swim - chapter 6
IMPORTANT DEBIAN DATABASES FOR NOT-INSTALLED
DATABASES
usage: swim --ftp
options: --Contents <DF|directory>
--Packages <DF|directory>
[--dists <distribution>] [--arch <architecture>]
[--onec] [--Release_only]
swim provides a method so that all information about
an existing Debian distribution is quickly accessible through databases.
Debian already provides flat file databases for all its distributions. One
database called ``Contents-(architecture)'' provides a complete
listing of all the files associated with each package, the other much more
important database called ``Packages'' provides everything from
the Package's description, to all the dependencies for that package. The
Packages database is a crucial database for other important Debian
administrative tools like dpkg and apt.
Debian Distributions choose a name which reflect the development state of
that distribution. The distribution named ``unstable'' is where
the majority of the development processing occurs, after unstable
has reached a certain level of maturity, it's copied over to a new
distribution called ``frozen'' which is tested extensively before
becoming the new ``stable'' distribution. The frozen
distribution retains the Release version number of the
unstable distribution, and the unstable distribution
receives a new Release version number. Eventually,
frozen becomes stable, and at this point both
frozen, and the older stable distribution are removed.
Code names are associated with the Release Version number given
for each of the distributions. This is much better for mirroring Debian
sites.
swim was designed to ignore these code names, and instead
shows the user the Release version number associated with the
distribution. Swim users must always use the real distribution name, or
swim will not work properly. This is a nice feature because it allows user
to make decisions related to the management of their databases, and makes
research much more easier.
The other Debian distribution which swim recognizes is
experimental. This distribution does not have any Release
version number, and contains packages which are considered risky
because of their development level.
Each Debian distribution has sections related to the relationship of
each of the packages to the Debian's Policy Manual. In
``main'' there are packages which have a correct relationship
with these Policies. Packages in ``contrib'' comply with the
DFSG (Debian Free Software Guidelines found in the
Debian Policy Manual) but have various limitations like requiring
a package which is found in non-free, or is not in the Debian archive.
Packages in ``non-free'' do not comply with the DFSG but
are electronically distributable across international borders. The
``non-us'' section is found outside of the United States and
exists for packages which have export restrictions.
Distributions also have architecture specific sections since not all
packages compiled for one architecture can run on all other
archictectures, however, there are a large percentage of packages which do
run on all architectures. The architectures are alpha,
arm, i386, m68k, powerpc,
sparc, and more recently hurd-i386 which represents
packages for the hurd GNU kernel for the i386 architecture.
--ftp uses a file called swimz.list which
has the same type of format (see format below) as the
sources.list(5) which apt uses. There are some
differences. The first difference mentioned above (see
DISTRIBUTION DEFINED
, section 6.3) requires that the distribution names never should be the
code names for the Release version. Secondly,
apt only retrieves databases specific to one
archictecture, normally the one you are running apt on.
With swim though you can fetch databases for any, or
every architecture by adding the architecture to ``deb'' with a hyphen
(deb-hurd-i386). If deb has no architecture appended it is assumed that
the architecture you want is the same as the system you are running
swim on. Thirdly, at this time
swim only supports the ftp method.
Fourthly, you can change swimz.list as often as
you want without worrying about databases being removed so that that the
swimz.list and the downloaded databases match. This would occur
with apt's sources.list(5) if you removed a
site. Fifthly, databases are kept in a compressed state.
Sixthly because the list is used for both Contents and
Packages, more flexibility is provided by only allowing the default
distribution/archictecture or distribution/architecture provided on the
commandline to be downloaded.
For apt users: If you are using apt, and
swim together it is a good strategy to use the real
distribution name in the sources list(8), and to have an exact
copy of the sources.list(5) ftp sites in the swimz.list.
Packages databases specific to the architecture apt is
using can be retrieved using swim --apt --update (this
also will keep track of the Release version), and then
swim can be used to fetch the architecture specific
Contents database as shown below. It should also be of interest
to note that Packages downloaded by either swim or apt can be used
interchangeably by using 'cp -a' and 'gzip -d' or 'gzip -9'.
