#ifndef HAVE_STRNCASECMP
/* From GNU libc. */
/* Compare no more than N characters of S1 and S2,
   ignoring case, returning less than, equal to or
   greater than zero if S1 is lexicographically less
   than, equal to or greater than S2.  */
int
strncasecmp(const char *s1, const char *s2, size_t n)
{
   register const unsigned char *p1 = (const unsigned char *) s1;
   register const unsigned char *p2 = (const unsigned char *) s2;
   unsigned char c1, c2;

   if (p1 == p2 || n == 0)
      return 0;

   do
   {
      c1 = tolower (*p1++);
      c2 = tolower (*p2++);
      if (c1 == '\0' || c1 != c2)
	 return c1 - c2;
   } while (--n > 0);

   return c1 - c2;
}
#endif /* HAVE_STRNCASECMP */