check-attr: add an internal check_attr() function

This step is preparation to introducing --stdin-paths option.

I have also added maybe_flush_or_die() at the end of main() to ensure that
we exit with the zero code only when we flushed the output successfully.

Signed-off-by: Dmitry Potapov <dpotapov@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

builtin-check-attr.c

@@ -6,6 +6,27 @@
 static const char check_attr_usage[] =
 "git check-attr attr... [--] pathname...";
 
+static void check_attr(int cnt, struct git_attr_check *check,
+	const char** name, const char *file)
+{
+	int j;
+	if (git_checkattr(file, cnt, check))
+		die("git_checkattr died");
+	for (j = 0; j < cnt; j++) {
+		const char *value = check[j].value;
+
+		if (ATTR_TRUE(value))
+			value = "set";
+		else if (ATTR_FALSE(value))
+			value = "unset";
+		else if (ATTR_UNSET(value))
+			value = "unspecified";
+
+		quote_c_style(file, NULL, stdout, 0);
+		printf(": %s: %s\n", name[j], value);
+	}
+}
+
 int cmd_check_attr(int argc, const char **argv, const char *prefix)
 {
 	struct git_attr_check *check;
@@ -42,23 +63,8 @@ int cmd_check_attr(int argc, const char **argv, const char *prefix)
 		check[i].attr = a;
 	}
 
-	for (i = doubledash; i < argc; i++) {
-		int j;
-		if (git_checkattr(argv[i], cnt, check))
-			die("git_checkattr died");
-		for (j = 0; j < cnt; j++) {
-			const char *value = check[j].value;
-
-			if (ATTR_TRUE(value))
-				value = "set";
-			else if (ATTR_FALSE(value))
-				value = "unset";
-			else if (ATTR_UNSET(value))
-				value = "unspecified";
-
-			quote_c_style(argv[i], NULL, stdout, 0);
-			printf(": %s: %s\n", argv[j+1], value);
-		}
-	}
+	for (i = doubledash; i < argc; i++)
+		check_attr(cnt, check, argv+1, argv[i]);
+	maybe_flush_or_die(stdout, "attribute to stdout");
 	return 0;
 }