Initial version

backup.sh

+#!/usr/bin/env bash
+
+declare -r basedir="${HOME}/.backup"
+declare -r lock="${basedir}/lock"
+declare -ra rsnapshotargs=("-c" "${HOME}/.rsnapshot.home.conf")
+
+shopt -s nullglob
+
+getoldest() {
+	local -r interval="$1"
+
+	local oldest="-1" current="" dir=""
+	for dir in "${basedir}/${interval}."*; do
+		current="${dir##*.}"
+		if (( $current > $oldest )); then
+			oldest="${current}"
+		fi
+	done
+
+	if (( oldest >= 0 )); then
+		echo "${interval}.${oldest}"
+		return 0
+	else
+		return 1
+	fi
+}
+
+getnewest() {
+	local -r newest="${interval}.0"
+	[[ -e "${basedir}/$newest" ]] && echo "$newest"
+}
+
+getmtime() {
+	stat -c %Y "${basedir}/${1}"
+}
+
+epochtodate() {
+	dconv -i %s "$1"
+}
+
+getmtimeepoch() {
+	epochtodate "$(getmtime "$1")"
+}
+
+testdifference() {
+	local -r date1="$1" date2="$2" difference="$3"
+
+	dtest "$(dadd "$date1" "$difference")" -ge "$date2"
+}
+
+needsdaily() {
+	local -r newestdaily="$(getnewest daily)"
+	if [[ -z "$newestdaily" ]]; then
+		return 0
+	fi
+
+	local -r oldesthourly="$(getoldest hourly)"
+	if testdifference "$(getmtimeepoch "$newestdaily")" "$(getmtimeepoch "$oldesthourly")" 1d; then
+		return 0
+	fi
+
+	return 1
+}
+
+dobackup() {
+	ionice -c 2 -n 7 nice rsnapshot "${rsnapshotargs[@]}" -v "$1"
+}
+
+
+(
+	if ! flock -x -w 60 200; then
+		notify-send -u critical -a backup "Backup failed" "Failed to acquire lock"
+		exit 1
+	fi
+
+	if needsdaily; then
+		dobackup daily
+	fi
+
+	dobackup hourly
+) 200>"$lock"