CONCEPT:
	news


DESCRIPTION:
	This document describes the news system used in Nightfall.
	News is intended to provide a general system for bulletin
	boards and similar objects. It is similar to the Usenet
	news system. Articles are stored in a central area, /news.
	Articles (Messages) are stored as files within this
	directory. Only the news demon object is allowed to write
	and read in the /news directory. Interfaceing to the
	news demon is done via interface functions in the news
	demon.
	
	Typically news are read and written by a bulletin
	board object or by a newsreader. Player buletin boards
	should of course be limited to specific news groups.
	A newsreader might be intelligent in that it autmatically
	shows new messages. Groups may be moderated, then only the
	moderator can write there. There are also flags whether a
	board is a wiz_only board and who may remove messages.

	Security is in several levels. It may be 0, then every
	effective userid might read and write and delete articles,
	although the news demon will still look for the match of
	the sender field with certain group requirements. This level
	of security is to make it possible to create groups
	accessible by bulletin boards which have no euid.

	Security level 1 means that euid check is done, for reading
	and writing. This still allows for bulltin boards, but those
	must have root euid and thus the ability to seteuid to the
	euid of the object using the bulletin board (normally the
	player). This feature requires native gamedriver mode.

	Saved news file format (formal notation):

	int security;	/* wheter euid check is done, 0 or 1 */
	mixed *accesslist = ({
	   mixed *readaccess;    /* who can read messages */
	   mixed *writeaccess;   /* who can write messages */
	   mixed *deleteaccess;  /* who can delete messages */
	   mixed *controlaccess; /* who can control the accesslist */
	})
	mixed *messages = ({
	   mixed *msg1; mixed *msg2; ... mixed *msgN;
	})

	An access entry can be be one of the following:
	- an effective userid (string)
	- one of the keywords "wizard", "all", "author"
	- a wizard level (integer) which is required minimal
	- an array of one of the plain types above (Alternative).

	A message looks as follows:

	mixed *message = ({
	   string author;       /* who wrote the message */
	   string subject;      /* the subject */
	   string *groups;      /* news groups where this was posted */
	   int date;            /* date of message written */
	   string messageid;    /* a unique string */
	   string *referenceid; /* list of references */
	   int expire;          /* when message expires */
	   string body;         /* the contents of the message */
	})

	The news demon (/secure/news, or /obj/news) provides the
	following functions:

	int success = PostMessage(mixed *message)
	  Tells the demon to insert the message in the news database.
	  Depending on security level, euid or message.author is
	  checked if this is allowed.

	int success = DeleteMessage(string *groups, string messageid)
	  Remove a message from the database.

	mixed *messagelist = ReadMessageHeaders(string group)
	  Get all message headers (complete info, but without
	  body) of newsgroup <group>.

	mixed *message = ReadMessage(string *groups, string messageid)
	  Retrieve a message from the database.


SEE ALSO: