won't *actually* change the code, but a subsequent call will imply that it did!!),
you might wanna do something like
function ehttp_response_code(int $response_code = NULL): int {
if ($response_code === NULL) {
return http_response_code();
}
if (headers_sent()) {
throw new Exception('tried to change http response code after sending headers!');
}
return http_response_code($response_code);
}
Editor: Steve Paine
Modified: 28.11.2022
Status codes, the status of a p[age being requested from a web server can be generated in a number of different ways. Here we show you how this is done in PHP code – a language that can be used to generate HTML web pages directly.
When browsing the internet as a user, you are probably unaware of the secret messaging that is being sent back and forth between where the website is being hosted and your browser.
For example, domain names are actually a series of numerical combinations. Status codes are similar in that they give information about if a page has loaded successfully or not, and the root cause of any errors. PHP is a scripting language that can generate status-code data.
While your content management system, possibly (WordPress) and your web server (possibly Apache) can generate these codes, the scripting language PHP, which is the basis of WordPress, can also generate these codes.
Why use PHP to generate status codes?
PHP is the language that WordPress is built on. If you are thinking of adapting your WordPress theme, or even writing additional pages using PHP, you might want to use status codes to return a positive status code, to redirect the request to another page or site, or to advise that a page is not available. For example, you have deleted a lot of content and you want to provide a special landing page to tell robots and users that this specific content has been removed, and why. Or, you may want to write a simple PHP script to tell users when the site is under maintenance.
What are Status Codes?
HTTP status codes are a way that servers communicate with clients (browsers). For the most part, the page loads successfully and so an ‘ok’ 2xx code will be generated. In such a case, status codes remain invisible to the user. But status codes are there to cover all eventualities, such as a 404 error or even a 502 bad gateway, which will be visually displayed on the page as an error message.
Understanding status codes will allow you to enhance your user experience, especially if your website visitors are receiving error codes that originate from your server as an example.
As the practice is quite technical, status codes are usually implemented manually by someone who understands coding such as a web developer. However, if your website is on WordPress, then plugins do exist to help you make sense and implement status codes.
Of course, as a website user, you may also come across status codes on other websites too. For example, 403 forbidden can be generated if you try to access a section of a website that you don’t have permission to view.
HTTP Status Code Types – Overview
- 1xx informational response
- 2xx success
- 3xx redirection
- 4xx client errors
- 5xx server errors
- Unofficial status codes
More detail is available in our http status code overview article.
PHP – An Overview
PHP stands for hypertext preprocessor. As you may have noticed, the acronym is a little confusing and that’s because PHP originally stood for personal home page. Remember, the way we develop websites has changed immensely in the short time the internet has existed, so sometimes terms need to be updated to keep up to modern standards.
Whenever you request a URL, a complex chain occurs between the server and the browser. PHP is usually involved in this process, as it’s responsible for interpreting the data. A common example of where you would see PHP in action is a login page. As you enter your credentials, a request to the server is made, and PHP will communicate with the database to log you in.
Essentially, PHP is a scripting language that is embedded into HTML. For a quick example, left click on any webpage and select ‘view page source’. Doing so will bring up the code that makes up that page. It is your browser that interprets the code into the functional version of the website.
With PHP, code can either be processed client side (HTML, Javascript and CSS) or server side (PHP). In essence, the server side of PHP is software that is installed on the server. This software can include Linux, Apache, MySQL and finally PHP. In that order, these 4 elements make up what’s known as a LAMP stack. The PHP is the scripting layer of this combination which websites and web applications run off.
Returning A Status Code In PHP
To return a status code in PHP, the simplest way is to use the http_response_code() function, along with the relevant HTTP status code parameter into your website, followed by the exit() command which stops any more output being set.
This means the likes of 400 bad requests and 404 not found can all be implemented with just one line of code.
Important: The http_response_code and header() commands must be used before any HTML is returned.
