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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 08 Jan 2016 10:43:16 +0200
From:	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:	Sergey Senozhatsky <sergey.senozhatsky.work@...il.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>
Subject: Re: [PATCH v1 1/8] lib/string: introduce match_string() helper

On Fri, 2016-01-08 at 09:13 +0900, Sergey Senozhatsky wrote:
> 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.

Like I answered to Rasmus, please, provide real examples.

> 
> > +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'.

Agreed. I would change it to plain 'n'.

> 
> > +{
> > +	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));
> }

See above.

-- 
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Intel Finland Oy