zsu

Zsu is a Perl module designed to update the serial numbers of zone files. The module can be run with one or more zonefile names as arguments, such as /etc/db.local, 0.0.127.in-add.arpa, and /var/named/db.example.com.

One of the most common uses of zsu is as part of revision control systems for zone files. This is because it can be used just before changes are committed to a repository. A simple script that utilizes zsu requires a single zonefile name as an argument, and uses ci/co/rcsdiff (all parts of RCS).

The script includes the following code:

#!/bin/sh
co -l $1
vi $1
rcsdiff -q $1 > /dev/null
if [ ! $? ]; then
zsu -cf $1
ci -u $1
fi

Zsu also has an option to ignore zone files where the originating host in the SOA record does not match the local hostname. Users can override this check by using the -f option.

In summary, zsu is a useful Perl module for updating zone file serial numbers, especially when used in revision control systems. Its functionality can be extended with the simple script provided, and it includes useful options such as ignoring certain zone files.