Re: CONFIG_KPROBES=y build requires gawk

From: H. Peter Anvin
Date: Wed Dec 16 2009 - 22:52:50 EST


On 12/16/2009 07:33 PM, Masami Hiramatsu wrote:
> Roland Dreier wrote:
>> Is there any reason not to apply the patch below, to allow more awk
>> implementations to be used? After all, it's not like we're going to put
>> non-ASCII characters into the map file...
>
> Actually, the reason why I decided to use character classes is
> [a-z] wasn't same as [[:lower:]] on some environment.
>
> For example, before the POSIX standard, to match alphanumeric charac-
> ters, you would have had to write /[A-Za-z0-9]/. If your character set
> had other alphabetic characters in it, this would not match them, and
> if your character set collated differently from ASCII, this might not
> even match the ASCII alphanumeric characters. With the POSIX character
> classes, you can write /[[:alnum:]]/, and this matches the alphabetic
> and numeric characters in your character set, no matter what it is.
>
> It seems that "your character set" doesn't mean "what character set are used
> in the data", it means "what character set build env. is using".
>
> So, actually, my first released script had used [a-z], but I needed to
> move onto [[:lower:]].
>

This is correct if you are not in the C locale, but I'm not sure if we
support building the kernel in a non-C locale in the first place.

Do you have a known failure case? There is also the option of
explicitly setting LC_CTYPE=C. Sigh.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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