Re: [PATCH V2 4/8] tools lib: Adopt str_has_prefix() from kernel

[Masami Hiramatsu (Google) <mhiramat@kernel.org>]

On Mon,  8 Apr 2024 11:52:26 +0530
Chaitanya S Prakash <ChaitanyaS.Prakash@arm.com> wrote:

> From: Chaitanya S Prakash <chaitanyas.prakash@arm.com>
> 
> Add str_has_prefix() to tools/include with the intention to replace
> strstarts().
> 
> Signed-off-by: Chaitanya S Prakash <chaitanyas.prakash@arm.com>
> ---
>  tools/include/linux/string.h |  2 ++
>  tools/lib/string.c           | 16 ++++++++++++++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/tools/include/linux/string.h b/tools/include/linux/string.h
> index e43c8f78d63c..e02292fa1fab 100644
> --- a/tools/include/linux/string.h
> +++ b/tools/include/linux/string.h
> @@ -44,6 +44,8 @@ static inline bool strstarts(const char *str, const char *prefix)
>  
>  size_t str_has_suffix(const char *str, const char *suffix);
>  
> +size_t str_has_prefix(const char *str, const char *prefix);
> +
>  extern char * __must_check skip_spaces(const char *);
>  
>  extern char *strim(char *);
> diff --git a/tools/lib/string.c b/tools/lib/string.c
> index 9cb515048239..76b15ee6493e 100644
> --- a/tools/lib/string.c
> +++ b/tools/lib/string.c
> @@ -252,3 +252,19 @@ size_t str_has_suffix(const char *str, const char *suffix)
>  
>  	return suffix_len;
>  }
> +
> +/**
> + * str_has_prefix - Test is a string has a given prefix
> + * @str: The string to be tested
> + * @prefix: The string to see if @str starts with
> + *
> + * Returns:
> + * * strlen(@prefix) if @str starts with @prefix
> + * * 0 if @str does not start with @prefix

Here, too. Is there any reason to return strlen(@prefix)?

Thank you,

> + */
> +size_t str_has_prefix(const char *str, const char *prefix)
> +{
> +	size_t prefix_len = strlen(prefix);
> +
> +	return strncmp(str, prefix, prefix_len) == 0 ? prefix_len : 0;
> +}
> -- 
> 2.30.2
> 
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>