event trigger after ack

[Leandro]

Hi guys.
Im thinking about a mechanism to fill a sql table with an updated leases 
status.
Something like

Time                  | Client-ip            |Client MAC    |  Relay IP
Oct  1 12:16:22 | 20.0.0.2           | d4:21:22:74:18:0a | 172.21.1.156

I achieved this using a perl tail script on the dhcp.log file matching 
the ACK lines.
I was wondering if is it possible to do the same using a triggered 
script executed by the daemon after an ACK event occurs.

Anyone can point some documentation about it ?
Is it true that this could be risky since a bad script can lead to wrong 
function of the service ?

Any advice would be usefull.
Regards.
Leandro.