Example: Return a 400 bad request status code
http_response_code(400);
exit;Example: Return a 404 not found status code
http_response_code(404);
exit;Example: Return a 301 moved permanently status code
This example php code also requires that you provide the new URL, to which the users browser will automatically redirect. For this you need to use the more details header() function.
http_response_code(301);
header('Location: /newlocation.html');
exit;The exit command means that no other php code or html code will be output from the page.
Here’s example code for a 503 temporary error page that also includes additional information that is shown in the browser.
<?php
http_response_code(503);
header( 'Retry-After: 600' );
?>
<!DOCTYPE html>
<html>
<head>
<title>php-generated 503</title>
</head>
<body>
This is a 503 error page.<br/> The error is returned in the HTTP header and this is just simple HTML that is displayed in the browser.
</body>
</html>Why Status Codes Matters For SEO
As the name suggests, SEO is all about catering to search engines, so that users are more likely to come across your site. Search engines actively crawl status codes and will determine how your site is indexed as a result.
For example, if your site has plenty of 404 errors that exist from internal or external, links then this can harm your rankings because this will not generate a helpful experience for users. In a nutshell, search engines are looking out for healthy status codes, as this indicates everything is ticking over as it should be.
Further Reading
The above gives a brief overview of returning status codes in PHP. However, given the complex nature of coding it’s impossible to cover everything in just one article alone. So we definitely suggest doing some further reading to increase your understanding.
Resources you may find helpful include the official PHP website. In particular, their Using PHP section covers common errors you may encounter, especially as you get to grips with it.
Remember, when building any code it’s essential to test it. Even a small error or even a bug can disrupt the final result, so it’s good to remember that PHP isn’t just about the writing of the script, but seeing it through to a working page. Plus, looking out for any errors that may occur further down the line.
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В статье представлена очередная попытка разобраться с ошибками, которые могут встретиться на вашем пути php-разработчика, их возможная классификация, примеры их возникновения, влияние ошибок на ответ клиенту, а также инструкции по написанию своего обработчика ошибок.
Статья разбита на четыре раздела:
- Классификация ошибок.
- Пример, демонстрирующий различные виды ошибок и его поведение при различных настройках.
- Написание собственного обработчика ошибок.
- Полезные ссылки.
Классификация ошибок
Все ошибки, условно, можно разбить на категории по нескольким критериям.
Фатальность:
- Фатальные
Неустранимые ошибки. Работа скрипта прекращается.
E_ERROR, E_PARSE, E_CORE_ERROR, E_COMPILE_ERROR. - Не фатальные
Устранимые ошибки. Работа скрипта не прекращается.
E_WARNING, E_NOTICE, E_CORE_WARNING, E_COMPILE_WARNING, E_USER_WARNING, E_USER_NOTICE, E_STRICT, E_DEPRECATED, E_USER_DEPRECATED. - Смешанные
Фатальные, но только, если не обработаны функцией, определенной пользователем в set_error_handler().
E_USER_ERROR, E_RECOVERABLE_ERROR.
Возможность перехвата ошибки функцией, определенной в set_error_handler():
- Перехватываемые (не фатальные и смешанные)
E_USER_ERROR, E_RECOVERABLE_ERROR, E_WARNING, E_NOTICE, E_USER_WARNING, E_USER_NOTICE, E_STRICT, E_DEPRECATED, E_USER_DEPRECATED. - Не перехватываемые (фатальные)
E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_ERROR, E_COMPILE_WARNING.
Инициатор:
- Инициированы пользователем
E_USER_ERROR, E_USER_WARNING, E_USER_NOTICE. - Инициированы PHP
E_ERROR, E_PARSE, E_CORE_ERROR, E_COMPILE_ERROR, E_WARNING, E_NOTICE, E_CORE_WARNING, E_COMPILE_WARNING, E_STRICT, E_DEPRECATED, E_USER_DEPRECATED, E_USER_ERROR, E_RECOVERABLE_ERROR.
