OSF  —  Environment_Note_Added

NAME

rwhod − The system status server

SYNOPSIS

rwhod

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 ability to broadcast messages on a network. 

The rwhod server 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 /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, 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 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(5) entry for each nonidle terminal line and a value indicating the time in seconds since a character 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 discarded.  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 previosly described. 

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

FILES

/usr/sbin/rwhod
Specifies the command path

ENVIRONMENT NOTES

This section describes system features that are not generic to OSF/1 but that are provided in this OSF/1 implementation. 

Digital Extensions

The -b and -l flags are specific to this OSF/1 implementation:

SYNOPSIS

rwhod [-b | -l]

FLAGS

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

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

RELATED INFORMATION

Commands: rwho(1), ruptime(1)