Here is a brief outline of the format required by swimz.list.
deb uri distribution [section ... ]
deb - represents a standard Debian distribution. And is
simply written as deb or with the architecture appended
(deb or deb-alpha).
uri - Universal Resource Identifier is exactly how you
would enter an address into a web browser. This address is the base of a
Debian distribution, generally this is right before the directory called
``dists''. So if dists is found in
/stuff/pub/debian/dists, and the site is
somewhere.com then the uri would be
ftp://somewhere.com/stuff/pub/debian.
distribution - This can be unstable,
frozen, stable, experimental. Distribution can
also be a path which must end with a slash like
unstable/binary-i386/. This is used when there is no section as
in the experimental distribution or in sites which do not have symlinks to
the non-us section. No section would be mentioned in this situation.
section - main, contrib,
non-free, non-US (write it this way).
Examples (each on one line):
deb-alpha ftp://somewhere.com/stuff/pub/debian unstable main contrib non-US
This will fetch the alpha databases from somewhere.com for the unstable
distribution for the main, contrib and non-US sections.
Note: In these next two examples you can not append any architecture to deb
with a hyphen.
deb ftp://somewhere.com/stuff/pub/debian project/experimental/
This will fetch the experimental database, but there is not a
Contents-(architecture) database for this distribution. Notice that it ends
with a slash.
deb ftp://somewhere.com/stuff/pub/debian-non-US stable/binary-i386/
This will fetch the i386 databases for the stable distribution for non-us,
How you use major mode --ftp depends on your goals.
Even if you are using apt, you may be interested in
keeping tabs on different architectures. In this case you would have to
download the Packages databases specific to these architectures.
If you are only interested in the architecture which apt
is interested in, then you only need to use --ftp to
fetch the Contents database(s). But, because it isn't a
requirement to set up a virtual filesystem, you are not required to fetch
the Contents database. The advantages of fetching the
Contents database is determined by the method you choose to make the
database (see MAKING NOT-INSTALLED DATABASES
, chapter 7). These advantages include the
ability to view a listing of the files and directories associated
with a package, the ability to query files and directories to
find out which packages relate to them, and the ability to perform a
powersearch on all the files and directories to find the
associated packages.
Remember: If you want to download a different
distribution/architecture other than the default specified in your
configuration file, you must specify this on the commandline.
--Packages determines where you want the Packages
database as well as the Release data put when they are downloaded. The
DF argument implies that the databases will be put in
your default directory (see swimrc(5)). These databases can later
be located by the major modes --initndb and --rebuildndb
just by using DF as an argument. Alternatively, these
databases can be put in any directory you choose by providing a
directory as an argument.
--Contents determines where you want the
Content-(architecture) database(s) put. (see
--Packages).
--onec will download only one Contents-arch per
distribution/architecture specified on the commandline or by default.
--Release_only will download only the Release data for
the swimz.list or particular Package(s) mentioned on the
command line.
--dists will only find the distribution which corresponds
to the argument provided this option.
--arch will only find the architecture which corresponds
to the argument provided this option. The different architecture needs to
be specified in swimz.list with a hyphen and the architecture appended to
deb (deb-(arch)).
usage: swim --apt
options: [--update] [--clean] [--autoclean] [--check]
Please read A. downloading the important databases with --ftp.
, section 6.1 for more information.
--update calls apt to download the
Packages databases.
--clean is a call to an apt option to
remove any packages stored in apt's storage area for
downloaded packages. The default for this storage area is
/var/cache/apt/arhives
--autoclean will only clean out packages which are not
found in apt's cache.
--check tests and updates apt's cache.
swim
-
Copyright © 1999 Jonathan D. Rosenbaum
Contents; next; back.
15 June 1999
Jonathan D. Rosenbaummttrader@access.mountain.net