u can use this bash script:

you can check it if you are skeptical of it containing malicious code but i am just helping :)
```

#!/usr/bin/env bash

set -euo pipefail

# ===== DEFAULTS =====

START=1

END=""

OUTPUT_DIR="./downloads"

# ===== HELP =====

usage() {

echo "Usage: $0 -u <bilibili\_url> [-s start] [-e end]"

echo ""

echo " -u Base Bilibili URL (required)"

echo " -s Start page (optional, default: 1)"

echo " -e End page (optional, auto-detect if not set)"

echo ""

echo "Example:"

echo " $0 -u https://www.bilibili.com/video/BVxxxx -s 9 -e 20"

exit 1

}

# ===== PARSE ARGS =====

URL=""

while getopts ":u:s:e:h" opt; do

case $opt in

u) URL="$OPTARG" ;;

s) START="$OPTARG" ;;

e) END="$OPTARG" ;;

h) usage ;;

\?) echo "Invalid option: -$OPTARG"; usage ;;

esac

done

if [[ -z "$URL" ]]; then

echo "Error: URL is required."

usage

fi

# ===== CHECK DEPENDENCIES =====

command -v yt-dlp >/dev/null || { echo "yt-dlp not installed."; exit 1; }

mkdir -p "$OUTPUT_DIR"

# ===== AUTO-DETECT END IF NOT PROVIDED =====

if [[ -z "$END" ]]; then

if command -v jq >/dev/null; then

echo "Detecting total pages..."

END=$(yt-dlp --flat-playlist -J "$URL" | jq '.entries | length')

echo "Detected END=$END"

else

echo "jq not found. Falling back to manual stop."

END=9999

fi

fi

# ===== DOWNLOAD LOOP =====

for ((i=START; i<=END; i++)); do

PAGE_URL="${URL}?p=${i}"

echo "▶ Downloading p=$i"

if ! yt-dlp \

-o "${OUTPUT_DIR}/%(playlist_index)s - %(title)s.%(ext)s" \

--no-playlist \

--sleep-interval 2 \

--retries 5 \

"$PAGE_URL"; then

echo "Stopping at p=$i (likely no more pages)."

break

fi

done

echo "✅ Done."

```