-<!doctype debiandoc system>
<!-- -*- mode: sgml; mode: fold -*- -->
+<!doctype debiandoc PUBLIC "-//DebianDoc//DTD DebianDoc//EN">
<book>
<title>APT Files</title>
<author>Jason Gunthorpe <email>jgg@debian.org</email></author>
-<version>$Id: files.sgml,v 1.2 1998/07/12 02:11:09 jgg Exp $</version>
+<version>$Id: files.sgml,v 1.12 2003/04/26 23:26:13 doogie Exp $</version>
<abstract>
This document describes the complete implementation and format of the
</abstract>
<copyright>
-Copyright © Jason Gunthorpe, 1998.
+Copyright © Jason Gunthorpe, 1998-1999.
<p>
"APT" and this document are free software; you can redistribute them and/or
modify them under the terms of the GNU General Public License as published
<p>
For more details, on Debian GNU/Linux systems, see the file
-/usr/doc/copyright/GPL for the full license.
+/usr/share/common-licenses/GPL for the full license.
</copyright>
<toc sect>
<p>
The var directory structure is as follows:
<example>
- /var/state/apt/
+ /var/lib/apt/
lists/
partial/
xstatus
+ userstatus
+ cdroms.list
/var/cache/apt/
pkgcache.bin
srcpkgcache.bin
partial/
/etc/apt/
sources.list
- cdromdevs.list
+ apt.conf
/usr/lib/apt/
methods/
cdrom
ftp
http
+ file
+ gzip
+ copy
</example>
<p>
-As is specified in the FHS 2.0 /var/state/apt is used for application
+As is specified in the FHS 2.1 /var/lib/apt is used for application
data that is not expected to be user modified. /var/cache/apt is used
for regeneratable data and is where the package cache and downloaded .debs
go.
fastest source listed first. The format of each line is:
<p>
-<var>type ui args</var>
+<var>type uri args</var>
<p>
The first item, <var>type</var>, indicates the format for the remainder
<p>
The <em>deb</em> type is to be a typical two level debian distributions,
dist/<var>distribution</var>/<var>component</var>. Typically distribution
- is one of stable, unstable or frozen while component is one of main,
+ is one of stable, unstable or testing while component is one of main,
contrib, non-free or non-us. The format for the deb line is as follows:
<p>
- deb <var>uri</var> <var>distribution</var> <var>compontent</var>
+ deb <var>uri</var> <var>distribution</var> <var>component</var>
[<var>component</var> ...]
<p>
necessary to list a number of deb lines for the same URI. APT will
sort the URI list after it has generated a complete set to allow
connection reuse. It is important to order things in the sourcelist
- from most prefered to least prefered (fastest to slowest).
+ from most preferred to least preferred (fastest to slowest).
</sect1>
<sect1>URI specification
<taglist>
<tag>cdrom<item>
- The cdrom scheme is special in that If Modifed Since queries are never
+ The cdrom scheme is special in that If Modified Since queries are never
performed and that APT knows how to match a cdrom to the name it
- was given when first inserted. It does this by examining the date
- and size of the package file. APT also knows all of the possible
- prefix paths for the cdrom drives and that the user should be prompted
+ was given when first inserted. APT also knows all of the possible
+ mount points the cdrom drives and that the user should be prompted
to insert a CD if it cannot be found. The path is relative to an
- arbitary mount point (of APT's choosing) and must not start with a
+ arbitrary mount point (of APT's choosing) and must not start with a
slash. The first pathname component is the given name and is purely
descriptive and of the users choice. However, if a file in the root of
- the cdrom is called 'cdname' its contents will be used instead of
+ the cdrom is called '.disk/info' its contents will be used instead of
prompting. The name serves as a tag for the cdrom and should be unique.
- APT will track the CDROM's based on their tag and package file
- properties.
