How Can I Get Useful Error Messages When Running PHP Scripts?

Error Handling in PHP: How to Display Useful Error Messages

When executing PHP scripts, it can sometimes be frustrating to encounter blank screens with no apparent error messages. This lack of information makes it challenging to pinpoint the source of the issue. So, what can be done to obtain useful error messages in PHP?

The PHP developer community understands this problem and provides ways to display informative messages.

Enabling Error Logging

One method is to enable error logging. By setting the log_errors configuration directive to On, all errors will be recorded in a log file. This allows you to examine the error messages without having to edit the script. On live servers, it's recommended to keep error logging enabled but disable display_errors. That way, you still access the error log but prevent users from seeing error messages on the front end.

Displaying Errors in the Browser

For real-time error feedback, you can use the following two lines:

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

These lines instruct PHP to report all errors (E_ALL) and display them on the screen. Keep in mind that setting display_errors to Off on production servers is crucial for security.

Syntax Errors: Using .htaccess

For syntax errors, the display_errors directive is not helpful. Instead, edit your server's .htaccess file and add the following lines:

php_flag  display_errors        on
php_value error_reporting       -1

This enables error display and sets the error reporting level to the highest (-1).

Editor-Based Error Checking

Lastly, consider using an editor with built-in error checking, such as PhpEd, VSCode, or PHPStorm. These editors can detect errors as you type and often provide detailed diagnostic information via a debugger.

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