rwhod(8c)																 rwhod(8c)

Name
       rwhod - system status server

Syntax
       /etc/rwhod [ -b ] [ -l ]

Description
       The  command  is the server which maintains the database used by the and programs.  Its operation is predicated on the ability to broadcast
       messages on a network.

       The command operates as both a producer and consumer of status information.  As a producer of information it periodically queries the state
       of the system and constructs status messages which are broadcast on a network.

       As a consumer of information, listens for the status messages of the other servers, validating them, then recording them in a collection of
       files located in the directory

       The server transmits and receives messages at the port indicated in the rwho service specification. For more information, see The  messages
       sent and received, take the following form:
       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 calculated by the 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  as	an
       integer.   The  host name included is the name returned by the 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 entry for
       each active terminal line and a value indicating the time since a character was last received on the terminal line.

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

       Status  messages are generated approximately once every 3 minutes.  The command performs an on every 30 minutes to guard against the possi-
       bility that this file is not the system image currently operating.

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

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

Restrictions
       Because the daemon sends its information in broadcast packets it generates a large amount of network traffic.  On large networks the  extra
       traffic	may  be  objectionable.   Therefore,  the  daemon is disabled by default.  To make use of the daemon for both the local and remote
       hosts, remove the comment symbols (#) from in front of the lines specifying in the file.

       If the daemon is not running on a remote machine, the machine may incorrectly appear to be down when you use the command to  determine  its
       status.	See the reference page for more information.

       If  a  system  has  more  than 40 users logged in at once, the number of users displayed by the and commands is incorrect.  Users who login
       after the fortieth user, will fail to appear in the output of the and commands. This is because the  maximum  size  limit  of  an  Ethernet
       packet is 1500 bytes, and the daemon must broadcast its information in a single packet.

See Also
       ruptime(1c), rwho(1c)

																	 rwhod(8c)