NAME

       mbsnrtowcs - convert a multibyte string to a wide character string

SYNOPSIS

       #include <wchar.h>

       size_t mbsnrtowcs (wchar_t *dest, const char **src,
                          size_t nms, size_t len, mbstate_t *ps);

DESCRIPTION

       The  mbsnrtowcs function is like the mbsrtowcs function, except that the number of bytes to be converted,
       starting at *src, is limited to nms.

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

       1.  An invalid multibyte sequence has been encountered. In this case *src is left pointing to the invalid
       multibyte sequence, (size_t)(-1) is returned, and errno is set to EILSEQ.

       2. The nms limit forces a stop, or len non-L'\0' wide characters have been stored at dest. In  this  case
       *src  is  left pointing to the next multibyte sequence to be converted, and the number of wide characters
       written to dest is returned.

       3. The multibyte string has been completely converted, including the terminating '\0' (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
       wide characters written to dest, excluding the terminating L'\0' character, is returned.

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

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

       The programmer must ensure that there is room for at least len wide characters at dest.

RETURN VALUE

       The mbsnrtowcs function returns the number of wide characters that make up the converted part of the wide
       character string, not including the terminating null wide character. If an invalid multibyte sequence was
       encountered, (size_t)(-1) is returned, and errno set to EILSEQ.

CONFORMING TO

       This function is a GNU extension.

SEE ALSO

       mbsrtowcs(3), iconv(3)

NOTES

       The behaviour of mbsnrtowcs depends on the LC_CTYPE category of the current locale.

       Passing NULL as ps is not multi-thread safe.

GNU                                               July 25, 1999                                    MBSNRTOWCS(3)