NAME
pristine-gz - regenerate pristine gz files
SYNOPSIS
pristine-gz [-vdk] gendelta file.gz delta
pristine-gz [-vdk] gengz delta file
DESCRIPTION
This is a complement to the pristine-tar(1) command. Normally you don’t
need to run it by hand, since pristine-tar calls it as necessary to
handle .tar.gz files.
pristine-gz gendelta takes the specified gz file, and generates a small
binary delta file that can later be used by pristine-gz gengz to
recreate the original file.
pristine-gz gengz takes the specified delta file, and compresses the
specified input file (which must be identical to the contents of the
original gz file). The resulting file will be identical to the original
gz file used to create the delta.
The approach used to regenerate the original gz file is to figure out
how it was produced -- what compression level was used, whether it was
built with GNU gzip(1) or with a library or BSD version, whether the
--rsyncable option was used, etc, and to reproduce this build
environment when regenerating the gz.
This approach will work for about 99.5% of cases. One example of a case
it cannot currently support is a gz file that has been produced by
appending together multiple gz files.
For the few where it doesn’t work, a binary diff will be included in
the delta between the closest regneratable gz file and the original. In
the worst case, the diff will include the entire content of the
original gz file, resulting in a larger than usual delta. If the delta
is much larger than usual, pristine-gz will print a warning.
If the delta filename is "-", pristine-gz reads or writes it to stdio.
OPTIONS
-v
--verbose
Verbose mode, show each command that is run.
-d
--debug
Debug mode.
-k
--keep
Don’t clean up the temporary directory on exit.
ENVIRONMENT
TMPDIR
Specifies a location to place temporary files, other than the
default.
AUTHOR
Joey Hess <joeyh@debian.org>, Faidon Liambotis <paravoid@debian.org>
Josh Triplett <josh@joshtriplett.org>
Licensed under the GPL, version 2.