Для нас, в рамках данной статьи, наиболее интересны классификации по первым двум критериям, о чем будет рассказано далее.
Примеры возникновения ошибок
Листинг index.php
<?php
// определеяем уровень протоколирования ошибок
error_reporting(E_ALL | E_STRICT);
// определяем режим вывода ошибок
ini_set('display_errors', 'On');
// подключаем файл с ошибками
require 'errors.php';Листинг errors.php
<?php
echo "Файл с ошибками. Начало<br>";
/*
* перехватываемые ошибки (ловятся функцией set_error_handler())
*/
// NONFATAL - E_NOTICE
// echo $undefined_var;
// NONFATAL - E_WARNING
// array_key_exists('key', NULL);
// NONFATAL - E_DEPRECATED
split('[/.-]', "12/21/2012"); // split() deprecated начиная с php 5.3.0
// NONFATAL - E_STRICT
// class c {function f(){}} c::f();
// NONFATAL - E_USER_DEPRECATED
// trigger_error("E_USER_DEPRECATED", E_USER_DEPRECATED);
// NONFATAL - E_USER_WARNING
// trigger_error("E_USER_WARNING", E_USER_WARNING);
// NONFATAL - E_USER_NOTICE
// trigger_error("E_USER_NOTICE", E_USER_NOTICE);
// FATAL, если не обработана функцией set_error_handler - E_RECOVERABLE_ERROR
// class b {function f(int $a){}} $b = new b; $b->f(NULL);
// FATAL, если не обработана функцией set_error_handler - E_USER_ERROR
// trigger_error("E_USER_ERROR", E_USER_ERROR);
/*
* неперехватываемые (не ловятся функцией set_error_handler())
*/
// FATAL - E_ERROR
// undefined_function();
// FATAL - E_PARSE
// parse_error
// FATAL - E_COMPILE_ERROR
// $var[];
echo "Файл с ошибками. Конец<br>";Примечание: для полной работоспособности скрипта необходим PHP версии не ниже 5.3.0.
В файле errors.php представлены выражения, инициирующие практически все возможные ошибки. Исключение составили: E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_WARNING, генерируемые ядром Zend. В теории, встретить их в реальной работе вы не должны.
В следующей таблице приведены варианты поведения этого скрипта в различных условиях (в зависимости от значений директив display_errors и error_reporting):
| Группа ошибок | Значения директив* | Статус ответа сервера | Ответ клиенту** |
|---|---|---|---|
| E_PARSE, E_COMPILE_ERROR*** | display_errors = off error_reporting = ANY |
500 | Пустое значение |
| display_errors = on error_reporting = ANY |
200 | Сообщение об ошибке | |
| E_USER_ERROR, E_ERROR, E_RECOVERABLE_ERROR | display_errors = off error_reporting = ANY |
500 | Вывод скрипта до ошибки |
| display_errors = on error_reporting = ANY |
200 | Сообщение об ошибке и вывод скрипта до ошибки | |
| Не фатальные ошибки | display_errors = off error_reporting = ANY и display_errors = on error_reporting = 0 |
200 | Весь вывод скрипта |
| display_errors = on error_reporting = E_ALL | E_STRICT |
200 | Сообщение об ошибке и весь вывод скрипта |
* Значение ANY означает E_ALL | E_STRICT или 0.
** Ответ клиенту может отличаться от ответов на реальных скриптах. Например, вывод какой-либо информации до включения файла errors.php, будет фигурировать во всех рассмотренных случаях.
*** Если в файле errors.php заменить пример для ошибки E_COMPILE_ERROR на require "missing_file.php";, то ошибка попадет во вторую группу.
Значение, приведенной выше, таблицы можно описать следующим образом:
- Наличие в файле скрипта ошибки, приводящей его в «негодное» состояние (невозможность корректно обработать), на выходе даст пустое значение или же только само сообщение об ошибке, в зависимости от значения директивы display_errors.
