interdiff Man page



interdiff – show differences between two diff files


interdiff [[-p n] | [–strip-match=n]] [[-U n] | [–unified=n]] [[-d PAT] | [–drop-context=PAT]] [[-q] | [–quiet]] [[-z] |
[–decompress]] [[-b] | [–ignore-space-change]] [[-B] |
[–ignore-blank-lines]] [[-i] | [–ignore-case]] [[-w] |
[–ignore-all-space]] [[–interpolate] | [–combine] |
[–flip]] [–no-revert-omitted] diff1 diff2

interdiff {[–help] | [–version]}


interdiff creates a unified format diff that expresses the difference
between two diffs. The diffs must both be relative to the same files.
For best results, the diffs must have at least three lines of context.

To reverse a patch, use /dev/null for diff2.

To reduce the amount of context in a patch, use:

interdiff -U1 /dev/null patchfile

Since interdiff doesn’t have the advantage of being able to look at the
files that are to be modified, it has stricter requirements on the
input format than patch does. The output of GNU diff will be okay,
even with extensions, but if you intend to use a hand-edited patch it
might be wise to clean up the offsets and counts using recountdiff

Note, however, that the two patches must both be relative to the
versions of the same original set of files.

The diffs may be in context format. The output, however, will be in
unified format.


Ignored, for compatibility with older versions of interdiff. This
option will go away soon.

-p n, –strip-match=n
When comparing filenames, ignore the first n pathname components
from both patches. (This is similar to the -p option to GNU

-q, –quiet
Quieter output. Don’t emit rationale lines at the beginning of each

-U n, –unified=n
Attempt to display n lines of context (requires at least n lines of
context in both input files). (This is similar to the -U option to
GNU diff.)

-d PATTERN, –drop-context=PATTERN
Don’t display any context on files that match the shell wildcard
PATTERN. This option can be given multiple times.

Note that the interpretation of the shell wildcard pattern does not
count slash characters or periods as special (in other words, no
flags are given to fnmatch). This is so that “*/basename”-type
patterns can be given without limiting the number of pathname

-i, –ignore-case
Consider upper- and lower-case to be the same.

-w, –ignore-all-space
Ignore whitespace changes in patches.

-b, –ignore-space-change
Ignore changes in the amount of whitespace.

-B, –ignore-blank-lines
Ignore changes whose lines are all blank.

-z, –decompress
Decompress files with extensions .gz and .bz2.

Run as “interdiff”. This is the default.

Run as “combinediff”. See combinediff for more information about
how the behaviour is altered in this mode.

(For interpolation mode only) When a file is changed by the first
patch but not by the second, don’t revert that change.

Display a short usage message.

Display the version number of interdiff.

Basic usage:

interdiff -z 3.2pre1.patch.gz 3.2pre2.patch.gz

Reversing a patch:

interdiff patch /dev/null

Reversing part of a patch (and ignoring the rest):

filterdiff -i file.c patchfile | \
interdiff /dev/stdin /dev/null


There are currently no known bugs in interdiff; but there are some
caveats. If you find a bug, please report it (along with a minimal test
case) to Tim Waugh .

There are some sets of patches in which there is just not enough
information to produce a proper interdiff. In this case, the strategy
employed is to revert the original patch and apply the new patch. This,
unfortunately, means that interdiffs are not guaranteed to be



Tim Waugh
Package maintainer

Michael K. Johnson
Original man page contributor

patchutils 23 June 2009 INTERDIFF(1)

Ils en parlent aussi

Side-by-side diffs for Mercurial (hg) « Ian Obermiller