Pacman hook: Take a snapshot of the root dataset before any operation

zfs_snapshot.hook

# ZFS Root Snapshot Pacman Hook
# 2021 Filipe Rodrigues<shello@shello.org>
#
# Take a snapshot of the root dataset before any pacman operation.
# See: https://man.archlinux.org/man/alpm-hooks.5
# Depends on: pacman, zfs, coreutils
# Location: /etc/pacman.d/hooks/zfs_snapshot.hook

[Trigger]
Operation = Install
Operation = Upgrade
Operation = Remove
Type = Package
Target = *

[Action]
Description = Taking a snapshot of root dataset 
When = PreTransaction
Exec = /bin/sh -c '/usr/bin/zfs snapshot "$(/usr/bin/zfs list -Ho name /)"@"auto-pacman-$(/usr/bin/date +%F_%T_%Z)"'