Get error reporting php

Вернуться к: Функции обработки ошибок

I still vividly remember the first time I learned about PHP error handling.

It was in my fourth year of programming, my second with PHP, and I’d applied for a developer position at a local agency. The application required me to send in a code sample (GitHub as we know it didn’t exist back then) so I zipped and sent a simple custom CMS I’d created the previous year.

The email I got back from the person reviewing the code still chills my bones to this day.

«I was a bit worried about your project, but once I turned error reporting off, I see it actually works pretty well».

That was the first time I searched «PHP error reporting», discovered how to enable it, and died inside when I saw the stream of errors that were hidden from me before.

PHP errors and error reporting are something that many developers new to the language might miss initially. This is because, on many PHP based web server installations, PHP errors may be suppressed by default. This means that no one sees or is even aware of these errors.

For this reason, it’s a good idea to know where and how to enable them, especially for your local development environment. This helps you pick up errors in your code early on.

If you Google «PHP errors» one of the first results you will see is a link to the error_reporting function documentation.

This function allows you to both set the level of PHP error reporting, when your PHP script (or collection of scripts) runs, or retrieve the current level of PHP error reporting, as defined by your PHP configuration.

The error_reporting function accepts a single parameter, an integer, which indicates which level of reporting to allow. Passing nothing as a parameter simply returns the current level set.

There is a long list of possible values you can pass as a parameter, but we’ll dive into those later.

For now it’s important to know that each possible value also exists as a PHP predefined constant. So for example, the constant E_ERROR has the value of 1. This means you could either pass 1, or E_ERROR to the error_reporting function, and get the same result.

As a quick example, if we create a php_error_test.php PHP script file, we can see the current error reporting level set, as well as set it to a new level.

<?php
// echo the current error reporting level
echo error_reporting();

<?php
// report all Fatal run-time errors.
echo error_reporting(1);

Error reporting configuration

Using the error_reporting function in this way is great when you just want to see any errors related to the piece of code you’re currently working on.

But it would be better to control which errors are being reported on in your local development environment, and log them somewhere logical, to be able to review as you code. This can be done inside the PHP initialization (or php.ini) file.

The php.ini file is responsible for configuring all the aspects of PHP’s behavior. In it you can set things like how much memory to allocate to PHP scripts, what size file uploads to allow, and what error_reporting level(s) you want for your environment.

If you’re not sure where your php.ini file is located, one way to find out is to create a PHP script which uses the phpinfo function. This function will output all the information relative to your PHP install.

<?php
phpinfo();

As you can see from my phpinfo, my current php.ini file is located at /etc/php/7.3/apache2/php.ini.

Once you’ve found your php.ini file, open it in your editor of choice, and search for the section called ‘Error handling and logging’. Here’s where the fun begins!

Error reporting directives

The first thing you’ll see in that section is a section of comments which include a detailed description of all the Error Level Constants. This is great, because you’ll be using them later on to set your error reporting levels.

Fortunately these constants are also documented in the online PHP Manual, for ease of reference.

Below this list is a second list of Common Values. This shows you how to set some commonly used sets of error reporting value combinations, including the default values, the suggested value for a development environment, and the suggested values for a production environment.

; Common Values:
;   E_ALL (Show all errors, warnings and notices including coding standards.)
;   E_ALL & ~E_NOTICE  (Show all errors, except for notices)
;   E_ALL & ~E_NOTICE & ~E_STRICT  (Show all errors, except for notices and coding standards warnings.)
;   E_COMPILE_ERROR|E_RECOVERABLE_ERROR|E_ERROR|E_CORE_ERROR  (Show only errors)
; Default Value: E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED
; Development Value: E_ALL
; Production Value: E_ALL & ~E_DEPRECATED & ~E_STRICT

Finally, at the bottom of all the comments is the current value of your error_reporting level. For local development, I’d suggest setting it to E_ALL, so as to see all errors.

error_reporting = E_ALL

This is usually one of the first things I set when I set up a new development environment. That way I’ll see any and all errors that are reported.

