From a Youtube user / channel URL find the RSS feed

yt-rss.bash

#!/usr/bin/env bash
#
# About : This script allows you to pass in the URL to a youtube users page as argument one and 
#         this script will output the RSS feed for the channel / user (simiilar to notifications)
#
# Copyright Henri Shustak 2024
# Licence : GNUGLP 3 later 
# https://www.gnu.org/licenses/gpl.html
#
#
# version 1.0 - inital implimentation - you can retrive rss feeds by user name or channel id
# version 1.1 - added support for playlists - now you can retrive rss feeds for a playlist

if [[ $# -ne 1 ]] ; then
    echo ""
    echo "   usage : ./yt-rss.bash <youtube-username>"
    echo "         : ./yt-rss.bash <youtube-url-to-users-page>"
    echo "         : ./yt-rss.bash <youtube-url-to-playlist>"
    echo ""
    echo " example : ./yt-rss.bash \"https://www.youtube.com/@tested\""
    echo ""
fi

list_mode=false
CHANNEL_URL="${1}"
if [[ $(echo "${CHANNEL_URL}" | grep "list=" > /dev/null ; echo $?) == 0 ]] ; then
  # find the list
  CHANNEL_URL=$(echo "${CHANNEL_URL}" | awk -F "list=" '{print$2}')
  list_mode=true
elif [[ $(echo "${CHANNEL_URL}" | grep "@" > /dev/null ; echo $?) == 0 ]] ; then
  # find the channel ID rather than the username
  CHANNEL_URL=$(curl -L "${CHANNEL_URL}" 2>/dev/null| grep '"externalId":"' | awk -F '"externalId":"' '{print $2}' | awk -F '"' '{print $1}')
elif [[ $(echo "${CHANNEL_URL}" | grep "youtube.com/channel/" > /dev/null ; echo $?) == 0 ]] ; then
  # extract the channel ID from the URL
  CHANNEL_URL=$(echo "${CHANNEL_URL}" | awk -F "youtube.com/channel/" '{print$2}')
fi

if [[ "${CHANNEL_URL}" == "" ]] ; then
  echo "ERROR! : Unable to extract the RSS Feed"
  exit -1
fi

if [[ "${list_mode}" == "true" ]] ; then
  # return playlist rss url
  echo "https://www.youtube.com/feeds/videos.xml?playlist_id=${CHANNEL_URL}"
else
  # return channel id rss url
  echo "https://www.youtube.com/feeds/videos.xml?channel_id=${CHANNEL_URL}"
fi

exit 0