<example>
cdrom:Debian 1.3/debian
</example>
<tag>http<item>
- This scheme specifies a HTTP server for the debian archive. HTTP is prefered
+ This scheme specifies a HTTP server for the debian archive. HTTP is preferred
over FTP because If Modified Since queries against the Package file are
- possible. Newer HTTP protcols may even support reget which would make
- http the protocol of choice.
+ possible as well as deep pipelining and resume capabilities.
<example>
http://www.debian.org/archive
</example>
</example>
<tag>file<item>
- The file scheme allows an arbitary directory in the file system to be
- considered as a debian archive. This is usefull for NFS mounts and
+ The file scheme allows an arbitrary directory in the file system to be
+ considered as a debian archive. This is useful for NFS mounts and
local mirrors/archives.
<example>
file:/var/debian
</example>
-<tag>mirror<item>
- The mirror scheme is special in that it does not specify the location of a
- debian archive but specifies the location of a list of mirrors to use
- to access the archive. Some technique will be used to determine the
- best choice for a mirror. The mirror file is specified in the Mirror File
- section. If/when URIs take off they should obsolete this field.
- <example>
- mirror:http://www.debian.org/archivemirrors
- </example>
-
<tag>smb<item>
A possible future expansion may be to have direct support for smb (Samba
servers).
<sect1>Hashing the URI
<p>
-All permanent information aquired from any of the sources is stored in the
+All permanent information acquired from any of the sources is stored in the
lists directory. Thus, there must be a way to relate the filename in the
lists directory to a line in the sourcelist. To simplify things this is
done by quoting the URI and treating _'s as quoteable characters and
converting / to _. The URI spec says this is done by converting a
sensitive character into %xx where xx is the hexadecimal representation
-from the ascii character set. Examples:
+from the ASCII character set. Examples:
<example>
http://www.debian.org/archive/dists/stable/binary-i386/Packages
-/var/state/apt/lists/www.debian.org_archive_dists_stable_binary-i386_Packages
+/var/lib/apt/lists/www.debian.org_archive_dists_stable_binary-i386_Packages
cdrom:Debian 1.3/debian/Packages
-/var/state/apt/info/Debian%201.3_debian_Packages
+/var/lib/apt/info/Debian%201.3_debian_Packages
</example>
<p>
structure but this poses two problems, it makes it very difficult to prune
directories back when sources are no longer used and complicates the handling
of the partial directory. This gives a very simple way to deal with all
-of the situations that can arise. The equals sign was choosen on the
-suggestion of Manoj because it is very infrequently used in filenames.
-Also note that the same rules described in the <em>Archive Directory</>
-section regarding the partial sub dir apply here as well.
+of the situations that can arise. Also note that the same rules described in
+the <em>Archive Directory</> section regarding the partial sub dir apply
+here as well.
</sect1>
</sect>
<sect>Extra Status File (xstatus)
<p>
-The extra status file serves the same purpose as the normal dpkg status file
-(/var/lib/dpkg/status) except that it stores information unique to diety.
+The extra status file serves the same purpose as the normal dpkg status file
+(/var/lib/dpkg/status) except that it stores information unique to apt.
This includes the autoflag, target distribution and version and any other
-uniqe features that come up over time. It duplicates nothing from the normal
+unique features that come up over time. It duplicates nothing from the normal
dpkg status file. Please see other APT documentation for a discussion
-of the exact internal behavior of these fields. The Package field is
+of the exact internal behaviour of these fields. The Package field is
placed directly before the new fields to indicate which package they
apply to. The new fields are as follows:
<tag>X-TargetDist<item>
The TargetDist item indicates which distribution versions are offered for
- installation from. It should be stable, unstable or frozen.
+ installation from. It should be stable, unstable or testing.
<tag>X-TargetVersion<item>
The target version item is set if the user selects a specific version, it
<p>
The archives directory is where all downloaded .deb archives go. When the
file transfer is initiated the deb is placed in partial. Once the file
-is fully downloaded and its MD5 hash and size are verifitied it is moved
+is fully downloaded and its MD5 hash and size are verified it is moved
from partial into archives/. Any files found in archives/ can be assumed
to be verified.
