updated spotify_playlist_tracks.sh

spotify_playlist_tracks.sh

@@ -27,9 +27,7 @@ usage_args="<playlist_id> [<curl_options>]"
 usage_description="
 Returns track names for the spotify playlist for given playlist id argument or \$SPOTIFY_PLAYLIST (get this from spotify_playlists.sh)
 
-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
-
-export SPOTIFY_ACCESS_TOKEN=\"\$('$srcdir/spotify_api_token.sh')\"
+Requires \$SPOTIFY_CLIENT_ID and \$SPOTIFY_CLIENT_SECRET to be defined in the environment
 "
 
 # shellcheck disable=SC1090
@@ -55,6 +53,10 @@ get_next(){
     jq -r '.next' <<< "$output"
 }
 
+if [ -z "${SPOTIFY_ACCESS_TOKEN:-}" ]; then
+    export SPOTIFY_ACCESS_TOKEN="$("$srcdir/spotify_api_token.sh")"
+fi
+
 while [ -n "$url_path" ] && [ "$url_path" != null ]; do
     output="$("$srcdir/spotify_api.sh" "$url_path" "$@")"
     # shellcheck disable=SC2181