git/Documentation/diff-format.txt

The output format from "git-diff-index", "git-diff-tree",
"git-diff-files" and "git diff --raw" are very similar.

These commands all compare two sets of things; what is
compared differs:

git-diff-index <tree-ish>::
        compares the <tree-ish> and the files on the filesystem.

git-diff-index --cached <tree-ish>::
        compares the <tree-ish> and the index.

git-diff-tree [-r] <tree-ish-1> <tree-ish-2> [<pattern>...]::
        compares the trees named by the two arguments.

git-diff-files [<pattern>...]::
        compares the index and the files on the filesystem.


An output line is formatted this way:

------------------------------------------------
in-place edit  :100644 100644 bcd1234... 0123456... M file0
copy-edit      :100644 100644 abcd123... 1234567... C68 file1 file2
rename-edit    :100644 100644 abcd123... 1234567... R86 file1 file3
create         :000000 100644 0000000... 1234567... A file4
delete         :100644 000000 1234567... 0000000... D file5
unmerged       :000000 000000 0000000... 0000000... U file6
------------------------------------------------

That is, from the left to the right:

. a colon.
. mode for "src"; 000000 if creation or unmerged.
. a space.
. mode for "dst"; 000000 if deletion or unmerged.
. a space.
. sha1 for "src"; 0\{40\} if creation or unmerged.
. a space.
. sha1 for "dst"; 0\{40\} if creation, unmerged or "look at work tree".
. a space.
. status, followed by optional "score" number.
. a tab or a NUL when '-z' option is used.
. path for "src"
. a tab or a NUL when '-z' option is used; only exists for C or R.
. path for "dst"; only exists for C or R.
. an LF or a NUL when '-z' option is used, to terminate the record.

<sha1> is shown as all 0's if a file is new on the filesystem
and it is out of sync with the index.

Example:

------------------------------------------------
:100644 100644 5be4a4...... 000000...... M file.c
------------------------------------------------

When `-z` option is not used, TAB, LF, and backslash characters
in pathnames are represented as `\t`, `\n`, and `\\`,
respectively.

diff format for merges
----------------------

"git-diff-tree", "git-diff-files" and "git-diff --raw"
can take '-c' or '--cc' option
to generate diff output also for merge commits.  The output differs
from the format described above in the following way:

. there is a colon for each parent
. there are more "src" modes and "src" sha1
. status is concatenated status characters for each parent
. no optional "score" number
. single path, only for "dst"

Example:

------------------------------------------------
::100644 100644 100644 fabadb8... cc95eb0... 4866510... MM	describe.c
------------------------------------------------

Note that 'combined diff' lists only files which were modified from
all parents.


include::diff-generate-patch.txt[]