True Realtime Status Monitoring with rmonitor

The rmonitor program is a true realtime status monitoring program that works with a low-bandwidth shell. It was conceived as an easier status monitor than using rstat (see Section 2.5.4) repeatedly.

rmonitor hooks into the daq system through userd with the same method as rush. Under normal usage, it is used as a companion to rush in a separate terminal window. Usage is easy; an alias will have been set up to properly link to the system files:

$ rmonitor

rmonitor requires the terminal window to be at least 80 columns by 24 rows (the default terminal size), or it will not run. It will take over the terminal screen and display something like the screen shot from Figure 2.1.

Figure 2.1: Screen shot from the popular rmonitor program.

The key values are put on the screen in a (hopefully) easy to read format. The ``Astronomical Stats'' are updated every 3 seconds. (This is configurable with the -t option on the command line). rmonitor polls the system every 0.3 seconds (configurable with -p) to determine if any values have changed, and updates the screen accordingly. Daemons that are running are put in bold face, and those that are not are put in regular type. In addition, if the screen is large enough vertically, rmonitor will tail the /var/log/rotse.log logfile in a separate ncurses window. The logfile window contains a buffer of 500 lines, and can be scrolled with the up arrow, down arrow, page up, page down, and end keys.

In addition, rmonitor is persistent. That is, it will remain running even if rotsed shuts down, and will continue to monitor the time, sun position and moon position. When another rotsed process is started, rmonitor automatically hooks in and displays the latest status information.