function doDiscover($command, $options, $params)
    {
        if (count($params) !== 1) {
            return $this->raiseError("No channel server specified");
        }

        // Look for the possible input format "<username>:<password>@<channel>"
        if (preg_match('/^(.+):(.+)@(.+)\\z/', $params[0], $matches)) {
            $username = $matches[1];
            $password = $matches[2];
            $channel  = $matches[3];
        } else {
            $channel = $params[0];
        }

        $reg = &$this->config->getRegistry();
        if ($reg->channelExists($channel)) {
            if (!$reg->isAlias($channel)) {
                return $this->raiseError("Channel \"$channel\" is already initialized", PEAR_COMMAND_CHANNELS_CHANNEL_EXISTS);
            }

            return $this->raiseError("A channel alias named \"$channel\" " .
                'already exists, aliasing channel "' . $reg->channelName($channel)
                . '"');
        }

        $this->pushErrorHandling(PEAR_ERROR_RETURN);
        $err = $this->doAdd($command, $options, array('http://' . $channel . '/channel.xml'));
        $this->popErrorHandling();
        if (PEAR::isError($err)) {
            if ($err->getCode() === PEAR_COMMAND_CHANNELS_CHANNEL_EXISTS) {
                return $this->raiseError("Discovery of channel \"$channel\" failed (" .
                    $err->getMessage() . ')');
            }
            // Attempt fetch via https
            $this->ui->outputData("Discovering channel $channel over http:// failed with message: " . $err->getMessage());
            $this->ui->outputData("Trying to discover channel $channel over https:// instead");
            $this->pushErrorHandling(PEAR_ERROR_RETURN);
            $err = $this->doAdd($command, $options, array('https://' . $channel . '/channel.xml'));
            $this->popErrorHandling();
            if (PEAR::isError($err)) {
                return $this->raiseError("Discovery of channel \"$channel\" failed (" .
                    $err->getMessage() . ')');
            }
        }

        // Store username/password if they were given
        // Arguably we should do a logintest on the channel here, but since
        // that's awkward on a REST-based channel (even "pear login" doesn't
        // do it for those), and XML-RPC is deprecated, it's fairly pointless.
        if (isset($username)) {
            $this->config->set('username', $username, 'user', $channel);
            $this->config->set('password', $password, 'user', $channel);
            $this->config->store();
            $this->ui->outputData("Stored login for channel \"$channel\" using username \"$username\"", $command);
        }

        $this->ui->outputData("Discovery of channel \"$channel\" succeeded", $command);
    }