Run a shell script when a database record is written to postgres

Question

Is there some mechanism in postgres that can fire off a shell script when a database record is written? I can write a script to just monitor the database and table but befor

Answer 1

Write a trigger function using PL/sh. That's what it's for.

Answer 2

You can probably use rule or trigger and start your shell script for whatever PL that supports it, but I think the better way is to use it for sending notification and monitor it from a separate process.