From b26823c19a12d9a06207ad3051e3d1059a9e1005 Mon Sep 17 00:00:00 2001 From: Ammar Faizi Date: Tue, 29 Mar 2022 17:17:36 +0700 Subject: tools/nolibc/string: Implement `strnlen()` size_t strnlen(const char *str, size_t maxlen); The strnlen() function returns the number of bytes in the string pointed to by sstr, excluding the terminating null byte ('\0'), but at most maxlen. In doing this, strnlen() looks only at the first maxlen characters in the string pointed to by str and never beyond str[maxlen-1]. The first use case of this function is for determining the memory allocation size in the strndup() function. Link: https://lore.kernel.org/lkml/CAOG64qMpEMh+EkOfjNdAoueC+uQyT2Uv3689_sOr37-JxdJf4g@mail.gmail.com Suggested-by: Alviro Iskandar Setiawan Acked-by: Willy Tarreau Signed-off-by: Ammar Faizi Signed-off-by: Paul E. McKenney --- tools/include/nolibc/string.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'tools') diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h index 75a453870498..f43d52a44d09 100644 --- a/tools/include/nolibc/string.h +++ b/tools/include/nolibc/string.h @@ -147,6 +147,15 @@ size_t nolibc_strlen(const char *str) #define strlen(str) nolibc_strlen((str)) #endif +static __attribute__((unused)) +size_t strnlen(const char *str, size_t maxlen) +{ + size_t len; + + for (len = 0; (len < maxlen) && str[len]; len++); + return len; +} + static __attribute__((unused)) size_t strlcat(char *dst, const char *src, size_t size) { -- cgit v1.2.3