After the error_reporting directive, there are some additional directives you can set. As before, the php.ini file includes descriptions of each directive, but I’ll give a brief description of the important ones below.

The display_errors directive allows you to toggle whether PHP outputs the errors or not. I usually have this set to On, so I can see errors as they happen.

display_errors=On

The display_startup_errors allows for the same On/Off toggling of errors that may occur during PHP’s startup sequence. These are typically errors in your PHP or web server configuration, not specifically your code. It’s recommended to leave this Off, unless you’re debugging a problem and you aren’t sure what’s causing it.

The log_errors directive tells PHP whether or not to log errors to an error log file. This is always On by default, and is recommended.

The rest of the directives can be left as the default, except for maybe the error_log directive, which allows you to specify where to log the errors, if log_errors is on. By default it will log the errors wherever your web server has defined them to be logged.

Custom error logging

I use the Apache web server on Ubuntu, and my project-specific virtual host configurations use the following to determine the location for the error log.

ErrorLog ${APACHE_LOG_DIR}/project-error.log

This means it will log to the default Apache log directory, which is /var/log/apache2, under a file called project-error.log. Usually I replace project with the name of the web project it relates to.

So, depending on your local development environment you may need to tweak this to suit your needs. Alternatively, if you can’t change this at the web server level, you can set it at the php.ini level to a specific location.

error_log = /path/to/php.log

It is worth noting that this will log all PHP errors to this file, and if you’re working on multiple projects that might not be ideal. However, always knowing to check that one file for errors might work better for you, so your mileage may vary.

Find and fix those errors

If you’ve recently started coding in PHP, and you decide to turn error reporting on, be prepared to deal with the fallout from your existing code. You may see some things you didn’t expect, and need to fix.

The advantage though, is now that you know how to turn it all on at the server level, you can make sure you see these errors when they happen, and deal with them before someone else sees them!

Oh, and if you were wondering, the errors I was referring to at the start of this post were related to the fact that I was defining constants incorrectly, by not adding quotes around the constant name.

define(CONSTANT, 'Hello world.');

PHP allowed (and might still allow) this, but it would trigger a notice.

Notice: Use of undefined constant CONSTANT - assumed 'CONSTANT' 

This notice was triggered every time I defined a constant, which for that project was about 8 or 9 times. Not great for someone to see 8 or 9 notices at the top of each page…

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Introduction

PHP is a server-side scripting language used in web development. As a scripting language, PHP is used to write code (or scripts) to perform tasks. If a script encounters an error, PHP can generate an error to a log file.

In this tutorial, learn how to enable PHP Error Reporting to display all warnings. We also dive into creating an error log file in PHP.

What is a PHP Error?

A PHP error occurs when there is an issue within the PHP code. Even something simple can cause an error, such as using incorrect syntax or forgetting a semicolon, which prompts a notice. Or, the cause may be more complex, such as calling an improper variable, which can lead to a fatal error that crashes your system.

If you do not see errors, you may need to enable error reporting.

To enable error reporting in PHP, edit your PHP code file, and add the following lines:

<?php
error_reporting(E_ALL);
?>

You can also use the ini_set command to enable error reporting:

<?php
ini_set('error_reporting', E_ALL);
?>

Edit php.ini to Enable PHP Error Reporting

If you have set your PHP code to display errors and they are still not visible, you may need to make a change in your php.ini file.

On Linux distributions, the file is usually located in /etc/php.ini folder.

Open php.ini in a text editor.

Then, edit the display_errors line to On.

This is an example of the correction in a text editor:

Edit .htaccess File to turn on Error Reporting

The .htaccess file, which acts as a master configuration file, is usually found in the root or public directory. The dot at the beginning means it’s hidden. If you’re using a file manager, you’ll need to edit the settings to see the hidden files.

