QuickstartΒΆ

Instantiate a logger for the current class:

/** @var $logger \TYPO3\CMS\Core\Log\Logger */
$logger = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance('TYPO3\CMS\Core\Log\LogManager')->getLogger(__CLASS__);

Log a simple message:

$logger->info('Everything went fine.');
$logger->warning('Something went awry, check your configuration!');

Provide additional information with the log message:

$logger->error(
  'This was not a good idea',
  array(
    'foo' => $bar,
    'bar' => $foo,
  )
);

$logger->warning() etc. are only shorthands - you can also call $logger->log() directly and pass the severity level:

$logger->log(
   \TYPO3\CMS\Core\Log\LogLevel::CRITICAL,
   'This is an utter failure!'
);

TYPO3 has the FileWriter enabled by default, so all log entries are written to a file. If the filename is not set, then the file will contain a hash like typo3temp/logs/typo3_<hash>.log, for example typo3temp/logs/typo3_7ac500bce5.log.

A sample output looks like this:

Fri, 08 Mar 2013 09:45:00 +0100 [INFO] request="5139a50bee3a1" component="TYPO3.Examples.Controller.DefaultController": Everything went fine.
Fri, 08 Mar 2013 09:45:00 +0100 [WARNING] request="5139a50bee3a1" component="TYPO3.Examples.Controller.DefaultController": Something went awry, check your configuration!
Fri, 08 Mar 2013 09:45:00 +0100 [ERROR] request="5139a50bee3a1" component="TYPO3.Examples.Controller.DefaultController": This was not a good idea - {"foo":"bar","bar":{}}
Fri, 08 Mar 2013 09:45:00 +0100 [CRITICAL] request="5139a50bee3a1" component="TYPO3.Examples.Controller.DefaultController": This is an utter failure!