In message <200006151559.LAA19262@ghost.whirlpool.com>, Andrew Gillham writes:
>I posted something like this a few years back.  Didn't get a lot of
>interest. :(

Amusingly, your sed script is within a small epsilon of the one BSD/OS uses.

>Here is what I have been using.
>#!/bin/sh
>#
># check for changes in the hardware configuration
>#
>if [ -f /var/log/dmesglog ]; then
>        echo -n 'checking hardware config:'
>        mv /var/log/dmesglog /var/log/dmesglog.0
>        dmesg | sed -n '/^NetBSD/h; /^NetBSD/!H; ${ x; p; q; }' \
>                > /var/log/dmesglog
>        diff -bc /var/log/dmesglog.0 /var/log/dmesglog > /tmp/diff.$$
>        if [ -s /tmp/diff.$$ ]; then
>                cat /tmp/diff.$$ | Mail -s "hardware change" root
>                echo ' changed.'
>        else
>                echo ' no change.'
>        fi
>        rm -f /tmp/diff.$$
>fi

I rather like this, although I'd want to use "rotate" so you could have
a few back, optionally.  :)

-s