wcsnrtombs - convert a wide-character string to a multibyte string


   #include <wchar.h>

   size_t wcsnrtombs(char *dest, const wchar_t **src, size_t nwc,
                     size_t len, mbstate_t *ps);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       Since glibc 2.10:
           _POSIX_C_SOURCE >= 200809L
       Before glibc 2.10:


   The  wcsnrtombs()  function  is  like the wcsrtombs(3) function, except
   that the number of wide characters to be converted, starting  at  *src,
   is limited to nwc.

   If  dest  is  not  NULL, the wcsnrtombs() function converts at most nwc
   wide characters from the wide-character  string  *src  to  a  multibyte
   string  starting  at dest.  At most len bytes are written to dest.  The
   shift state *ps is updated.  The conversion is effectively performed by
   repeatedly  calling  wcrtomb(dest,  *src,  ps),  as  long  as this call
   succeeds, and then incrementing dest by the number of bytes written and
   *src by one.  The conversion can stop for three reasons:

   1. A wide character has been encountered that can not be represented as
      a multibyte sequence (according to the  current  locale).   In  this
      case,   *src  is  left  pointing  to  the  invalid  wide  character,
      (size_t) -1 is returned, and errno is set to EILSEQ.

   2. nwc wide characters have been converted without encountering a  null
      wide  character (L'\0'), or the length limit forces a stop.  In this
      case, *src is left  pointing  to  the  next  wide  character  to  be
      converted, and the number of bytes written to dest is returned.

   3. The  wide-character  string has been completely converted, including
      the terminating null wide character (which has the  side  effect  of
      bringing  back *ps to the initial state).  In this case, *src is set
      to NULL, and the number of bytes  written  to  dest,  excluding  the
      terminating null byte ('\0'), is returned.

   If  dest is NULL, len is ignored, and the conversion proceeds as above,
   except that the converted bytes are not written out to memory, and that
   no destination length limit exists.

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

   The programmer must ensure that there is room for at least len bytes at


   The  wcsnrtombs() function returns the number of bytes that make up the
   converted part of multibyte sequence,  not  including  the  terminating
   null  byte.   If  a  wide  character was encountered which could not be
   converted, (size_t) -1 is returned, and errno set to EILSEQ.


   For  an  explanation  of  the  terms  used   in   this   section,   see

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




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

   Passing NULL as ps is not multithread safe.


   iconv(3), mbsinit(3), wcsrtombs(3)


   This page is part of release 4.09 of the Linux  man-pages  project.   A
   description  of  the project, information about reporting bugs, and the
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