grub-btrfs/41_snapshots-btrfs

#! /usr/bin/bash
set -e

. /usr/share/grub/grub-mkconfig_lib
. /etc/default/grub

######################################
### variables in /etc/default/grub ###
######################################
## Submenu name
submenuname=${GRUB_BTRFS_SUBMENUNAME:-"ArchLinux Snapshots"}
## Prefix entry
prefixentry=${GRUB_BTRFS_PREFIXENTRY:-"Snapshot"}
## Kernel(s) name(s)
nkernel=("${GRUB_BTRFS_NKERNEL[@]:-vmlinuz-linux}")
## Initramfs name(s)
ninit=("${GRUB_BTRFS_NINIT[@]:-initramfs-linux.img initramfs-linux-fallback.img}")
## Intel-ucode name(s)
intel_ucode=("${GRUB_BTRFS_INTEL_UCODE[@]:-intel-ucode.img}")

########################
### variables script ###
########################
## Internationalization (default : english)
export TEXTDOMAIN=grub-btrfs-git
export TEXTDOMAINDIR="/usr/share/locale"
## fr: paramêtre des chaînes --hint
## en: Parameter of the chains --hint (Translation unclear)
pboot=$(${grub_probe} --target="hints_string" "/boot" 2>/dev/null)
## UUID of the root partition
uuid=$(${grub_probe} "/" --target="fs_uuid" 2>/dev/null)
## UUID of the boot partition
buuid=$(${grub_probe} --target="fs_uuid" "/boot" 2>/dev/null)
## Parameters passed to the kernel
params="$GRUB_CMDLINE_LINUX $GRUB_CMDLINE_LINUX_DEFAULT"

##############
### Script ###
##############

typeset -A date_time
unset snapshots

# Create list of filesystem snapshots
oldIFS=$IFS
IFS=$'\n'

for snap in $($bindir/btrfs subvolume list -sa / --sort=-ogen | $bindir/awk '{gsub(/^["<FS_TREE>/"]+/,"",$NF);print $11" "$12"?"$NF}'); do
        snap_name="${snap#*"?"}"
        # Discard deleted snapshots
        if [ $snap_name = "DELETED" ]; then continue; fi
        snapshots+=("$snap_name")
        date_time[$snap_name]="${snap%"?"*}"
done
IFS=$oldIFS

# fr: on affiche le menu
# en: Display the menu
echo "submenu '$submenuname' {"

# fr: on traite la variable kernel
# en: Treat the kernel variables (Translation unclear)
for kernel in ${nkernel[@]}; do
	# fr: on test si le(s) nom(s) du(des) kernel existe(nt), autrement on affiche une erreur et on sort
	# en: Check the specified kernel(s) exist, if it/they don't, display an error and exit
	if [ ! -f /boot/$kernel ]; then gettext_printf $"Error: /boot/$kernel, kernel does not exist" >&2; exit 1; fi
	# fr: on vérifie le nombre de kernel présent, si >1 on crée un menu
	# en: If there are >1 kernels, create a menu
	if [ ${#nkernel[*]} != 1 ]; then echo "	submenu '$kernel' {
		submenu '---> Kernel: $kernel <---' { echo }"; fi
	# fr: On traite la variable snapshots
	# en: Treat the snapshots variable
	for item in ${snapshots[@]}; do
		# fr: affiche la liste des snapshots trouvés
		# en: Output name of snapshot
		gettext_printf $"Found Snapshot: %s\n" "$item ${date_time[$item]}" >&2
		# fr: on crée un menu pour chaque snapshot présent (nom + date de création)
		# en: Create a menu for remaining snapshots (name + creation date)
		echo "		submenu '$prefixentry $item [${date_time[$item]}]' {"
		# fr: si plusieurs kernel on été trouvé, on affiche un titre indicatif
		# en: if more than one kernel is found, create a menu
		if [ ${#nkernel[*]} != 1 ]; then echo "			submenu '---> Kernel: $kernel <---' { echo }"; fi
		# fr: on traite la variable de l'initramfs
		# en: Treat the initramfs variables (Translation unclear)
		for init in ${ninit[@]}; do
			# fr: on test si le(s) nom(s) du(des) initramfs existe(nt), autrement on affiche une erreur et on sort
			# en: Check the specified initramfs(es) exist, if it/they don't, display an error and exit
			if [ ! -f /boot/$init ]; then gettext_printf $"Error: /boot/$init, initramfs does not exist" >&2; exit 1; fi
			# fr: on traite chaque entrée des snapshots avec leurs kernel et initramfs respectifs
			# en: Specify a kernel and initramfs for every snapshot
			echo "\
			menuentry '$item $init' --class arch --class gnu-linux --class gnu --class os "\$menuentry_id_option" 'gnulinux-snapshots-$uuid'{
				load_video
				set gfxpayload=$GRUB_GFXPAYLOAD_LINUX
				if [ x"\$feature_platform_search_hint" = xy ]; then
					search --no-floppy --fs-uuid --set=root $pboot $buuid
				else
					search --no-floppy --fs-uuid --set=root $buuid
				fi
				echo	'Loading Linux snapshot ...'"
				# fr: on vérifie l'emplacement de la partition /boot
				# en: Check the location of the /boot partition
				if [ $uuid = $buuid ]; then
					echo "\
				linux	/$item/boot/$kernel root=UUID=$uuid rw rootflags=subvol=$item $params
				echo    'Loading initial ramdisk ...'"
				# fr: on vérifie la présence du microcode intel
				# en: Check intel microcode exist
					if [ -f /boot/$intel_ucode ]; then
						echo "\
				initrd	/$item/boot/$intel_ucode /$item/boot/$init"
					else
						echo "\
				initrd	/$item/boot/$init"
					fi
				else
					echo "\
				linux	/$kernel root=UUID=$uuid rw rootflags=subvol=$item $params
				echo    'Loading initial ramdisk ...'"
				# fr: on vérifie la présence du microcode intel
				# en: Check intel microcode exist
				if [ -f /boot/$intel_ucode ]; then
						echo "\
				initrd	/$intel_ucode /$init"
					else
						echo "\
				initrd  /$init"
					fi
				fi
				echo "\
			}"
		done
		echo "		}"
	done
	# fr: on oubli pas de fermer le menu si plusieurs kernels ont été trouvé
	# en: Don't forget to close menus if more than one kernel is found
	if [ ${#nkernel[*]} != 1 ]; then echo "	}"; fi
done
echo "}"