Cake\Console\Shell::err PHP Method

Outputs a single or multiple error messages to stderr. If no parameters are passed outputs just a newline.

public err ( string \| array \| null $message = null, integer $newlines = 1 ) : integer \| boolean
$message	string \| array \| null	A string or an array of strings to output
$newlines	integer	Number of newlines to append
return	integer \| boolean	The number of bytes returned from writing to stderr.

    public function err($message = null, $newlines = 1)
    {
        return $this->_io->err('<error>' . $message . '</error>', $newlines);
    }

Shell