Re: strcasestr.c

[Rich Felker <dalias@aerifal.cx>]

On Thu, Feb 14, 2013 at 09:59:56AM -0500, Todd C. Miller wrote:
> When investigating using the musl strstr.c ofr OpenBSD I noticed
> that musl only has a stub for strcasestr() that calls strstr().  I
> was curious whether the twoway algorithm could be adapted to do a
> case-insensitive search.  It turned out to be pretty trivial to
> just add calls to tolower() in the right places, making sure to
> avoid sign extension.
> 
> The changes are mostly mechanical.  You might wish to inline
> _strcasechr() though the compiler will probably do that for you.

Unfortunately, as far as I can tell making this correct is nontrivial;
your version only works for ascii, not the rest of ucs. I don't see
any easy way to adapt 2way to the case where matching classes contain
characters of different lengths...

Rich