bootstrap: Without --allow-disk-wipe just ask for confirmation

bootstrap.sh

@@ -39,6 +39,7 @@ while [[ $# -gt 0 ]]; do
       echo "        Repeatable. Specify target path relative to target system's /"
       echo "    --allow-disk-wipe"
       echo "        Allow the script to wipe the disk and proceed with the installation."
+      echo "        Without this option the user will be asked interactively for confirmation."
       echo "    --kernel-param PARAMETER"
       echo "        Add PARAMETER to EFI kernel command line."
       echo "    --vm"
@@ -158,16 +159,19 @@ if [ -n "$raid_action" -a "$bios" = false ]; then
   >&2 echo "This combination is currently NOT tested and may or may not work."
   >&2 echo "Known bug: Multiple EFI system partitions are created, but only one populated (that is, if you're lucky and nothing else breaks before that)."
   >&2 echo "(For redundancy in case of disk failure you might want to copy grubx64.efi as EFI/BOOT/BOOTX64.EFI onto all ESPs or something...)"
-  >&2 read -p answer "Continue anyway? [yN] "
+  >&2 read -r -p answer "Continue anyway? [yN] "
   if [ "y" != "$answer" ]; then
     exit 1
   fi
 fi
 
 if [ "$wipe" != true ]; then
-  >&2 echo "disk wiping not allowed. cannot proceed."
-  >&2 echo "use --allow-disk-wipe to proceed"
-  exit 1
+  echo "This script will wipe some or all data on the following disks:"
+  lsblk -o name,size,type,fstype,label,mountpoint "${devices[@]}"
+  read -r -p "Allow wiping data? [yN] " answer
+  if [ "y" != "$answer" ]; then
+    exit 1
+  fi
 fi