pdar: Portable Delta Archives

pdar is a Python module to support creation and application of Portable Delta Archives. These files are similar to patch files, but they can be used on binary data files as well as text files.

File Format

Internally .pdar files are slightly modified .pax (POSIX.1-2001 tar) files, and the deltas are stored in bsdiff format.

Utilities

The following command line utilities are provided when the pdar Python module is installed.

pdar

The pdar utility contains a number of commands for creation and manipulation of .pdar files

Full Usage:

usage: pdar [-h] [-V] [-d | -q] {info,apply,create} ...

utility for manipulating portable delta archives

optional arguments:
  -h, --help           show this help message and exit
  -V, --version        show version message and exit
  -d, --debug
  -q, --quiet

commands:
  {info,apply,create}
    create             create pdar archive
    apply              apply pdar archive as patch
    info               show info about pdar archive

pdar create

The create command is used to create a new .pdar file by comparing two directory trees. It's similar to diff -r.

Example:

$ pdar create patch.pdar /path/to/orig_files /path/to/modified files

Full Usage:

usage: pdar create [-h] [-f] [-b]
                   archive_name path1 path2
                   [pattern [pattern ...]]

create pdar archive

positional arguments:
  archive_name  path to output pdar archive
  path1         path to source data
  path2         path to modified data
  pattern

optional arguments:
  -h, --help    show this help message and exit
  -f, --force   overwrite existing archives
  -b, --backup  backup existing archive before overwriting
                (implies force, existing backups may be lost).

pdar info

The info command displays information about the .pdar file and it's contents.

Example:

$ pdar info patch.pdar

Full Usage:

usage: pdar info [-h] archive_name

show info about pdar archive

positional arguments:
  archive_name  path to output pdar archive

optional arguments:
  -h, --help    show this help message and exit

pdar apply

The apply command is used to apply a .pdar file to a path, similar to the patch utility.

Example:

$ pdar apply patch.pdar /path/to/old_files

Full Usage:

usage: pdar apply [-h] [-o OUTPUT_PATH] archive_name path

apply pdar archive as patch

positional arguments:
  archive_name          path to output pdar archive
  path                  path to which pdar will be applied

optional arguments:
  -h, --help            show this help message and exit
  -o OUTPUT_PATH, --output-path OUTPUT_PATH
                        apply patch in alternate location,
                        rather than overwriting original files