steam_is_user_logged_on();
Returns: String
This function will return true if the Steam client
currently has a live connection to the Steam servers. If it returns
false, it means there is no active connection due to
either a networking issue on the local machine, or the Steam server
being down or busy.
if steam_is_user_logged_on()
{
steam_publish_workshop_file("SaveData.txt", "",
"Save Text", "Workshop saved text file");
}
The above code will check to see if the user is logged onto the Steam server and if so it will publish a file to the Workshop.