|item_list||A (previously created) DS list index.|
This function will populate a DS list with all the published
file IDs for the items that the user is currently subscribed to.
You must first create the list and store the index in a variable,
then pass this to the function. The function will return
true if everything is correct and the Steam API is
initialised, or false if there is an error.
steam_list = ds_list_create();
The above code will create an empty DS list and then populate it with the file IDs for all subscribed items for the user.