linux-kernel - Re: [PATCH v1 1/8] lib/string: introduce match

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Date:	Fri, 8 Jan 2016 09:13:05 +0900
From:	Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
To:	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:	Tejun Heo <tj@...nel.org>,
	Linus Walleij <linus.walleij@...aro.org>,
	Dmitry Eremin-Solenikov <dbaryshkov@...il.com>,
	linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
	"David S. Miller" <davem@...emloft.net>,
	David Airlie <airlied@...ux.ie>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Rasmus Villemoes <linux@...musvillemoes.dk>,
	Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
Subject: Re: [PATCH v1 1/8] lib/string: introduce match_string() helper

On (01/07/16 14:06), Andy Shevchenko wrote:
> 
> From time to time we have to match a string in an array. Make a simple helper
> for that purpose.
> 

Hello,

strncmp() case seems to be quite common.

> +int match_string(const char * const *array, size_t len, const char *string)
                                                  ^^^^^^^
a nitpick, [to me] `len' looks a bit confusing, usually it's array 'size'.

> +{
> +	int index = 0;
> +	const char *item;
> +
> +	do {
> +		item = array[index];
> +		if (!item)
> +			break;
> +		if (!strcmp(item, string))
> +			return index;
> +	} while (++index < len || !len);
> +
> +	return -ENODATA;
> +}


do you want to do something like this:

/*
 * hm, how to name this thing... nmatch_string() or match_nstring()...
 * nmatch_string() _probably_ better, match_nstring() is totally cryptic.
 */
int nmatch_string(array, array_size, string, string_len)
{
	do {
		strncmp();
	} while ();
}

int match_string(array, array_size, string)
{
	return nmatch_string(array, array_size, string, strlen(string));
}

	-ss