rwhod(8)rwhod(8)NAMErwhod - The system status server
SYNOPSIS
/usr/sbin/rwhod [-b | -l]
OPTIONS
Sets the broadcast only mode. Sends outgoing rwho packets, but ignores
incoming ones. Sets the listen only mode. Collects incoming rwho
packets from the network, but does not broadcast rwho data.
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 have the following format:
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 gethost‐
name(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(4) 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 origi‐
nated 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 previously
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 oper‐
ating.
FILES
Specifies the command path Contains the most recent valid message
received by rwhod from hostname.
SEE ALSO
Commands: rwho(1), ruptime(1)rwhod(8)