Rewrite

dns/clear-cache.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env sh
+
+verify_commands() {
+  commands=("systemd-resolve" "resolvectl")
+  for command in "${commands[@]}"; do
+    which $command &> /dev/null
+    if [ $? -ne 0 ]; then
+      echo "command '$command' not found"
+      exit 1
+    fi
+  done
+}
+
+main() {
+  verify_commands
+
+  # elevate root rights if not present
+  if [ "$UID" -ne 0 ]; then
+    sudo "$0" "$@"
+    exit $?
+  else
+    systemd-resolve --flush-caches
+    resolvectl flush-caches
+    systemd-resolve --statistics
+
+    if [ $? -ne 0 ]; then
+      echo "Failed to flush cache. Maybe the systemd-resolved service is not started/enabled?"
+      exit 1
+    fi
+  fi
+}
+
+main $@