[CentOS] how to find out the number of updates for a system

Once upon a time, mark <m.roth at 5-cent.us> said:
> Ralf Prengel wrote:
> > Hallo,
> > I need the information how many updates are available for a system.
> > What is the best way to find it out in a one line bash script.
> >
> yum check-update, perhaps?

Note that "yum check-update" or "yum list updates" won't tell you how
many packages would be installed with "yum update"... dependencies and
such are not resolved for check-update/list updates.

-- 
Chris Adams <linux at cmadams.net>