[AuckLUG] Settle an arguement for me! apt-get, apititude and dpkg

[Daniel Pittman]

Tim Giffney <swift at swift.4hv.org> writes:

> This is how I understand it, please correct me if you don't agree.
>
> dpkg is the base program, which handles the actual installation of
> packages (.debs).  It takes the downloaded package, checks the
> dependencies, and if they are ok unpacks, installs and configures the
> package.
>
> apt-get is the standard frontend for dpkg, 

Traditional, more than standard, since some of the other front ends are
on roughly equal footing.

> which is always present on a debian system. It handles the
> selection of packages, management of package lists (ie if you ask
> for "nano" it checks in the package list downloaded earlier, and
> resolves the package name to the right version, and the version to
> a file on the source - eg. "nano-1.0-r1_arm.deb", and does this for
> all the dependencies of nano and their dependencies and so on.
> Then apt-get downloads the package from the source url eg.
> "ftp://ftp.debian.org/debian/pool/main/n/nano/nano_1.2.4-5_arm.deb"
> , and passes the downloaded package to dpkg to install.  It seems
> to be the standard way to manage a debian system's packages - it
> can do anything necessary.

In terms of installing packages and dependencies, yes.  It has some
limitations though: it can't install from a local .deb file at all, so
can't resolve dependencies for them.

It also does nothing about suggested or recommended packages, and does
nothing about tracking which packages were installed as dependencies vs
user requests.

> aptitude is an optional frontend, while usually there it may not
> always be present.  It provides an ncurses (like the interface of the
> text editor nano or "make menuconfig") interface to dpkg, which some
> people find easier to use.  

It also provides a similar but not identical command line interface to
apt-get and friends.

> As well as the commands in apt-get you can browse through and select
> packages from lists, and also play minesweeper :)

It also allows you to handle suggested and recommended packages, though
not always as nicely as you might hope.  

It tracks packages that were installed "automatically" to satisfy a
dependency and, if you remove all dependent packages, will offer to
eliminate the now obsolete files.


Other front ends have other, disparate, features such as the ability to
install local packages with dependency resolution and the like.

Regards,
        Daniel
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