MBSRTOWCS
Section: Linux Programmer's Manual (3)
Updated: 2017-09-15
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NAME
mbsrtowcs - convert a multibyte string to a wide-character string
SYNOPSIS
#include <wchar.h>
size_t mbsrtowcs(wchar_t *dest, const char **src,
size_t len, mbstate_t *ps);
DESCRIPTION
If
dest
is not NULL, the
mbsrtowcs()
function converts 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.
-
len
non-Laq\0aq 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 (aq\0aq), 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 length limit exists.
In both of the above cases,
if
ps
is NULL, a static anonymous
state known only to the
mbsrtowcs()
function is used instead.
The programmer must ensure that there is room for at least
len
wide
characters at
dest.
RETURN VALUE
The
mbsrtowcs()
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
|
|
mbsrtowcs()
| Thread safety | MT-Unsafe race:mbsrtowcs/!ps
|
CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C99.
NOTES
The behavior of
mbsrtowcs()
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),
mbsnrtowcs(3),
mbstowcs(3)
COLOPHON
This page is part of release 4.13 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/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ATTRIBUTES
-
- CONFORMING TO
-
- NOTES
-
- SEE ALSO
-
- COLOPHON
-
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