flake parts

scripts/home-manager-backup.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [[ $# -eq 0 ]]; then
+  exit 0
+fi
+
+target_path="${1:?expected target path}"
+base_backup="${target_path}.hm-bak"
+
+if [[ ! -e "$base_backup" ]]; then
+  mv "$target_path" "$base_backup"
+  exit 0
+fi
+
+timestamp="$(date +%Y%m%d-%H%M%S)"
+backup_path="${base_backup}.${timestamp}"
+suffix=0
+
+while [[ -e "$backup_path" ]]; do
+  suffix=$((suffix + 1))
+  backup_path="${base_backup}.${timestamp}.${suffix}"
+done
+
+mv "$target_path" "$backup_path"