Add HDD device previews and root guards

HDD/erase-storage.sh

@@ -9,12 +9,19 @@ SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 # shellcheck source=lib/common.sh
 source "${SCRIPT_DIR}/../lib/common.sh"
 
+if [[ "$EUID" -ne 0 ]]; then
+    common::log "WARNING: This script must be run as root (for example, with sudo)."
+    common::die "stopping before processing arguments or checking dependencies"
+fi
+
 SCRIPT_HELP=$(cat <<'HELP'
 Usage: sudo ./HDD/erase-storage.sh DEVICE [zero|random]
 
 For a partition, writes one full pass of zeros (default) or pseudorandom data.
 For a whole disk, detects and runs a supported ATA Secure Erase or NVMe Sanitize
 operation. Whole-disk erasure requires two separate confirmations.
+Lists available block devices and mount points before continuing, highlighting
+the selected device in red when run in a terminal.
 At startup, asks you to confirm that you can keep the computer and drive
 powered and connected for the hours the operation may take.
 
@@ -53,20 +60,17 @@ case "$FILL_MODE" in
         ;;
 esac
 
-common::log "WARNING: Erasing data may take hours. Do not power off, reboot, or suspend the computer, or disconnect power or the drive."
-common::confirm "Can the computer and drive remain powered and connected until the operation finishes?" || exit 0
-
-for required_command in findmnt lsblk readlink swapon date dd sleep; do
+for required_command in awk findmnt lsblk readlink swapon date dd sleep; do
     common::require_cmd "$required_command"
 done
 
-[[ "$EUID" -eq 0 ]] || common::die "this script must be run as root (for example, with sudo)"
 [[ -b "$DEVICE_INPUT" ]] || common::die "$DEVICE_INPUT does not exist or is not a block device"
 
 DEVICE="$(readlink -f -- "$DEVICE_INPUT")" || common::die "cannot resolve device path: $DEVICE_INPUT"
 DEVICE_TYPE="$(lsblk -dnro TYPE -- "$DEVICE")" || common::die "cannot determine device type"
 [[ "$DEVICE_TYPE" == "part" || "$DEVICE_TYPE" == "disk" ]] \
     || common::die "only a partition or a whole disk is accepted (detected: $DEVICE_TYPE)"
+common::show_block_devices "$DEVICE" || common::die "cannot list available block devices"
 
 ROOT_SOURCE="$(findmnt -n -o SOURCE /)" || common::die "cannot determine the root filesystem device"
 ROOT_SOURCE="${ROOT_SOURCE%%\[*}"
@@ -117,6 +121,9 @@ while IFS= read -r child_device; do
     done <<< "$ACTIVE_SWAP_DEVICES"
 done <<< "$DEVICE_TREE"
 
+common::log "WARNING: Erasing data may take hours. Do not power off, reboot, or suspend the computer, or disconnect power or the drive."
+common::confirm "Can the computer and drive remain powered and connected until the operation finishes?" || exit 0
+
 if [[ "$DEVICE_TYPE" == "part" ]]; then
     [[ $# -eq 1 || "$FILL_MODE" == "zero" || "$FILL_MODE" == "random" ]] \
         || common::die "invalid fill mode; use 'zero' or 'random'"