MBSNRTOWCS
Section: Linux Programmer's Manual (3)
Updated: 2014-03-18
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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 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.
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.
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)
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- CONFORMING TO
-
- NOTES
-
- SEE ALSO
-
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Time: 02:55:03 GMT, September 18, 2014