code/Debug/Model/Logging.php
public function getLastFilePosition($filePath)
    {
        if (!file_exists($filePath)) {
            return 0;
        }

        $f = fopen($filePath, 'r');
        fseek($f, -1, SEEK_END);
        return ftell($f);
    }
public function getLastFilePosition($filePath)
    {
        if (!file_exists($filePath)) {
            return 0;
        }

        $f = fopen($filePath, 'r');
        fseek($f, -1, SEEK_END);
        return ftell($f);
    }
Returns current end position for specified file path

@param string $filePath
@return int