mbsnrtowcs

MBSNRTOWCS(3)              Linux Programmer's Manual             MBSNRTOWCS(3)



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' char-
       acter, 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 mem-
       ory, 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                               1999-07-25                     MBSNRTOWCS(3)