WCSRTOMBS(3P)                                       POSIX Programmer's Manual                                      WCSRTOMBS(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

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 contin-
       ues 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  com-
       pletely 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  con-
       version  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, Copy-
       right (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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                 WCSRTOMBS(3P)