utils: add a safe version of basename

So we don't need to worry about the libgen.h include game.
And we can switch trunkname over to that, making it a bit simpler.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

src/util-strings.c

@@ -156,6 +156,30 @@ strv_join(char **strv, const char *joiner)
 	return str;
 }
 
+/**
+ * Return a pointer to the basename within filename.
+ * If the filename the empty string or a directory (i.e. the last char of
+ * filename is '/') NULL is returned.
+ */
+const char *
+safe_basename(const char *filename)
+{
+	const char *basename;
+
+	if (*filename == '\0')
+		return NULL;
+
+	basename = strrchr(filename, '/');
+	if (basename == NULL)
+		return filename;
+
+	if (*(basename + 1) == '\0')
+		return NULL;
+
+	return basename + 1;
+}
+
+
 /**
  * Similar to basename() but returns the trunk only without the (last)
  * trailing suffix, so that:
@@ -170,19 +194,15 @@ strv_join(char **strv, const char *joiner)
 char *
 trunkname(const char *filename)
 {
-	/* See basename(3), there are two versions and they depend on
-	 * whether libgen.h is included. We can't be sure which basename()
-	 * applies here, so let's play it safe and assume it's the POSIX
-	 * one. */
-	char *tmp = strdup(filename);
-	char *base = basename(tmp);
+	const char *base = safe_basename(filename);
 	char *suffix;
-	char *trunk;
 
-	if ((suffix = rindex(base, '.')))
-	    *suffix = '\0';
+	if (base == NULL)
+		return strdup("");
 
-	trunk = strdup(base);
-	free(tmp);
-	return trunk;
+	suffix = rindex(base, '.');
+	if (suffix == NULL)
+		return strdup(base);
+	else
+		return strndup(base, suffix-base);
 }

src/util-strings.h

@@ -392,5 +392,8 @@ strstartswith(const char *str, const char *prefix)
 	return prefixlen > 0 ? strneq(str, prefix, strlen(prefix)) : false;
 }
 
+const char *
+safe_basename(const char *filename);
+
 char *
 trunkname(const char *filename);

test/test-utils.c

@@ -1292,6 +1292,35 @@ START_TEST(strneq_test)
 }
 END_TEST
 
+START_TEST(basename_test)
+{
+	struct test {
+		const char *path;
+		const char *expected;
+	} tests[] = {
+		{ "a", "a" },
+		{ "foo.c", "foo.c" },
+		{ "foo", "foo" },
+		{ "/path/to/foo.h", "foo.h" },
+		{ "../bar.foo", "bar.foo" },
+		{ "./bar.foo.baz", "bar.foo.baz" },
+		{ "./", NULL },
+		{ "/", NULL },
+		{ "/bar/", NULL },
+		{ "/bar", "bar" },
+		{ "", NULL },
+	};
+	struct test *t;
+
+	ARRAY_FOR_EACH(tests, t) {
+		const char *result = safe_basename(t->path);
+		if (t->expected == NULL)
+			ck_assert(result == NULL);
+		else
+			ck_assert_str_eq(result, t->expected);
+	}
+}
+END_TEST
 START_TEST(trunkname_test)
 {
 	struct test {
@@ -1300,6 +1329,7 @@ START_TEST(trunkname_test)
 	} tests[] = {
 		{ "foo.c", "foo" },
 		{ "/path/to/foo.h", "foo" },
+		{ "/path/to/foo", "foo" },
 		{ "../bar.foo", "bar" },
 		{ "./bar.foo.baz", "bar.foo" },
 		{ "./", "" },
@@ -1362,6 +1392,7 @@ litest_utils_suite(void)
 	tcase_add_test(tc, streq_test);
 	tcase_add_test(tc, strneq_test);
 	tcase_add_test(tc, trunkname_test);
+	tcase_add_test(tc, basename_test);
 
 	suite_add_tcase(s, tc);