rwhod(1M)                                               rwhod(1M)



NAME
     rwhod - invokes the system status server

SYNOPSIS
     in.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.

     The rwhod command both produces and consumes status
     information.  It periodically queries the state of the
     system and constructs status messages that are broadcast on
     a network.  It also listens for the status messages of other
     rwhod servers, validates the messages, 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 calculated by the kernel
     and represent load averages 5, 10, and 15 minutes.  The host
     name is 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
     line and the time since a character was last received on the



January 1992                                                    1

rwhod(1M)                                               rwhod(1M)



     terminal line.

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

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

LIMITATIONS
     The rwhod command should relay status information between
     networks. People often interpret the server dying as a
     machine going down.

FILES
     /usr/etc/rwhod
          Executable file

SEE ALSO
     rwho(1N), ruptime(1N) in A/UX Command Reference

     services(4N) in A/UX Programmer's Reference



























2                                                    January 1992