Scripting during Linux boot: how to test when boot is "complete"?

I've got a script that gets run during boot on a Debian server. It's getting run too early, but I can't control when it's fired off. I can force the script to delay its own run with:

sleep 60

...or, alternately, I could just try the action a few times, like this:

TESTRUN=0
ACTIONWORKED=0
while [ $ACTIONWORKED -eq 0 ] && [ $TESTRUN -le 5 ]; do
      # run the action i want
      # quick test if it worked
      # if yes, set ACTIONWORKED=1
      # if no, sleep 10
      # increment TESTRUN
done

What's a better way to test that the system is ready? The script will be run at other times during system operation, so the test is needed to differentiate between "booting-can't-do-this-yet" and "not-booting-run-now" states. I don't want it to wait every time the script runs.

Edit: Thanks for the ideas so far. Keep 'em coming if you have alternatives to what's already been posted.

To those who've asked for specifics, I've left them out of the question specifically to gather answers that work with the general Linux boot process.

Assume a "fully booted" system has presented a login prompt (via console, X, or whatever).

Solution 1:

Really the best way to do what you want is to insert a call to the script in the proper place in SysV init. I'd recommend that you write a script that calls your script, and cajole your sysadmin until he or she installs it in the proper place.

EDIT: Okay, I just read your other question, and I see that you are talking about a script that is fired asynchronously, when someone plugs in a device. What you want to do is check the runlevel to see if it's 2 (or whatever your default runlevel is if you've changed it, and also 1 if you want this to run in single-user mode.) If I'm reading the Debian FAQ correctly, the runlevel does not change to the default until the boot is complete.

Solution 2:

I would watch the init levels.

This should get you started..

 [[ `/sbin/runlevel | cut -d " " -f 2` == 5 ]] && echo "Ready"

HTH