Open the .htaccess file for editing, and add the following:

php_flag display_startup_errors on
php_flag display_errors on

If these values are already listed, make sure they’re set to on.

Save the file and exit.

Other Useful Commands

To display only the fatal warning and parse errors, use the following:

<?php
error_reporting(E_ERROR | E_WARNING | E_PARSE);
?>

You can add any other error types you need. Just separate them with the pipe | symbol.

This list contains all the predefined constants for PHP error types.

One useful feature is the “not” symbol.

To exclude a particular error type from reporting:

<?php
error_reporting(E_ALL & ~E_NOTICE)
?>

In this example, the output displays all errors except for notice errors.

How to Turn Off PHP Error Reporting

To turn off or disable error reporting in PHP, set the value to zero. For example, use the code snippet:

<?php
error_reporting(0);
?>

How to Create an Error Log File in PHP

Error logs are valuable resources when dealing with PHP issues.

To display PHP error logs, edit the .htaccess file by adding the following:

php_value error_log logs/all_errors.log

If you don’t have access to the .htaccess file, you can edit the httpd.conf or apache2.conf file directly.

This log is typically stored in the /var/log/httpd/ or /var/log/apache2/ directory.

To enable error logging, edit your version of the file and add the following:

ErrorLog “/var/log/apache2/website-name-error.log”

You may substitute httpd for apache2 if needed. Likewise, if you’re using nginx, you can use that directory for the error log.

How to Display PHP Errors on a Webpage

Error logs are valuable resources when dealing with PHP issues.

To display PHP error logs, edit the .htaccess file by adding the following:

php_value error_log logs/all_errors.log

If you don’t have access to the file, you can edit the httpd.conf or apache2.conf file directly.

This log is typically stored in the /var/log/httpd/ or /var/log/apache2/ directory.

To enable error logging, edit your version of the file and add the following:

ErrorLog “/var/log/apache2/website-name-error.log”

You may substitute httpd for apache2 if needed. Likewise, if you’re using nginx, you can use that directory for the error log.

Conclusion

This tutorial has provided you with multiple alternatives to enable and show all PHP errors and warnings. By receiving error notifications quickly and accurately, you can improve the ability to troubleshoot PHP issues. If you are implementing new features, installing a new PHP-based app, or trying to locate a bug on your website, it is important to know which PHP version your web server is running before taking any steps.

PHP предлагает гибкие настройки вывода ошибок, среди которых функия error_reporting($level) – задает, какие ошибки PHP попадут в отчет, могут быть значения:

• E_ALL – все ошибки,
• E_ERROR – критические ошибки,
• E_WARNING – предупреждения,
• E_PARSE – ошибки синтаксиса,
• E_NOTICE – замечания,
• E_CORE_ERROR – ошибки обработчика,
• E_CORE_WARNING – предупреждения обработчика,
• E_COMPILE_ERROR – ошибки компилятора,
• E_COMPILE_WARNING – предупреждения компилятора,
• E_USER_ERROR – ошибки пользователей,
• E_USER_WARNING – предупреждения пользователей,
• E_USER_NOTICE – уведомления пользователей.

1

Вывод ошибок в браузере

error_reporting(E_ALL);
ini_set('display_errors', 'On'); 

PHP

В htaccess

php_value error_reporting "E_ALL"
php_flag display_errors On

htaccess

На рабочем проекте вывод ошибок лучше сделать только у авторизированного пользователя или в крайнем случаи по IP.

