Mage log in Magento 2 - PHP

When working with Magento 2, logging is an essential aspect of debugging and troubleshooting issues. A log file can reveal errors, warning messages, and other system messages. The mage log command is a powerful and useful tool for logging in Magento 2.

How to Use mage log

The mage log command allows developers to view and manage the Magento 2 log file. To use this command, open up a terminal or command prompt and navigate to the Magento 2 root directory. Here is the basic syntax of the mage log command:

php bin/magento mage:log [--clear]

The --clear flag is optional and can be used to clear the log file. By default, running the mage log command will display the contents of the system log file, which is located in the var/log/system.log file.

Logging Levels

Magento 2 provides several logging levels that can be used to control the verbosity of the log file. The available logging levels are:

• EMERGENCY: An emergency situation.
• ALERT: An urgent situation.
• CRITICAL: A critical situation.
• ERROR: An error that needs attention.
• WARNING: A warning message.
• NOTICE: A normal but significant event.
• INFO: An informational message.
• DEBUG: A debug message.

How to Write Logs

Developers can write logs either through the Magento 2 logging framework or using the mage log command. To use Magento 2's logging framework, developers can inject the Psr\Log\LoggerInterface interface into their classes or controllers. Here is an example of how to log an error message using the logging interface:

use Psr\Log\LoggerInterface;

class MyClass {
    private $logger;

    public function __construct(LoggerInterface $logger) {
        $this->logger = $logger;
    }

    public function doSomething() {
        try {
            // something that might throw an exception
        } catch (Exception $e) {
            $this->logger->error('An error occurred: ' . $e->getMessage());
        }
    }
}

Alternatively, developers can use the mage log command to write logs directly from the command line. Here is an example of how to log an error message using the mage log command:

php bin/magento mage:log --level=error "An error occurred"

Conclusion

Logging is a crucial aspect of Magento 2 development. The mage log command provides developers with an easy and efficient way to view and manage their log files. By understanding how to use this command and the available logging levels, developers can effectively troubleshoot and debug their Magento 2 applications.