<p>
-No dirctory structure is transfered from the receiving site and all .deb
+No directory structure is transfered from the receiving site and all .deb
file names conform to debian conventions. No short (msdos) filename should
be placed in archives. If the need arises .debs should be unpacked, scanned
and renamed to their correct internal names. This is mostly to prevent
-file name conflicts but other programs may depend on this if convenient.
+file name conflicts but other programs may depend on this if convenient.
+A conforming .deb is one of the form, name_version_arch.deb. Our archive
+scripts do not handle epochs, but they are necessary and should be re-inserted.
+If necessary _'s and :'s in the fields should be quoted using the % convention.
+It must be possible to extract all 3 fields by examining the file name.
Downloaded .debs must be found in one of the package lists with an exact
name + version match..
</sect>
<sect> The Methods Directory (/usr/lib/apt/methods)
<p>
-Like dselect, APT will support plugable acquisition methods to complement
-its internaly supported methods. The files in
-this directory are execultables named after the URI type. APT will
-sort the required URIs and spawn these programs giving a full sorted, quoted
-list of URIs.
-
-<p>
-The interface is simple, the program will be given a list
-of URIs on the command line. The URIs will be a pairs of strings, the first
-being the actual URI and the second being the filename to write the data to.
-The current directory will be set properly by APT and it is
-expected the method will put files relative to the current directory.
-The output of these programs is strictly speficied. The programs must accept
-nothing from stdin (stdin will be an invalid fd) and they must output
-status information to stdout according to the format below.
-Stderr will be redirected to the logging facility.
-
-<p>
-Each line sent to stdout must be a line that has a single letter and a
-space. Strings after the first letter do not need quoting, they are taken
-as is till the end of the line. The tag letters, listed in expected order,
-is as follows:
-
-<taglist>
-
-<tag>F - Change URI<item>
-This specifies a change in URI. All information after this will be applied
-to the new URI. When the URI is changed it is assumed that the old URI has
-completed unless an error is set. The format is <var>F URI</>
-
-<tag>S - Object Size<item>
-This specifies the expected size of the object. APT will use this to
-compute percent done figures. If it is not sent then a kilobyte meter
-will be used instead of a percent display. The foramat is <var>S INTEGER</>
-
-<tag>E - Error Information<item>
-Exactly one line of error information can be set for each URI. The
-information will be summarized for the user. If an E tag is send before
-any F tags then the error is assumed to be a fatal method error and all URI
-fetches for that method are aborted with that error string. The format
-is <var>E String</>
-
-<tag>I - Informative progress information<item>
-The I tag allows the method to specify the status of the connection.
-Typically the GUI will show the last recieved I line. The format is
-<var>I String</> As a general rule an I tag should be ommitted before a
-lengthy operation only. Things that always take a short period are not
-suited for I tags. I tags should change wnenever the methods state changes.
-Some standard forms, in order of occurance, are <var>Connecting to SITE</>,
-<var>Connecting to SITE (1.1.1.1)</>, <var>Waiting for file</>,
-<var>Authenticating</>, <var>Downloading</>, <var>Resuming (size)</>,
-<var>Computing MD5</> <var>I</> lines should never print out information that
-APT is already aware of, such as file names.
-
-<tag>R - Set final path<item>
-The R tag allows the method to tell APT that the file is present in the
-local file system. APT might copy it into a the download directory. The format
-is <var>R String</>
-
-<tag>M - MD5Sum of the file<item>
-The method is expected to compute the md5 hash on the fly as the download
-progresses. The final md5 of the file is to be output when the file is
-completed. If the md5 is not output it will not be checked! Some methods
-such as the file method will not check md5's because they are most
-commonly used on mirrors or local CD-ROM's, a paranoid option may be
-provided in future to force checking. The format is <var>M MD5-String</>
-
-<tag>L - Log output<item>
-This tag indicates a string that should be dumped to some log file. The
-string is for debugging and is not ment to be seen by the user. The format
-is <var>L String</> Log things should only be used in a completed method
-if they have special relavence to what is happening.