2

Запись ошибок в лог файл

error_reporting(E_ALL);
ini_set('display_errors', 'Off'); 
ini_set('log_errors', 'On');
ini_set('error_log', $_SERVER['DOCUMENT_ROOT'] . '/logs/php-errors.log');

PHP

Файлы логов также не должны быть доступны из браузера, храните их в закрытой директории с файлом .htaccess:

Order Allow,Deny
Deny from all

htaccess

Или запретить доступ к файлам по расширению .log (заодно и другие системные файлы и исходники):

<FilesMatch ".(htaccess|htpasswd|bak|ini|log|sh|inc|config|psd|fla|ai)$">
Order Allow,Deny
Deny from all
</FilesMatch>

htaccess

3

Отправка ошибок на e-mail

Ошибки можно отправлять на е-mail разработчика, но приведенные методы не работает при критических ошибках.

Первый – register_shutdown_function() регистрирует функцию, которая выполнится при завершении работы скрипта, error_get_last() получает последнюю ошибку.

register_shutdown_function('error_alert');

function error_alert() 
{ 
	$error = error_get_last();
	if (!empty($error)) {
		mail('mail@example.com', 'Ошибка на сайте example.com', print_r($error, true)); 
	}
}

PHP

Стоит учесть что оператор управления ошибками (знак @) работать в данном случаи не будет и письмо будет отправляться при каждой ошибке.

Второй метод использует «пользовательский обработчик ошибок», поэтому в браузер ошибки выводится не будут.

function error_alert($type, $message, $file, $line, $vars)
{
	$error = array(
		'type'    => $type,
		'message' => $message,
		'file'    => $file,
		'line'    => $line
	);
	error_log(print_r($error, true), 1, 'mail@example.com', 'From: mail@example.com');
}

set_error_handler('error_alert');

PHP

4

Пользовательские ошибки

PHP позволяет разработчику самому объявлять ошибки, которые выведутся в браузере или в логе. Для создания ошибки используется функция trigger_error():

trigger_error('Пользовательская ошибка', E_USER_ERROR);

PHP

Результат:

Fatal error: Пользовательская ошибка in /public_html/script.php on line 2

• E_USER_ERROR – критическая ошибка,
• E_USER_WARNING – не критическая,
• E_USER_NOTICE – сообщения которые не являются ошибками,
• E_USER_DEPRECATED – сообщения о устаревшем коде.

10.10.2019, обновлено 09.10.2021

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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:

1. Классификация ошибок.
2. Пример, демонстрирующий различные виды ошибок и его поведение при различных настройках.
3. Написание собственного обработчика ошибок.
4. 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:

1. 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.
2. Скрипт в файле с фатальной ошибкой, не относящейся к первому пункту, будет выполняться в штатном режиме до самой ошибки.
3. Наличие в файле фатальной ошибки при display_errors = Off обозначит 500 статус ответа.
4. 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

During the execution of a PHP application, it can generate a wide range of warnings and errors. For developers seeking to troubleshoot a misbehaving application, being able to check these errors is critical. Developers, on the other hand, frequently encounter difficulties when attempting to display errors from their PHP applications. Instead, their applications simply stop working.

First and foremost, you should be aware that with PHP, some errors prevent the script from being executed. Some errors, on the other hand, just display error messages with a warning. Then you’ll learn how to use PHP to show or hide all error reporting.

In PHP, there are four types of errors:

1. Notice Error – When attempting to access an undefined index in a PHP code, an error occurs. The execution of the PHP code is not halted by the notice error. It just alerts you to the fact that there is an issue.
2. Warning Error – The most common causes of warning errors are omitting a file or invoking a function with improper parameters. It’s comparable to seeing a mistake, but it doesn’t stop the PHP code from running. It just serves as a reminder that the script has a flaw.
3. Fatal Error – When undefined functions and classes are called in a PHP code, a fatal error occurs. The PHP code is stopped and an error message is displayed when a fatal error occurs.
4. Parse Error – When a syntax issue occurs in the script, it is referred to as a parse error. The execution of the PHP code is also stopped when a parse error occurs, and an error message is displayed.

You’ve come to the right place if you’re having troubles with your PHP web application and need to see all of the errors and warnings. We’ll go through all of the different ways to activate PHP errors and warnings in this tutorial.

