Re: Removing the --enable-utf8 flag

On Sat, 2002-07-20 at 22:26, Karl Fogel wrote:

> Hmmm, I re-read your definition and think I now understand what you
> mean by "the ASCII encoding" above, and that it effectively is the
> definition I was expecting.
>
> [karl makes a try...] Care to patch?

I never managed to find time to build svn myself. I'm honestly
frustated that there is not one single repository where all the needed
sources can be get and a simple configure script to get the build
started. So all I can do is provide code which you'll have to bend to
fit in. is_ascii_text is the main function. You should call it before
accepting the bytes of the text as ASCII. I don't know how to get the
current locale's coset name in your environment (on Unix systems that'd
be a nl_langinfo(CODESET) call) so please fill this in.

The code (completely untested but it should work):

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
static const char *
normalize_codeset (const char *name)
{
  name = strdup (name);
  if (name != NULL)
    {
      char *rp = name;
      char *wp = name;

      while (*rp != '\0')
        {
          if (isalnum (*rp))
            *wp++ = *rp;
          ++rp;
        }
      *wp = '\0';
    }
  return name;
}

/* Keep sorted according to strcmp. */
static const char *ascii_safe_names[] =
{
  "ascii", "iso88591", "iso88592"
};
const size_t nascii_safe_names = sizeof (ascii_safe_names) / sizeof
(ascii_safe_names[0]);

static int
xstrcmp (const void *a, const void *b)
{
  return strcmp (*(const char **) a, *(const char **) b);
}

bool
is_ascii_text (const char *buf, size_t len)
{
  const char *codeset;
  size_t cnt;
  bool result = false;

  /* Get the codeset for the current locale. */
  // XXX fill in
  codeset = get_current_codeset ();
  if (codeset == NULL)
    /* Out of memory. */
    return false;

  /* Normalize. This creates a copy of the string. */
  codeset = normalize_codeset (codeset);

  /* Check whether this is the name of a ASCII-save codeset. */
  if (bsearch (&codeset, ascii_safe_names, nascii_safe_names,
               sizeof (ascii_safe_names[0]), xstrcmp) == NULL)
    /* No. We cannot use the text. */
    goto out;

  /* Check whether the buffer contains any non-ASCII characters. */
  while (len-- > 0)
    {
      if (*buf < 0x20 || *buf >= 0x7f)
        goto out;
      ++buf;
    }

  /* All went well. */
  result = true;

 out:
  free (codeset);

  return result;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

-- 
---------------.                          ,-.   1325 Chesapeake Terrace
Ulrich Drepper  \    ,-------------------'   \  Sunnyvale, CA 94089 USA
Red Hat          `--' drepper at redhat.com   `------------------------