ruptime(1c)
Name
ruptime − show host status of local machines
Syntax
ruptime [ options ] [ machinename ]
Description
The ruptime command gives a status line like uptime() for each machine on the local network. If a machinename is given, the status of only the named machine is given. These status lines are formed from packets broadcast by each host on the network once a minute.
Machines for which no status report has been received for 5 minutes are shown as being down.
Options
−aUsers idle an hour or more are not counted unless this option is specified.
−dDisplay only those hosts that are considered down.
−lSort the status list by load average. If more than one sort option is given, ruptime uses the last one.
−rShow only hosts that are up and running.
−tSort the status list by uptime. If more than one sort option is given, ruptime uses the last one.
−uSort the status list by number of users. If more than one sort option is given, ruptime uses the last one.
−nnShow only those hosts with nn or more users.
Restrictions
Because the rwhod daemon sends its information in broadcast packets it generates a large amount of network traffic. On large networks the extra traffic may be objectionable. Therefore, the rwhod daemon is disabled by default. To make use of the rwhod daemon for both the local and remote hosts, remove the comment symbols (#) from in front of the lines specifying rwhod in the /etc/rc file.
If the rwhod daemon is not running on a remote machine, the machine may incorrectly appear to be down when you use the ruptime command to determine its status. See the rwhod() reference page for more information.
If a system has more than 40 users logged in at once, the number of users displayed by the ruptime command is incorrect. Users who login to a machine after that point fail to increment the user count that appears in the output of the ruptime command. This is due to the maximum size limit of an Ethernet packet, which is 1500 bytes, and the fact that the rwhod daemon must broadcast its information in a single packet.
Files
/usr/spool/rwho/whod.*Information about other machines