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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON |
MBSNRTOWCS(3) Linux Programmer's Manual MBSNRTOWCS(3)
mbsnrtowcs - convert a multibyte string to a wide-character string
#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
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
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 null wide character ('\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 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.
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.
For an explanation of the terms used in this section, see
attributes(7).
┌─────────────┬───────────────┬───────────────────────────────┐
│Interface │ Attribute │ Value │
├─────────────┼───────────────┼───────────────────────────────┤
│mbsnrtowcs() │ Thread safety │ MT-Unsafe race:mbsnrtowcs/!ps │
└─────────────┴───────────────┴───────────────────────────────┘
POSIX.1-2008.
The behavior of mbsnrtowcs() depends on the LC_CTYPE category of the
current locale.
Passing NULL as ps is not multithread safe.
iconv(3), mbrtowc(3) mbsinit(3), mbsrtowcs(3)
This page is part of release 4.12 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 2016-12-12 MBSNRTOWCS(3)
Pages that refer to this page: mbsrtowcs(3)