run_command example

    /** * Changes current directory. * * @since 2.7.0 * * @param string $dir The new current directory. * @return bool True on success, false on failure. */
    public function chdir( $dir ) {
        return $this->run_command( 'cd ' . $dir, true );
    }

    /** * Changes the file group. * * @since 2.7.0 * * @param string $file Path to the file. * @param string|int $group A group name or number. * @param bool $recursive Optional. If set to true, changes file group recursively. * Default false. * @return bool True on success, false on failure. */