usage_args="<command to execute per playlist> [<spotify_user> [<curl_options>]"
# shellcheck disable=SC2034
usage_description="
Executes a command per Spotify playlist for a given user
The command must be quoted as the first argument and is templated, replacing the placeholders {playlist} and {playlist_id} in the command string
Useful for combining with other spotify_*.sh scripts, such as downloading all the 'Artist - Track' names or all the Spotify URIs as backups
Requires \$SPOTIFY_USER be set in the environment or else given as the second arg
Requires \$SPOTIFY_ACCESS_TOKEN in the environment (can generate from spotify_api_token.sh) or will auto generate from \$SPOTIFY_CLIENT_ID and \$SPOTIFY_CLIENT_SECRET if found in the environment