Re: [RFC][PATCH] lib/string: introduce sysfs_strncpy() and sysfs_strlcpy()

[Andy Shevchenko]

On Tue, 2018-08-21 at 20:44 +0900, Sergey Senozhatsky wrote:

> Something like below? Not tested, since we are still in "is this
> what we want" phase.

> Returning the length of dst/-EOVERFLOW is a bit inconvenient, because
> "the length" forces us to have size_t return, which is unsigned.

We have for ages ssize_t to workaround that.

> size_t strcpy_trim(char *dst, size_t dstsz, const char *src, size_t
> srcsz)
> {
> 	const char *end;
> 	size_t ret = 0;
> 	size_t len = 0;
> 
> 	if (!dstsz || !srcsz)
> 		goto out;
> 
> 	end = src + srcsz - 1;
> 	while (end >= src && isspace(*end))
> 		end--;
> 	end++;
> 	while (src < end && isspace(*src))
> 		src++;
> 	len = (src >= end) ? 0 : end - src;
> 	if (!len)
> 		goto out;
> 
> 	ret = len;
> 	if (len >= dstsz)
> 		len = dstsz - 1;
> 	memcpy(dst, src, len);
> out:
> 	dst[len] = '\0';
> 	return ret == len ? ret : -EOVERFLOW;
> }

Wouldn't be better to split out something like

strnstrip() out of strim(), with simultaneous changes to strim(),
strstrip(), and use it here?


-- 
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy