delta is a library (and an associated utility) which allow

us to perform binary diff and patching in an efficient way. It

is similar in function to xdelta and vcdiff (RFC 3284), but more

(space-)efficient.

-rw-r--r-- 1 agc users 10107 Apr 14 10:41 1

-rw-r--r-- 1 agc users 206 Apr 19 16:50 1.bsd

-rw-r--r-- 1 agc users 109 Apr 21 17:52 1.delta

-rw-r--r-- 1 agc users 222 Apr 19 16:48 1.xd

-rw-r--r-- 1 agc users 158 Apr 21 17:48 1.xd3

-rw-r--r-- 1 agc users 10113 Apr 14 10:41 2

The delta(1) utility takes 3 arguments - oldfile, newfile and

patchfile - and creates the patchfile from the binary difference of

the old and new files. There's an optional -d or -p to diff and

to patch, respectively. The default is to patch.

% delta -d 2 1 2.diff

% delta -p 2 1.new 2.diff

% diff 1 1.new

%

The patchfile uses bzip2, and is more efficient than both xdelta (v1

and v3) by Josh MacDonald, and bsdiff from Colin Percival, dated

2005, at least in the amount of space used for the generated patch

file. It also uses zigzag encoding for the numbers stored internally,

in order to be space-efficient.