NAME

       wcsrtombs - convert a wide-character string to a character string (restartable)

SYNOPSIS

       #include <wchar.h>

       size_t wcsrtombs(char *restrict dst, const wchar_t **restrict src,
              size_t len, mbstate_t *restrict ps);

DESCRIPTION

       The wcsrtombs() function shall convert a sequence of wide characters from the array indirectly pointed to
       by  src  into  a sequence of corresponding characters, beginning in the conversion state described by the
       object pointed to by ps. If dst is not a null pointer, the converted characters shall then be stored into
       the array pointed to by dst. Conversion continues up to and including a terminating null wide  character,
       which shall also be stored. Conversion shall stop earlier in the following cases:

        * When a code is reached that does not correspond to a valid character

        * When the next character would exceed the limit of len total bytes to be stored in the array pointed to
          by dst (and dst is not a null pointer)

       Each conversion shall take place as if by a call to the wcrtomb() function.

       If  dst  is  not  a  null  pointer,  the pointer object pointed to by src shall be assigned either a null
       pointer (if conversion stopped due to reaching a terminating null wide character)  or  the  address  just
       past the last wide character converted (if any). If conversion stopped due to reaching a terminating null
       wide character, the resulting state described shall be the initial conversion state.

       If  ps  is a null pointer, the wcsrtombs() function shall use its own internal mbstate_t object, which is
       initialized at program start-up to the initial conversion state. Otherwise, the mbstate_t object  pointed
       to  by  ps  shall be used to completely describe the current conversion state of the associated character
       sequence.  The  implementation  shall  behave  as  if   no   function   defined   in   this   volume   of
       IEEE Std 1003.1-2001 calls wcsrtombs().

       If  the  application  uses  any  of  the  _POSIX_THREAD_SAFE_FUNCTIONS  or  _POSIX_THREADS functions, the
       application shall ensure that the wcsrtombs() function is called with a non-NULL ps argument.

       The behavior of this function shall be affected by the LC_CTYPE category of the current locale.

RETURN VALUE

       If conversion stops because a code is reached that does not correspond to a valid character, an  encoding
       error occurs. In this case, the wcsrtombs() function shall store the value of the macro [EILSEQ] in errno
       and  return (size_t)-1; the conversion state is undefined. Otherwise, it shall return the number of bytes
       in the resulting character sequence, not including the terminating null (if any).

ERRORS

       The wcsrtombs() function may fail if:

       EINVAL ps points to an object that contains an invalid conversion state.

       EILSEQ A wide-character code does not correspond to a valid character.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       mbsinit() , wcrtomb() , the Base Definitions volume of IEEE Std 1003.1-2001, <wchar.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
       Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open  Group  Base
       Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers,
       Inc  and  The  Open Group. In the event of any discrepancy between this version and the original IEEE and
       The Open Group Standard, the original IEEE and The Open Group  Standard  is  the  referee  document.  The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group                                   2003                                          WCSRTOMBS(P)