debdeltas - compute deltas between Debian packages
computes deltas between the old and new versions of Debian
The explanation of what a delta is is in debdelta
In all of the following, ARGS
can be, a Debian binary file (usually, a
file ending in .deb
), or a directory containing such files, or a
file (that is, an index file such as those found in Debian
mirrors - even the zipped ones - see apt-ftparchive
(1) ). We will call
all such args that are not related to an option.
As a first step, debdeltas
builds an internal list of Debian packages. To
this end, it parses all ARGS
of the options --alt
, and those ARGS
given as non-option arguments (the aforementioned
cmdline args). If the argument is a Debian package, debdeltas
to the list; if the argument is a directory, debdeltas
scans it for
Debian packages to be added to the list; if the argument is Packages
parses it and adds all Debian packages to the list.
Then debdeltas groups all found Debian packages by name and architecture.
For each group, the newest cmdline version is isolated, and then deltas are
computed from all --old versions to that version.
These deltas are stored in many delta files with appropriate names of the form
; the location of the
delta files is specified by the "--dir" option.
Note that the location of files in a Packages
index is specified relative
to the base of the mirror, e.g. Filename:
For this reason, any Packages
argument must presented with a long path (that contains at least the
Note also that the same directory or index can be provided many times, as --old,
as --alt, and as cmdline argument.
Note also that debdeltas will skip all packages that are smaller than 10KB.
- --dir DIR
- force saving of deltas in this DIR (otherwise they go in
the dir of the newer deb_file).
- --alt ARGS
- this is parsed as the non-option command line, but the
found packages are never considered for a delta. They are considered
though when --clean-deltas is used, to decide if to delete a delta; and
are useful to find debs that are deleted from indexes and moved elsewhere.
Multiple --alt can be specified.
- --old ARGS
- this is parsed as the non-option command line, and the
found packages are considered as the older versions. Multiple --old can be
specified. Moreover, when scanning a Packages index, it is not an
error if files do not exist, as long as they have been moved in a --alt
directory. Note that, if no --old is specified, then no deltas will be
- --forensicdir DIR
- write hashes files; these are to be compared with those
produced by debdelta-upgrade --forensic=... when a delta fails
If a directory path is provided as argument to --dir, and it ends in // , then
this triggers a specific behaviour related to files found in Packages
indexes (as presented in the commandline). If a package in a index is stored
, and --dir is /tmp/foobar//
then the delta will be saved in
. The same is true for
--alt (and is useful to find old versions of a package).
- --signing-key KEY
- key used to sign the deltas (using GnuPG)
- -n N
- how many deltas to produce at maximum for each unique
package/arch (default unlimited)
- delete deltas that upgrade to packages versions that are
not found in the cmdline ARGS, and are at least two days old (according to
- do not include MD5 info in debdelta.
- create a patch that can only be used if the old .deb is
- --delta-algo ALGO
- use a specific backend for computing binary diffs; possible
values are: xdelta xdelta-bzip xdelta3 bsdiff
- -M Mb
- maximum memory to use (for 'bsdiff' or 'xdelta').
- check that the patch does apply.
- verbose (can be added multiple times).
- print traceback on errors; save useful info in temporary
files in case that a backend crashes.
(If '-d' is added multiple times, it also adds to the patches other extra
debugging checks: only for advanced bug tracking).
- keep temporary files (use for debugging).
- specify a different home for GnuPG, default for root is
/etc/debdelta/gnupg while for other users is unset. See
--homedir in gpg(1) for details.
- --disable-feature FEATURE
- disable an internal feature. See the documentation in
- Just list the deltas that would be created.
debdeltas --dir /tmp/ --old ~/mydebs ~/mydebs
will generate all deltas to
upgrade from the old versions in ~/mydebs to the newest version in ~/mydebs ,
and store the deltas in /tmp/
debdeltas --dir /tmp// --old
all deltas to upgrade main/i386 from lenny to squeeze, and store the deltas in
a pool structure under /tmp/
See also the example scripts /usr/share/debdelta/debmirror-delta-security
Report bugs to <email@example.com>.
Debdelta was written and is copyright © 2006-09 Andrea Mennucci.
This man page was written by Jegou Pierre-yves <firstname.lastname@example.org>.
This is free software. You may redistribute copies of it under the terms of the
GNU Library General Public License
<http://www.gnu.org/licenses/lgpl-2.0.html>. There is NO WARRANTY, to
the extent permitted by law.