-</taglist>
-
-<p>
-APT monitors the progress of the transfer by watching the file size. This
-means the method must not create any temp files and must use a fairly small
-buffer. The method is also responsible for If-Modified-Since (IMS) queries
-for the object. It should check ../outputname to get the time stamp but not
-size. The size may be different because the file was uncompressed after
-it was transfed. A method must <em>never</> change the file in .., it may
-only change the output file in the current directory.
-
-<p>
-The APT 'http' program is the reference implementation of this specification,
-it implements all of the features a method is expected to do.
+The Methods directory is more fully described in the APT Methods interface
+document.
</sect>
<!-- }}} -->
<!-- The Mirror List {{{ -->
<p>
The mirror list is stored on the primary debian web server (www.debian.org)
-and contains a machine readable list of all known debian mirrors. The mirror
-URI type will cause this list to be downloaded and considered. It has the
-same form as the source list. When the source list specifies mirror
-as the target the mirror list is scanned to find the nescessary parts for
-the requested distributions and components. This means the user could
-have a line like:
+and contains a machine readable list of all known debian mirrors. It's
+format and style mirror the Package file.
+
+<taglist>
+<tag>Site<item>
+This is the proper host name of the site. It should not be a host within
+debian.org and generally cnames should be avoided here.
+
+<tag>Aliases<item>
+These list any commonly used aliases for the site. This field is used to make
+sure that a site is not added twice.
+
+<tag>Type<item>
+This field can either be <em>Push-Primary</> or <em>leaf</>.
+<em>Push-Primary</> are authorized top level mirrors of the archive, all
+other mirrors are leaf.
+
+<tag>Archive-[access]<item>
+The Archive field gives the path(s) to the debian archive. [access]
+specifies the access method and may be one of ftp, http, rsync, nfs, or
+smb. For many of the types it is possible to prefix the path with :###
+indicating that an alternate port should be used. Generally paths
+start with a / and end with a /, rsync is an exception in that the
+first directory component is not a path but a label.
+
+<tag>WWW-[access]<item>
+The WWW field gives the path(s) to the debian web site.
-<var>deb mirror:http://www.debian.org/mirrorlist stable main non-us</var>
+<tag>CDImage-[access]<item>
+The WWW field gives the path(s) to the debian CD-ROM images
-which would likely cause APT to choose two separate sites to download from,
-one for main and another for non-us.
+<tag>Incoming-[access]<item>
+The Incoming field gives the path(s) to a mirror of the debian incoming
+directory.
+
+<tag>nonUS-[access]<item>
+The nonUS field gives the path(s) to a mirror of the non-US distribution.
+
+<tag>Maintainer<item>
+This is the email address of the maintainer of the mirror.
+
+<tag>Location<item>
+Location gives the general geographical region the mirror is in.
+
+<tag>Sponsor<item>
+The Sponsor field indicates who owns the mirror and a URL to a web page
+describing the organization.
+
+<tag>Comment<item>
+General free-form text.
+
+</taglist>
<p>
Some form of network measurement will have to be used to gauge performance
<em>unstable</>.
<tag>Component<item>
-Referes to the sub-component of the archive, <em>main</>, <em>contrib</>
-etc.
+Refers to the sub-component of the archive, <em>main</>, <em>contrib</>
+etc. Component may be omitted if there are no components for this archive.
<tag>Version<item>
This is a version string with the same properties as in the Packages file.
<example>
Archive: stable
-Compontent: main
+Component: main
Version: 1.3.1r6
Origin: Debian
Label: Debian
And unstable,
<example>
Archive: unstable
-Compontent: main
+Component: main
Version: 2.1
Origin: Debian
Label: Debian
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