== What vendor updates are pending on your Linux system?

One of those routine system management tasks these days is
checking to make sure that I'm up to date on vendor security releases
and other updates. And when I'm not up to date, I generally want to
know what's out of date; being out of date on _diff_ is one thing,
being out of date on a kernel or _glibc_ is quite another. (For a
start, I probably want to test the kernel a bit more before pushing it
into our local update queue.)

Since I have a lot of systems, I like a concise report; say, one line
with all the pending packages for systems that need updates, and total
silence from systems that are current (in other words, I'm a Unix geek
and I like Unix-style output).

Unfortunately, most package management systems are not quite as
eager to accommodate my minimalism as I would like, so it takes some
scripting work.

For anything with yum (Fedora Core, current Red Hat Enterprise, and
probably others):

>  yum -d 1 check-update |
>    awk '{print $1}'

In at least Fedora Core 4, this doesn't give you the literal package
names; you get a bonus architecture glued on the back that you'll have
to slice off if you really care. You also get a bonus blank line at
the start (this may be a _yum_ bug).

Debian makes it a little bit more annoying. I get to do:

>  apt-get -qq update
>  apt-get -qq -s -u upgrade |
>    awk '$1 == "Inst" {print $2}'

(Assuming that Debian does not change _apt-get_'s output someday. They
might, and this is one reason
[[apt is not my favorite program|AptNonFavorite]].)

In theory '_apt-get -qq update_' could be dangerous, but I think the
odds are pretty low.

Converting these to produce single-line output is left as an exercise
to the reader.