Re: CONFIG_KPROBES=y build requires gawk

Masami Hiramatsu
2009-12-17T04:55:18Z

Roland Dreier wrote:
>
> > 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.
>
> I'm not sure I understand this, although I'm not a character set expert.
> But is there really some possible locale + awk implementation where an
> awk script, written in pure ASCII, operating on a pure ASCII input file,
> will have [A-Za-z0-9] match a different set of ASCII characters than
> [[:alnum:]] will match?

I assume that in utf-8 locale(nowadays default in most of distro) alphabets
may be sorted as aAbBcC...zZ(or AaBb...), and in this case a-z means
aAbBcC...z.

As Al Viro said, if we run awk with LC_ALL=C, then the characters will be
sorted as ASCII. So, your patch is OK if you can add LC_ALL=C just before
$(AWK). (I'm not so sure whether Makefile can accept it...)

Thank you,

--
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com