NAME
debdelta - compute changes between Debian packages
SYNOPSIS
debdelta [OPTION]... FROMFILE TOFILE DELTA
DESCRIPTION
This program computes changes between Debian packages FROMFILE and
TOFILE. These changes are stored in the file DELTA. The DELTA file may
later be used by the "debpatch" program to recreate TOFILE from FROM‐
FILE. In a sense, the pair of programs "debdelta"/"debpatch" operate on
Debian packages similar to how the pair "diff"/"patch" operate on text
files; indeed, the output of "debdelta" may be used to store and trans‐
mit only the changes between Debian packages; but, contrary to the
"diff" output, the output of "debdelta" is not human readable, but
rather it is intended to be as small as possible (to optimize for less
disk usage and/or faster transmission).
OPTIONS
--signing-key KEY
key used to sign the delta (using GnuPG).
--no-md5
do not include MD5 info in delta.
--needsold
create a patch that can only be used if the old .deb is avail‐
able.
--delta-algo ALGO
use a specific backend for computing binary diffs; possible val‐
ues are: xdelta xdelta-bzip xdelta3 bsdiff
-M Mb maximum memory to use (for 'bsdiff' or 'xdelta').
-v verbose (can be added multiple times).
-d print full traceback on Python errors; save useful info in tem‐
porary 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).
-k keep temporary files (use for debugging).
--gpg-home
specify a different home for GnuPG, default for root is
/etc/debdelta/gnupg while for other users is unset. See --home‐
dir in gpg(1) for details.
--disable-feature FEATURE
disable an internal feature. See the documentation in
README.features.
EXAMPLE
The command
debdelta libglib_2.12_all.deb libglib_2.14_all.deb /tmp/glib.debdelta
will express the difference between two versions of libglib in
/tmp/glib.debdelta ; the command
debpatch -A /tmp/glib.debdelta libglib_2.12_all.deb /tmp/glib.deb
will create in /tmp/glib.deb a perfect copy of libglib_2.14_all.deb.
SECURITY
A Debian package that is recreated using debpatch is byte-by-byte iden‐
tical to the original one; so the cryptographic archive authentication
support for APT (see apt-secure(8) ) may be used to assert that it can
be trusted to be installed. Moreover, if a GnuPG key is specified
using --signing-key then the delta file itself is cryptograhically pro‐
tected using GnuPG, MD5 and SHA1 (using the same method as dpkg-sig(1)
). Note that, for non-root users, the master debdelta keyring
/usr/share/keyrings/debian-debdelta-archive-keyring.gpg is added to the
list of keyrings for gnupg.
EXIT STATUS
0 if OK,
1 if there was a retriable problem (e.g., out-of-disk-space, or an
auxiliary program such 'lzma' is missing and the user is asked
to install the package 'lzma'),
2 if there was a non-retriable problem,
3 if there was an error in a command-line option, or in a config‐
uration file,
4 if there is an internal error, and
5 if exited due to keyboard interrupt.
REPORTING BUGS
Report bugs to <mennucc1@debian.org>.
AUTHORS
Debdelta was written and is copyright © 2006-09 Andrea Mennucci.
This man page was written by Jegou Pierre-yves <pier‐
reyves.jeg@voila.fr>.
COPYING
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.
SEE ALSO
debdelta-upgrade(1), debpatch(1), debdeltas(1), /usr/share/doc/deb‐
delta/README.
