-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
+These commands all compare two sets of things; what is
compared differs:
git-diff-index <tree-ish>::
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.
+
Generating patches with -p
--------------------------
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
--- a/describe.c
+++ b/describe.c
@@@ -98,20 -98,12 +98,20 @@@
- return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
+ return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
}
-
+
- static void describe(char *arg)
-static void describe(struct commit *cmit, int last_one)
++static void describe(char *arg, int last_one)
{
+ unsigned char sha1[20];
+ struct commit *cmit;
- struct commit_list *list;
- static int initialized = 0;
- struct commit_name *n;
-
+ struct commit_list *list;
+ static int initialized = 0;
+ struct commit_name *n;
+
+ if (get_sha1(arg, sha1) < 0)
+ usage(describe_usage);
+ cmit = lookup_commit_reference(sha1);
+ if (!cmit)
+ usage(describe_usage);
+
- if (!initialized) {
- initialized = 1;
- for_each_ref(get_name);
+ if (!initialized) {
+ initialized = 1;
+ for_each_ref(get_name);
------------
1. It is preceded with a "git diff" header, that looks like
two unresolved merge parents with the working tree file
(i.e. file1 is stage 2 aka "our version", file2 is stage 3 aka
"their version").
-