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);

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

       mbsnrtowcs():
	   Since glibc 2.10:
	       _XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
	   Before glibc 2.10:
	       _GNU_SOURCE

DESCRIPTION

       The  mbsnrtowcs() function is like the mbsrtowcs(3) 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  incre-
       menting 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'' 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 '' (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'' 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.

NOTES

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

       Passing NULL as ps is not multithread safe.

SEE ALSO

       iconv(3), mbsrtowcs(3)

COLOPHON

       This  page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

GNU
								    2010-09-15							     MBSNRTOWCS(3)