git stat -s: short status output

Give -s(hort) option to "git stat" that shows the status of paths in a
more concise way.

    XY PATH1 -> PATH2

format to be more machine readable than output from "git status", which is
about previewing of "git commit" with the same arguments.

PATH1 is the path in the HEAD, and " -> PATH2" part is shown only when
PATH1 corresponds to a different path in the index/worktree.

For unmerged entries, X shows the status of stage #2 (i.e. ours) and Y
shows the status of stage #3 (i.e. theirs).  For entries that do not have
conflicts, X shows the status of the index, and Y shows the status of the
work tree.  For untracked paths, XY are "??".

    X          Y     Meaning
    -------------------------------------------------
              [MD]   not updated
    M        [ MD]   updated in index
    A        [ MD]   added to index
    D        [ MD]   deleted from index
    R        [ MD]   renamed in index
    C        [ MD]   copied in index
    [MARC]           index and work tree matches
    [ MARC]     M    work tree changed since index
    [ MARC]     D    deleted in work tree

    D           D    unmerged, both deleted
    A           U    unmerged, added by us
    U           D    unmerged, deleted by them
    U           A    unmerged, added by them
    D           U    unmerged, deleted by us
    A           A    unmerged, both added
    U           U    unmerged, both modified

    ?           ?    untracked

When given -z option, the records are terminated by NUL characters for
better machine readability.  Because the traditional long format is
designed for human consumption, NUL termination does not make sense.
For this reason, -z option implies -s (short output).

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-commit.c

@@ -902,19 +902,97 @@ static int git_status_config(const char *k, const char *v, void *cb)
 	return git_diff_ui_config(k, v, NULL);
 }
 
+#define quote_path quote_path_relative
+
+static void short_unmerged(int null_termination, struct string_list_item *it,
+			   struct wt_status *s)
+{
+	struct wt_status_change_data *d = it->util;
+	const char *how = "??";
+
+	switch (d->stagemask) {
+	case 1: how = "DD"; break; /* both deleted */
+	case 2: how = "AU"; break; /* added by us */
+	case 3: how = "UD"; break; /* deleted by them */
+	case 4: how = "UA"; break; /* added by them */
+	case 5: how = "DU"; break; /* deleted by us */
+	case 6: how = "AA"; break; /* both added */
+	case 7: how = "UU"; break; /* both modified */
+	}
+	printf("%s ", how);
+	if (null_termination) {
+		fprintf(stdout, "%s%c", it->string, 0);
+	} else {
+		struct strbuf onebuf = STRBUF_INIT;
+		const char *one;
+		one = quote_path(it->string, -1, &onebuf, s->prefix);
+		printf("%s\n", one);
+		strbuf_release(&onebuf);
+	}
+}
+
+static void short_status(int null_termination, struct string_list_item *it,
+			 struct wt_status *s)
+{
+	struct wt_status_change_data *d = it->util;
+
+	printf("%c%c ",
+	       !d->index_status ? ' ' : d->index_status,
+	       !d->worktree_status ? ' ' : d->worktree_status);
+	if (null_termination) {
+		fprintf(stdout, "%s%c", it->string, 0);
+		if (d->head_path)
+			fprintf(stdout, "%s%c", d->head_path, 0);
+	} else {
+		struct strbuf onebuf = STRBUF_INIT;
+		const char *one;
+		if (d->head_path) {
+			one = quote_path(d->head_path, -1, &onebuf, s->prefix);
+			printf("%s -> ", one);
+			strbuf_release(&onebuf);
+		}
+		one = quote_path(it->string, -1, &onebuf, s->prefix);
+		printf("%s\n", one);
+		strbuf_release(&onebuf);
+	}
+}
+
+static void short_untracked(int null_termination, struct string_list_item *it,
+			    struct wt_status *s)
+{
+	if (null_termination) {
+		fprintf(stdout, "?? %s%c", it->string, 0);
+	} else {
+		struct strbuf onebuf = STRBUF_INIT;
+		const char *one;
+		one = quote_path(it->string, -1, &onebuf, s->prefix);
+		printf("?? %s\n", one);
+		strbuf_release(&onebuf);
+	}
+}
+
 int cmd_stat(int argc, const char **argv, const char *prefix)
 {
 	struct wt_status s;
+	static int null_termination, shortstatus;
+	int i;
 	unsigned char sha1[20];
 	static struct option builtin_stat_options[] = {
 		OPT__VERBOSE(&verbose),
+		OPT_BOOLEAN('s', "short", &shortstatus,
+			    "show status concicely"),
+		OPT_BOOLEAN('z', "null", &null_termination,
+			    "terminate entries with NUL"),
 		{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg,
 		  "mode",
 		  "show untracked files, optional modes: all, normal, no. (Default: all)",
 		  PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
 		OPT_END(),
 	};
 
+	if (null_termination)
+		shortstatus = 1;
+
 	wt_status_prepare(&s);
 	git_config(git_status_config, &s);
 	argc = parse_options(argc, argv, prefix,
@@ -930,14 +1008,34 @@ int cmd_stat(int argc, const char **argv, const char *prefix)
 	s.is_initial = get_sha1(s.reference, sha1) ? 1 : 0;
 	wt_status_collect(&s);
 
-	s.verbose = verbose;
-	if (s.relative_paths)
-		s.prefix = prefix;
-	if (s.use_color == -1)
-		s.use_color = git_use_color_default;
-	if (diff_use_color_default == -1)
-		diff_use_color_default = git_use_color_default;
-	wt_status_print(&s);
+	if (shortstatus) {
+		for (i = 0; i < s.change.nr; i++) {
+			struct wt_status_change_data *d;
+			struct string_list_item *it;
+
+			it = &(s.change.items[i]);
+			d = it->util;
+			if (d->stagemask)
+				short_unmerged(null_termination, it, &s);
+			else
+				short_status(null_termination, it, &s);
+		}
+		for (i = 0; i < s.untracked.nr; i++) {
+			struct string_list_item *it;
+
+			it = &(s.untracked.items[i]);
+			short_untracked(null_termination, it, &s);
+		}
+	} else {
+		s.verbose = verbose;
+		if (s.relative_paths)
+			s.prefix = prefix;
+		if (s.use_color == -1)
+			s.use_color = git_use_color_default;
+		if (diff_use_color_default == -1)
+			diff_use_color_default = git_use_color_default;
+		wt_status_print(&s);
+	}
 	return 0;
 }