Re: No space calculation in wcstombs?

[Christoph Ender <chrender-cygwin-1 at spellbreaker dot org>]

Hi,

thanks for your quick answer. I've taken a look at the source
from the CVS and "fixed" the issue by replacing the contents of
the file "wcstombs_r.c" with the quick-and-dirty solution appended
below (which may still contain some serious flaw since I've never
fiddled with a c-lib before but it works for me).

Since I also need fwprintf and other functions which are currently
not implemented I might extend newlib a bit more to get my program
working. Would it make sense to mail the new code to some official
maintainer so that someday these functions might be available in a
regular release?


Regards,
Christoph.


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#include <stdlib.h>
#include <wchar.h>

size_t
_DEFUN (_wcstombs_r, (reent, s, pwcs, n, state),
        struct _reent *r    _AND
        char          *s    _AND
        const wchar_t *pwcs _AND
        size_t         n    _AND
        mbstate_t     *state)
{
  char *ptr = s;
  size_t max = n;
  char buff[8];
  int i, num_to_copy;
  int sum_bytes;

  if (s == NULL)
  {
    sum_bytes = 0;

    while (*pwcs != 0)
    {
      sum_bytes += _wctomb_r (r, buff, *pwcs, state);
      pwcs++;
    }

    return sum_bytes;
  }
  else
  {
    while (n > 0)
      {
        int bytes = _wctomb_r (r, buff, *pwcs, state);
        if (bytes == -1)
          return -1;
        num_to_copy = (n > bytes ? bytes : (int)n);
        for (i = 0; i < num_to_copy; ++i)
          *ptr++ = buff[i];

        if (*pwcs == 0x00)
          return ptr - s - (n >= bytes);
        ++pwcs;
        n -= num_to_copy;
      }

    return max;
  }
}

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> On Oct 23 11:52, Christoph Ender wrote:
> > Hi all,
> > when converting wchar_t*- to (mb)char*-Strings I've been
> > so far using the wcstombs function in two steps: One call
> > [...]
> > I've just noticed that the first step does not work with
> > cygwin and  I've attached a small example to demonstrate
> > [...]

On October 23, 2007 at 12:42 Corinna Vinschen wrote:
> No, it's a newlib problem.  The wide character support in newlib
> is somewhat rudimentary.  The reason is that newlib is mainly
> targeting embedded systems which don't need full wchar support.
> However, as this is an open source project, patches are always
> welcome.
> Corinna