NAME

       wcrtomb - convert a wide-character code to a character (restartable)

SYNOPSIS

       #include <stdio.h>

       size_t wcrtomb(char *restrict s, wchar_t wc, mbstate_t *restrict ps);

DESCRIPTION

       If s is a null pointer, the wcrtomb() function shall be equivalent to the call:

              wcrtomb(buf, L'\0', ps)

       where buf is an internal buffer.

       If  s  is  not  a null pointer, the wcrtomb() function shall determine the number of bytes
       needed to represent the character that corresponds to  the  wide  character  given  by  wc
       (including  any  shift  sequences), and store the resulting bytes in the array whose first
       element is pointed to by s. At most {MB_CUR_MAX} bytes are stored. If wc is  a  null  wide
       character,  a  null byte shall be stored, preceded by any shift sequence needed to restore
       the initial shift state. The resulting state described shall  be  the  initial  conversion
       state.

       If  ps  is  a  null  pointer,  the wcrtomb() 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 wcrtomb().

       If  the  application  uses  any  of  the  _POSIX_THREAD_SAFE_FUNCTIONS  or  _POSIX_THREADS
       functions, the application shall ensure that the wcrtomb() 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

       The wcrtomb() function shall return the  number  of  bytes  stored  in  the  array  object
       (including  any shift sequences). When wc is not a valid wide character, an encoding error
       shall occur.  In this case, the function shall store the value of the  macro  [EILSEQ]  in
       errno and shall return (size_t)-1; the conversion state shall be undefined.

ERRORS

       The wcrtomb() function may fail if:

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

       EILSEQ Invalid wide-character code is detected.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       mbsinit() , 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 .