From: Jani Nikula <jani.nikula@linux.intel.com>
To: Markus Mayer <markus.mayer@broadcom.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Chris Metcalf <cmetcalf@ezchip.com>,
Kees Cook <keescook@chromium.org>,
devel@driverdev.osuosl.org, linux-scsi@vger.kernel.org,
nouveau@lists.freedesktop.org, speakup@linux-speakup.org,
Linux Kernel <linux-kernel@vger.kernel.org>,
dri-devel@lists.freedesktop.org, linux-acpi@vger.kernel.org,
target-devel@vger.kernel.org, devel@acpica.org
Subject: Re: [PATCH 1/6] lib: string: add function strtolower()
Date: Fri, 01 Jul 2016 20:33:18 +0300 [thread overview]
Message-ID: <87vb0pqn4x.fsf@intel.com> (raw)
In-Reply-To: <CAGt4E5teRyMJMfxz3s6PHmTgCApBWWdAiNu1VwQtdJybST3RTw@mail.gmail.com>
On Fri, 01 Jul 2016, Markus Mayer <markus.mayer@broadcom.com> wrote:
> On 1 July 2016 at 03:52, Jani Nikula <jani.nikula@linux.intel.com> wrote:
>> On Fri, 01 Jul 2016, Markus Mayer <mmayer@broadcom.com> wrote:
>>> Add a function called strtolower() to convert strings to lower case
>>> in-place, overwriting the original string.
>>>
>>> This seems to be a recurring requirement in the kernel that is
>>> currently being solved by several duplicated implementations doing the
>>> same thing.
>>>
>>> Signed-off-by: Markus Mayer <mmayer@broadcom.com>
>>> ---
>>> include/linux/string.h | 1 +
>>> lib/string.c | 14 ++++++++++++++
>>> 2 files changed, 15 insertions(+)
>>>
>>> diff --git a/include/linux/string.h b/include/linux/string.h
>>> index 26b6f6a..aad605e 100644
>>> --- a/include/linux/string.h
>>> +++ b/include/linux/string.h
>>> @@ -116,6 +116,7 @@ extern void * memchr(const void *,int,__kernel_size_t);
>>> #endif
>>> void *memchr_inv(const void *s, int c, size_t n);
>>> char *strreplace(char *s, char old, char new);
>>> +char *strtolower(char *s);
>>>
>>> extern void kfree_const(const void *x);
>>>
>>> diff --git a/lib/string.c b/lib/string.c
>>> index ed83562..6e3b560 100644
>>> --- a/lib/string.c
>>> +++ b/lib/string.c
>>> @@ -952,3 +952,17 @@ char *strreplace(char *s, char old, char new)
>>> return s;
>>> }
>>> EXPORT_SYMBOL(strreplace);
>>> +
>>
>> This needs a kernel-doc comment right here.
>
> Will add it.
>
>>> +char *strtolower(char *s)
>>> +{
>>> + char *p;
>>> +
>>> + if (unlikely(!s))
>>> + return NULL;
>>
>> Using spaces for indentation? See scripts/checkpatch.pl.
>
> Not on purpose. Thanks for spotting it.
>
>>> +
>>> + for (p = s; *p; p++)
>>> + *p = tolower(*p);
>>> +
>>> + return s;
>>
>> Why does it return a value? Could be void?
>
> It could be void, but I thought that would make the function's use
> less flexible. As is, the return value is there if anybody wants it,
> but it can be ignored if it is not needed. Also, it seems customary
> for string functions to be returning the string that was passed in.
>
> I'll change it to void if there are strong opinions leaning that way.
> Personally, I like that it returns a char * better.
I don't have strong opinions on this. Just a general aversion to
returning something redundant. Avoids questions like, does it allocate a
new string, should I use the return value instead of the string I passed
in, should I check the return value or can I ignore it, should I check
both the string I pass in and the return value for != NULL, etc. But I
could be persuaded either way.
BR,
Jani.
>
>> BR,
>> Jani.
>>
>>> +}
>>> +EXPORT_SYMBOL(strtolower);
>>
>> --
>> Jani Nikula, Intel Open Source Technology Center
--
Jani Nikula, Intel Open Source Technology Center
next prev parent reply other threads:[~2016-07-01 17:33 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-30 23:50 [PATCH 0/6] lib: string: add function strtolower() Markus Mayer
2016-06-30 23:50 ` [PATCH 1/6] " Markus Mayer
2016-07-01 10:52 ` Jani Nikula
2016-07-01 17:14 ` Markus Mayer
2016-07-01 17:33 ` Jani Nikula [this message]
2016-07-01 21:08 ` Rasmus Villemoes
2016-07-04 20:18 ` Markus Mayer
2016-06-30 23:50 ` [PATCH 2/6] drm/nouveau/core: make use of new strtolower() function Markus Mayer
2016-07-02 1:18 ` [Nouveau] " Alexandre Courbot
2016-07-02 15:21 ` Markus Mayer
2016-07-04 1:37 ` Alexandre Courbot
2016-07-04 3:39 ` Alexandre Courbot
2016-06-30 23:50 ` [PATCH 3/6] ACPICA: " Markus Mayer
2016-07-01 1:11 ` Moore, Robert
[not found] ` <CAGt4E5uqbjaubPWE4rq-T7MvqAmwpUhvakM+jv+Sen8est9U5g@mail.gmail.com>
[not found] ` <94F2FBAB4432B54E8AACC7DFDE6C92E37E4C381C@ORSMSX110.amr.corp.intel.com>
2016-07-01 4:13 ` Markus Mayer
2016-07-01 4:32 ` Moore, Robert
2016-06-30 23:50 ` [PATCH 4/6] ACPI / device_sysfs: " Markus Mayer
2016-07-01 20:44 ` Rafael J. Wysocki
2016-06-30 23:50 ` [PATCH 5/6] staging: speakup: replace spk_strlwr() with strtolower() Markus Mayer
2016-06-30 23:53 ` Samuel Thibault
2016-06-30 23:50 ` [PATCH 6/6] iscsi-target: replace iscsi_initiatorname_tolower() " Markus Mayer
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