Hi Tjerk:
yes, substr_compare can do it, and it also supports negative
length argument too.
but I am proposal to improve strn(case)cmp, so they are not conflict . :)
thanks
2011/8/15 Tjerk Anne Meesters <datib...@php.net>:
> Hi,
>
> Doesn't substr_compare() accomplish the same thing since 5.1.0?
>
> The only thing I couldn't figure out is how to make it case
> insensitive without specifying an explicit value to $length
>
>
> Best,
> Tjerk
>
> On Mon, Aug 15, 2011 at 11:18 AM, Laruence <larue...@php.net> wrote:
>> Hi:
>> compare to use substr, strncmp supporting negative lenght can
>> save a temp variable.
>>
>> thanks
>>
>> 2011/8/15 Rasmus Lerdorf <ras...@php.net>:
>>> On 08/14/2011 02:37 PM, Rasmus Lerdorf wrote:
>>>> On 08/14/2011 02:03 PM, Stas Malyshev wrote:
>>>>> Hi!
>>>>>
>>>>> On 8/14/11 11:40 AM, Rasmus Lerdorf wrote:
>>>>>> My main issue with changing strncmp/strncasecmp is that these are
>>>>>> currently exact mappings of the underlying libc functions. For people
>>>>>
>>>>> And why should anybody care? 99% of people using PHP never used a libc
>>>>> function and can hardly tell libc from gcc. If we can extend this
>>>>> function with useful functionality, nobody cares about what libc does.
>>>>>
>>>>>> For example, I could imagine people writing code along these lines:
>>>>>>
>>>>>> $len = strlen($user_data) - strlen($suffix);
>>>>>> if(!strncmp($user_data, $string, $len)) {
>>>>>> // do something
>>>>>> }
>>>>>
>>>>> Warning doesn't fix the bug - and unless you're in 0.0001% of the
>>>>> population that actually reads the logs daily and checks every message
>>>>> there it would be little to help you. We should have more useful
>>>>> functions, not more warnings. Warning won't make this code to work.
>>>>
>>>> I agree, however this change would potentially change the return value
>>>> of the function. Before it would warn and not match. Even if you never
>>>> saw the warning, at least length -1 would not give you a match. Now if
>>>> the user data happens to end with the right character we now have a
>>>> string match which is not at all what the code was written to do.
>>>
>>> Put more succinctly. Subtle BC breaks like this worry me. Any strncmp()
>>> call with a computed length where that length may in some cases go
>>> negative will now potentially return a match where it wouldn't before.
>>> This would be very hard to track down. And the reason for introducing
>>> this subtle BC break is so that you can rewrite:
>>>
>>> if (substr("prefix_num", -3) == "num") {
>>> echo "they have same suffix\n";
>>> }
>>>
>>>
>>> into:
>>>
>>> if (strncmp("prefix_num", "num", -3) === 0) {
>>> echo "they have same suffix\n";
>>> }
>>>
>>> That doesn't seem like a big win to me.
>>>
>>> -Rasmus
>>>
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>>>
>>
>>
>>
>> --
>> Laruence Xinchen Hui
>> http://www.laruence.com/
>>
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>> PHP Internals - PHP Runtime Development Mailing List
>> To unsubscribe, visit: http://www.php.net/unsub.php
>>
>>
>
>
>
> --
> --
> Tjerk
>
--
Laruence Xinchen Hui
http://www.laruence.com/
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