backup-home

#!/bin/bash
#
# backup-home - back up home folder using rdiff-backup
#
# Copyright (C) 2019 Rodrigo Silva (MestreLion) <linux@rodrigosilva.com>
# License: GPLv3 or later, at your choice. See <http://www.gnu.org/licenses/gpl>
#------------------------------------------------------------------------------

set -Eeuo pipefail  # Exit on most errors.
trap '>&2 echo "error: line $LINENO, status $?: $BASH_COMMAND"' ERR
# See https://fvue.nl/wiki/Bash:_Error_handling for caveats

# Factory default options, configurable by config file
# See notes on default config file creation
dest=${1:-}
mount=
sudo_mount=0
excludes=(
	"$HOME"/.cache
	"$HOME"/.thumbnails
	"$HOME"/.local/share/Trash
	'**/.Trash-*'
	'**/*cache*/*'
	'**/Temp/*'
	'**/Temporary Internet Files/*'
)
options=(
	--print-statistics
	--terminal-verbosity 5
	--exclude-other-filesystems
	--exclude-special-files   # Exclude all device files, fifo files, socket files, and symbolic links.
	--include-symbolic-links  # Re-include symbolic links
)

# Config file location
config=${XDG_CONFIG_HOME:-$HOME/.config}/backup-home.conf

myname="${0##*/}"

fatal()   { [[ "${1:-}" ]] && echo "$myname: error: $@" >&2 ; exit 1; }
exists()  { type "$@" >/dev/null 2>&1; }
escape()  { printf '%q' "$1"; }

if ! exists rdiff-backup; then
	sudo apt install -y rdiff-backup
fi

if ! [[ -f "$config" ]]; then
	echo "warning: config file not found, creating blank one at $config" >&2
	cat > "$config" <<-EOF
	# backup-home config file
	# Sourced by bash, mind the syntax!

	# Full path to backup destination directory
	# Can also be set on each run by command line argument
	target=$(escape "$dest")

	# Mountpoint to auto-mount, usually backup destination dir or a parent
	# Usually requires an entry on /etc/fstab for the device, set to 'noauto'
	# Leave blank to disable automount
	mount=

	# If auto-mount and its mountpoint require sudo or not. 0 = no, 1 = yes
	sudo_mount=0

	# rdiff-backup general options
	# Must be a Bash array
	options=(
		--print-statistics
		--terminal-verbosity 5
		--exclude-special-files   # Exclude all device files, fifo files, socket files, and symbolic links.
		--include-symbolic-links  # Re-include symbolic links
	)

	# Paths to exclude from backup. Each entry will be prepended with
	# '--exclude=' and included to rdiff-backup options
	# Must be a Bash array
	excludes=(
		"\$HOME"/.cache
		"\$HOME"/.thumbnails
		"\$HOME"/.local/share/Trash
		'**/.Trash-*'
		'**/*cache*/*'
		'**/Temp/*'
		'**/Temporary Internet Files/*'  # Wine "bottles"
	)

	EOF
fi

source "$config" || fatal "could not read config file $config"

dest=${dest:-$target}
[[ "$dest" ]] || fatal "backup destination directory not set"

for exclude in "${excludes[@]}"; do
	options+=(--exclude="$exclude")
done

if [[ "$mount" ]]; then
	if ((sudo_mount)); then sudo=sudo; else sudo=env; fi
	$sudo mount "$mount"
fi

cd "$HOME" &&
rdiff-backup "${options[@]}" -- "$HOME" "$dest"