1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" from: @(#)rwhod.8 8.2 (Berkeley) 12/11/93 33.\" $NetBSD: rwhod.8,v 1.12 2002/02/02 01:47:36 wiz Exp $ 34.\" 35.Dd December 11, 1993 36.Dt RWHOD 8 37.Os 38.Sh NAME 39.Nm rwhod 40.Nd system status server 41.Sh SYNOPSIS 42.Nm 43.Sh DESCRIPTION 44.Nm 45is the server which maintains the database used by the 46.Xr rwho 1 47and 48.Xr ruptime 1 49programs. Its operation is predicated on the ability to 50.Em broadcast 51messages on a network. 52.Pp 53.Nm 54operates as both a producer and consumer of status information. 55As a producer of information it periodically 56queries the state of the system and constructs 57status messages which are broadcast on a network. 58As a consumer of information, it listens for other 59.Nm 60servers' status messages, validating them, then recording 61them in a collection of files located in the directory 62.Pa /var/rwho . 63.Pp 64The server transmits and receives messages at the port indicated 65in the ``who'' service specification; see 66.Xr services 5 . 67The messages sent and received, are of the form: 68.Bd -literal -offset indent 69struct outmp { 70 char out_line[8]; /* tty name */ 71 char out_name[8]; /* user id */ 72 int32_t out_time; /* time on */ 73}; 74 75struct whod { 76 char wd_vers; 77 char wd_type; 78 char wd_fill[2]; 79 int32_t wd_sendtime; 80 int32_t wd_recvtime; 81 char wd_hostname[32]; 82 int32_t wd_loadav[3]; 83 int32_t wd_boottime; 84 struct whoent { 85 struct outmp we_utmp; 86 int32_t we_idle; 87 } wd_we[1024 / sizeof (struct whoent)]; 88}; 89.Ed 90.Pp 91All fields are converted to network byte order prior to 92transmission. The load averages are as calculated by the 93.Xr w 1 94program, and represent load averages over the 5, 10, and 15 minute 95intervals prior to a server's transmission; they are multiplied by 100 96for representation in an integer. The host name 97included is that returned by the 98.Xr gethostname 3 99function call, with any trailing domain name omitted. 100The array at the end of the message contains information about 101the users logged in to the sending machine. This information 102includes the contents of the 103.Xr utmp 5 104entry for each non-idle terminal line and a value indicating the 105time in seconds since a character was last received on the terminal line. 106.Pp 107Messages received by the 108.Xr rwho 1 109server are discarded unless they originated at an 110rwho 111server's port. In addition, if the host's name, as specified 112in the message, contains any unprintable 113.Tn ASCII 114characters, the 115message is discarded. Valid messages received by 116.Nm 117are placed in files named 118.Pa whod.hostname 119in the directory 120.Pa /var/rwho . 121These files contain only the most recent message, in the 122format described above. 123.Pp 124Status messages are generated approximately once every 1253 minutes. 126.Sh SEE ALSO 127.Xr ruptime 1 , 128.Xr rwho 1 129.Sh HISTORY 130The 131.Nm 132command appeared in 133.Bx 4.2 . 134.Sh BUGS 135There should be a way to relay status information between networks. 136Status information should be sent only upon request rather than continuously. 137People often interpret the server dying 138or network communication failures 139as a machine going down. 140