# phpman > man > interdiff(1)

> **TLDR:** Show differences between two diff files.
>
- Compare diff files:
  `interdiff {{old_file}} {{new_file}}`
- Compare diff files, ignoring whitespace:
  `interdiff {{-w|--ignore-all-space}} {{old_file}} {{new_file}}`

*Source: tldr-pages*

---

[INTERDIFF(1)](https://www.chedong.com/phpMan.php/man/INTERDIFF/1/markdown)                                  Man pages                                 [INTERDIFF(1)](https://www.chedong.com/phpMan.php/man/INTERDIFF/1/markdown)



## NAME
       interdiff - show differences between two diff files

## SYNOPSIS
       **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]}

## DESCRIPTION
       **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**(1)](https://www.chedong.com/phpMan.php/man/patch/1/markdown) 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**(1)](https://www.chedong.com/phpMan.php/man/recountdiff/1/markdown) first.

       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.

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

### -p --strip-match=
           When comparing filenames, ignore the first _n_ pathname components from both patches. (This
           is similar to the **-p** option to GNU [**patch**(1)](https://www.chedong.com/phpMan.php/man/patch/1/markdown).)

### -q --quiet
           Quieter output. Don't emit rationale lines at the beginning of each patch.

### -U --unified=
           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**(1)](https://www.chedong.com/phpMan.php/man/diff/1/markdown).)

### -d --drop-context=
           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
           components.

### -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.

### --interpolate
           Run as “interdiff”. This is the default.

### --combine
           Run as “combinediff”. See [**combinediff**(1)](https://www.chedong.com/phpMan.php/man/combinediff/1/markdown) for more information about how the behaviour is
           altered in this mode.

### --no-revert-omitted
           (For interpolation mode only) When a file is changed by the first patch but not by the
           second, don't revert that change.

### --help
           Display a short usage message.

### --version
           Display the version number of interdiff.

## EXAMPLES
       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

## BUGS
       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 <<twaugh@redhat.com>>.

       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
       reversible.

## SEE ALSO
       [**combinediff**(1)](https://www.chedong.com/phpMan.php/man/combinediff/1/markdown)

## AUTHORS
       **Tim** **Waugh** <<twaugh@redhat.com>>
           Package maintainer

       **Michael** **K.** **Johnson** <<johnsonm@redhat.com>>
           Original man page contributor



patchutils                                  23 June 2009                                [INTERDIFF(1)](https://www.chedong.com/phpMan.php/man/INTERDIFF/1/markdown)