The output format from "git-diff-index", "git-diff-tree" and
"git-diff-files" 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
+----------------------
-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.
-
-The patch generation can be customized at two levels.
-
-1. When the environment variable 'GIT_EXTERNAL_DIFF' is not set,
- these commands internally invoke "diff" like this:
+"git-diff-tree" and "git-diff-files" 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:
- diff -L a/<path> -L b/<path> -pu <old> <new>
-+
-For added files, `/dev/null` is used for <old>. For removed
-files, `/dev/null` is used for <new>
-+
-The "diff" formatting options can be customized via the
-environment variable 'GIT_DIFF_OPTS'. For example, if you
-prefer context diff:
-
- GIT_DIFF_OPTS=-c git-diff-index -p HEAD
-
-
-2. When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
- program named by it is called, instead of the diff invocation
- described above.
-+
-For a path that is added, removed, or modified,
-'GIT_EXTERNAL_DIFF' is called with 7 parameters:
+. 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"
- path old-file old-hex old-mode new-file new-hex new-mode
-+
-where:
+Example:
- <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
- contents of <old|new>,
- <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
- <old|new>-mode:: are the octal representation of the file modes.
+------------------------------------------------
+::100644 100644 100644 fabadb8... cc95eb0... 4866510... MM describe.c
+------------------------------------------------
-+
-The file parameters can point at the user's working file
-(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
-when a new file is added), or a temporary file (e.g. `old-file` in the
-index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
-temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
+Note that 'combined diff' lists only files which were modified from
+all parents.
-For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
-parameter, <path>.
+Generating patches with -p
+--------------------------
-git specific extension to diff format
--------------------------------------
+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.
-What -p option produces is slightly different from the
-traditional diff format.
+What the -p option produces is slightly different from the traditional
+diff format.
1. It is preceded with a "git diff" header, that looks like
this:
- diff --git a/file1 b/file2
+ diff --git a/file1 b/file2
+
The `a/` and `b/` filenames are the same unless rename/copy is
involved. Especially, even for a creation or a deletion,
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
--------------------
--- 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
deleted file mode <mode>,<mode>
+
The `mode <mode>,<mode>..<mode>` line appears only if at least one of
-the <mode> is diferent from the rest. Extended headers with
+the <mode> is different from the rest. Extended headers with
information about detected contents movement (renames and
copying detection) are designed to work with diff of two
<tree-ish> and are not used by combined diff format.
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").
-