This is a simple script, to visualize data, which is output to a screen-window. To do this mainly gnu screen and gnuplot are used.

Zur deutschen Beschreibung.

screen-graph is a bash-script, which utilizes the following additional tools:

• gnuplot
• sed
• perl
• screen

All of this tools should be available with every linux-distribution. I have not tested the script on other operation systems!

To create a graph the following simple steps are necessary:

First of all start screen in a terminal:

$ screen

Get the ID of this screen, which is saved in the environment-variable $STY

$ echo $STY
2294.pts-0.fun

Now create a window in this screen to output the data to. If you didn’t change the keybindings press CTRL-a c (create new window) and CTRL-a :title aname[RETURN] (set the window-title to “aname”)

You now can output the data to this window. They have to follow this format:

UNIXTIMESTAMP datavalue

As an example lets check the load of your server. Enter the following line in the data-window:

$ while true; do echo -n $(date +%s)' '; cat /proc/loadavg | cut -f 1 -d ' '; sleep 10; done

The output should look something like this:

1144870745 0.22
1144870755 0.18
1144870765 0.39
1144870775 0.64
1144870785 0.85

Don’t stop this line. Just let it output the data. Now go to another window in the same screen, or even to another terminal (on the same computer, with the same user!). Now comes the magic:

$ screen-graph.sh 2294.pts-0.fun aname

Change the parameters according to the above done commands. You should see an graph in your terminal filling it up.

The current version of screen-graph can be download here:

• screen-graph-0.1.tar.gz first published version 0.1

To get my current development version of this script, you can use the following line to get it from my darcs-repository:

darcs get http://www.jerri.de/darcs/screengraph

Here is a screenshot of screengraph in action showing the example from above. The windowmanager used is ratpoison.