Re: [PATCH v3 0/7] lib: string: add functions to case-convert strings

From: Markus Mayer
Date: Sun Jul 10 2016 - 00:11:29 EST


On 9 July 2016 at 20:13, Chris Metcalf <cmetcalf@xxxxxxxxxxxx> wrote:
> On 7/8/2016 6:43 PM, Markus Mayer wrote:
>>
>> This series introduces a family of generic string case conversion
>> functions. This kind of functionality is needed in several places in
>> the kernel. Right now, everybody seems to be implementing their own
>> copy of this functionality.
>>
>> Based on the discussion of the previous version of this series[1] and
>> the use cases found in the kernel, it does look like having several
>> flavours of case conversion functions is beneficial. The use cases fall
>> into three categories:
>> - copying a string and converting the case while specifying a
>> maximum length to mimic strlcpy()
>> - copying a string and converting the case without specifying a
>> length to mimic strcpy()
>> - converting the case of a string in-place (i.e. modifying the
>> string that was passed in)
>>
>> Consequently, I am proposing these new functions:
>> void strlcpytoupper(char *dst, const char *src, size_t len);
>> void strlcpytolower(char *dst, const char *src, size_t len);
>> void strcpytoupper(char *dst, const char *src);
>> void strcpytolower(char *dst, const char *src);
>> void strtoupper(char *s);
>> void strtolower(char *s);
>
>
> You may want to read the article here:
>
> https://lwn.net/Articles/659214/

I'll read that. Thanks.

> and follow up some of the discussion threads on LKML about the best
> semantics to advertise for the strlcpy/strscpy variants. It might be
> helpful to return some kind of overflow/truncation error from your
> copy functions so people can error-check the result.

I am inclined to agree. However, everybody has been telling me that
these functions should be void. Originally they weren't.

Regards,
-Markus