In a typical setup with PHP 5 running on Apache using FastCGI and managed through cPanel, the PHP error log can be stored in various locations depending on the configuration. Here’s how to determine where PHP stores its error logs and how to configure it:

Default Error Log Locations

1. PHP Configuration File (php.ini):

• The location of the PHP error log is specified in the php.ini configuration file. The directive to look for is error_log.
  To find your php.ini file:

   php --ini

Within php.ini, the error_log directive specifies the path to the error log file:

   error_log = /path/to/php-error.log

2. Apache Configuration:

• If error_log is not specified in php.ini, PHP errors might be logged to the Apache error log. The Apache error log file is typically defined in the Apache configuration file (httpd.conf or a file in the conf.d directory). Common locations for Apache error logs:

   ErrorLog "/var/log/apache2/error_log"  # Debian/Ubuntu
   ErrorLog "/var/log/httpd/error_log"    # Red Hat/CentOS

3. cPanel Configuration:

• When using cPanel, error logs can also be found in user-specific directories. Each cPanel user has an error log file located at:

   /home/username/logs/domain.com-php.error.log

Checking and Configuring the Error Log

1. Locate and Edit php.ini:

• Access your server via SSH or cPanel’s File Manager.
• Open the php.ini file. The location of this file may vary, but common locations include:
  /etc/php5/apache2/php.ini /usr/local/lib/php.ini
• Set the error_log directive:
  ini error_log = /home/username/public_html/php-errors.log

2. Configure Error Logging:

• Ensure error logging is enabled in php.ini:
  ini log_errors = On

3. Restart Apache:

• After making changes to php.ini or Apache configuration files, restart Apache to apply the changes:
  bash
sudo systemctl restart apache2 # Debian/Ubuntu
sudo systemctl restart httpd # Red Hat/CentOS

Viewing the Error Log

• You can view the error log using command-line tools such as tail or through the cPanel File Manager. Command to view the last few lines of the error log:

   tail -f /home/username/public_html/php-errors.log

Summary

• Default Location: If error_log is not set in php.ini, errors might go to the Apache error log.
• Configured Location: Set the error_log directive in php.ini to a specific path to ensure PHP errors are logged to your desired location.
• cPanel Users: Check /home/username/logs/domain.com-php.error.log for user-specific error logs.

By following these steps, you can ensure that you correctly locate and configure the PHP error log in an environment using PHP 5, Apache, FastCGI, and cPanel.