-The output format from "git-diff-index", "git-diff-tree" and
-"git-diff-files" are very similar.
+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:
diff format for merges
----------------------
-"git-diff-tree" and "git-diff-files" can take '-c' or '--cc' option
+"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:
--------------------------
When "git-diff-index", "git-diff-tree", or "git-diff-files" are run
-with a '-p' option, they do not produce the output described above;
-instead they produce a patch file. You can customize the creation
-of such patches via the GIT_EXTERNAL_DIFF and the GIT_DIFF_OPTS
-environment variables.
+with a '-p' option, or "git diff" without the '--raw' option, they
+do not produce the output described above; instead they produce a
+patch file. You can customize the creation of such patches via the
+GIT_EXTERNAL_DIFF and the GIT_DIFF_OPTS environment variables.
What the -p option produces is slightly different from the traditional
diff format.
If there is need for such substitution then the whole
pathname is put in double quotes.
+The similarity index is the percentage of unchanged lines, and
+the dissimilarity index is the percentage of changed lines. It
+is a rounded down integer, followed by a percent sign. The
+similarity index value of 100% is thus reserved for two equal
+files, while 100% dissimilarity means that no line from the old
+file made it into the new one.
+
combined diff format
--------------------
-git-diff-tree and git-diff-files can take '-c' or '--cc' option
-to produce 'combined diff', which looks like this:
+"git-diff-tree", "git-diff-files" and "git-diff" can take '-c' or
+'--cc' option to produce 'combined diff', which looks like this:
------------
diff --combined describe.c