1. To Show All PHP Errors
2. .htaccess Configuration to Show PHP Errors
3. Enable Detailed Warnings and Notices
4. In-depth with the error_reporting() function
5. Use error_log() Function to Log PHP Error
6. Use Web Server Configuration to Log PHP Errors
7. Collect PHP Errors using Atatus

1. To Show All PHP Errors

Adding these lines to your PHP code file is the quickest way to output all PHP errors and warnings:

ini_set ('display_errors', 1);
ini_set ('display_startup_errors', 1);
error_reporting (E_ALL);

The ini_set() function will attempt to override the PHP ini file’s configuration.

The display_errors and display_startup_errors directives are just two of the options.

1. The display_errors directive determines whether or not the errors are visible to the user. After development, the dispay_errors directive should usually be disabled.
2. The display_startup_errors directive, on the other hand, is separate since display errors do not handle errors that occur during PHP’s startup sequence.

The official documentation contains a list of directives that can be overridden by the ini_set() function. Unfortunately, parsing problems such as missing semicolons or curly brackets will not be displayed by these two directives. The PHP ini configuration must be changed in this scenario.

To display all errors, including parsing errors, in xampp, make the following changes to the php.ini example file and restart the apache server.

display_errors = on

In the PHP.ini file, set the display errors directive to turn on. It will show all errors that can’t be seen by just calling the ini_set() function, such as syntax and parsing errors.

2. .htaccess Configuration to Show PHP Errors

The directory files are normally accessible to developers. The .htaccess file in the project’s root or public directory can also be used to enable or disable the directive for displaying PHP errors.

php_flag display_startup_errors on
php_flag display_errors on

.htaccess has directives for display_startup_errors and display_errors, similar to what will be added to the PHP code to show PHP errors. The benefit of displaying or silencing error messages in this way is that development and production can have separate .htaccess files, with production suppressing error displays.

You may want to adjust display_errors in .htaccess or your PHP.ini file depending on which files you have access to and how you handle deployments and server configurations. Many hosting companies won’t let you change the PHP.ini file to enable display errors.

3. Enable Detailed Warnings and Notices

Warnings that appear to not affect the application at first might sometimes result in fatal errors under certain circumstances. These warnings must be fixed because they indicate that the application will not function normally in certain circumstances. If these warnings result in a large number of errors, it would be more practical to hide the errors and only display the warning messages.

error_reporting(E_WARNING);

Showing warnings and hiding errors are as simple as adding a single line of code for a developer. The parameter for the error reporting function will be “E_WARNING | E_NOTICE” to display warnings and notifications. As bitwise operators, the error reporting function can accept E_ERROR, E_WARNING, E_PARSE, and E_NOTICE parameters.

For ease of reference, these constants are also detailed in the online PHP Manual.

To report all errors except notices, use the option «E_ALL & E_NOTICE,» where E_ALL refers to all of the error reporting function’s potential parameters.

4. In-depth with the error_reporting() Function

One of the first results when you browser «PHP errors» is a link to the error_reporting() function documentation.

The PHP error_reporting() function allows developers to choose which and how many errors should be displayed in their applications. Remember that this function will set the error reporting directive in the PHP ini configuration during runtime.

error_reporting(0);

The value zero should be supplied to the error_reporting() function to delete all errors, warnings, parse messages, and notices. This line of code would be impractical to include in each of the PHP files. It is preferable to disable report messages in the PHP ini file or the .htaccess file.

error_reporting(-1);

An integer value is also passed as an input to the error_reporting() function. In PHP, we may use this method to display errors. In PHP, there are many different types of errors. All PHP errors are represented by the -1 level. Even with new levels and constants, passing the value -1 will work in future PHP versions.

error_reporting(E_NOTICE);

Variables can be used even if they aren’t declared in PHP. This isn’t recommended because undeclared variables can create issues in the application when they’re utilized in loops and conditions.

