wcrtomb(3)

NAME

   wcrtomb - convert a wide character to a multibyte sequence

SYNOPSIS

   #include <wchar.h>

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

DESCRIPTION

   The  main  case for this function is when s is not NULL and wc is not a
   null wide character (L'\0').  In  this  case,  the  wcrtomb()  function
   converts  the  wide  character  wc  to its multibyte representation and
   stores it at the beginning of the character array pointed to by s.   It
   updates  the  shift state *ps, and returns the length of said multibyte
   representation, that is, the number of bytes written at s.

   A different case is when s is not NULL, but wc is a null wide character
   (L'\0').   In this case, the wcrtomb() function stores at the character
   array pointed to by s the shift sequence needed to bring  *ps  back  to
   the initial state, followed by a '\0' byte.  It updates the shift state
   *ps (i.e., brings it into the initial state), and returns the length of
   the shift sequence plus one, that is, the number of bytes written at s.

   A  third  case is when s is NULL.  In this case, wc is ignored, and the
   function effectively returns

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

   where buf is an internal anonymous buffer.

   In all of the above cases, if ps is  NULL,  a  static  anonymous  state
   known only to the wcrtomb() function is used instead.

RETURN VALUE

   The  wcrtomb()  function  returns the number of bytes that have been or
   would have been written to the byte array at  s.   If  wc  can  not  be
   represented  as a multibyte sequence (according to the current locale),
   (size_t) -1 is returned, and errno set to EILSEQ.

ATTRIBUTES

   For  an  explanation  of  the  terms  used   in   this   section,   see
   attributes(7).

   
   Interface  Attribute      Value                      
   
   wcrtomb()  Thread safety  MT-Unsafe race:wcrtomb/!ps 
   

CONFORMING TO

   POSIX.1-2001, POSIX.1-2008, C99.

NOTES

   The  behavior  of  wcrtomb()  depends  on  the LC_CTYPE category of the
   current locale.

   Passing NULL as ps is not multithread safe.

SEE ALSO

   mbsinit(3), wcsrtombs(3)

COLOPHON

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