rwhod(1M)                                               rwhod(1M)



     NAME
          rwhod - system status server

     SYNOPSIS
          /etc/rwhod

     DESCRIPTION
          rwhod is the server maintaining the database used by rwho(1)
          and ruptime(1).  Its operation is predicated on the ability
          to broadcast messages on a network.

          rwhod both produces and consumes status information.  It
          periodically queries the state of the system and constructs
          status messages which are broadcast on a network.  It also
          listens for other rwhod servers' status messages, validates
          them, then records them in files in the directory
          /usr/spool/rwho.

          The rwho server transmits and receives messages at the port
          indicated in the rwho service specification, see
          services(4N).  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 {
                    struct    outmp we_utmp;
                    int  we_idle;
               } wd_we[1024 / sizeof (struct whoent)];
          };

          All fields are converted to network byte order before being
          transmitted.  The load averages are as calculated by
          ruptime(1N), and represent load averages 5, 10, and 15
          minutes before the server is transmitted.  The host name is
          that returned by the gethostname(2N) system call.  The array
          at the end of the message contains information about the
          users logged in to the sending machine. This includes the
          contents of the utmp(4) entry for each non-idle terminal



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     rwhod(1M)                                               rwhod(1M)



          line and the time since a character was last received on the
          terminal line.

          The rwho server discards messages it receives if they don't
          originate at a rwho server's port or if the host's name
          specified in the message contains any unprintable ASCII
          characters.  rwhod places valid messages it receives in
          files named whod.hostname in the directory /usr/spool/rwho.
          These files contain only the most recent message.

          rwhod generates status messages approximately every 60
          seconds. rwhod performs an nlist(3C) on /vmunix every 10
          minutes to ensure that this file is the system image
          currently operating.

     FILES
          /etc/rwhod

     SEE ALSO
          rwho(1), ruptime(1), services(4N).

     BUGS
          Should relay status information between networks. People
          often interpret the server dying as a machine going down.































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