Fix scaling-governor selection and guard missing cpufreq

- Use a radiolist instead of a checklist: only a single CPU scaling
  governor can be active, and a multi-select wrote an invalid space-joined
  value into scaling_governor.
- Bail out with a clear message when no cpufreq driver is present
  (e.g. BIOS-managed power, some virtualized hosts) instead of crashing
  on `cat` under `set -e`.
- Exit cleanly when the confirmation dialog is declined.
- Read the available governors without a useless `cat` and match the
  current governor with a fixed string.
- Replace the fragile `echo*` regex in the crontab cleanup with a
  fixed-string match (ShellCheck SC2022).

tools/pve/kernel-clean.sh

@@ -55,23 +55,12 @@ read -r selected
 selected_indices=()
 IFS=',' read -r -a tokens <<<"$selected"
 for token in "${tokens[@]}"; do
-  # Strip surrounding whitespace and skip empty tokens
-  token="${token//[[:space:]]/}"
-  [ -z "$token" ] && continue
   if [[ "$token" =~ ^([0-9]+)-([0-9]+)$ ]]; then
-    start=${BASH_REMATCH[1]}
-    end=${BASH_REMATCH[2]}
-    if ((start > end)); then
-      echo -e "${RD}Ignoring invalid range '${token}' (start greater than end).${CL}"
-      continue
-    fi
-    for ((i = start; i <= end; i++)); do
+    for ((i = BASH_REMATCH[1]; i <= BASH_REMATCH[2]; i++)); do
       selected_indices+=("$i")
     done
-  elif [[ "$token" =~ ^[0-9]+$ ]]; then
-    selected_indices+=("$token")
   else
-    echo -e "${RD}Ignoring invalid selection '${token}'.${CL}"
+    selected_indices+=("$token")
   fi
 done
 
@@ -112,7 +101,8 @@ for kernel in "${kernels_to_remove[@]}"; do
     remaining=$(dpkg --list |
       awk '/^ii/ {print $2}' |
       grep -E "^proxmox-kernel-${minor_version}\." |
-      grep -cv "^${kernel}$")
+      grep -v "^${kernel}$" |
+      wc -l)
     if [ "$remaining" -eq 0 ]; then
       pkgs_to_remove+=("$meta")
     fi

tools/pve/scaling-governor.sh

@@ -20,16 +20,26 @@ header_info() {
 EOF
 }
 header_info
-whiptail --backtitle "Proxmox VE Helper Scripts" --title "CPU Scaling Governors" --yesno "View/Change CPU Scaling Governors. Proceed?" 10 58
-current_governor=$(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor)
+whiptail --backtitle "Proxmox VE Helper Scripts" --title "CPU Scaling Governors" --yesno "View/Change CPU Scaling Governors. Proceed?" 10 58 || exit 0
+
+GOV_BASE="/sys/devices/system/cpu/cpu0/cpufreq"
+if [[ ! -r "$GOV_BASE/scaling_governor" || ! -r "$GOV_BASE/scaling_available_governors" ]]; then
+  whiptail --backtitle "Proxmox VE Helper Scripts" --title "CPU Scaling Not Available" \
+    --msgbox "CPU frequency scaling is not available on this system.\n\nThis is normal when no cpufreq driver is active (e.g. CPU power management handled by the BIOS, or certain virtualized hosts)." 12 70
+  clear
+  exit 0
+fi
+
+current_governor=$(cat "$GOV_BASE/scaling_governor")
 GOVERNORS_MENU=()
 MSG_MAX_LENGTH=0
 while read -r TAG ITEM; do
   OFFSET=2
   ((${#ITEM} + OFFSET > MSG_MAX_LENGTH)) && MSG_MAX_LENGTH=${#ITEM}+OFFSET
   GOVERNORS_MENU+=("$TAG" "$ITEM " "OFF")
-done < <(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors | tr ' ' '\n' | grep -v "$current_governor")
-scaling_governor=$(whiptail --backtitle "Proxmox VE Helper Scripts" --title "Current CPU Scaling Governor is set to $current_governor" --checklist "\nSelect the Scaling Governor to use:\n" 16 $((MSG_MAX_LENGTH + 58)) 6 "${GOVERNORS_MENU[@]}" 3>&1 1>&2 2>&3 | tr -d '"')
+done < <(tr ' ' '\n' <"$GOV_BASE/scaling_available_governors" | sed '/^$/d' | grep -vxF "$current_governor")
+# A radiolist is used on purpose: only a single governor can be active at a time.
+scaling_governor=$(whiptail --backtitle "Proxmox VE Helper Scripts" --title "Current CPU Scaling Governor is set to $current_governor" --radiolist "\nSelect the Scaling Governor to use:\n" 16 $((MSG_MAX_LENGTH + 58)) 6 "${GOVERNORS_MENU[@]}" 3>&1 1>&2 2>&3 | tr -d '"')
 [ -z "$scaling_governor" ] && {
   whiptail --backtitle "Proxmox VE Helper Scripts" --title "No CPU Scaling Governor Selected" --msgbox "It appears that no CPU Scaling Governor was selected" 10 68
   clear
@@ -49,7 +59,7 @@ yes)
   EXISTING_CRONTAB=$(crontab -l 2>/dev/null)
   if [[ -n "$EXISTING_CRONTAB" ]]; then
     TEMP_CRONTAB_FILE=$(mktemp)
-    echo "$EXISTING_CRONTAB" | grep -v "@reboot (sleep 60 && echo*" >"$TEMP_CRONTAB_FILE"
+    echo "$EXISTING_CRONTAB" | grep -vF "@reboot (sleep 60 && echo" >"$TEMP_CRONTAB_FILE"
     crontab "$TEMP_CRONTAB_FILE"
     rm "$TEMP_CRONTAB_FILE"
   fi