On Thu, 28 Jan 2016 15:14:17 +0200 Andy Shevchenko
<andriy.shevche...@linux.intel.com> wrote:
> >From time to time we have to match a string in an array. Make a simple helper
> for that purpose.
>
> ...
>
> --- a/include/linux/string.h
> +++ b/include/linux/string.h
> @@ -131,6 +131,8 @@ extern void argv_free(char **argv);
> extern bool sysfs_streq(const char *s1, const char *s2);
> extern int strtobool(const char *s, bool *res);
>
> +int match_string(const char * const *array, size_t n, const char *string);
> +
> #ifdef CONFIG_BINARY_PRINTF
> int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
> int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
> diff --git a/lib/string.c b/lib/string.c
> index 0323c0d..ba01d4f 100644
> --- a/lib/string.c
> +++ b/lib/string.c
> @@ -631,6 +631,32 @@ bool sysfs_streq(const char *s1, const char *s2)
> EXPORT_SYMBOL(sysfs_streq);
>
> /**
> + * match_string - matches given string in an array
I can't say I'm in love with the name, but I guess it will suffice.
search_string() doesn't seem much better.
> + * @array: array of strings
> + * @n: number of strings in the array or -1 for NULL
> terminated arrays
> + * @string: string to match with
> + *
> + * Return:
> + * index of a @string in the @array if matches, or %-ENODATA otherwise.
> + */
> +int match_string(const char * const *array, size_t n, const char *string)
> +{
> + int index;
> + const char *item;
> +
> + for (index = 0; index < n; index++) {
So we're taking an int and comparing that with (size_t)-1, relying upon
the compiler promoting the int to an unsigned type because size_t is
unsigned. It works, but it isn't pretty - there wasn't really much
point in making size have type size_t.
> + item = array[index];
> + if (!item)
> + break;
> + if (!strcmp(item, string))
> + return index;
> + }
> +
> + return -ENODATA;
> +}
> +EXPORT_SYMBOL(match_string);