- Скрипт в файле с фатальной ошибкой, не относящейся к первому пункту, будет выполняться в штатном режиме до самой ошибки.
- Наличие в файле фатальной ошибки при display_errors = Off обозначит 500 статус ответа.
- Не фатальные ошибки, как и следовало ожидать, в контексте возможности исполнения скрипта в целом, на работоспособность не повлияют.
Собственный обработчик ошибок
Для написания собственного обработчика ошибок необходимо знать, что:
- для получения информации о последней произошедшей ошибке существует функция error_get_last();
- для определения собственного обработчика ошибок существует функция set_error_handler(), но фатальные ошибки нельзя «перехватить» этой функцией;
- используя register_shutdown_function(), можно зарегистрировать свою функцию, выполняемую по завершении работы скрипта, и в ней, используя знания из первого пункта, если фатальная ошибка имела место быть, предпринять необходимые действия;
- сообщение о фатальной ошибке в любом случае попадет в буфер вывода;
- воспользовавшись функциями контроля вывода можно предотвратить отображение нежелательной информации;
- при использовании оператора управления ошибками (знак @) функция, определенная в set_error_handler() все равно будет вызвана, но функция error_reporting() в этом случае вернет 0, чем и можно пользоваться для прекращения работы или определения другого поведения своего обработчика ошибок.
Третий пункт поясню: зарегистрированная нами функция при помощи register_shutdown_function() выполнится в любом случае — корректно ли завершился скрипт, либо же был прерван в связи с критичной (фатальной) ошибкой. Второй вариант мы можем однозначно определить, воспользовавшись информацией предоставленной функцией error_get_last(), и, если ошибка все же была, выполнить наш собственный обработчик ошибок.
Продемонстрируем вышесказанное на модифицированном скрипте index.php:
<?php
/**
* Обработчик ошибок
* @param int $errno уровень ошибки
* @param string $errstr сообщение об ошибке
* @param string $errfile имя файла, в котором произошла ошибка
* @param int $errline номер строки, в которой произошла ошибка
* @return boolean
*/
function error_handler($errno, $errstr, $errfile, $errline)
{
// если ошибка попадает в отчет (при использовании оператора "@" error_reporting() вернет 0)
if (error_reporting() & $errno)
{
$errors = array(
E_ERROR => 'E_ERROR',
E_WARNING => 'E_WARNING',
E_PARSE => 'E_PARSE',
E_NOTICE => 'E_NOTICE',
E_CORE_ERROR => 'E_CORE_ERROR',
E_CORE_WARNING => 'E_CORE_WARNING',
E_COMPILE_ERROR => 'E_COMPILE_ERROR',
E_COMPILE_WARNING => 'E_COMPILE_WARNING',
E_USER_ERROR => 'E_USER_ERROR',
E_USER_WARNING => 'E_USER_WARNING',
E_USER_NOTICE => 'E_USER_NOTICE',
E_STRICT => 'E_STRICT',
E_RECOVERABLE_ERROR => 'E_RECOVERABLE_ERROR',
E_DEPRECATED => 'E_DEPRECATED',
E_USER_DEPRECATED => 'E_USER_DEPRECATED',
);
// выводим свое сообщение об ошибке
echo "<b>{$errors[$errno]}</b>[$errno] $errstr ($errfile на $errline строке)<br />n";
}
// не запускаем внутренний обработчик ошибок PHP
return TRUE;
}
/**
* Функция перехвата фатальных ошибок
*/
function fatal_error_handler()
{
// если была ошибка и она фатальна
if ($error = error_get_last() AND $error['type'] & ( E_ERROR | E_PARSE | E_COMPILE_ERROR | E_CORE_ERROR))
{
// очищаем буффер (не выводим стандартное сообщение об ошибке)
ob_end_clean();
// запускаем обработчик ошибок
error_handler($error['type'], $error['message'], $error['file'], $error['line']);
}
else
{
// отправка (вывод) буфера и его отключение
ob_end_flush();
}
}
// определеяем уровень протоколирования ошибок
error_reporting(E_ALL | E_STRICT);
// определяем режим вывода ошибок
ini_set('display_errors', 'On');
// включаем буфферизацию вывода (вывод скрипта сохраняется во внутреннем буфере)
ob_start();
// устанавливаем пользовательский обработчик ошибок
set_error_handler("error_handler");
// регистрируем функцию, которая выполняется после завершения работы скрипта (например, после фатальной ошибки)
register_shutdown_function('fatal_error_handler');
require 'errors.php';
Не забываем, что ошибки смешанного типа, после объявления собственного обработчика ошибок, стали не фатальными. Плюс к этому, весь вывод скрипта до фатальной ошибки вместе с стандартным сообщением об ошибке будет сброшен.
