three column dataset - additions and deletions

[draeath]

The only reason I want the hash is that I don't want a copy of this 
string laying around. I also don't need to know what it is, I just need 
to know if it's different. Think of this as a tripwire - if someone's 
user access level is changed, we find out.

I still think using a separate database (sqlite or not) is entirely 
unnecessary. The task simply isn't large enough of a scale to justify 
going to that extreme. That's like cutting a string with a chainsaw. 
Granted, the next time I'm at my workstation I'll just give it a go and 
just stick with whatever turns out "best"

The alternatives are what I was looking for, and you all did provide 
them :)

So here's the goal, since it seems it's still unclear:

Cron will call my script on an interval (probably once a day... so yea). 
The script will determine if users were added, removed, or changed. If 
so, an email will be constructed with generic details "users bjoe, jdoe 
created; user mwallace deleted; user psouter access level changed" and 
sent to the MUA/MTA/whatever for delivery to myself and the other admins.