_swapon_module()
{
	local cur prev OPTS
	COMPREPLY=()
	cur="${COMP_WORDS[COMP_CWORD]}"
	prev="${COMP_WORDS[COMP_CWORD-1]}"
	case $prev in
		'-p'|'--priority')
			# Priority range is -1 to 32767.  Perhaps these
			# few are enough.
			COMPREPLY=( $(compgen -W "{-1..9} 32767" -- $cur) )
			return 0
			;;
		'--show')
			# FIXME: how to append to a string with compgen?
			local OUTPUT
			OUTPUT="NAME TYPE SIZE USED PRIO"
			compopt -o nospace
			COMPREPLY=( $(compgen -W "$OUTPUT" -S ',' -- $cur) )
			return 0
			;;
		'-U')
			local UUIDS
			UUIDS="$(lsblk -nrp -o FSTYPE,UUID | awk '$1 ~ /swap/ { print $2 }')"
			COMPREPLY=( $(compgen -W "$UUIDS" -- $cur) )
			return 0
			;;
		'-L')
			local LABELS
			LABELS="$(lsblk -nrp -o FSTYPE,LABEL | awk '$1 ~ /swap/ { print $2 }')"
			COMPREPLY=( $(compgen -W "$LABELS" -- $cur) )
			return 0
			;;
		'-h'|'--help'|'-V'|'--version')
			return 0
			;;
	esac
	case $cur in
		-*)
			OPTS="--all
				--discard
				--ifexists
				--fixpgsz
				--priority
				--summary
				--show
				--noheadings
				--raw
				--bytes
				--verbose
				--help
				--version"
			COMPREPLY=( $(compgen -W "${OPTS[*]}" -- $cur) )
			return 0
			;;
	esac
	local DEVS
	DEVS="$(lsblk -nrp -o FSTYPE,NAME | awk '$1 ~ /swap/ { print $2 }')"
	COMPREPLY=( $(compgen -W "$DEVS" -- $cur) )
	return 0
}
complete -F _swapon_module swapon