fstab-uuidify

fstab-uuidify

#! /bin/sh

# fstab-uuidify - change /dev to UUID entries in fstab(5)
# Copyright (C) 2023 Matous Jan Fialka, <https://mjf.cz/>
# Released under the terms of the "MIT" license.

# Usage: fstab2uuid /etc/fstab |tee /etc/fstab.new

oprobe=
if [ $UID -eq 0 ]; then
	# extra opts passed to blkid(8) if run as root
	oprobe='-p'
fi

squeeze=0
if [ "$1" = '-s' ]; then
	squeeze=1
	shift
fi

cat $1|

while read dev rest; do
	case "$dev" in
	'/dev/'?*)
		# get dev UUID
		uuid=$(
			blkid $oprobe -o export "$dev"|
			grep -E '^UUID='|
			grep -Eo '[0-9a-fA-F-]+$'
			# never change letter case here
		)
		echo "# $dev"
		echo "UUID=$uuid $rest"
		;;
	'UUID='[0-9a-fA-F]*)
		# add dev comment for existing UUID= record
		uuid=$(
			echo "$dev"|
			grep -Eo '[0-9a-fA-F-]+$'
		)
		cdev=$(
			# no probing for a non-device
			blkid -U "$uuid"
		)
		echo "# $cdev"
		echo "$dev $rest"
		;;
	*)
		# keep the rest as is
		echo "$dev $rest"
		;;
	esac
done |

if [ $squeeze -eq 1 ]; then
	sed '/^UUID=/ s/[ \t]\+/ /g'
else
	cat
fi

# vi:ft=sh