You don't mention what version and distribution you are using. Upstream parted does have -l in the manpage so I'd file a bug with the distribution.
parted now (or will, depending on whether your distribution includes patches from master) has a --fix option for your exact problem. When used along with --script it will automatically fix the size of the disk and write the backup partition table. Brian -- Brian C. Lane (PST8PDT) - weldr.io - lorax - parted - pykickstart
