git-clean: add ask each interactive action

Add a new action for interactive git-clean: ask each. It's just like
the "rm -i" command, that the user must confirm one by one for each
file or directory to be cleaned.

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/clean.c

@@ -717,6 +717,40 @@ static int select_by_numbers_cmd(void)
 	return 0;
 }
 
+static int ask_each_cmd(void)
+{
+	struct strbuf confirm = STRBUF_INIT;
+	struct strbuf buf = STRBUF_INIT;
+	struct string_list_item *item;
+	const char *qname;
+	int changed = 0, eof = 0;
+
+	for_each_string_list_item(item, &del_list) {
+		/* Ctrl-D should stop removing files */
+		if (!eof) {
+			qname = quote_path_relative(item->string, NULL, &buf);
+			printf(_("remove %s? "), qname);
+			if (strbuf_getline(&confirm, stdin, '\n') != EOF) {
+				strbuf_trim(&confirm);
+			} else {
+				putchar('\n');
+				eof = 1;
+			}
+		}
+		if (!confirm.len || strncasecmp(confirm.buf, "yes", confirm.len)) {
+			*item->string = '\0';
+			changed++;
+		}
+	}
+
+	if (changed)
+		string_list_remove_empty_items(&del_list, 0);
+
+	strbuf_release(&buf);
+	strbuf_release(&confirm);
+	return MENU_RETURN_NO_LOOP;
+}
+
 static int quit_cmd(void)
 {
 	string_list_clear(&del_list, 0);
@@ -731,6 +765,7 @@ static int help_cmd(void)
 		    "clean               - start cleaning\n"
 		    "filter by pattern   - exclude items from deletion\n"
 		    "select by numbers   - select items to be deleted by numbers\n"
+		    "ask each            - confirm each deletion (like \"rm -i\")\n"
 		    "quit                - stop cleaning\n"
 		    "help                - this screen\n"
 		    "?                   - help for prompt selection"
@@ -748,6 +783,7 @@ static void interactive_main_loop(void)
 			{'c', "clean",			0, clean_cmd},
 			{'f', "filter by pattern",	0, filter_by_patterns_cmd},
 			{'s', "select by numbers",	0, select_by_numbers_cmd},
+			{'a', "ask each",		0, ask_each_cmd},
 			{'q', "quit",			0, quit_cmd},
 			{'h', "help",			0, help_cmd},
 		};