This can also happen when the stated variable is spelled differently than the variable used in conditions or loops. These undeclared variables will be displayed in the web application if E_NOTICE is supplied in the error_reporting() function.

error_reporting(E_ALL & ~E_NOTICE);

You can filter which errors are displayed using the error_reporting() function. The “~” character stands for “not” or “no,” hence the parameter ~E_NOTICE indicates that notices should not be displayed.

In the code, keep an eye out for the letters «&» and «|.» The “&” symbol stands for “true for all,” whereas the “|” character stands for “true for either.” In PHP, these two characters have the same meaning: OR and AND.

5. Use error_log() Function to Log PHP Error

Error messages must not be displayed to end-users during production, but they must be logged for tracing purposes. The best approach to keep track of these error messages in a live web application is to keep track of them in log files.

The error_log() function, which accepts four parameters, provides a simple way to use log files. The first parameter, which contains information about the log errors or what should be logged, is the only one that must be provided. This function’s type, destination, and header parameters are all optional.

error_log("Whoosh!!! Something is wrong!", 0);

If the type option is not specified, it defaults to 0, which means that this log information will be appended to the web server’s log file.

error_log("Email this error to Justin!", 1, "Justin@mydomain.com");

The error logs supplied in the third parameter will be emailed using the type 1 parameter. To use this feature, the PHP ini must have a valid SMTP configuration to send emails.

Host, encryption type, username, password, and port are among the SMTP ini directives. This kind of error reporting is recommended for logging or notifying errors that must be corrected as soon as possible.

error_log("Write this error down to a file!", 3, "logs/php-errors.log");

Type 3 must be used to log messages in a different file established by the web server’s configuration. The third parameter specifies the log file’s location, which must be writable by the webserver. The log file’s location might be either a relative or absolute library to where this code is invoked.

You can also refer to the error_log() function documentation to know more.

6. Use Web Server Configuration to Log PHP Errors

The ideal technique to record errors is to define them in the web server configuration file, rather than modifying parameters in the .htaccess or adding lines in the PHP code to show errors.

ErrorLog "/var/log/apache2/my-website-error.log"

These files must be added to the virtual host of a specific HTML page or application in Apache, which is commonly found in the sites-available folder in Ubuntu or the httpd-vhosts file in Windows.

error_log /var/log/nginx/my-website-error.log;

The directive is just called error_log() in Nginx, as it is in Apache. The log files for both Apache and Nginx web servers must be writable by the webserver. Fortunately, the folders for the log files of these two web servers are already writable after installation.

7. Collect PHP Errors using Atatus

Atatus is an Application Performance Management (APM) solution that collects all requests to your PHP applications without requiring you to change your source code. However, the tool does more than just keep track of your application’s performance. Atatus’ ability to automatically gather all unhandled errors in your PHP application is one of its best features.

To fix PHP exceptions, gather all necessary information such as class, message, URL, request agent, version, and so on. Every PHP error is logged and captured with a full stack trace, with the precise line of source code marked, to make bug fixes easy.

Read the guide to know more about PHP Performance Monitoring.

All errors are automatically logged and structured in Atatus so that they can be easily viewed. Not only will Atatus show you what errors have happened, but it will also examine where and why they occurred. The logs also display the time and number of occurrences, making it much easier to focus on which issue to address.

Start your 14-day free trial of Atatus, right now!!!

Summary

When there is an issue with the PHP code, a PHP error occurs. Even something as simple as incorrect syntax or forgetting a semicolon can result in an error, prompting a notification. Alternatively, the cause could be more complicated, such as invoking an incorrect variable, which can result in a fatal error and cause your system to crash.

This tutorial has shown you several ways to enable and display all PHP errors and warnings. You can boost your ability to debug PHP issues by receiving error notifications fast and precisely.

Let us know what you think about displaying PHP errors in the below comment section.