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This little Bash snippets scans the Debian dpkg database for packages whose configurations files have been modified.

This only touches configurations files which are packaged and made known to dpkg. Some package manually handle their configuration file in maintainer scripts. A good example of that is /etc/network/interfaces which is an important configuration file but not automatically handled by dpkg.

This is as useful as you want to make it. I use it to track changes I’ve done which could end up with a conflict during a package upgrade. If you want a more thorough tracking of configuration changes, use something like etckeeper.

Notice I took some care to use more Bash’isms, to optimize the script. I was able to optimize by just a few percents. The bulk of the time must spent calculating MD5 sums.

#!/bin/bash

for pkg in /var/lib/dpkg/info/*.conffiles; do
    p1=${pkg#/var/lib/dpkg/info/}
    p=${p1%%.conffiles}
    IFS=$'n'
    for cfsum in $(dpkg-query -W -f='${Conffiles}' $p); do
        IFS=' '
        c=($(eval "echo $cfsum"))
        if [ -r ${c[0]} ]; then
            sum=${c[1]}
            cur_sum=($(eval "md5sum ${c[0]}"))
            if [ $sum != ${cur_sum[0]} ]; then
                echo "$p: ${c[0]}"
            fi
        else
            echo "Can't access file: ${c[0]}." > /dev/stderr
        fi
    done
done

This will output something like this:

$ ./check_changed
bash: /etc/bash.bashrc
console-tools: /etc/console-tools/config
libldap2: /etc/ldap/ldap.conf
ntp: /etc/ntp.conf
...