youtube-dl playlist

build-cache-for-existing.sh

#!/usr/bin/env sh

for n in *.mp3
do if [[ "$n" =~ -[-_0-9a-zA-Z]{11}.mp3$ ]]
   then echo "youtube ${n: -15: 11}" >> downloaded.txt
   fi
done

download-playlist.sh

#!/usr/bin/env sh

export PLAYLIST_ID=XXXXXXXXXXXXXX
youtube-dl \
  --download-archive downloaded.txt \
  --continue \
  --no-post-overwrites \
  --no-overwrites \
  --format bestaudio --extract-audio --audio-format mp3 \
  --yes-playlist $PLAYLIST_ID