Close monitoring of your site’s PHP errors is crucial to operating a healthy, secure, and well-performing website. When left undetected, PHP errors can reduce performance, waste bandwidth, and leave your site vulnerable to malicious attack. PHP errors usually occur unpredictably and spontaneously, and may be triggered by even the slightest changes to your server configuration, database setup, or WordPress files. Even if your site appears to working properly on the surface, it may in fact be suffering from undetected PHP errors that should be fixed as soon as possible.

Monitoring PHP errors is something that all responsible WordPress administrators should be doing. In this DiW article, we’ll show you three easy ways to monitor PHP errors for WordPress. The first method is exclusive to WordPress, and the second two methods work great for any website.

Error Logging via the WordPress configuration file.

Perhaps the easiest way to implement PHP error-logging for your WordPress-powered site is to add a few simple lines of code to your wp-config.php file. The WordPress wp-config.php file may be used to specify various PHP initiation settings to modify the functionality of your PHP installation. In this method, we will take advantage of this feature by implementing basic error monitoring for your site. Here’s how to do it:

Step 1: Create a log file.

Create an empty file called “php-errors.log”. This file will serve as your site’s PHP error log. Your server will need write access to this file, so make sure to set the appropriate permissions. This file may be placed in any directory, but placing it above the web-accessible root directory of your site is advisable for security reasons. Once this file is created, writable, and in place, take note of its absolute directory path and continue to the final step.

Step 2: Add the magic code.

Next, open your site’s wp-config.php file (located in the root WordPress directory) and place the following code immediately above the line that says, “That's all, stop editing! Happy blogging.”:

// log php errors 
@ini_set('log_errors','On'); // enable or disable php error logging (use 'On' or 'Off') 
@ini_set('display_errors','Off'); // enable or disable public display of errors (use 'On' or 'Off') 
@ini_set('error_log','/home/path/logs/php-errors.log'); // path to server-writable log file

Once in place, edit the third line with the absolute directory path to the php-errors.log file created in the first step. Upload to your server and call it done. All PHP errors will now be logged to your php-errors.log file, thereby enabling you to monitor and resolve errors as quickly as possible. The other two directives in this tasty little snippet enable you to log and display PHP errors at your will. The current configuration is ideal for production sites, but you may want to enable PHP error display for development purposes. See the code comments for more information on changing these settings.

Cool tips

A couple of notes regarding this method.. First, if you place the following definition to your wp-config.php file, all WordPress debug errors will also be written to your php-errors.log file:

define('WP_DEBUG', true); // enable debugging mode

Also note that the code used for this example demonstrates a very basic implementation. You may add any number of additional @ini_set() directives to enhance and customize your error-logging system as needed.