RWHOD(8N)               COMMAND REFERENCE               RWHOD(8N)



NAME
     rwhod - system status server

SYNOPSIS
     /etc/rwhod [ -s ]

DESCRIPTION
     Rwhod is the server which maintains the database used by the
     rwho and ruptime programs.  Its operation is predicated on
     the ability to broadcast messages on a network.

     Rwhod 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, it listens for other rwhod servers' status
     messages, validating them, then recording them in a
     collection of files located in the database files
     /usr/lib/rwhod.dir and /usr/lib/rwhod.pag.

     The rwho server transmits and receives messages at the port
     indicated in the rwho service specification, see
     services(5n).  The messages sent and received, are of the
     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 {
               structoutmp 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
     uptime program, and represent load averages over the 5, 10,
     and 15 minute intervals prior to a server's transmission.
     The host name included is that returned by the
     gethostname(2) system call.  The array at the end of the



Printed 10/17/86                                                1

RWHOD(8N)               COMMAND REFERENCE               RWHOD(8N)



     message contains information about the users logged in to
     the sending machine.  This information includes the contents
     of the utmp(5) entry for each non-idle terminal line and a
     value indicating the time since a character was last
     received on the terminal line.

     Messages received by the rwho server are discarded unless
     they originated at a rwho 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 rwhod are placed in the database.

     Status messages are generated approximately once every 3
     minutes.

OPTIONS
     -s   Send only mode; act as a transmiter only.  No
          information is collected on this host.

RETURN VALUE
     [0] Rwhod is running.

     [1] Rwhod is not running.

SEE ALSO
     ruptime(1n), rwho(1n).

CAVEATS
     The number of users reported is limited to fifty.

     As the number of hosts on the network increases, the number
     of rwho packets increases as the square of the number of
     hosts.  This version of rwhod is more efficient than
     previous versions but it a full loaded network can have a
     noticeable impact on performance.




















Printed 10/17/86                                                2

%%index%%
na:72,64;
sy:136,153;
de:289,2177;2610,771;
op:3381,168;
rv:3549,199;
ca:3858,464;
se:3748,110;
%%index%%000000000129