xdelta3

VCDIFF binary delta encoding

TLDR

Create delta

$ xdelta3 -e -s [old_file] [new_file] [patch.xd3]

Apply patch

$ xdelta3 -d -s [old_file] [patch.xd3] [new_file]

High compression

$ xdelta3 -9 -e -s [old_file] [new_file] [patch.xd3]

Encode to stdout (for piping)

$ xdelta3 -e -c -s [old_file] [new_file] > [patch.xd3]

Show delta information

$ xdelta3 printdelta [patch.xd3]

Decode without source

$ xdelta3 -d [patch.xd3] [output_file]

SYNOPSIS

xdelta3 [command] [options] [input [output]]

xdelta3 creates and applies binary delta patches using the VCDIFF format defined in RFC 3284. Encoding compares a source file with a target file and produces a compact delta that captures only the differences, while decoding reconstructs the target by applying the delta to the original source.Compression levels from 0 to 9 trade processing speed for smaller delta sizes. A streaming mode processes data in chunks, enabling memory-efficient handling of very large files. Self-contained patches can be created without requiring the original source file for decoding, embedding the necessary data within the delta itself.

PARAMETERS

-e

Encode (compress/create delta).

-d

Decode (decompress/apply delta).

-s FILE

Source file to copy from.

-0 to -9

Compression level.

-f

Force overwrite of existing files.

-c

Output to stdout.

-v

Verbose output (may be specified up to 2 times).

-q

Quiet, suppress output messages.

-B bytes

Source window size.

-W bytes

Input window size.

-S [djw|fgk]

Enable/disable secondary compression.

-n

Disable checksum.

-V

Show version.

COMMANDS

encode

Compress the input (default). Also set by -e.

decode

Decompress the input. Also set by -d.

printdelta

Print information about the entire delta.

printhdr

Print information about the first window.

printhdrs

Print information about all windows.

config

Print xdelta3 configuration.

recode

Re-encode with new application/secondary settings.

CAVEATS

The source file must be available for decoding unless the delta was created without a source. Memory options (-B, -W) may need tuning for very large files. The command-line syntax is similar to gzip.

HISTORY

xdelta3 is the third version of xdelta, implementing RFC 3284 VCDIFF. It provides efficient binary delta compression.