From 197b3f3c70d61ff1c7ca24f66d567e06fe8ed3d9 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Wed, 12 Nov 2025 14:55:30 +0100 Subject: [PATCH] string: provide strends() Implement a function for checking if a string ends with a different string and add its kunit test cases. Acked-by: Linus Walleij Link: https://lore.kernel.org/r/20251112-gpio-shared-v4-1-b51f97b1abd8@linaro.org Signed-off-by: Bartosz Golaszewski --- include/linux/string.h | 18 ++++++++++++++++++ lib/tests/string_kunit.c | 13 +++++++++++++ 2 files changed, 31 insertions(+) diff --git a/include/linux/string.h b/include/linux/string.h index fdd3442c6bcbd..929d05d1247c7 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -562,4 +562,22 @@ static inline bool strstarts(const char *str, const char *prefix) return strncmp(str, prefix, strlen(prefix)) == 0; } +/** + * strends - Check if a string ends with another string. + * @str - NULL-terminated string to check against @suffix + * @suffix - NULL-terminated string defining the suffix to look for in @str + * + * Returns: + * True if @str ends with @suffix. False in all other cases. + */ +static inline bool strends(const char *str, const char *suffix) +{ + unsigned int str_len = strlen(str), suffix_len = strlen(suffix); + + if (str_len < suffix_len) + return false; + + return !(strcmp(str + str_len - suffix_len, suffix)); +} + #endif /* _LINUX_STRING_H_ */ diff --git a/lib/tests/string_kunit.c b/lib/tests/string_kunit.c index 0ed7448a26d3a..f9a8e557ba773 100644 --- a/lib/tests/string_kunit.c +++ b/lib/tests/string_kunit.c @@ -602,6 +602,18 @@ static void string_test_memtostr(struct kunit *test) KUNIT_EXPECT_EQ(test, dest[7], '\0'); } +static void string_test_strends(struct kunit *test) +{ + KUNIT_EXPECT_TRUE(test, strends("foo-bar", "bar")); + KUNIT_EXPECT_TRUE(test, strends("foo-bar", "-bar")); + KUNIT_EXPECT_TRUE(test, strends("foobar", "foobar")); + KUNIT_EXPECT_TRUE(test, strends("foobar", "")); + KUNIT_EXPECT_FALSE(test, strends("bar", "foobar")); + KUNIT_EXPECT_FALSE(test, strends("", "foo")); + KUNIT_EXPECT_FALSE(test, strends("foobar", "ba")); + KUNIT_EXPECT_TRUE(test, strends("", "")); +} + static struct kunit_case string_test_cases[] = { KUNIT_CASE(string_test_memset16), KUNIT_CASE(string_test_memset32), @@ -623,6 +635,7 @@ static struct kunit_case string_test_cases[] = { KUNIT_CASE(string_test_strlcat), KUNIT_CASE(string_test_strtomem), KUNIT_CASE(string_test_memtostr), + KUNIT_CASE(string_test_strends), {} }; -- 2.47.3