Has anybody already written a script to convert UUID to LABEL identifiers
in a file? To save me duplicating the effort?

Some of the latest Linux distros like Mandriva 2008.1 use UUID
(Universally Unique Identifier) strings to identify partitions in fstab
and in grub's menu.lst rather than the old /dev/* device ids. I can see
that this has it's advantages, but the UUIDs are long strings of random
numbers which are not so easy to maintain for people that tweak these
files by hand. So I've set volume-labels on all partitions, and now I
need to change fstab and menu.lst to use labels instead of UUIDs.

I've already noted useful commands:

$ e2label [new-label] # display/set label on ext2/3
$ mlabel -i /dev/hdaX -s :: # display dos label (from mtools)
$ mlabel -i /dev/hdaX :: # set dos label
$ ntfslabel /dev/hdaX # set ntfs label (from ntfsprogs)
$ mkswap -L /dev/hdaX # set swap label - CHANGES UUID
$ findfs LABEL= # find device by label (script)
$ findfs UUID= # find device by UUID (script)
$ vol_id -l /dev/hdaX # show label (script)
$ vol_id -u /dev/hdaX # show uuid (script)
$ vol_id /dev/hdaX # shows UUID, label, and more
$ vol_id /dev/hdaX ID_FS_UUID= # set UUID - only if fs is closed
$ tune2fs /dev/hdaX -U # set UUID on ext2/3
$ blkid -s UUID /dev/hda* # list all UUIDs (non-ntfs)
$ blkid -s LABEL /dev/hda* # list all labels (non-ntfs)
$ blkid /dev/hda* # All labels & UUIDs (non-ntfs)
$ dumpe2fs /dev/hdaX | grep UUID # extract UUID from ext2/3 header
$ dumpe2fs /dev/hdaX | grep volume.name # extract label from ext2/3 head

--
Dave Farrance