actually

modules/home/programs/terminal/scripts/bin/plan-disk-burns.sh

@@ -1,5 +1,117 @@
 #!/usr/bin/env bash
+#
+# plan-disk-burns.sh - Split a set of files into per-disc manifests that each
+# fit on a Blu-ray (BD-R). Packs files greedily by accumulated size and writes
+# one manifest per disc, then prints a summary you can review before burning.
+#
+# It does NOT burn anything. It only produces discNN_files.txt manifests.
+
 set -euo pipefail
 
-echo "plan-disk-burns: placeholder"
+usage() {
-echo "runtime tools available: smartctl, lsblk"
+  cat <<'EOF'
+Usage: plan-disk-burns.sh [options]
+
+Options:
+  -s DIR       Source directory to scan (default: current directory)
+  -p GLOB      Filename pattern, case-insensitive (default: *.raf)
+  -o DIR       Output directory for manifests (default: ./br-manifests)
+  -l LABEL     Volume label prefix for the burn commands; disc number is
+               appended, e.g. -l PHOTOS yields PHOTOS_1 (default: DISK)
+  -c GiB       Per-disc capacity in GiB, may be fractional e.g. 22.5 (default: 23)
+  -h           Show this help
+
+Output:
+  DIR/disc01_files.txt, disc02_files.txt, ...   absolute file paths (one per line)
+
+Manifests use absolute paths so burning works from any directory. The printed
+xorriso command strips the source root and roots everything at the disc root.
+EOF
+}
+
+src="."
+pattern="*.raf"
+outdir="./br-manifests"
+label="DISK"
+cap_gib=23
+
+while getopts ":s:p:o:l:c:h" opt; do
+  case "$opt" in
+    s) src="$OPTARG" ;;
+    p) pattern="$OPTARG" ;;
+    o) outdir="$OPTARG" ;;
+    l) label="$OPTARG" ;;
+    c) cap_gib="$OPTARG" ;;
+    h) usage; exit 0 ;;
+    \?) echo "Unknown option: -$OPTARG" >&2; usage; exit 2 ;;
+    :)  echo "Option -$OPTARG requires an argument" >&2; exit 2 ;;
+  esac
+done
+
+[[ -d "$src" ]] || { echo "Source directory not found: $src" >&2; exit 1; }
+[[ "$cap_gib" =~ ^[0-9]+(\.[0-9]+)?$ ]] || { echo "Capacity must be a number (GiB), e.g. 23 or 22.5: $cap_gib" >&2; exit 1; }
+
+# Resolve to an absolute path so manifests and the burn command are CWD-independent.
+src=$(realpath "$src")
+
+limit=$(awk -v c="$cap_gib" 'BEGIN { printf "%d", c * 1024 * 1024 * 1024 }')
+mkdir -p "$outdir"
+rm -f "$outdir"/disc*_files.txt
+
+# Collect files sorted by path so discs group naturally by folder/date.
+mapfile -d '' entries < <(find "$src" -type f -iname "$pattern" -printf '%s\t%p\0' | sort -z -t$'\t' -k2)
+
+if [[ ${#entries[@]} -eq 0 ]]; then
+  echo "No files matching '$pattern' under '$src'." >&2
+  exit 1
+fi
+
+disc=1
+disc_bytes=0
+total_bytes=0
+total_files=0
+declare -A disc_bytes_map disc_files_map
+
+manifest() { printf '%s/disc%02d_files.txt' "$outdir" "$1"; }
+
+for entry in "${entries[@]}"; do
+  size="${entry%%$'\t'*}"
+  path="${entry#*$'\t'}"
+
+  if (( size > limit )); then
+    echo "WARNING: '$path' ($((size/1024/1024)) MiB) exceeds disc capacity (${cap_gib} GiB); skipping." >&2
+    continue
+  fi
+
+  if (( disc_bytes + size > limit )); then
+    disc=$(( disc + 1 ))
+    disc_bytes=0
+  fi
+
+  printf '%s\n' "$path" >> "$(manifest "$disc")"
+  disc_bytes=$(( disc_bytes + size ))
+  disc_bytes_map[$disc]=$disc_bytes
+  disc_files_map[$disc]=$(( ${disc_files_map[$disc]:-0} + 1 ))
+  total_bytes=$(( total_bytes + size ))
+  total_files=$(( total_files + 1 ))
+done
+
+echo "=== Manifest summary (cap ${cap_gib} GiB/disc) ==="
+for ((d=1; d<=disc; d++)); do
+  [[ -f "$(manifest "$d")" ]] || continue
+  mib=$(( disc_bytes_map[$d] / 1024 / 1024 ))
+  printf '  disc%02d: %5d files, %6d MiB  ->  %s\n' \
+    "$d" "${disc_files_map[$d]}" "$mib" "$(manifest "$d")"
+done
+printf '  TOTAL : %5d files, %6d MiB across %d disc(s)\n' \
+  "$total_files" "$(( total_bytes / 1024 / 1024 ))" "$disc"
+
+echo
+echo "=== Burn commands (review, then run one per disc) ==="
+for ((d=1; d<=disc; d++)); do
+  [[ -f "$(manifest "$d")" ]] || continue
+  # SC2016 - The $(cat ...) is literal text printed for the user to run later, not meant to expand here.
+  # shellcheck disable=SC2016
+  printf 'xorriso -outdev /dev/sr0 -volid "%s_%d" \\\n  -map_l %q / $(cat %q) -- -commit -eject\n\n' \
+    "$label" "$d" "$src" "$(manifest "$d")"
+done

modules/home/programs/terminal/scripts/default.nix

@@ -16,7 +16,7 @@ let
   #     my-new-thing    = { runtimeInputs = with pkgs; [ jq curl ]; };
   #   };
   scriptDefs = {
-    plan-disk-burns = { runtimeInputs = with pkgs; [ smartmontools util-linux ]; };
+    plan-disk-burns = { runtimeInputs = with pkgs; [ coreutils findutils gawk xorriso ]; };
   };
 
   mkScript = name: def: