I've been working on a command line principal / collection administration
tool for davical for the last few months.
There are still several points where it could use cleanup (such as adding
short command line options for the common options) but I think it's ready
for a wider audience at this point.
It's downloadable from https://sourceforge.net/projects/davical-cmdlnut/ as
either a dpkg, a rpm or a plain python script. On paper should run on osx
as well but I've only tested under linux.
So give it a go and see what you think.
p.s. Since this will be the first time anybody besides me and Andrew have
tested this just to be on the safe side I'd recommend either testing on a
development database or making sure you have a full database backup before
using davical-cmdlnut for the first time just incase there is a major bug