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:
	       _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 at most nms bytes.

       If dest is not NULL, the mbsnrtowcs() function converts at most nms bytes from the multibyte string *src to a wide-character string  start-
       ing 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'' 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 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 wide characters written to dest,  exclud-
	  ing the terminating null wide character, is returned.

       According  to  POSIX.1, if the input buffer ends with an incomplete character, it is unspecified whether conversion stops at the end of the
       previous character (if any), or at the end of the input buffer.	The glibc implementation adopts the former behavior.

       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 NULL, a static anonymous state known only 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.

ATTRIBUTES

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

       +-------------+---------------+-------------------------------+
       |Interface    | Attribute     | Value			     |
       +-------------+---------------+-------------------------------+
       |mbsnrtowcs() | Thread safety | MT-Unsafe race:mbsnrtowcs/!ps |
       +-------------+---------------+-------------------------------+

CONFORMING TO

       POSIX.1-2008.

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), mbrtowc(3) mbsinit(3), mbsrtowcs(3)

COLOPHON

       This page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and  the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

GNU
								    2017-09-15							     MBSNRTOWCS(3)