Вообще, рассмотренный пример обработчика ошибок, обработкой, как таковой, не занимается, а только демонстрирует саму возможность. Дальнейшее его поведение зависит от ваших желаний и/или требований. Например, все случаи обращения к обработчику можно записывать в лог, а в случае фатальных ошибок, дополнительно, уведомлять об этом администратора ресурса.
Полезные ссылки
- Первоисточник: php.net/manual/ru/book.errorfunc.php
- Описание ошибок: php.net/manual/ru/errorfunc.constants.php
- Функции контроля вывода: php.net/manual/ru/ref.outcontrol.php
- Побитовые операторы: php.net/manual/ru/language.operators.bitwise.php и habrahabr.ru/post/134557
- Тематически близкая статья: habrahabr.ru/post/134499
I just found this question and thought it needs a more comprehensive answer:
As of PHP 5.4 there are three methods to accomplish this:
Assembling the response code on your own (PHP >= 4.0)
The header() function has a special use-case that detects a HTTP response line and lets you replace that with a custom one
header("HTTP/1.1 200 OK");
However, this requires special treatment for (Fast)CGI PHP:
$sapi_type = php_sapi_name();
if (substr($sapi_type, 0, 3) == 'cgi')
header("Status: 404 Not Found");
else
header("HTTP/1.1 404 Not Found");
Note: According to the HTTP RFC, the reason phrase can be any custom string (that conforms to the standard), but for the sake of client compatibility I do not recommend putting a random string there.
Note: php_sapi_name() requires PHP 4.0.1
3rd argument to header function (PHP >= 4.3)
There are obviously a few problems when using that first variant. The biggest of which I think is that it is partly parsed by PHP or the web server and poorly documented.
Since 4.3, the header function has a 3rd argument that lets you set the response code somewhat comfortably, but using it requires the first argument to be a non-empty string. Here are two options:
header(':', true, 404);
header('X-PHP-Response-Code: 404', true, 404);
I recommend the 2nd one. The first does work on all browsers I have tested, but some minor browsers or web crawlers may have a problem with a header line that only contains a colon. The header field name in the 2nd. variant is of course not standardized in any way and could be modified, I just chose a hopefully descriptive name.
http_response_code function (PHP >= 5.4)
The http_response_code() function was introduced in PHP 5.4, and it made things a lot easier.
http_response_code(404);
That’s all.
Compatibility
Here is a function that I have cooked up when I needed compatibility below 5.4 but wanted the functionality of the «new» http_response_code function. I believe PHP 4.3 is more than enough backwards compatibility, but you never know…
// For 4.3.0 <= PHP <= 5.4.0
if (!function_exists('http_response_code'))
{
function http_response_code($newcode = NULL)
{
static $code = 200;
if($newcode !== NULL)
{
header('X-PHP-Response-Code: '.$newcode, true, $newcode);
if(!headers_sent())
$code = $newcode;
}
return $code;
}
}