sed 输出文件中指定的行

stack@zuul:~/cinder_for_submit/cinder/cinder/volume$ sed -n '2544,2569p' driver.py
    def _do_iscsi_discovery(self, volume):
        # TODO(justinsb): Deprecate discovery and use stored info
        # NOTE(justinsb): Discovery won't work with CHAP-secured targets (?)
        LOG.warning("ISCSI provider_location not stored, using discovery")

        volume_name = volume['name']

        try:
            # NOTE(griff) We're doing the split straight away which should be
            # safe since using '@' in hostname is considered invalid

            (out, _err) = self._execute('iscsiadm', '-m', 'discovery',
                                        '-t', 'sendtargets', '-p',
                                        volume['host'].split('@')[0],
                                        run_as_root=True)
        except processutils.ProcessExecutionError as ex:
            LOG.error("ISCSI discovery attempt failed for:%s",
                      volume['host'].split('@')[0])
            LOG.debug("Error from iscsiadm -m discovery: %s", ex.stderr)
            return None

        for target in out.splitlines():
            if (self.configuration.target_ip_address in target
                    and volume_name in target):
                return target
        return None