Niklas Tech Blog

I often need logging in my applications so instead of inventing the wheel every time I decided to write a reusable log function. This is what I came up with (PHP 5.3.3)

/**
 * Log function with log file rotation
 * and loglevel restrictions
 *
 * @param <int> $level
 * @param <string> $event
 * @param <string> $text
 */
function logger($level, $event, $text = null){
        $maxsize = 5242880; //Max filesize in bytes (e.q. 5MB)
        $dir = "log/";
        $filename = "myapplication.log";
        $loglevel = 5;

        if(file_exists($dir.$filename) &&
                  filesize($dir.$filename) > $maxsize){
            $nb = 1;
            $logfiles = scandir($dir);
            foreach ($logfiles as $file) {                
                $tmpnb = substr($file, strlen($filename));
                if($nb < $tmpnb){
                    $nb = $tmpnb;
                }
            }
            rename($dir.$filename, $dir.$filename.($nb + 1));
        }
        if($level <= $loglevel) { 
           $data = date('Y-m-d H:i:s')." LEVEL: ".$level." ";
           $data .= "EVENT: ".$event." ".$text.PHP_EOL;
           file_put_contents($dir.$filename, $data, FILE_APPEND);
        }
}

This function will write a log row with a timestamp, error level, event name and error text (optional) to the logfile specified if the error level is below or equal to the general log level ($loglevel). If the logfile is bigger then $maxsize it vill rename the logfile by appending the next inline number to the end and create a new logfile.