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rwhod(8)							     rwhod(8)



NAME

  rwhod	- The system status server

SYNOPSIS

  /usr/sbin/rwhod [-b  | -l]

OPTIONS

  -b  Sets the broadcast only mode.  Sends outgoing rwho packets, but ignores
      incoming ones.

  -l  Sets the listen only mode.  Collects incoming rwho packets from the
      network, but does	not broadcast rwho data.

DESCRIPTION

  The rwhod daemon is the server that maintains	the database used by the
  rwho(1) and ruptime(1) programs.  Its	operation is predicated	on the abil-
  ity to broadcast messages on a network.

  The rwhod server operates as both a producer and consumer of status infor-
  mation. As a producer	of information,	it periodically	queries	the state of
  the system and constructs status messages, which are broadcast on a net-
  work.	As a consumer of information, it listens for other rwhod servers'
  status messages, validating them, then recording them	in a collection	of
  files	located	in the /var/rwho directory.

  The server transmits and receives messages at	the port indicated in the
  rwho service specification; see services(4). The messages sent and received
  have the following format:

       struct  outmp {
	       char    out_line[8];	       /* tty name */
	       char    out_name[8];	       /* user id */
	       long    out_time;	       /* time on */
       };

       struct  whod {
	       char    wd_vers;
	       char    wd_type;
	       char    wd_fill[2];
	       int     wd_sendtime;
	       int     wd_recvtime;
	       char    wd_hostname[32];
	       int     wd_loadav[3];
	       int     wd_boottime;
	       struct  whoent {
		       struct  outmp we_utmp;
		       int     we_idle;
	       } wd_we[1024 / sizeof (struct whoent)];
       };

  All fields are converted to network byte order prior to transmission.	 The
  load averages	are as calculated by the w(1) program, and represent load
  averages over	the 5-,	10-, and 15-minute intervals prior to a	server's
  transmission;	they are multiplied by 100 for representation in an integer.
  The hostname included	is that	returned by the	gethostname(2) system call,
  with any trailing domain name	omitted. The array at the end of the message
  contains information about the users logged in to the	sending	machine.
  This information includes the	contents of the	utmp(4)	entry for each noni-
  dle terminal line and	a value	indicating the time in seconds since a char-
  acter	was last received on the terminal line.

  Messages received by the rwho	server are discarded unless they originated
  at an	rwho server's port.  In	addition, if the host's	name, as specified in
  the message, contains	any unprintable	ASCII characters, the message is dis-
  carded.  Valid messages received by rwhod are	placed in files	named
  whod.hostname	in the /var/rwho directory.  These files contain only the
  most recent message, in the format previously	described.

  Status messages are generated	approximately once every 3 minutes.  rwhod
  performs an nlist(3) on /vmunix every	30 minutes to guard against the	pos-
  sibility that	this file is not the system image currently operating.

FILES

  /usr/sbin/rwhod
      Specifies	the command path

  /var/rwho/whod.hostname
      Contains the most	recent valid message received by rwhod from hostname.

SEE ALSO

  Commands: rwho(1), ruptime(1)